Epilepsy Res., 7 (1990) 230-239 230
Elsevier
EPIRES 00366
Clinical and electroencephalographic characteristics of epilepsy in rural Ethiopia: a community-based study Redda Tekle-Haimanot a, Lars Forsgren b, Mekonnen Abebe a, Ayele Gebre-Mariam c, Jan Heijbel d, G6sta Holmgren e and Jan Ekstedt b "Department of Interred Medicine, Addis Ababa University, Addis Ababa (Ethiopia), bDepartment of Neurology, Umed University, Univet:~ity Hospital, S.901 85 Umed (Sweden), "Department of Pediatrics, Addis Ababa University, Addis Ababa (Ethiopia), aDepartment of Pediatrics, Umed University, University Hospital, S.901 85 Umed (Sweden) and eDepartment of Clinical Genetics, Umett University, University Hospital, S.901 85 Umett (Sweden) (Received 29 March 1990; revision received 28 June 1990; accepted 3 July 1990)
Key words: Epidemiology; Epilepsy; Prevalence; Electroencephalography; Treatment; Ethiopia
A community-based epidemiological study of neurological disorders was performed in a rural area in Ethiopia. The most prevalent neurological disorder identified was epilepsy, found in 316 persons, The prevalence of epilepsy was 5.211000 inhabitants at risk, 5.8 for males, 4.6 for females. The highest age-specific prevalence was found for ages 10-19 years, Generalized tonic-clonic seizures were the most common seizure type and occurred ill 81%, On clinical grounds, partial seizures occurred in 20% and in 29% of these secondary generalization followed. During seizures, 8.5% had been injured by burns and 5,7% by trauma. Eighty-four percent had seizures at least monthly. Seizures occurred in 4.8% of siblings, Traditional treatment with local herbs, holy water and amulets was the most common, Only 1,6% had been treated with recognized antiepileptic drugs, Mental retardation was the most common associated disorder, found in 7.9% of the persons with epilepsy, During a period of 2 years, 8 persons died of status epilepticus and I from severe burns as a result of faUing into a domestic fire during a seizure, EEG was recorded in 73%. Epileptiform activity occurred in 18%.
INTRODUCTION Epilepsy is a common disorder a!l over the world, affecting about 0.4-2.0% of populations surveyed "~2,In the developing countries epilepsy is a major neurological problem where in many cases treatment is possible but often not available. Many previous epidemiological studies of epilepsy in Africa have been urban- and hospital-based 2:'1°-12" ,..~.,..s.33.3~.37 or carried out in subgroups of the popCorrespondence t,:: Dr. Redda Tekle-Haimanot, P.O. Box 4147, Addis Ababa. Ethiopia.
ulation a, often where the disorder has been particular,y ct~mmon 17'2-''3s. Because of selection bias, the results from these studies may not reflect the situation of epilepsy in the general population. Epilepsy among rural populations in Africa has only been investigated in a few studies ~4'25-28.The only epidemiological study of epilepsy from Africa where the problem of selection bias has been largely avoided was carried out in Nigeria by Osuntokun et al. 3°, using a screening instrument for neuroepidemiological survey that was developed within the Neurosciences Programme of the World Health Organization 29.
0920-1211/90f$03.50 (~ 1990 Elsevier Science Publishers B,V. (Biomedical Division)
231 A community-based rural epidemiological study of neurological disorders was performed in Ethiopia during 1986-1988. Thi~ paper is a clinical and electroencephalographic presentation of the persons with epilepsy identified in that study 35. MATERIALS AND METHODS The study was performed in the rura~ sub-district (woreda) of Meskan and Mareko in the district (awraja) of Haykoch and Butajira, 130 km south of the Ethiopian capital Addis Ababa. The population of Meskan and Mareko sub-district at the time of the study was 181,883 (ref. 6), organized into peasant and urban dweller's associations. The area consists of 3 small towns and 82 peasant associations. The survey was carried out in the 3 towns and 25 randomly selected peasant associations, ineluding all households in the selected area. The population was found to be fairly stable during the investigation period, although there was a continuous increase of the population due to the birth rate exceeding the death rate. Migration in and out of the villages was limited. In order to get reliable information on the denominator, a census of the sampled area was performed simultaneously with the identification of cases. The population of the selected area was 60,820. Secondary-school graduates from the community with a sound knowledge of the local customs, cultures and language were recruited and employed as lay health-workers (enumerators). They were trained in interview methodology for field surveys and instructed on simple observations and examinations of persons with neurological problems. Their supervision was undertaken by a Public Health Officer and neurologists. In the study area, after informed consents had been obtained, the lay health-workers made doorto-door interviews and administered questionnaires to screen those with neurokrgical disorders. The head of the household or his wif,, gave information on each member of the family. A special epilepsy form was administered for additional information from persons in the household with unconsciousness fits with or without frothing, or biting of the tongue or incontinence of urine, and from persons who had sudden jerky movements in
part of the body. These persons were later examined close to their villages by neurologists who, on the basis of the previous information and their own interview with the affected person and relatives, made the final diagnosis. Attitudinal studies on epilepsy were also performed on sampled adults. An overview of the study is shown in Fig. 1. The sensitivity and specificity of the screening instrumeh~ were pretested and found to be 91% and 85% respectively for detection of epilepsy 35. Since large-scale surveys, such as the present one, take several months to complete, and the survey was performed in a society where calenders and knowledge of exact dates were lacking, the use of a sp*,cific prevalence day was not feasible. The whole survey was performed during 20 months, from October 1986 to May 1988. The collection of demographic data (number, sex, age) and screening-for identification of cases took place during approximately 2 months in each town and peasant association. This information, later supplemented with a medical interview and examination, was used for the calculation of rates. Only persons found to be permanent residents for over 6 months in the selected towns and peasant associations at the time of the collection of demographic and medical data were included in the study. With the method used, a point prevalence on one specific day during the investigation period was established for a household in the survey area. The point prevalenees of the 13,469 households surveyed during any one day of the investigation period of 29 months were the constituents of the prevalence rates provided for ~he whole investigation period. The latter prevalence should be regarded as a point prevalence rate with multiple point prevalence components and not as a period prevalence, the sum of point l:revalence and incidence. Persons who had moved from other towns or peasant associations that b~ longed to the study sample were not included if t~'~cy had been registered by field workers in their former residence. When ~:'enders and knowledge of exact dates were lacking in a household, ages and dates given by respondents were counterchecked in relation to the 'local event calender,' i.e., important past social events (e.g., local battles, coronation of the Emperor, the Italian invasion, the 1974 Ethiopian
232 MeskanMareko subdistrict
Sample:
[Sampling~ !
25 peasant and (Sampling I 6 urban dwellers 181,~i83 associainhabitants tions
!
.-----(Interview )----~"----( Supcrvisi°n
13,460 households
---[Identification
60,820 persons
I
'---
]['A,,,,o,o.,
Prevalence investigation ,
Basic demographic data on
Attltudm data
Persons wt~ suspected neurologi,~al diseases
6O,82O
Imrsons
Validity I control by ] neurologists
from 1546 persons
(households)
~_fNeurological 1
908 cases with neurological disorders
Epidemiological analysis
91i~qm~muummmmu
316 easeswith
epilepsy
Fig. 1, Schemeof the survey,
revolution, etc.) or other events (e.g., rainy seasons, epidemics, etc.) well known to the inhabitants. Frequencies of seizures were counterchecked with two or more members of the family. The criteria to be included in the study were for all persons of all ages that they should have active epilepsy, i.e., they should have had at least 2 unprovoked :~ seizures of which at least one should have occurred during the last 5 years, and/or they should be on antiepileptic treatment because of seizures at the time of the investigation. Persons who only had seizures in association with fever, alcohol abuse or which only occurred during acute diseases were excluded. Seizures were classified according to the International Classification of
Epileptic Seizures, ICES 7. Since the subclassification of partial seizures as simple and complex partial seizures is difficult to use in epidemiological studies of epilepsy, no subclassification of partial seizures was made except for the occurrence of secondary generalization. Electroencephalographic (EEG) recordings were only performed on persons who fulfilled the criteria for active epilepsy. The reason for the examination and how it was to be carried out was carefully explained beforehand. For the purpose of this study the EEG machine was transported from Addis Ababa to the Health Center in the town of Butajira, the administrative center of the sub-district, and installed in a building of 18 m E,
233 made out of a transport container. Transport was provided for the persons with epilepsy who did not live nearby. Some problem was faced during preparation for the EEG recording. Females in the villages traditionally wear their hair in the form of braids, often with oil and butter applied on it. In order to ensure proper application of electrodes, shaving the hair and washing of the scalp was proposed for all patients. This was accepted by the males but strongly opposed by the females. A compromise was worked out in which the females agreed to have their hair washed and the braids restyled in accordance with the pattern of electrode application. A local girl with braiding experience was employed for the purpose. The EEG recording was carried out using a Nihon-Kohden Neurofax 7314F machine, with the standard array of electrodes used in the 10-20 international system. The patients were awake and provoked by photostimulation and hyperventilation. EEGs were classified as normal, paroxysmal abnormalities, unspecific abnormal (slowing) or epileptiform (spikes, sharp waves or spike-wave acu city). According to localization, the pathological findings were designated as bilateral, unilateral or focal (restricted to one or two electrodes). All patients with recurrent partial seizures (with or without secondary generalization) or recurrent primary generalized tonic.clonic seizures were started on the cheapest and most (at times the only) available anticonvulsant, phenobarbital. Testing instruments for intelligence assessment for field work using native speakers did not exist. A diagnosis of severe mental retardation was made clinically. Such diagnosed persons relied heavily on their family members for help with the primary activities of daily life such as hygiene, dressing, feeding, etc., and they had no or only very limited communication capabilities.
TABLE I Age- and sex-specific prevalence (cases/lO00) of epilepsy in a rural Ethiopian community Actual number of persons in parentheses. Age group (years)
Males
Females
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-59 350
3.7 4.1 9.7 8.6 8.9 7.8 7.3 5.4 5.3 3.2 2.4
1.3 4.2 5.5 9.3 5.8 5.1 7.7 4.3 3.7 6.0 3.3
Total
5.8 (173)
(20) (23) (43) (26) (14) (10) (11) (8) (7) (3) (8)
(7) (23) (23) (24) (10) (11) (15) (8) (5) (6) (11)
4.6 (143)
the age group 10-19 years. The remaining 40.2% were 20 years or older with 5.7% being 55 years or older. Age- and sex-specific rates are shown in Table I and age-specific rates for the sexes combined are shown in Fig. 2. The crude prevalence rate for the sexes combined was 5.2/1000 inhabitants at risk. The highest rate for males was found between ages 10 and 14 years, and for females between ages 15 and 19 years. All households participated in the study and none of the persons suspected to have neurological disease during the screening phase refused interview and examination. Repeated visits to households by the lay health-workers resulted in a participation rate ranging from 95 to 100% in the different towns/villages surveyed. Prevalence/l,000 inhabitants at risk q,00 8,00 7,00 6,00 5,00
RESULTS Epilepsy was the most common neurological disorder identified in the general epidemiological study and was found in 316 persons, 173 males (54.7%) and 143 females (45.3%). Children 0-9 years old constituted 23.1%, and 36.7% were in
0,00
-~ 0-4
5-9
., .4 .4 ~ . -g 10. 14 15-19 20-24 25.29 30.34 35.39 40.44 45-49 ~50
Age in years
Fig. 2. Age-specific prevalence (cases/1000) of 316 persons with epilepsy in a rural Ethiopian community.
234 TABLE II
TABLE III
Age at first seizure in 314persons with epilepsy in rural Ethiopia
Duration of epilepsy in 314 persons in rural Ethiopia
Age at first seizm '
%
Duration
%
0-1 months 2-11 months 1-4 years 5-9 years 10-14 years 15-19 years 20-29 years 30-39 years 40-49 years ~>50years
1.9 2.9 27.1 18.5 20.1 9,6 10,8 3,8 2,9 2,5
20 years
5.4 19.4 24.5 26.8 17.8 2.9
Age at first seizure and duration of epilepsy Age at first seizure was known for 314 cases and is shown in Table II. The first seizure occurred before ages 5 and 15 years, in 31.9% and 70.5%, respectively. The interval from the first seizure to the identification of a person with epilepsy in the study is shown in Table III. The duration in the majority was between 3 and 10 years. Seizure types Seizures consistent with generalized tonic-clonic seizures (GTCS) were described in 256 persons (81.0%). They were associated with frothing and tongue biting in 99.2% and with incontinence of urine in 45.7%. The GTCS seizures were, on clinical grounds, judged to be primary in 238 persons (75.3%). There was one person with absence seizures. This person had no other type of seizure, Partial seizures occurred in 62 persons (19.6%). Most of these, 44 persons (13.9%), had seizures
that were only partial, while 18 persons (5.7%) had partial seizures that sometimes or always evolved into secondarily generalized seizures. Since the state of consciousness could not systematically be observed during seizures, the proportion of partial seizures that were simple or complex cannot be presented. Seizures of unclassified type occurred in 15 persons (4.7%). During seizures, 8.5% had been injured by burns and 5.7% by trauma.
Seizure frequency and occurrence The seizure frequency for different seizure types is shown in Table IV, Information on seizure fiequency was available in 288 (91%). Eighty-six of 313 persons (27.5%) reported that seizures were sometimes associated with fever. Seizures had been noted to occur only during sleep in 11.2%, at awakening in 3.8%, only when awake in 53.8% and both during sleep and when awake in 31.2%. Familial occurrence The history for occurrence of seizures in rel-
TABLE IV
Seizure frequeno, by clinical type of seizure in 316 persons with epilepsy Seizure type
n
GTCS a Absence Partial Unclassified
238 l 62 15
Total
316
(%)
(75) (0.3) (20) (5) (100)
a GTCS: generalized tonic-clonic seizures,
Seizure frequency n (%) Daily
Weekly
Monthly
Every 4th month
Yearly
Unknown
21 (7)
66(21)
101 (32)
5 (2)
33 (10)
12 (4)
5 (2) 4 (1)
9 (3) 3 (1)
27 (9) 7 (2)
1(0.3)
30 (10)
78 (25)
135(43)
1 (0.3)
6(2)
5 (2) 1 (0.3) 39(12)
15(5) 28(9)
235 atives was obtained for 314 cases and is shown in Table V. One-third (31.9%) had relatives who had had one or several seizures. Seizures occurred in 9 of the 628 parents (1.4%), in 27 of the 558 siblings (4.8%) and in 5 of 296 children (1.7%). The proportion of siblings with seizures should be regarded as a minimum figure since seizures in siblings were only known for 189 cases (many adults wit~ epilepsy were not willing to give information about the presence of seizures in siblings). One case had 2 first-degree relatives, 2 siblings, with seizures. Altogether, 41 first-degree relatives (parents, siblings and children) had experienced seizures, which constitutes 2.8% of all first-degree relatives.
Treatment of and beliefs about epik,psy Information about treatment was obtained from 306 persons. Neither traditional nor conventional treatments had been given in 23.5% of the persons with epilepsy. Local herbs was the most common treatment used and had been tried by 36.0%. Holy water had been tried by 12.4%. Kitab, a protective amulet, was used by 7.5% and 2 persons (0.7%) had sacrificed animals. Some type of medication was used by 19.3% but only 8.5% used it as the only treatment, while 10.8% combined it with some type of traditional treatment. What these medications were is unclear since recognized antiepileptic drugs were not available in the area. Addis Ababa is the only close place for supply of antiepileptic drugs which were obtained by only 5 patients. Of the persons with epilepsy, 74.4% did not have any idea what caused the seizures, 17.4% thought they were due to evil spirits, 6.2% to tenTABLE V
Familial occurrence of seizures in 314 persons with epilepsy Relation to person with seizures
Number
%
No relatives with seizures Parent(s) Siblings Grandparents Children Cousins Other relatives
214 9 23 3 5 53 7
68.2 2.9 7.3 0.9 1.6 16.9 2.2
sion state, 1.7% to head trauma and 0.3% to poison.
Other diseases The most prevalent disease/impairments combined with the epilepsy were severe mental retardation and hemiparesis, found in 7.9% and 2.5%, respectively.
Mortality During the last 2 years, 20 of the 316 persons with epilepsy died (6.3%). Death was related to epilepsy in 9 of the 20 persons, of whom 8 died in status epilepticus and 1 from severe burns from falling into a domestic fire during a seizure. The seizure frequency was high in these 9 persons. Four had daily seizures, I had weekly seizures and 4 had monthly seizures. In 7 persons, deaths were related to infections (malaria 1, epidemic meningitis 3, gastroenteritis 2, pneumonia 1) and 1 person died following trauma unrelated to seizure. Cause of death was unknown in the remaining 3 cases.
Electroencephalography (EEG) EEG was performed on 230 persons (72.8%) and the findings are shown in Table VI. Abnormalities were demonstrated in 42.6%. Unspecific slow wave abnormalities were detected in 16.5%, paroxysmal disturbances in 7.8% and epileptiform discharges in 18.3%. Twenty-six persons had focal TABLE VI
Electroencephalographic findings in 230 persons with epilepsy, in rural Ethiopia Finding
No. of persons
%
Normal Epileptiforma, total Focal Unilateral Bilateral Paroxysmalb rhythms Focal/unilateral Bilateral Unspecific abnormality, total Focal Unilateral Bilateral
132 42 9 4 29 18 6 12 38 4 3 31
57.4 18.3 3.9 1.7 12.6 7.8 2.6 5.2 16.5 1.7 1.3 13.5
a 2 and ~ 3 persons also had unspecific abnormalities.
236 unilateral or non-focal unila~,:ral abnormalities on the EEG, of whom 13 had epileptiform activity, 6 paroxysmal activity and 7 an unspecific abnormality. Of these 26 persons, 21 had a clinical diagnosis of generalized tonic-clonic seizures without focal seizure manifestations. The results of the EEG investigation indicate that these 21 persons probably had a foc~d lesion (partial epilepsy) and the seizures were secondarily generalized. Thus, altogether 83 persons (26.3%) had clinically partial seizures or EEG findings which made a diagnosis of epilepsy of focal origin probable. This leaves 217 persons with primarily GTCS (68.7%). DISCUSSION The vast majority of populations in developing countries live in rucal areas. In Ethiopia this is the case for over 90% of the population 6. Epilepsy is a common neurological disorder which can be effectively treated in the majority of patients. It was therefore important to study persons with epilepsy who had been identified in a community-based rural study in order to gain information for future health education and planning of therapeutic programmes. This is, to the best of our knox~edge, the first major community-based study of epilepsy in a rural African community. Despite the social stigma associated with epilepsy3t', there was no refusal of interview or examination. Possible explanations for this may be that because of the villagization programme (creation of large nucleated villages) and newly established strict social orders, there was a certain degree of regimentation within the communities surveyed. All the officials, community leaders and village elders cooperated and helped us to reach the people. Another factor, which probably contributed significantly to the positive attitude of the study population towards the investigators, was the anticonvulsant treatment offered to all cases actually at the time of diagnosis in accordance with the WHO motto 'no survey without service.' Repeated house calls were made if an adult person was not available at the first visits. There was a slight excess of males, which was most pronounced in the youngest age group. This was also found in the study of Cowan et al.S but not
by Osuntokun et al. 31. In both of these studies, rates of epilepsy in the age group 0-4 years were higher than in the present study. A possible explanation for this may be the very high infant and childhood mortality in Ethiopia ~3, which probably makes vulnerable children, such as those with epilepsy, less likely to survive. In the study of Osuntokun et al. 3~, prevalence rates also tended to be higher for males than females in the older age groups while the opposite was found in the present study. Due to the low number of persons in the older age groups in both studies, these differences may have occurred by chance. In this study, the age-specific prevalence rates decreased in the adult age ranges. Previous studies show fairly stable prevalence rates in different adult age groups with a drop in rates after age 60 years 4'18. Studies considered to have a more complete ascertainment of cases among the elderly found the highest rates in the older age groups 2m9. Although cases might have been missed in older age groups in the present study, other plausible explanations are either that people remit from their epilepsy or that they die because of epileptic seizures or factors related to epilepsy, e.g., trauma and tumours. However, the prognosis is not always bad. Over one-fifth of cases in the present study had a duration of epilepsy exceeding 10 years even without medical treatment. The crude prevalence rate for active epilepsy was 5.2/1000, which is comparable with the community-based study of Osuntokun et al. 3° who found a prevalence of 5.3/1000. The African studies that have found a prevalence of epilepsy exceeding 1% of the population ~°'~7'22'29are based on investigations on either specially selected and/or small populations. The results of our study and that of Osuntokun et al. 3° may indicate that the prevalence of active epilepsy in the general African population is comparable to that which has been found in European and U.S. populations, 3.4-7.8/1000 (see refs. 8, 16, 19, 20, 21, 22, 39). However, due to a possible high mortality caused by untreated epilepsy in African populations, the prevalence rate of epilepsy found may underestimate the magnitude of the medical and social problem created by epilepsy. High prevalence rates (12.7-19.5/1000) have been reported from
237 South America with a high proportion of primary generalized seizures 9'15. Precautions were taken to minimize the number of unidentified cases. Provision of free anticonvulsant treatment with the readily available drug phenobarbital created a positive impression in the community, which probably made families with the disease more willing to volunteer the necessary information. In a few cases, heads of households withheld information because of the social stigma commonly associated with epilepsy. In the few instances where this occurred, mainly with young girls, community leaders came up with the required information. Considering the relatively low proportion of partial seizures found, it is likely that there are, nevertheless, cases that were not identified. This may partly be an effect of informants and con~munity members not recognizing partial seizures as epileptic phenomena and possibly due to the relative insensitivity of the questionnaire to identify partial seizures. Moreover, many persons became scared when seeing a person with a generalized tonic-cionic seizure (e.g., fear of contagion by evil spritis). Therefore, partial seizure signs may not have been observed and only the secondary generalized phase has been reported. The first seizure occurred during childhood in the majority of cases. Due to the retrospective character of this information, it is not known for how many of the children with a first seizure before age 5 years this may have been a febrile convulsion. For the vast majority of those with the first seizure after this age, the initial seizure was probably the first unprovoked seizure, being the first manifestation of the epilepsy disorder. Most studies 19'21"24'3°'39 have defined active epilepsy as the occurrence of unprovoked seizures during the last 2-5 years and/or treatment with antiepileptic drugs (AED). Thus, cases with >5 years since the last seizure are included because continuous AED treatment and factors related to the decision on when to stop AED treatment (e.g., EEG findings, type of vocation, pharmacological tradition, knowledge of prognosis) influence prevalence rates. In the present study, 98.4% were not treated with AED and as no persons with many years of freedom from seizure on AED treatment were included, the prevalence rates presented
were largely unaffected by factors related to the use of AED. Primary generalized tonic-clonic seizures were found to be the most common type of seizure. The distribution of different types of seizures depends, among other factors, on the age distribution of the population from which cases were collected. Primary generalized seizures dominated in children/ adolescents 8. The relatively high proportion of primarily generalized seizures as compared te other studies 21'23 may depend on the large proportion of children/adolescents in the present study in which 59.1% were in the age group 0-19 years. Osuntokun et al. 3° found that 55.4% had partial epilepsy in a population in Nigeria where the proportion of children/adolescents was similar to the present study but where the proportion of persons in ages 40 years and older was higher. In other previous epidemiological studies of epilepsy from Africa, primary generalized epilepsies dominate 2,s'10,22'2s-28' 33,34,37 with the exception of the studies of Danesi 12 and Van der Waals et al. 3s where partial epilepsies were most common. It is to be no~ec! ~hat Danesi studied a group of persons with epilepsy attending a specialized neurological clinic. Important information from rural African studies where the majority of the epileptic population were not treated is data on the seizure frequency in persons in whom the disease has not been affected by medical treatment. Such basic background data may be of importance in evaluating the practical management of rural persons with epilepsy within the limited resources of a poor country. Levy et al. ~5 found in a group of untreated persons, where over 90% had generalized seizures, that seizures occurred daily in 11%, monthly in 27%, several per year in 45% and once a year or less in 14% (3% unknown). In the study of Van der Waals et al/8 only 3.3% were treated by antiepileptic drugs. They found the mean seizure frequency of primarily GTCS to be 0.99 seizures/week, while it was 1.08/week for simple partial seizures with secondary generalization and 2.69/week for complex partial seizures (of which 64% became generalized). Severe epilepsy was common in the present study, as 84% of persons with known seizure frequency had seizures at least monthly and the seizure frequency was higher
238 than in the study of Lev~ et al. 25. However, information on seizure frequency was not available for 8.9% in the present study, and it is likely that information was missing because of low seizure frequency in that group. Osuntokun et al. 3° found seizures or 'similar illness' in 5% of first- or second-degree relatives while 24% had relatives who had experienced childhood febrile convulsions. This is close to the 31% in the present study who had a relative with experience of at least 1 seizure. The risk for epilepsy in siblings of persons with epilepsy has been estimated to be 5-15% if the proband had a generalized epilepsy, and 3-15% if the proband had a partial epilepsy, while the sibling risk is 1-2% in the general population j. In the present study, the proportion of siblings affected was 4.8%. This may be an underestimate considering the lack of information from many siblings of adult cases. One has also to consider the effect of the low age of many siblings, with a consequent low number of person years at risk. A follow-up at higher ages would probably yield a higher proportion of epilepsy in REFERENCES 1 Anderson, V.E. and Hauscr, W,A,, Genetics, In: J, Laidlaw, A. Richens and J. Oxley (Eds.), A Textbook of Epilep. sy, Churchill Liviagstonc, Edinburgh, 1988, pp, 49-77, 2 Billinghurst, J,R., German, G,A. and Orlcy, J.H., The pattern of epilepsy in Uganda, Trop. Geogr. Med,. 25 (1973) 226-232, 3 Bird, A.V,, Heinz, H,J, and Klintworth, G,, Convulsive disorders in Bantu mine-workers, Epilepsia, 3 (1962) 175-187, 4 Brewis, M,, Poskanzer, D,, Rolland, C, and Miller, H,, Neurological disease in an English city, Aeta Neurol, Scand., 42, Suppl, 24 (1966) 1-89. 5 Cardozo, L,J, and Patel, M,G., Epilepsy in Zambia, East Afr. Med, J,, 53 (I976) 488-493, 6 Central Statistical Office, Ethiopia, Population and Housing Census 1984. Analytical report on Shewa region, Addis Ababa, 1989, 7 Commission on the Classification and Terminology of the ILAE, Proposal for revised clinical and electroencephalo, graphic classification of epileptic seizures, Epilepsia, 22 (1981) 489-501, 8 Cowan, L.D., Bodensteiner, J,B,, Leviton, A, and Doherty, L,, Prevalence of the epilepsies in children and adolescents, Epilepsia, 30 (1984) 94-106. 9 Cruz, M,E., Barberis, P. and Schoenberg, B.S., Epidemiology of epilepsy. In: K. Poeck, H.J. Freund and H. I
siblings. Mental retardation has been reported in 20-22% of European epilepsy populations 2°'39. The lower proportion found in the present study is probably an effect of including only cases with severe mental retardation. A higher mortality during early childhood due to lack of medical facilities and low priority for nutritional supply to the mentally retarded in times of inadequate availability of food for the family may also have contributed.
ACKNOWLEDGEMENTS
The study was funded by the Swedish Agency for Research Cooperation with Developing Countries (SAREC) and the Addis Ababa University. We also thank the Ethiopian Science and Technology Commission for its invaluable assistance. We are particularly indebted to our lay health-workers who made the interviews with devotion. We also gratefully acknowledge the enthusiastic and positive participation of the community studied. G~inshirt (Eds,), Neurology. Proc. Xlli World Congress of Neurology, Springer, Berlin 1986, pp. 108-116. 10 Dada, T.O,, Epilepsy in Lagos, Nigeria, Aft. J. Med. Sci., 1 (1970) 161-184, I I Danesi, M,A. and Oni, K., Profile of epilepsy in Lagos, Nigeria, Trop, Geogr. Med,, 35 (1983)9-13. 12 Danesi, M,A,, Classification of the epilepsies: an investigation of 945 patients in a developing country, Epilepsia, 26 (1985) 131-136, 13 Ethiopian Ministry of Health, Comprehensive Health Service Directory 1986/87, Addis Ababa, 1988. 14 Giel, R,, The problem of epilepsy in Ethiopia, Trop. Geogr, Med,, 22 (1970) 439-442. 15 Gomez, J,G,, Arciniegas, E. and Tortes, J., Prevalence of epilepsy in Bogota, Columbia, Neurology, 28 (1978) 90-95, 16 Goodridge, D.M.G. and Shorvon, S.D., Epileptic seizures in a population of 6000, I. Demography, diagnosis and classification, and role of the hospital services, Br. Med. J., 287 (1983) 641-644. 17 Goudsmit, J., Van der Waals, F.W. and Gajdusek, D.C., Epilepsy in the Gbawein and Wroughbarh clan of Grand Bassa county, Liberia: the endemic occurrence of 'See-ee' in the native population, Neuroepidemioiogy, 2 (1983) 24-34. 18 Graaf, A.S., Epidemioiogical aspects of epilepsy in northern Norway, Epilepsia, 15 (1974) 291-299. 19 Granieri, E., Rosati, G., Tola, R., Pavoni, M. Paolino, E.,
239 Pinna, L. and Monetti, V.C., A descriptive study of epilepsy in the district of Copporo, Italy, 1964-1978, Epilepsia, 24 (1983) 502-514. 20 Gudmundsson, G., Epilepsy in Iceland, Acta Neurol. Scand., 43, Suppl. 25 (1966). 21 Hauser, W.A. and Kurland, L.T., The epidemiology of epilepsy in Rochester, Minnesota, 1935 through 1967, Epilepsia, 16 (1975) 1-66. 22 Jilek-Aall, L., Jilek, W. and Miller, J.R., Clinical and genetic aspects of seizure disorders prevalent in an isolated African population, Epilepsia. 20 (1979) 613-622. 23 Joshi, V., Katiyar, B.C., Mohan, P.K., Misra, S. and Shukla, G.D., Profile of epilepsy in a developing country: a study of 1000 patients based on the international classification, Epilepsia, 18 (1977) 549-554. 24 Ker~inen, T., Riekkinen, P.J. and Sillanp/i~i, M., Incidence and prevalence of epilepsy in adults in eastern Finland, Epilepsia, 30 (1989) 413-421. 25 Levy, L.F., Forbes, J.L. and Parirenyatwa, T.S., Epilepsy in Africans, Cemr. Afr. J. Med., 10 (1961)241-249. 26 Levy, L.F., Epilepsy in Rhodesia, Zambia and Malawi, Ajar. J. Med. Sci., 1 (1970) 291-303. 27 Orley, J., Epilepsy in Uganda (rural). A study of eightythree cases, Aft. J. Med. Sci., 1 (1970) 155-160. 28 Osantokun, B.O. and Odeku, E.L., Epilepsy in Ibadan, Nigeria, Aft. J. Med. Sci., 1 (1970) 185-200. 29 Osuntokun, B.O., Schoenberg, B.S., Nottidge, V.A., Adeuja, A., Kale, O., Adeyefa, A., Bademosi, O., Olumide, A., Oyediran, A.B.O., Pearson, C.A. and Bolis, C.L., Research protocol for measuring the prevalence of neurologic disorders in developing countries. Results of a pilot study in Nigeria, Neuroepidemiology, 1 (1982) 143-153. 30 Osuntokun, B.O., Adeuja, A.O.G., Nottidge, V.A., Bademosi, O., Olumide, A., Ige, O., Yaria, F., Bolis, C.L. and Schoenberg, B.S., Prevalence of the epilepsies in Nigerian Africans: a community-based study, Epilepsia, 28
(1987) 272-279. 31 Osuntokun, B.O., Adeuja, A.O.G., Schoenberg, B.S., Bademosi, O., Nottidge, V.A., Olumide, A.O., Ige, O., Yaria, F. and Bolis, C.L., Neurological disorders in Nigerian Africans: a community-based study, Acta Neuroi. Scand., 75 (1987) 13-21. 32 Sander, J.W.A.S. and Shorvon, S.D., Incidence and prevalence studies in epilepsy and their methodological problems: a review, J. Neurol. Neurosurg. Psychiat., 50 (1987) 829-839. 33 Sridharan, R., Radhakrishnan, K., Ashok, P.P. and Mousa, M.E., Epidemiological and clinical study of epilepsy in Benghazi, Libya, Epilepsia, 27 (1986) 60-65. 34 Tekle-Haimanot, R., The pattern of epilepsy in Ethiopia: analysis of 468 cases, Ethiop. Med. J., 22 (1984) 113-118. 35 Tekle-Haimanot, R., Abebe, M., Gebre-Mariam, A., Forsgren, L., Holmgren, G., Heijbel, J. and Ekstedt, J., Community-based study of neurological disorders in Ethiopia: development of a screening instrument, Ethiop. ivied. J., 28 (1990) 123-137. 36 Tekle-Haimanot, R., Abebe, M., Forsgren, L., Gebre-Mariam, A., Holmgren, G., Heijbei, J. and Ekstedt, J., Attitudes of rural people toward epilepsy in central Ethiopia, Soc. Sci. Med., in press. 37 Telang, B.V. and Hettiaratchi, E.S.G., Patterns of epilepsy in Kenya m a clinical analysis of 115 cases, East Aft. Med. J., 58 (1981) 437-444. 38 Van der Waals, F.W., Goudsmit, J. and Gajdusek, D.C., See-ee: clinical characteristics of highly prevalent seizure disorders in the Gbawein and Wroughbarh Clan region of Grand Bassa county, Liberia, Neuroepidemiology, 2 (1983) 35-44. 39 Zielinski, J.J., Epidemiology and Medicosocial Problems of Epilepsy in Warsaw. Final Report on Research Program No. 19-P-58325-F-OI, Psychoneurological Institute, Warsaw, 1974.
Elsevier
EPIRES 00366
Clinical and electroencephalographic characteristics of epilepsy in rural Ethiopia: a community-based study Redda Tekle-Haimanot a, Lars Forsgren b, Mekonnen Abebe a, Ayele Gebre-Mariam c, Jan Heijbel d, G6sta Holmgren e and Jan Ekstedt b "Department of Interred Medicine, Addis Ababa University, Addis Ababa (Ethiopia), bDepartment of Neurology, Umed University, Univet:~ity Hospital, S.901 85 Umed (Sweden), "Department of Pediatrics, Addis Ababa University, Addis Ababa (Ethiopia), aDepartment of Pediatrics, Umed University, University Hospital, S.901 85 Umed (Sweden) and eDepartment of Clinical Genetics, Umett University, University Hospital, S.901 85 Umett (Sweden) (Received 29 March 1990; revision received 28 June 1990; accepted 3 July 1990)
Key words: Epidemiology; Epilepsy; Prevalence; Electroencephalography; Treatment; Ethiopia
A community-based epidemiological study of neurological disorders was performed in a rural area in Ethiopia. The most prevalent neurological disorder identified was epilepsy, found in 316 persons, The prevalence of epilepsy was 5.211000 inhabitants at risk, 5.8 for males, 4.6 for females. The highest age-specific prevalence was found for ages 10-19 years, Generalized tonic-clonic seizures were the most common seizure type and occurred ill 81%, On clinical grounds, partial seizures occurred in 20% and in 29% of these secondary generalization followed. During seizures, 8.5% had been injured by burns and 5,7% by trauma. Eighty-four percent had seizures at least monthly. Seizures occurred in 4.8% of siblings, Traditional treatment with local herbs, holy water and amulets was the most common, Only 1,6% had been treated with recognized antiepileptic drugs, Mental retardation was the most common associated disorder, found in 7.9% of the persons with epilepsy, During a period of 2 years, 8 persons died of status epilepticus and I from severe burns as a result of faUing into a domestic fire during a seizure, EEG was recorded in 73%. Epileptiform activity occurred in 18%.
INTRODUCTION Epilepsy is a common disorder a!l over the world, affecting about 0.4-2.0% of populations surveyed "~2,In the developing countries epilepsy is a major neurological problem where in many cases treatment is possible but often not available. Many previous epidemiological studies of epilepsy in Africa have been urban- and hospital-based 2:'1°-12" ,..~.,..s.33.3~.37 or carried out in subgroups of the popCorrespondence t,:: Dr. Redda Tekle-Haimanot, P.O. Box 4147, Addis Ababa. Ethiopia.
ulation a, often where the disorder has been particular,y ct~mmon 17'2-''3s. Because of selection bias, the results from these studies may not reflect the situation of epilepsy in the general population. Epilepsy among rural populations in Africa has only been investigated in a few studies ~4'25-28.The only epidemiological study of epilepsy from Africa where the problem of selection bias has been largely avoided was carried out in Nigeria by Osuntokun et al. 3°, using a screening instrument for neuroepidemiological survey that was developed within the Neurosciences Programme of the World Health Organization 29.
0920-1211/90f$03.50 (~ 1990 Elsevier Science Publishers B,V. (Biomedical Division)
231 A community-based rural epidemiological study of neurological disorders was performed in Ethiopia during 1986-1988. Thi~ paper is a clinical and electroencephalographic presentation of the persons with epilepsy identified in that study 35. MATERIALS AND METHODS The study was performed in the rura~ sub-district (woreda) of Meskan and Mareko in the district (awraja) of Haykoch and Butajira, 130 km south of the Ethiopian capital Addis Ababa. The population of Meskan and Mareko sub-district at the time of the study was 181,883 (ref. 6), organized into peasant and urban dweller's associations. The area consists of 3 small towns and 82 peasant associations. The survey was carried out in the 3 towns and 25 randomly selected peasant associations, ineluding all households in the selected area. The population was found to be fairly stable during the investigation period, although there was a continuous increase of the population due to the birth rate exceeding the death rate. Migration in and out of the villages was limited. In order to get reliable information on the denominator, a census of the sampled area was performed simultaneously with the identification of cases. The population of the selected area was 60,820. Secondary-school graduates from the community with a sound knowledge of the local customs, cultures and language were recruited and employed as lay health-workers (enumerators). They were trained in interview methodology for field surveys and instructed on simple observations and examinations of persons with neurological problems. Their supervision was undertaken by a Public Health Officer and neurologists. In the study area, after informed consents had been obtained, the lay health-workers made doorto-door interviews and administered questionnaires to screen those with neurokrgical disorders. The head of the household or his wif,, gave information on each member of the family. A special epilepsy form was administered for additional information from persons in the household with unconsciousness fits with or without frothing, or biting of the tongue or incontinence of urine, and from persons who had sudden jerky movements in
part of the body. These persons were later examined close to their villages by neurologists who, on the basis of the previous information and their own interview with the affected person and relatives, made the final diagnosis. Attitudinal studies on epilepsy were also performed on sampled adults. An overview of the study is shown in Fig. 1. The sensitivity and specificity of the screening instrumeh~ were pretested and found to be 91% and 85% respectively for detection of epilepsy 35. Since large-scale surveys, such as the present one, take several months to complete, and the survey was performed in a society where calenders and knowledge of exact dates were lacking, the use of a sp*,cific prevalence day was not feasible. The whole survey was performed during 20 months, from October 1986 to May 1988. The collection of demographic data (number, sex, age) and screening-for identification of cases took place during approximately 2 months in each town and peasant association. This information, later supplemented with a medical interview and examination, was used for the calculation of rates. Only persons found to be permanent residents for over 6 months in the selected towns and peasant associations at the time of the collection of demographic and medical data were included in the study. With the method used, a point prevalence on one specific day during the investigation period was established for a household in the survey area. The point prevalenees of the 13,469 households surveyed during any one day of the investigation period of 29 months were the constituents of the prevalence rates provided for ~he whole investigation period. The latter prevalence should be regarded as a point prevalence rate with multiple point prevalence components and not as a period prevalence, the sum of point l:revalence and incidence. Persons who had moved from other towns or peasant associations that b~ longed to the study sample were not included if t~'~cy had been registered by field workers in their former residence. When ~:'enders and knowledge of exact dates were lacking in a household, ages and dates given by respondents were counterchecked in relation to the 'local event calender,' i.e., important past social events (e.g., local battles, coronation of the Emperor, the Italian invasion, the 1974 Ethiopian
232 MeskanMareko subdistrict
Sample:
[Sampling~ !
25 peasant and (Sampling I 6 urban dwellers 181,~i83 associainhabitants tions
!
.-----(Interview )----~"----( Supcrvisi°n
13,460 households
---[Identification
60,820 persons
I
'---
]['A,,,,o,o.,
Prevalence investigation ,
Basic demographic data on
Attltudm data
Persons wt~ suspected neurologi,~al diseases
6O,82O
Imrsons
Validity I control by ] neurologists
from 1546 persons
(households)
~_fNeurological 1
908 cases with neurological disorders
Epidemiological analysis
91i~qm~muummmmu
316 easeswith
epilepsy
Fig. 1, Schemeof the survey,
revolution, etc.) or other events (e.g., rainy seasons, epidemics, etc.) well known to the inhabitants. Frequencies of seizures were counterchecked with two or more members of the family. The criteria to be included in the study were for all persons of all ages that they should have active epilepsy, i.e., they should have had at least 2 unprovoked :~ seizures of which at least one should have occurred during the last 5 years, and/or they should be on antiepileptic treatment because of seizures at the time of the investigation. Persons who only had seizures in association with fever, alcohol abuse or which only occurred during acute diseases were excluded. Seizures were classified according to the International Classification of
Epileptic Seizures, ICES 7. Since the subclassification of partial seizures as simple and complex partial seizures is difficult to use in epidemiological studies of epilepsy, no subclassification of partial seizures was made except for the occurrence of secondary generalization. Electroencephalographic (EEG) recordings were only performed on persons who fulfilled the criteria for active epilepsy. The reason for the examination and how it was to be carried out was carefully explained beforehand. For the purpose of this study the EEG machine was transported from Addis Ababa to the Health Center in the town of Butajira, the administrative center of the sub-district, and installed in a building of 18 m E,
233 made out of a transport container. Transport was provided for the persons with epilepsy who did not live nearby. Some problem was faced during preparation for the EEG recording. Females in the villages traditionally wear their hair in the form of braids, often with oil and butter applied on it. In order to ensure proper application of electrodes, shaving the hair and washing of the scalp was proposed for all patients. This was accepted by the males but strongly opposed by the females. A compromise was worked out in which the females agreed to have their hair washed and the braids restyled in accordance with the pattern of electrode application. A local girl with braiding experience was employed for the purpose. The EEG recording was carried out using a Nihon-Kohden Neurofax 7314F machine, with the standard array of electrodes used in the 10-20 international system. The patients were awake and provoked by photostimulation and hyperventilation. EEGs were classified as normal, paroxysmal abnormalities, unspecific abnormal (slowing) or epileptiform (spikes, sharp waves or spike-wave acu city). According to localization, the pathological findings were designated as bilateral, unilateral or focal (restricted to one or two electrodes). All patients with recurrent partial seizures (with or without secondary generalization) or recurrent primary generalized tonic.clonic seizures were started on the cheapest and most (at times the only) available anticonvulsant, phenobarbital. Testing instruments for intelligence assessment for field work using native speakers did not exist. A diagnosis of severe mental retardation was made clinically. Such diagnosed persons relied heavily on their family members for help with the primary activities of daily life such as hygiene, dressing, feeding, etc., and they had no or only very limited communication capabilities.
TABLE I Age- and sex-specific prevalence (cases/lO00) of epilepsy in a rural Ethiopian community Actual number of persons in parentheses. Age group (years)
Males
Females
0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-59 350
3.7 4.1 9.7 8.6 8.9 7.8 7.3 5.4 5.3 3.2 2.4
1.3 4.2 5.5 9.3 5.8 5.1 7.7 4.3 3.7 6.0 3.3
Total
5.8 (173)
(20) (23) (43) (26) (14) (10) (11) (8) (7) (3) (8)
(7) (23) (23) (24) (10) (11) (15) (8) (5) (6) (11)
4.6 (143)
the age group 10-19 years. The remaining 40.2% were 20 years or older with 5.7% being 55 years or older. Age- and sex-specific rates are shown in Table I and age-specific rates for the sexes combined are shown in Fig. 2. The crude prevalence rate for the sexes combined was 5.2/1000 inhabitants at risk. The highest rate for males was found between ages 10 and 14 years, and for females between ages 15 and 19 years. All households participated in the study and none of the persons suspected to have neurological disease during the screening phase refused interview and examination. Repeated visits to households by the lay health-workers resulted in a participation rate ranging from 95 to 100% in the different towns/villages surveyed. Prevalence/l,000 inhabitants at risk q,00 8,00 7,00 6,00 5,00
RESULTS Epilepsy was the most common neurological disorder identified in the general epidemiological study and was found in 316 persons, 173 males (54.7%) and 143 females (45.3%). Children 0-9 years old constituted 23.1%, and 36.7% were in
0,00
-~ 0-4
5-9
., .4 .4 ~ . -g 10. 14 15-19 20-24 25.29 30.34 35.39 40.44 45-49 ~50
Age in years
Fig. 2. Age-specific prevalence (cases/1000) of 316 persons with epilepsy in a rural Ethiopian community.
234 TABLE II
TABLE III
Age at first seizure in 314persons with epilepsy in rural Ethiopia
Duration of epilepsy in 314 persons in rural Ethiopia
Age at first seizm '
%
Duration
%
0-1 months 2-11 months 1-4 years 5-9 years 10-14 years 15-19 years 20-29 years 30-39 years 40-49 years ~>50years
1.9 2.9 27.1 18.5 20.1 9,6 10,8 3,8 2,9 2,5
20 years
5.4 19.4 24.5 26.8 17.8 2.9
Age at first seizure and duration of epilepsy Age at first seizure was known for 314 cases and is shown in Table II. The first seizure occurred before ages 5 and 15 years, in 31.9% and 70.5%, respectively. The interval from the first seizure to the identification of a person with epilepsy in the study is shown in Table III. The duration in the majority was between 3 and 10 years. Seizure types Seizures consistent with generalized tonic-clonic seizures (GTCS) were described in 256 persons (81.0%). They were associated with frothing and tongue biting in 99.2% and with incontinence of urine in 45.7%. The GTCS seizures were, on clinical grounds, judged to be primary in 238 persons (75.3%). There was one person with absence seizures. This person had no other type of seizure, Partial seizures occurred in 62 persons (19.6%). Most of these, 44 persons (13.9%), had seizures
that were only partial, while 18 persons (5.7%) had partial seizures that sometimes or always evolved into secondarily generalized seizures. Since the state of consciousness could not systematically be observed during seizures, the proportion of partial seizures that were simple or complex cannot be presented. Seizures of unclassified type occurred in 15 persons (4.7%). During seizures, 8.5% had been injured by burns and 5.7% by trauma.
Seizure frequency and occurrence The seizure frequency for different seizure types is shown in Table IV, Information on seizure fiequency was available in 288 (91%). Eighty-six of 313 persons (27.5%) reported that seizures were sometimes associated with fever. Seizures had been noted to occur only during sleep in 11.2%, at awakening in 3.8%, only when awake in 53.8% and both during sleep and when awake in 31.2%. Familial occurrence The history for occurrence of seizures in rel-
TABLE IV
Seizure frequeno, by clinical type of seizure in 316 persons with epilepsy Seizure type
n
GTCS a Absence Partial Unclassified
238 l 62 15
Total
316
(%)
(75) (0.3) (20) (5) (100)
a GTCS: generalized tonic-clonic seizures,
Seizure frequency n (%) Daily
Weekly
Monthly
Every 4th month
Yearly
Unknown
21 (7)
66(21)
101 (32)
5 (2)
33 (10)
12 (4)
5 (2) 4 (1)
9 (3) 3 (1)
27 (9) 7 (2)
1(0.3)
30 (10)
78 (25)
135(43)
1 (0.3)
6(2)
5 (2) 1 (0.3) 39(12)
15(5) 28(9)
235 atives was obtained for 314 cases and is shown in Table V. One-third (31.9%) had relatives who had had one or several seizures. Seizures occurred in 9 of the 628 parents (1.4%), in 27 of the 558 siblings (4.8%) and in 5 of 296 children (1.7%). The proportion of siblings with seizures should be regarded as a minimum figure since seizures in siblings were only known for 189 cases (many adults wit~ epilepsy were not willing to give information about the presence of seizures in siblings). One case had 2 first-degree relatives, 2 siblings, with seizures. Altogether, 41 first-degree relatives (parents, siblings and children) had experienced seizures, which constitutes 2.8% of all first-degree relatives.
Treatment of and beliefs about epik,psy Information about treatment was obtained from 306 persons. Neither traditional nor conventional treatments had been given in 23.5% of the persons with epilepsy. Local herbs was the most common treatment used and had been tried by 36.0%. Holy water had been tried by 12.4%. Kitab, a protective amulet, was used by 7.5% and 2 persons (0.7%) had sacrificed animals. Some type of medication was used by 19.3% but only 8.5% used it as the only treatment, while 10.8% combined it with some type of traditional treatment. What these medications were is unclear since recognized antiepileptic drugs were not available in the area. Addis Ababa is the only close place for supply of antiepileptic drugs which were obtained by only 5 patients. Of the persons with epilepsy, 74.4% did not have any idea what caused the seizures, 17.4% thought they were due to evil spirits, 6.2% to tenTABLE V
Familial occurrence of seizures in 314 persons with epilepsy Relation to person with seizures
Number
%
No relatives with seizures Parent(s) Siblings Grandparents Children Cousins Other relatives
214 9 23 3 5 53 7
68.2 2.9 7.3 0.9 1.6 16.9 2.2
sion state, 1.7% to head trauma and 0.3% to poison.
Other diseases The most prevalent disease/impairments combined with the epilepsy were severe mental retardation and hemiparesis, found in 7.9% and 2.5%, respectively.
Mortality During the last 2 years, 20 of the 316 persons with epilepsy died (6.3%). Death was related to epilepsy in 9 of the 20 persons, of whom 8 died in status epilepticus and 1 from severe burns from falling into a domestic fire during a seizure. The seizure frequency was high in these 9 persons. Four had daily seizures, I had weekly seizures and 4 had monthly seizures. In 7 persons, deaths were related to infections (malaria 1, epidemic meningitis 3, gastroenteritis 2, pneumonia 1) and 1 person died following trauma unrelated to seizure. Cause of death was unknown in the remaining 3 cases.
Electroencephalography (EEG) EEG was performed on 230 persons (72.8%) and the findings are shown in Table VI. Abnormalities were demonstrated in 42.6%. Unspecific slow wave abnormalities were detected in 16.5%, paroxysmal disturbances in 7.8% and epileptiform discharges in 18.3%. Twenty-six persons had focal TABLE VI
Electroencephalographic findings in 230 persons with epilepsy, in rural Ethiopia Finding
No. of persons
%
Normal Epileptiforma, total Focal Unilateral Bilateral Paroxysmalb rhythms Focal/unilateral Bilateral Unspecific abnormality, total Focal Unilateral Bilateral
132 42 9 4 29 18 6 12 38 4 3 31
57.4 18.3 3.9 1.7 12.6 7.8 2.6 5.2 16.5 1.7 1.3 13.5
a 2 and ~ 3 persons also had unspecific abnormalities.
236 unilateral or non-focal unila~,:ral abnormalities on the EEG, of whom 13 had epileptiform activity, 6 paroxysmal activity and 7 an unspecific abnormality. Of these 26 persons, 21 had a clinical diagnosis of generalized tonic-clonic seizures without focal seizure manifestations. The results of the EEG investigation indicate that these 21 persons probably had a foc~d lesion (partial epilepsy) and the seizures were secondarily generalized. Thus, altogether 83 persons (26.3%) had clinically partial seizures or EEG findings which made a diagnosis of epilepsy of focal origin probable. This leaves 217 persons with primarily GTCS (68.7%). DISCUSSION The vast majority of populations in developing countries live in rucal areas. In Ethiopia this is the case for over 90% of the population 6. Epilepsy is a common neurological disorder which can be effectively treated in the majority of patients. It was therefore important to study persons with epilepsy who had been identified in a community-based rural study in order to gain information for future health education and planning of therapeutic programmes. This is, to the best of our knox~edge, the first major community-based study of epilepsy in a rural African community. Despite the social stigma associated with epilepsy3t', there was no refusal of interview or examination. Possible explanations for this may be that because of the villagization programme (creation of large nucleated villages) and newly established strict social orders, there was a certain degree of regimentation within the communities surveyed. All the officials, community leaders and village elders cooperated and helped us to reach the people. Another factor, which probably contributed significantly to the positive attitude of the study population towards the investigators, was the anticonvulsant treatment offered to all cases actually at the time of diagnosis in accordance with the WHO motto 'no survey without service.' Repeated house calls were made if an adult person was not available at the first visits. There was a slight excess of males, which was most pronounced in the youngest age group. This was also found in the study of Cowan et al.S but not
by Osuntokun et al. 31. In both of these studies, rates of epilepsy in the age group 0-4 years were higher than in the present study. A possible explanation for this may be the very high infant and childhood mortality in Ethiopia ~3, which probably makes vulnerable children, such as those with epilepsy, less likely to survive. In the study of Osuntokun et al. 3~, prevalence rates also tended to be higher for males than females in the older age groups while the opposite was found in the present study. Due to the low number of persons in the older age groups in both studies, these differences may have occurred by chance. In this study, the age-specific prevalence rates decreased in the adult age ranges. Previous studies show fairly stable prevalence rates in different adult age groups with a drop in rates after age 60 years 4'18. Studies considered to have a more complete ascertainment of cases among the elderly found the highest rates in the older age groups 2m9. Although cases might have been missed in older age groups in the present study, other plausible explanations are either that people remit from their epilepsy or that they die because of epileptic seizures or factors related to epilepsy, e.g., trauma and tumours. However, the prognosis is not always bad. Over one-fifth of cases in the present study had a duration of epilepsy exceeding 10 years even without medical treatment. The crude prevalence rate for active epilepsy was 5.2/1000, which is comparable with the community-based study of Osuntokun et al. 3° who found a prevalence of 5.3/1000. The African studies that have found a prevalence of epilepsy exceeding 1% of the population ~°'~7'22'29are based on investigations on either specially selected and/or small populations. The results of our study and that of Osuntokun et al. 3° may indicate that the prevalence of active epilepsy in the general African population is comparable to that which has been found in European and U.S. populations, 3.4-7.8/1000 (see refs. 8, 16, 19, 20, 21, 22, 39). However, due to a possible high mortality caused by untreated epilepsy in African populations, the prevalence rate of epilepsy found may underestimate the magnitude of the medical and social problem created by epilepsy. High prevalence rates (12.7-19.5/1000) have been reported from
237 South America with a high proportion of primary generalized seizures 9'15. Precautions were taken to minimize the number of unidentified cases. Provision of free anticonvulsant treatment with the readily available drug phenobarbital created a positive impression in the community, which probably made families with the disease more willing to volunteer the necessary information. In a few cases, heads of households withheld information because of the social stigma commonly associated with epilepsy. In the few instances where this occurred, mainly with young girls, community leaders came up with the required information. Considering the relatively low proportion of partial seizures found, it is likely that there are, nevertheless, cases that were not identified. This may partly be an effect of informants and con~munity members not recognizing partial seizures as epileptic phenomena and possibly due to the relative insensitivity of the questionnaire to identify partial seizures. Moreover, many persons became scared when seeing a person with a generalized tonic-cionic seizure (e.g., fear of contagion by evil spritis). Therefore, partial seizure signs may not have been observed and only the secondary generalized phase has been reported. The first seizure occurred during childhood in the majority of cases. Due to the retrospective character of this information, it is not known for how many of the children with a first seizure before age 5 years this may have been a febrile convulsion. For the vast majority of those with the first seizure after this age, the initial seizure was probably the first unprovoked seizure, being the first manifestation of the epilepsy disorder. Most studies 19'21"24'3°'39 have defined active epilepsy as the occurrence of unprovoked seizures during the last 2-5 years and/or treatment with antiepileptic drugs (AED). Thus, cases with >5 years since the last seizure are included because continuous AED treatment and factors related to the decision on when to stop AED treatment (e.g., EEG findings, type of vocation, pharmacological tradition, knowledge of prognosis) influence prevalence rates. In the present study, 98.4% were not treated with AED and as no persons with many years of freedom from seizure on AED treatment were included, the prevalence rates presented
were largely unaffected by factors related to the use of AED. Primary generalized tonic-clonic seizures were found to be the most common type of seizure. The distribution of different types of seizures depends, among other factors, on the age distribution of the population from which cases were collected. Primary generalized seizures dominated in children/ adolescents 8. The relatively high proportion of primarily generalized seizures as compared te other studies 21'23 may depend on the large proportion of children/adolescents in the present study in which 59.1% were in the age group 0-19 years. Osuntokun et al. 3° found that 55.4% had partial epilepsy in a population in Nigeria where the proportion of children/adolescents was similar to the present study but where the proportion of persons in ages 40 years and older was higher. In other previous epidemiological studies of epilepsy from Africa, primary generalized epilepsies dominate 2,s'10,22'2s-28' 33,34,37 with the exception of the studies of Danesi 12 and Van der Waals et al. 3s where partial epilepsies were most common. It is to be no~ec! ~hat Danesi studied a group of persons with epilepsy attending a specialized neurological clinic. Important information from rural African studies where the majority of the epileptic population were not treated is data on the seizure frequency in persons in whom the disease has not been affected by medical treatment. Such basic background data may be of importance in evaluating the practical management of rural persons with epilepsy within the limited resources of a poor country. Levy et al. ~5 found in a group of untreated persons, where over 90% had generalized seizures, that seizures occurred daily in 11%, monthly in 27%, several per year in 45% and once a year or less in 14% (3% unknown). In the study of Van der Waals et al/8 only 3.3% were treated by antiepileptic drugs. They found the mean seizure frequency of primarily GTCS to be 0.99 seizures/week, while it was 1.08/week for simple partial seizures with secondary generalization and 2.69/week for complex partial seizures (of which 64% became generalized). Severe epilepsy was common in the present study, as 84% of persons with known seizure frequency had seizures at least monthly and the seizure frequency was higher
238 than in the study of Lev~ et al. 25. However, information on seizure frequency was not available for 8.9% in the present study, and it is likely that information was missing because of low seizure frequency in that group. Osuntokun et al. 3° found seizures or 'similar illness' in 5% of first- or second-degree relatives while 24% had relatives who had experienced childhood febrile convulsions. This is close to the 31% in the present study who had a relative with experience of at least 1 seizure. The risk for epilepsy in siblings of persons with epilepsy has been estimated to be 5-15% if the proband had a generalized epilepsy, and 3-15% if the proband had a partial epilepsy, while the sibling risk is 1-2% in the general population j. In the present study, the proportion of siblings affected was 4.8%. This may be an underestimate considering the lack of information from many siblings of adult cases. One has also to consider the effect of the low age of many siblings, with a consequent low number of person years at risk. A follow-up at higher ages would probably yield a higher proportion of epilepsy in REFERENCES 1 Anderson, V.E. and Hauscr, W,A,, Genetics, In: J, Laidlaw, A. Richens and J. Oxley (Eds.), A Textbook of Epilep. sy, Churchill Liviagstonc, Edinburgh, 1988, pp, 49-77, 2 Billinghurst, J,R., German, G,A. and Orlcy, J.H., The pattern of epilepsy in Uganda, Trop. Geogr. Med,. 25 (1973) 226-232, 3 Bird, A.V,, Heinz, H,J, and Klintworth, G,, Convulsive disorders in Bantu mine-workers, Epilepsia, 3 (1962) 175-187, 4 Brewis, M,, Poskanzer, D,, Rolland, C, and Miller, H,, Neurological disease in an English city, Aeta Neurol, Scand., 42, Suppl, 24 (1966) 1-89. 5 Cardozo, L,J, and Patel, M,G., Epilepsy in Zambia, East Afr. Med, J,, 53 (I976) 488-493, 6 Central Statistical Office, Ethiopia, Population and Housing Census 1984. Analytical report on Shewa region, Addis Ababa, 1989, 7 Commission on the Classification and Terminology of the ILAE, Proposal for revised clinical and electroencephalo, graphic classification of epileptic seizures, Epilepsia, 22 (1981) 489-501, 8 Cowan, L.D., Bodensteiner, J,B,, Leviton, A, and Doherty, L,, Prevalence of the epilepsies in children and adolescents, Epilepsia, 30 (1984) 94-106. 9 Cruz, M,E., Barberis, P. and Schoenberg, B.S., Epidemiology of epilepsy. In: K. Poeck, H.J. Freund and H. I
siblings. Mental retardation has been reported in 20-22% of European epilepsy populations 2°'39. The lower proportion found in the present study is probably an effect of including only cases with severe mental retardation. A higher mortality during early childhood due to lack of medical facilities and low priority for nutritional supply to the mentally retarded in times of inadequate availability of food for the family may also have contributed.
ACKNOWLEDGEMENTS
The study was funded by the Swedish Agency for Research Cooperation with Developing Countries (SAREC) and the Addis Ababa University. We also thank the Ethiopian Science and Technology Commission for its invaluable assistance. We are particularly indebted to our lay health-workers who made the interviews with devotion. We also gratefully acknowledge the enthusiastic and positive participation of the community studied. G~inshirt (Eds,), Neurology. Proc. Xlli World Congress of Neurology, Springer, Berlin 1986, pp. 108-116. 10 Dada, T.O,, Epilepsy in Lagos, Nigeria, Aft. J. Med. Sci., 1 (1970) 161-184, I I Danesi, M,A. and Oni, K., Profile of epilepsy in Lagos, Nigeria, Trop, Geogr. Med,, 35 (1983)9-13. 12 Danesi, M,A,, Classification of the epilepsies: an investigation of 945 patients in a developing country, Epilepsia, 26 (1985) 131-136, 13 Ethiopian Ministry of Health, Comprehensive Health Service Directory 1986/87, Addis Ababa, 1988. 14 Giel, R,, The problem of epilepsy in Ethiopia, Trop. Geogr, Med,, 22 (1970) 439-442. 15 Gomez, J,G,, Arciniegas, E. and Tortes, J., Prevalence of epilepsy in Bogota, Columbia, Neurology, 28 (1978) 90-95, 16 Goodridge, D.M.G. and Shorvon, S.D., Epileptic seizures in a population of 6000, I. Demography, diagnosis and classification, and role of the hospital services, Br. Med. J., 287 (1983) 641-644. 17 Goudsmit, J., Van der Waals, F.W. and Gajdusek, D.C., Epilepsy in the Gbawein and Wroughbarh clan of Grand Bassa county, Liberia: the endemic occurrence of 'See-ee' in the native population, Neuroepidemioiogy, 2 (1983) 24-34. 18 Graaf, A.S., Epidemioiogical aspects of epilepsy in northern Norway, Epilepsia, 15 (1974) 291-299. 19 Granieri, E., Rosati, G., Tola, R., Pavoni, M. Paolino, E.,
239 Pinna, L. and Monetti, V.C., A descriptive study of epilepsy in the district of Copporo, Italy, 1964-1978, Epilepsia, 24 (1983) 502-514. 20 Gudmundsson, G., Epilepsy in Iceland, Acta Neurol. Scand., 43, Suppl. 25 (1966). 21 Hauser, W.A. and Kurland, L.T., The epidemiology of epilepsy in Rochester, Minnesota, 1935 through 1967, Epilepsia, 16 (1975) 1-66. 22 Jilek-Aall, L., Jilek, W. and Miller, J.R., Clinical and genetic aspects of seizure disorders prevalent in an isolated African population, Epilepsia. 20 (1979) 613-622. 23 Joshi, V., Katiyar, B.C., Mohan, P.K., Misra, S. and Shukla, G.D., Profile of epilepsy in a developing country: a study of 1000 patients based on the international classification, Epilepsia, 18 (1977) 549-554. 24 Ker~inen, T., Riekkinen, P.J. and Sillanp/i~i, M., Incidence and prevalence of epilepsy in adults in eastern Finland, Epilepsia, 30 (1989) 413-421. 25 Levy, L.F., Forbes, J.L. and Parirenyatwa, T.S., Epilepsy in Africans, Cemr. Afr. J. Med., 10 (1961)241-249. 26 Levy, L.F., Epilepsy in Rhodesia, Zambia and Malawi, Ajar. J. Med. Sci., 1 (1970) 291-303. 27 Orley, J., Epilepsy in Uganda (rural). A study of eightythree cases, Aft. J. Med. Sci., 1 (1970) 155-160. 28 Osantokun, B.O. and Odeku, E.L., Epilepsy in Ibadan, Nigeria, Aft. J. Med. Sci., 1 (1970) 185-200. 29 Osuntokun, B.O., Schoenberg, B.S., Nottidge, V.A., Adeuja, A., Kale, O., Adeyefa, A., Bademosi, O., Olumide, A., Oyediran, A.B.O., Pearson, C.A. and Bolis, C.L., Research protocol for measuring the prevalence of neurologic disorders in developing countries. Results of a pilot study in Nigeria, Neuroepidemiology, 1 (1982) 143-153. 30 Osuntokun, B.O., Adeuja, A.O.G., Nottidge, V.A., Bademosi, O., Olumide, A., Ige, O., Yaria, F., Bolis, C.L. and Schoenberg, B.S., Prevalence of the epilepsies in Nigerian Africans: a community-based study, Epilepsia, 28
(1987) 272-279. 31 Osuntokun, B.O., Adeuja, A.O.G., Schoenberg, B.S., Bademosi, O., Nottidge, V.A., Olumide, A.O., Ige, O., Yaria, F. and Bolis, C.L., Neurological disorders in Nigerian Africans: a community-based study, Acta Neuroi. Scand., 75 (1987) 13-21. 32 Sander, J.W.A.S. and Shorvon, S.D., Incidence and prevalence studies in epilepsy and their methodological problems: a review, J. Neurol. Neurosurg. Psychiat., 50 (1987) 829-839. 33 Sridharan, R., Radhakrishnan, K., Ashok, P.P. and Mousa, M.E., Epidemiological and clinical study of epilepsy in Benghazi, Libya, Epilepsia, 27 (1986) 60-65. 34 Tekle-Haimanot, R., The pattern of epilepsy in Ethiopia: analysis of 468 cases, Ethiop. Med. J., 22 (1984) 113-118. 35 Tekle-Haimanot, R., Abebe, M., Gebre-Mariam, A., Forsgren, L., Holmgren, G., Heijbel, J. and Ekstedt, J., Community-based study of neurological disorders in Ethiopia: development of a screening instrument, Ethiop. ivied. J., 28 (1990) 123-137. 36 Tekle-Haimanot, R., Abebe, M., Forsgren, L., Gebre-Mariam, A., Holmgren, G., Heijbei, J. and Ekstedt, J., Attitudes of rural people toward epilepsy in central Ethiopia, Soc. Sci. Med., in press. 37 Telang, B.V. and Hettiaratchi, E.S.G., Patterns of epilepsy in Kenya m a clinical analysis of 115 cases, East Aft. Med. J., 58 (1981) 437-444. 38 Van der Waals, F.W., Goudsmit, J. and Gajdusek, D.C., See-ee: clinical characteristics of highly prevalent seizure disorders in the Gbawein and Wroughbarh Clan region of Grand Bassa county, Liberia, Neuroepidemiology, 2 (1983) 35-44. 39 Zielinski, J.J., Epidemiology and Medicosocial Problems of Epilepsy in Warsaw. Final Report on Research Program No. 19-P-58325-F-OI, Psychoneurological Institute, Warsaw, 1974.
