Epilepsia, 16:7 31-733, 1975
Raven Press, New York
Isolated Seizures: An EEG and Clinical Assessment Michael Saunders and Clive Marshall Departments of Neurology and Electroencephalography, Middlesbrough General Hospital, Middlesbrough, Cleveland, England
(Received August 19,1975) INTRODUCTION
METHODS AND MATERIALS
Little has been written about the prognosis o r special features of the patient who presents to an EEG department with an isolated epileptic attack. Epilepsy is by nature a recurrent phenomenon and it is important, if possible, to adopt a clearly defined attitude to the management of such patients. In a study of diagnostic factors in adult males following initial seizures, Johnson et al. (1972)found that the predictors of second seizures were type of seizure (major motor), EEG abnormalities, and the presence of postictal confusion and disorientation. However, this study was not restricted to patients definitely diagnosed as having an epileptic seizure, and 18%of the patients ended up with a psychiatric diagnosis. In the seventh Gowers Memorial Lecture Williams (1975)refers to the benign nature of single seizures and the notion that in many cases emotional and psychic factors may be relevant. This article reports the study of 39 patients who were referred to the EEG department with an isolated seizure. They were compared with a similar number of patients controlled for age and sex with recurrent attacks. Fits related to drug withdrawal, alcohol intake, head injury, and heart disease were excluded. Any attacks thought to be hysterical or possibly syncopal were exluded.
The 39 patients with single isolated attacks ranged in age from 15 to 57,with a mean age of 36. There were 19 males and 20 females in the two groups. Each patient was assessed o n the basis of a single EEG using a 16-channel S.L.E. machine. Notes were taken about the time of day of the attack, the existence of any EEG abnormality, the underlying cause of the attack, if known, and the eventual outcome. The delay between the attack and the EEG recording was noted in the single-seizure group. All patients had a clinical examination.
Key words: Isolated seizures - Prognosis EEG
RESULTS In the isolated fit group 13 attacks were nocturnal during sleep, and eight occurred on waking in the early morning and before the patient had gotten out of bed. Seventeen attacks were diurnal; the time of one attack was unknown.
TABLE 1. Time of day of single seizure and recurrent attacks
Single Sleep On waking Nocturnal and diurnal Diurnal Unknown
fit 13 8 0 17
1
Recurrent attacks 2 3 1 32 1
In the control group 2 patients had attacks exclusively during sleep, 2 exclusively on wak731
732
M. SAUNDERS AND C. MARSHALL
naire. For the 22 who were known to be well and who were receiving no anticonvulsants, the followup period varied from 10 months to 4 years and 4 months. The mean followup period was 26 months. TABLE 2. Clinical type of epilepsy in single Examination of the relationship between fit seizures and recurrent attacks type and time of day showed no significant Single Recurrent findings other than the obvious fact that fit attacks temporal lobe epilepsy is not recognized in 37 21 sleep and that temporal lobe epilepsy does not Major Focal motor 2 3 present with a single attack. Temporal lobe 0 12 With regard to the underlying cause, in many Adversive 0 2 instances no conclusion was reached. Of the Drop attack 0 1 isolated attacks 34 were of unknown cause, one was associated with the Shy-Drager syndrome, In the single fit group 37 patients presented and one was associated with birth trauma. Two with a major seizure and 2 had focal motor fits. were thought to be due to cerebrovascular In the control group 21 patients had major fits, disease and one was associated with spike and 12 had temporal lobe attacks, 3 had focal wave in the EEG. In the control group three motor fits, 2 had adversive seizures, and 1 had were associated with birth injury, four were due drop attacks. to primary subcortical epilepsy, one followed a cerebral abscess, one was associated with TABLE 3. EEG abnormalities in single seizures tuberose sclerosis, two were postmeningitic, and recurrent attacks two were due to cerebrovascular disease, and one was due to a brain tumor. The cause Single Recurrent remained uncertain in 25 cases. fit attacks 15 14 Normal DISCUSSION 1 4 Spike and wave Temporal lobe 16 15 In this study 22 patients had no recurrence General excess slow 7 3 of their seizures over a period ranging from 10 Frontal focus 0 1 Slow wave asymmetry 0 2 months to over 4 years. Only time shows whether a patient has had an isolated fit or has epilepsy. We felt that a convenient way of EEG abnormalities in the two groups were naming an attack as isolated was at the time of very similar. In the isolated fit group 15 EEGs the initial EEG. However, this would not be were normal. One showed spike-and-wave suitable in every situation depending o n the activity, 16 showed temporal lobe abnormal- waiting limit for electroencephalograms. We ities, and 7 had a general excess of slow agree with Williams (1975)that the occurrence activity. In the control group 14 had a normal of a fit can be a solitary happening and that EEG, 4 had spike-and-wave abnormalities, 15 obscure factors operate in that particular cirhad temporal lobe abnormalities, 3 had a cumstance to produce the attack. In contrast, general excess of slow activity, 1 had a frontal electroencephalography was not helpful in asfocus, and 2 showed asymmetry with excess of sessing prognosis and there was no obvious slow activity over one hemisphere. factor which helped to distinguish the group The interval between the attack and the who would subsequently have recurrent EEG recording was noted in the isolated fit seizures. This is in contrast to the findings of group. This varied between 3 weeks and 5 Johnson et al. (1972). The difference in findmonths, and in the majority of instances the ings probably lies in the more rigid criteria for accepting a case as a true fit. Our conclusion is time interval was 1 to 2 months. In the single-seizure group 11 subsequently that patients presenting with isolated fits must developed recurrent attacks, 22 had no further be assessed in the same way as those with attacks, and 6 failed to respond to the question- established epilepsy. ing, and 1 during sleep and o n waking. Thirtytwo were diurnal, one was diurnal and nocturnal, and one occurred at an unknown time.
ISOLATED SEIZURES SUMMARY A study has been made of 39 patients with isolated fits presenting to an EEG department. Patients were excluded when there was a doubtful history, alcoholism, or drug abuse. The 39 patients were compared with a control group of patients with epilepsy matched for age and sex. No basic difference was found between the two gyoups. In particular the EEG examination showed similar changes. In conclusion, patients with isolated fits should be assessed in the same way as those with established epilepsy, while recognizing that in the majority of instances no serious underlying cause will be found.
RESUME On a etudie une population d e 39 patients qui se sont presentes au departement EEG avec une histoire de crises isolees. On a exclus des patients lorsqu’ils avaient une histoire imprecise, une notion d’alcoolisme ou bien d’abus d e drogues. Les 39 patients o n t 6t6 compares i une population d e contrBle de sujets epileptiques du m t m e Ige et du mdme sexe. On n’a pas observe de differences entre les deux groupes. En particulier, les donnees EEG Btaient semblables. On arrive i la conclusion que les sujets ayant une crise isolke doivent t t r e consider& d e la mdme facon que ceux avec une epilepsie chronique, tout en reconnaissant que dans la majorit6 des cas o n ne retrouvera pas d’affections serieuses. (C. A. Tassinari, Marseilles)
RESUMEN
Se han estudiado 39 enfermos con ataques aislados que han acudido a un laboratorio
733
electroencefalogdfico. Se excluyeron 10s enfermos con historia dudosa o 10s que tenian historia de alcoholismo o abuso d e drogas. Los 39 enfermos se compararon con grupos controles d e enfermos epilCpticos de la misma edad y sexo. No se encontraron diferencias entre 10s dos grupos. La exploraci6n electroencefalogriifica mostr6 alteraciones similares. Se concluye que 10s enfermos con ataques aislados deben ser considerados d e la misma manera que 10s que tienen epilepsia establecida reconociendo que no se encuentran causas serias en la mayoria de 10s casos. (A. Portera Sanchez, Madrid)
ZUSAMMENFASSUNG Untersuchung an 39 Patienten mit isolierten Anfallen die an eine EEG-Abteilung iibenviesen wurden. Patienten rnit zweifelhafter Vorgeschichte und Alkoholisrnus oder Drogenmissbrauch wurden ausgeschlossen. Die 39 Patienten wurden rnit einer Kontrollgruppe von Patienten mit Epilepsie verglichen, denen sie in Alter und Geschlecht entsprachen. Zwischen beiden Gruppen fanden sich keine grundlegenden Unterschiede. Speziell die EEG-Untersuchung ergab ahnliche Veranderungen. Daraus ist zu schliessen, dass Patienten rnit isolierten Anfallen in genau der gleichen Weise untersucht werden sollten wie solche rnit chronischer Epilepsie, auch in Anbetracht der Tatsache, dass bei der Mehrzahl der Falle keine schwerwiegenden Ursachen zu finden sein werden. (D. Scheffner, Heidelberg)
REFERENCES Johnson LC, DeBolt WL, Long MT, Ross JJ, Sassin JF, Arthur RJ, and Walter RD. Diagnostic factors in adult males following initial seizures. Arch Neurol 27:193-197, 1972. Williams D. The border land of epilepsy revisited. Brain 98:l-12, 1975.
Raven Press, New York
Isolated Seizures: An EEG and Clinical Assessment Michael Saunders and Clive Marshall Departments of Neurology and Electroencephalography, Middlesbrough General Hospital, Middlesbrough, Cleveland, England
(Received August 19,1975) INTRODUCTION
METHODS AND MATERIALS
Little has been written about the prognosis o r special features of the patient who presents to an EEG department with an isolated epileptic attack. Epilepsy is by nature a recurrent phenomenon and it is important, if possible, to adopt a clearly defined attitude to the management of such patients. In a study of diagnostic factors in adult males following initial seizures, Johnson et al. (1972)found that the predictors of second seizures were type of seizure (major motor), EEG abnormalities, and the presence of postictal confusion and disorientation. However, this study was not restricted to patients definitely diagnosed as having an epileptic seizure, and 18%of the patients ended up with a psychiatric diagnosis. In the seventh Gowers Memorial Lecture Williams (1975)refers to the benign nature of single seizures and the notion that in many cases emotional and psychic factors may be relevant. This article reports the study of 39 patients who were referred to the EEG department with an isolated seizure. They were compared with a similar number of patients controlled for age and sex with recurrent attacks. Fits related to drug withdrawal, alcohol intake, head injury, and heart disease were excluded. Any attacks thought to be hysterical or possibly syncopal were exluded.
The 39 patients with single isolated attacks ranged in age from 15 to 57,with a mean age of 36. There were 19 males and 20 females in the two groups. Each patient was assessed o n the basis of a single EEG using a 16-channel S.L.E. machine. Notes were taken about the time of day of the attack, the existence of any EEG abnormality, the underlying cause of the attack, if known, and the eventual outcome. The delay between the attack and the EEG recording was noted in the single-seizure group. All patients had a clinical examination.
Key words: Isolated seizures - Prognosis EEG
RESULTS In the isolated fit group 13 attacks were nocturnal during sleep, and eight occurred on waking in the early morning and before the patient had gotten out of bed. Seventeen attacks were diurnal; the time of one attack was unknown.
TABLE 1. Time of day of single seizure and recurrent attacks
Single Sleep On waking Nocturnal and diurnal Diurnal Unknown
fit 13 8 0 17
1
Recurrent attacks 2 3 1 32 1
In the control group 2 patients had attacks exclusively during sleep, 2 exclusively on wak731
732
M. SAUNDERS AND C. MARSHALL
naire. For the 22 who were known to be well and who were receiving no anticonvulsants, the followup period varied from 10 months to 4 years and 4 months. The mean followup period was 26 months. TABLE 2. Clinical type of epilepsy in single Examination of the relationship between fit seizures and recurrent attacks type and time of day showed no significant Single Recurrent findings other than the obvious fact that fit attacks temporal lobe epilepsy is not recognized in 37 21 sleep and that temporal lobe epilepsy does not Major Focal motor 2 3 present with a single attack. Temporal lobe 0 12 With regard to the underlying cause, in many Adversive 0 2 instances no conclusion was reached. Of the Drop attack 0 1 isolated attacks 34 were of unknown cause, one was associated with the Shy-Drager syndrome, In the single fit group 37 patients presented and one was associated with birth trauma. Two with a major seizure and 2 had focal motor fits. were thought to be due to cerebrovascular In the control group 21 patients had major fits, disease and one was associated with spike and 12 had temporal lobe attacks, 3 had focal wave in the EEG. In the control group three motor fits, 2 had adversive seizures, and 1 had were associated with birth injury, four were due drop attacks. to primary subcortical epilepsy, one followed a cerebral abscess, one was associated with TABLE 3. EEG abnormalities in single seizures tuberose sclerosis, two were postmeningitic, and recurrent attacks two were due to cerebrovascular disease, and one was due to a brain tumor. The cause Single Recurrent remained uncertain in 25 cases. fit attacks 15 14 Normal DISCUSSION 1 4 Spike and wave Temporal lobe 16 15 In this study 22 patients had no recurrence General excess slow 7 3 of their seizures over a period ranging from 10 Frontal focus 0 1 Slow wave asymmetry 0 2 months to over 4 years. Only time shows whether a patient has had an isolated fit or has epilepsy. We felt that a convenient way of EEG abnormalities in the two groups were naming an attack as isolated was at the time of very similar. In the isolated fit group 15 EEGs the initial EEG. However, this would not be were normal. One showed spike-and-wave suitable in every situation depending o n the activity, 16 showed temporal lobe abnormal- waiting limit for electroencephalograms. We ities, and 7 had a general excess of slow agree with Williams (1975)that the occurrence activity. In the control group 14 had a normal of a fit can be a solitary happening and that EEG, 4 had spike-and-wave abnormalities, 15 obscure factors operate in that particular cirhad temporal lobe abnormalities, 3 had a cumstance to produce the attack. In contrast, general excess of slow activity, 1 had a frontal electroencephalography was not helpful in asfocus, and 2 showed asymmetry with excess of sessing prognosis and there was no obvious slow activity over one hemisphere. factor which helped to distinguish the group The interval between the attack and the who would subsequently have recurrent EEG recording was noted in the isolated fit seizures. This is in contrast to the findings of group. This varied between 3 weeks and 5 Johnson et al. (1972). The difference in findmonths, and in the majority of instances the ings probably lies in the more rigid criteria for accepting a case as a true fit. Our conclusion is time interval was 1 to 2 months. In the single-seizure group 11 subsequently that patients presenting with isolated fits must developed recurrent attacks, 22 had no further be assessed in the same way as those with attacks, and 6 failed to respond to the question- established epilepsy. ing, and 1 during sleep and o n waking. Thirtytwo were diurnal, one was diurnal and nocturnal, and one occurred at an unknown time.
ISOLATED SEIZURES SUMMARY A study has been made of 39 patients with isolated fits presenting to an EEG department. Patients were excluded when there was a doubtful history, alcoholism, or drug abuse. The 39 patients were compared with a control group of patients with epilepsy matched for age and sex. No basic difference was found between the two gyoups. In particular the EEG examination showed similar changes. In conclusion, patients with isolated fits should be assessed in the same way as those with established epilepsy, while recognizing that in the majority of instances no serious underlying cause will be found.
RESUME On a etudie une population d e 39 patients qui se sont presentes au departement EEG avec une histoire de crises isolees. On a exclus des patients lorsqu’ils avaient une histoire imprecise, une notion d’alcoolisme ou bien d’abus d e drogues. Les 39 patients o n t 6t6 compares i une population d e contrBle de sujets epileptiques du m t m e Ige et du mdme sexe. On n’a pas observe de differences entre les deux groupes. En particulier, les donnees EEG Btaient semblables. On arrive i la conclusion que les sujets ayant une crise isolke doivent t t r e consider& d e la mdme facon que ceux avec une epilepsie chronique, tout en reconnaissant que dans la majorit6 des cas o n ne retrouvera pas d’affections serieuses. (C. A. Tassinari, Marseilles)
RESUMEN
Se han estudiado 39 enfermos con ataques aislados que han acudido a un laboratorio
733
electroencefalogdfico. Se excluyeron 10s enfermos con historia dudosa o 10s que tenian historia de alcoholismo o abuso d e drogas. Los 39 enfermos se compararon con grupos controles d e enfermos epilCpticos de la misma edad y sexo. No se encontraron diferencias entre 10s dos grupos. La exploraci6n electroencefalogriifica mostr6 alteraciones similares. Se concluye que 10s enfermos con ataques aislados deben ser considerados d e la misma manera que 10s que tienen epilepsia establecida reconociendo que no se encuentran causas serias en la mayoria de 10s casos. (A. Portera Sanchez, Madrid)
ZUSAMMENFASSUNG Untersuchung an 39 Patienten mit isolierten Anfallen die an eine EEG-Abteilung iibenviesen wurden. Patienten rnit zweifelhafter Vorgeschichte und Alkoholisrnus oder Drogenmissbrauch wurden ausgeschlossen. Die 39 Patienten wurden rnit einer Kontrollgruppe von Patienten mit Epilepsie verglichen, denen sie in Alter und Geschlecht entsprachen. Zwischen beiden Gruppen fanden sich keine grundlegenden Unterschiede. Speziell die EEG-Untersuchung ergab ahnliche Veranderungen. Daraus ist zu schliessen, dass Patienten rnit isolierten Anfallen in genau der gleichen Weise untersucht werden sollten wie solche rnit chronischer Epilepsie, auch in Anbetracht der Tatsache, dass bei der Mehrzahl der Falle keine schwerwiegenden Ursachen zu finden sein werden. (D. Scheffner, Heidelberg)
REFERENCES Johnson LC, DeBolt WL, Long MT, Ross JJ, Sassin JF, Arthur RJ, and Walter RD. Diagnostic factors in adult males following initial seizures. Arch Neurol 27:193-197, 1972. Williams D. The border land of epilepsy revisited. Brain 98:l-12, 1975.
