Acta Pcediatr Scand 80: 36 1-369, 1991
Aetiological and Precipitating Factors for Childhood Enuresis M. R. JARVELIN, I. MOILANEN, P. KANGAS,' K. MORING, L. VIKEVAINEN-TERVONEN, N.-P. HUTTUNEN and J. SEPPANEN From the Department of Paediatrics and 'Applied Mathematics and Statistics, Uniuersity of Oulu, Finland
ABSTRACT. J h e l i n , M. R., Moilanen, I., Kangas, P., Moring, K., VikeviiinenTervonen, L., Huttunen, N.-P.and Seppjinen, J. (Department of Paediatrics, University Central Hospital, Oulu, Finland.) Aetiological and precipitating factors for childhood enuresis. Acta Paediatr Scand 80: 361,1991. Aetiological factors for enuresis in 68 nightwetting (NW) and 73 day and mixed day and nightwetting (DW/MW) children were examined against a random sample of 142 control children drawn from a population of 3 375 seven-year-old children. Twenty-six variables concerning age, sex, social background, life changes, familial and perinatal history, development, growth, neurological damage, psychic structure and urinary tract disorders were included in the logistic regression analysis. The familial influence on enuresis was clearly seen in both nightwetters and daywetters. The NW children were further discriminated from the controls by items connected with delayed develop ment, such as slower growth and poorer visuomotor and spatial perception. Marital separation or birth of a sibling were also found to be precipitating factors especially for nightwetters. The DW/MW children were discriminated from the controls by perinatal risk factors, signs of neurological dysfunction and smaller voided volume, and especially secondary daywetters by urinary tract infections. These models showed that there are similarities between nocturnal and diurnal enuresis, although there are still many differences and every individual case requires consideration of all these disposing factors. Key words: nightwetting, daywetting, developmental delay, neurological damage, life changes, repression, logistic regression model. A wide variety of factors such as delayed maturation of the nervous system controlling bladder function, deep sleep, genetic, social and psychological factors and other organic features such as allergic reactions and malformations of the urinary tract system have been thought to cause wetting, theories about its aetiology varying greatly with the fashion of the times (1-1 1). In addition, the different causes of day and nightwetting have been emphasized previously but most research has been based on more or less selected groups of enuretic children (8, 11). The aim was to examine the importance and implications of different factors connected with wetting and possibly causally related to it in an unselected group of 7-year-old children and to identify differences between the day and nightwetters and the primary and secondary wetters.
MATERIAL AND METHODS Definition of enuresis. The term enuresis is used here as a synonym for wetting and enuretic children are classified according to diurnal or nocturnal symptoms without any restrictions on the definition which would exclude possible organic aetiological groups. All except six nightwetting (NW) children in the enuresis group in a prospective follow-up fulfilled the definition recommended by DSM I11 of one wet night or day in a month (Table 1) (12). Wetting was termed primary if the child had never had a non-wetting period of six months or more and secondary in the reverse case. A child with mixed day and nightwetting (MW) was defined as a primary wetter if either daywetting (DW) or NW was of the primary type. Subjects. Both the enuretic children and their controls were drawn from a population of
362 M . R. Jarvelin et al.
Acta Paediatr Scand 80
3 375 7-year-old children living in four local government districts close to the University of Oulu during 1983-1984, by the use of a mailed questionnaire. One whole age class was recruited each year, and 3 190 completed replies were received (94.5 O/o). Two hundred and fifty children were reported to have wet themselves at least once during the previous six months, although in eleven cases wetting had ceased before the invitation to a clinical examination. A total of 98 children were omitted because of refusal (n=45), missing data ( n = 15) or infrequent nightwetting ( n = 3 8 ) . Of those omitted 76.5 9’0 were occasional wetters with a frequency of twice or less in a month. Thus a total of 141 children, 73 with DW or MW and 68 with pure NW, were included. A random sample of 142 sex-matched non-wetting control children was chosen from the same target population as the enuretic children (Table 1). The mean age of the enuretic children was 7.4 (95 YO confidence limits 7.3-7.4) years and that of the controls 7.5 (95% confidence limit 7.4-7.3, the difference of 0.1 years being statistically significant at the level ofgtO.O1. This was taken into account by including age in the analysis. Factors related to previous history and clinical examination. Both the enuretic and the control children were examined clinically (MRJ and LVT). The parents filled in a prospective one-month follow-up chart recording the wettings and a questionnaire concerning the child’s history of life events, urinary tract infections (UTI) and febrile or non-febrile cerebral convulsions, the forms being returned and checked at the outpatient clinics. The parents were interviewed personally (MRJ) about the type of wetting, wetting in relatives after the age of 4 years and the family constellation. Perinatal histories were gathered from hospital records. The classification by social groups comprised an evaluation of the social standing of the father’s or mother’s occupation (13). The influence of life changes was analysed using weighted life change (WLC) units, a method which takes into account the number of life changes and the age-specific adaptational strain (14-16). The neurological examination (MRJ) was performed according to the Test of Motor Impairment (TMI) concerning fine and gross motor performance (17). Visuomotor and spatial perception and praxis were evaluated by imitation of gestures, performing items 5-10 of Berges & Lezine (18). Urinary flow studies were performed using a DISA Electronic Mictiometer and voided volume was included in this analysis (19, 20). The height of children is expressed here as the difference between relative height and expected height in SD scores (SDS). The Bender test (21) and the Children’s Apperception Test (CAT) (22) were performed by a psychologist (LVT). The variables representing self-confidence, indepence, self-control, basic trust and repression were included and scored according to the Finnish method of Kiviluoto & Parkkinen (23), the first four being summed to form a measure of ego strength. The EEGs were analysed with regard to the following aspects (KM): background activity, epileptiform activity (spikes, spike wave complexes, paroxysmal epileptiform discharges),
Table 1. Numbers of enuretic and control children grouped by type andfrequency of wetting NW=nightwetting, DW =daywetting and MW =mixed day and nightwetting, Prim=primary type and Sec =secondary type Enuretics NW
DWiMW
Frequency per30 nights or days
Prim
Sec
Unknown Prim
14
3 25 15
3 9 3
2
Unknown frequency Total
Aetiological and Precipitating Factors for Childhood Enuresis M. R. JARVELIN, I. MOILANEN, P. KANGAS,' K. MORING, L. VIKEVAINEN-TERVONEN, N.-P. HUTTUNEN and J. SEPPANEN From the Department of Paediatrics and 'Applied Mathematics and Statistics, Uniuersity of Oulu, Finland
ABSTRACT. J h e l i n , M. R., Moilanen, I., Kangas, P., Moring, K., VikeviiinenTervonen, L., Huttunen, N.-P.and Seppjinen, J. (Department of Paediatrics, University Central Hospital, Oulu, Finland.) Aetiological and precipitating factors for childhood enuresis. Acta Paediatr Scand 80: 361,1991. Aetiological factors for enuresis in 68 nightwetting (NW) and 73 day and mixed day and nightwetting (DW/MW) children were examined against a random sample of 142 control children drawn from a population of 3 375 seven-year-old children. Twenty-six variables concerning age, sex, social background, life changes, familial and perinatal history, development, growth, neurological damage, psychic structure and urinary tract disorders were included in the logistic regression analysis. The familial influence on enuresis was clearly seen in both nightwetters and daywetters. The NW children were further discriminated from the controls by items connected with delayed develop ment, such as slower growth and poorer visuomotor and spatial perception. Marital separation or birth of a sibling were also found to be precipitating factors especially for nightwetters. The DW/MW children were discriminated from the controls by perinatal risk factors, signs of neurological dysfunction and smaller voided volume, and especially secondary daywetters by urinary tract infections. These models showed that there are similarities between nocturnal and diurnal enuresis, although there are still many differences and every individual case requires consideration of all these disposing factors. Key words: nightwetting, daywetting, developmental delay, neurological damage, life changes, repression, logistic regression model. A wide variety of factors such as delayed maturation of the nervous system controlling bladder function, deep sleep, genetic, social and psychological factors and other organic features such as allergic reactions and malformations of the urinary tract system have been thought to cause wetting, theories about its aetiology varying greatly with the fashion of the times (1-1 1). In addition, the different causes of day and nightwetting have been emphasized previously but most research has been based on more or less selected groups of enuretic children (8, 11). The aim was to examine the importance and implications of different factors connected with wetting and possibly causally related to it in an unselected group of 7-year-old children and to identify differences between the day and nightwetters and the primary and secondary wetters.
MATERIAL AND METHODS Definition of enuresis. The term enuresis is used here as a synonym for wetting and enuretic children are classified according to diurnal or nocturnal symptoms without any restrictions on the definition which would exclude possible organic aetiological groups. All except six nightwetting (NW) children in the enuresis group in a prospective follow-up fulfilled the definition recommended by DSM I11 of one wet night or day in a month (Table 1) (12). Wetting was termed primary if the child had never had a non-wetting period of six months or more and secondary in the reverse case. A child with mixed day and nightwetting (MW) was defined as a primary wetter if either daywetting (DW) or NW was of the primary type. Subjects. Both the enuretic children and their controls were drawn from a population of
362 M . R. Jarvelin et al.
Acta Paediatr Scand 80
3 375 7-year-old children living in four local government districts close to the University of Oulu during 1983-1984, by the use of a mailed questionnaire. One whole age class was recruited each year, and 3 190 completed replies were received (94.5 O/o). Two hundred and fifty children were reported to have wet themselves at least once during the previous six months, although in eleven cases wetting had ceased before the invitation to a clinical examination. A total of 98 children were omitted because of refusal (n=45), missing data ( n = 15) or infrequent nightwetting ( n = 3 8 ) . Of those omitted 76.5 9’0 were occasional wetters with a frequency of twice or less in a month. Thus a total of 141 children, 73 with DW or MW and 68 with pure NW, were included. A random sample of 142 sex-matched non-wetting control children was chosen from the same target population as the enuretic children (Table 1). The mean age of the enuretic children was 7.4 (95 YO confidence limits 7.3-7.4) years and that of the controls 7.5 (95% confidence limit 7.4-7.3, the difference of 0.1 years being statistically significant at the level ofgtO.O1. This was taken into account by including age in the analysis. Factors related to previous history and clinical examination. Both the enuretic and the control children were examined clinically (MRJ and LVT). The parents filled in a prospective one-month follow-up chart recording the wettings and a questionnaire concerning the child’s history of life events, urinary tract infections (UTI) and febrile or non-febrile cerebral convulsions, the forms being returned and checked at the outpatient clinics. The parents were interviewed personally (MRJ) about the type of wetting, wetting in relatives after the age of 4 years and the family constellation. Perinatal histories were gathered from hospital records. The classification by social groups comprised an evaluation of the social standing of the father’s or mother’s occupation (13). The influence of life changes was analysed using weighted life change (WLC) units, a method which takes into account the number of life changes and the age-specific adaptational strain (14-16). The neurological examination (MRJ) was performed according to the Test of Motor Impairment (TMI) concerning fine and gross motor performance (17). Visuomotor and spatial perception and praxis were evaluated by imitation of gestures, performing items 5-10 of Berges & Lezine (18). Urinary flow studies were performed using a DISA Electronic Mictiometer and voided volume was included in this analysis (19, 20). The height of children is expressed here as the difference between relative height and expected height in SD scores (SDS). The Bender test (21) and the Children’s Apperception Test (CAT) (22) were performed by a psychologist (LVT). The variables representing self-confidence, indepence, self-control, basic trust and repression were included and scored according to the Finnish method of Kiviluoto & Parkkinen (23), the first four being summed to form a measure of ego strength. The EEGs were analysed with regard to the following aspects (KM): background activity, epileptiform activity (spikes, spike wave complexes, paroxysmal epileptiform discharges),
Table 1. Numbers of enuretic and control children grouped by type andfrequency of wetting NW=nightwetting, DW =daywetting and MW =mixed day and nightwetting, Prim=primary type and Sec =secondary type Enuretics NW
DWiMW
Frequency per30 nights or days
Prim
Sec
Unknown Prim
14
3 25 15
3 9 3
2
Unknown frequency Total
