ORIGINAL RESEARCH PAPER
A clinical study on seizure disorder in intellectually disabled patients in Barak Valley, North-Eastern India
Kamal Nath1, Subrata Naskar2
1Associate Professor, Department of Psychiatry, Silchar Medical College and Hospital, Silchar, Assam, India
2Postgraduate Trainee, Department of Psychiatry, Silchar Medical College and Hospital, Silchar, Assam, India
Abstract
Background: Intellectual disability (ID) is a state of developmental deficit, beginning in childhood which results in significant limitation of intellect or cognition and poor adaption to the demands of everyday life. The relationship between seizure disorders and ID, and their socio-demographic correlations is a current topic of research to implement proper psychosocial interventions and to eliminate the preventable causes of ID as well as seizure disorder.
Aims: To find out the prevalence of seizure disorders and their types in the intellectually disabled patients, and find out their socio-demographic correlations.
Materials and methods: A cross-sectional study sample comprising of 100 intellectually disabled patients of Silchar Medical College and Hospital was taken, and the study was conducted after obtaining institutional ethical committee approval and permission from the college. Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria were used for diagnosing ID. A standardised proforma describing socio-demographic variables, Malin’s Intelligence Scale for Indian Children (MISIC) for children in age group six to 17 years, Wechsler Adult Intelligence Scale, third edition for subjects above 18 years, and the Vineland Social Maturity Scale were applied to diagnose and classify ID. International League Against Epilepsy guidelines were used to classify seizure disorder.
Results: Prevalence of seizure disorder was found to be 22% among the intellectually disabled population in our sample. A significant association was found between the severity of ID and increased incidence of seizure disorder (p=0.0045). Seizure disorder was more prevalent in the low intelligence quotient (IQ) group (p=0.0067). Generalised tonic clonic seizure (GTCS) was the commonest among the types of seizure disorder (n=11, 50%). Among the GTCS cases, eight out of 11 (72.7%) were from severe/profound ID group and from an IQ range of one to 35.
Conclusion: A strong association was observed in our study between seizure disorder and poor IQ group, and with increasing severity of ID (severe and profound ID). As expected, GTCS variety was found to be more strongly associated out of all types of seizures with the groups of poor IQ and severe forms of ID. In addition, we have also observed a significant association between seizure disorder, ID, and few important socio-demographic variables.
Keywords: Developmental Disorder. Cognition. Adaptation. Demography.
Corresponding author: Dr Subrata Naskar, Postgraduate Trainee, Department of Psychiatry, Silchar Medical College and Hospital, Ghungoor, Silchar-788014, Assam, India. nsubrata09@gmail.com
Received: 8 October 2015
Revised: 5 November 2015
Accepted: 6 November 2015
Epub: 11 November 2015
DOI: 10.5958/2394-2061.2015.00023.3
Introduction
The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5)[1] defines intellectual disability (ID) as a disorder with onset during the developmental period that includes both intellectual and adaptive functioning deficits in conceptual, social, and practical domains. It affects approximately one to four per cent of the population in developed countries.[2] In general, it is considered that two per cent of the Indian population constitutes persons with this disability.[3]
The definition of epileptic seizure accepted by the International League Against Epilepsy (ILAE)[4] is ‘‘a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.’’ It was Gowers[5] who first explained about the possible relationship between seizure disorder and intellectual disability. He explained that “certain cerebral deformity” may be the cardinal reason behind both of them. O’Donohoe[6] inferred that true prevalence of epilepsy in intellectually disabled individual is difficult to estimate; but, he was certain that the proportion increases as the severity of ID increases. It has been established in numerous studies that ID and seizure disorders are highly correlated, and may have common aetiologies in many a times. It is also true that repeated seizure attacks in an otherwise normal neonate may give rise to ID. The various psychosocial, demographic factors and stressors that a mother faces during pregnancy also influence the intellectual development of the growing child after his or her birth. Hence, the study of correlations between these various socio-demographic factors in the intellectually disabled population with seizure disorder is a worthy area of research.
In this part of India, a lot of patients with ID are attending the outpatient and inpatient departments of Silchar Medical College and Hospital (SMCH), Assam. But, no such studies have been conducted here before. This study is an attempt to find out the prevalence of seizure disorder and its types, and different related socio-demographic variables in these patients, attending this tertiary care health centre.
Aims and objectives
1. To find out the prevalence of seizure disorders and its types in the intellectually disabled patients.
2. To correlate the different important socio-demographic variables in intellectually disabled patients with seizure disorder.
Materials and methods
Case: Any patient above the age of four years attending the inpatient or outpatient department of the Department of Psychiatry, SMCH fulfilling the DSM-5 criteria for ID.[1]
Place of study: This study was conducted in SMCH, which is a tertiary care centre. The average patients coming to the hospital is about 800-1000 per day. The study was started after taking proper approval of the institutional ethical committee.
Catchment area: Main catchment area of this hospital is the whole Barak Valley, which comprises of the districts of Cachar, Karimganj, and Hailakandi, and along with the neighbouring states like Manipur, Mizoram, and Tripura.
Selection criteria: Cases from both the sex were included. All patients above the age of four years were included in the study. Seizure disorder patients were diagnosed as per guidelines provided by ILAE.[4]
Regarding age, we have not selected any case below four years, particularly because at times it becomes extremely difficult to differentiate between the types of ID below this age.
Exclusion criteria: Patients suffering from other severe debilitating diseases, patients with history of any type of substance abuse, patients’ parents/guardians not giving consent to participate in study, if the information provided is not adequate or reliable.
Sampling procedures: Cases were selected serially both from outpatient and inpatient department of the Department of Psychiatry of SMCH. A total of 100 patients were selected who fulfil the diagnostic criteria according to DSM-5.[1]
Description of tools
I. Socio-demographic proforma:
a. A standard proforma, describing socio-demographic variables, was used which was designed and standardised in the Department of Psychiatry, SMCH.
b. The socio-demographic proforma informs of age, gender, religions, family type, domicile, socioeconomic status, education of subject, education of parents.
II. DSM-5 criteria were used for diagnosing ID, which are:[1]
a. Deficits in intellectual functions, such as reasoning, problem solving, planning, abstract thinking, judgement, academic learning, and learning from experience, confirmed by both clinical assessment and individualised, standardised intelligence testing.
b. Deficits in adaptive functioning that result in failure to meet developmental and socio-cultural standards for personal independence and social responsibility. Without ongoing support, the adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation, and independent living, across multiple environments, such as home, school, work, and community.
c. Onset of intellectual and adaptive deficits during the developmental period.
III. Seizure disorder patients were classified as per guidelines provided by ILAE.[4]
IV. Scales used:
1. Malin’s Intelligence Scale for Indian Children (MISIC),[7] an Indian adaptation of Wechsler Intelligence Scale for Children (WISC-III) was used for individual intelligence test for age group of six to 17 years. This scale was developed by Dr Arthur J Malin.
2. Wechsler Adult Intelligence Scale, third edition (WAIS-III)[8] was applied to subjects above 18 years of age.
3. Vineland Social Maturity Scale (VSMS) was applied to assess the adaptive behaviour in the subjects. The scale was originally developed by EA Doll in 1935, which was then adapted by Malin in the year 1965. It is used to measure differential social capacity of an individual and it provides an estimate of social age (SA) and social quotient (SQ). VSMS shows high co-relation (0.80) with intelligence and is designed to measure social maturation in eight social areas. The scale consists of 89 items divided into 13 age groups. It can be used for the age group from birth to 15 years.[9]
The IQ score estimation as well as the adaptive behaviour scoring in our study was done by an experienced clinical psychologist who also happens to be a faculty of this institution.
Interview procedure: After obtaining the informed consents from their parents/guardians, all subjects were interviewed without time limit, in details, using the various tools to elicit the maximum data and confidentiality was maintained. Parents or the caregivers were also interviewed where it was necessary.
Scoring: Scoring was done as described by the manuals for the three types of scales applied, i.e. MISIC, WAIS-III, and VSMS. According to IQ scores and adaptive behaviour scores obtained, the study subjects were classified as having mild, moderate, severe or profound ID respectively.
Analysis of data: Data was collected and tabulated, and appropriate statistical tests like chi-square and Fisher’s exact t-test were applied to evaluate p-value whenever it was required, to test the significance. The Statistical Package for the Social Sciences (SPSS v 22) was used for analysis of the collected data.
Results and observations
The socio-demographic data obtained from the subjects is tabulated in Table 1. Here, we find that most of the subjects were from the age group of 11-20 years (43%), 59% being male. Fifty per cent of our study sample was Hindus, whereas 46% were Muslims. Most were illiterates (56%), from lower middle class socioeconomic group (49%), joint families (59%), rural background (52%) with a paternal education up to primary school (38%) and illiteracy prevailing among mothers (52%), and most parents working as an unskilled labour (46%). The mean IQ of the study population was 47.95 ± 13.0061, the minimum being 19 and maximum 70.
|
Table 1: The socio-demographic data of total study subjects |
||||||
|
|
Seizure disorder |
|||||
|
Variables |
Total ID subjects |
Absent |
Present |
|||
|
Age (years) |
||||||
|
1-10 |
31 |
24 (30.77%) |
7 (31.82%) |
|||
|
11-20 |
43 |
32 (41.03%) |
11 (50%) |
|||
|
21-30 |
14 |
13 (16.67%) |
1 (4.55%) |
|||
|
31-40 |
9 |
8 (10.26%) |
1 (4.55%) |
|||
|
41-50 |
2 |
1 (1.28%) |
1 (4.55%) |
|||
|
51-60 |
1 |
0 |
1 (4.55%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Sex |
||||||
|
Female |
41 |
31 (39.74%) |
10 (45.45%) |
|||
|
Male |
59 |
47 (60.26%) |
12 (54.55%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Religion |
||||||
|
Christian |
4 |
2 (2.56%) |
2 (9.09%) |
|||
|
Hindu |
50 |
40 (51.28%) |
10 (45.45%) |
|||
|
Muslim |
46 |
36 (46.15%) |
10 (45.45%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Domicile |
||||||
|
Rural |
52 |
41 (52.56%) |
11 (50%) |
|||
|
Semi-urban |
19 |
14 (17.95%) |
5 (22.73%) |
|||
|
Urban |
29 |
23 (29.49%) |
6 (27.27%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Type of family |
||||||
|
Extended |
5 |
4 (5.13%) |
1 (4.55%) |
|||
|
Joint |
49 |
38 (48.72%) |
11 (50%) |
|||
|
Nuclear |
46 |
36 (46.15%) |
10 (45.45%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Education of subject |
||||||
|
Illiterate |
59 |
40 (51.28%) |
19 (86.36%) |
|||
|
Primary |
33 |
30 (38.46%) |
3 (13.64%) |
|||
|
Secondary |
8 |
8 (10.26%) |
0 |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Education of father |
||||||
|
Illiterate |
30 |
24 (30.77%) |
6 (27.27%) |
|||
|
Primary |
38 |
30 (38.46%) |
8 (36.36%) |
|||
|
Secondary |
19 |
13 (16.67%) |
6 (27.27%) |
|||
|
Higher secondary |
5 |
5 (6.41%) |
0 |
|||
|
Graduation and above |
8 |
6 (7.69%) |
2 (9.09%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Education of mother |
||||||
|
Illiterate |
52 |
42 (53.85%) |
10 (45.45%) |
|||
|
Primary |
30 |
24 (30.77%) |
6 (27.27%) |
|||
|
Secondary |
10 |
6 (7.69%) |
4 (18.18%) |
|||
|
Higher secondary |
7 |
6 (7.69%) |
1 (4.55%) |
|||
|
Graduation |
1 |
0 |
1 (4.55%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Socioeconomic status |
||||||
|
Lower |
27 |
22 (28.21%) |
5 (22.73%) |
|||
|
Lower middle |
49 |
38 (48.72%) |
11 (50%) |
|||
|
Middle |
18 |
13 (16.67%) |
5 (22.73%) |
|||
|
Upper middle |
6 |
5 (6.41%) |
1 (4.55%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
Occupation of parents |
||||||
|
Business |
19 |
13 (16.67%) |
6 (27.27%) |
|||
|
Professional |
3 |
3 (3.85%) |
0 |
|||
|
Retired |
4 |
3 (3.85%) |
1 (4.55%) |
|||
|
Service |
7 |
5 (6.41%) |
2 (9.09%) |
|||
|
Skilled worker |
16 |
12 (15.38%) |
4 (18.18%) |
|||
|
Unemployed |
5 |
5 (6.41%) |
0 |
|||
|
Unskilled worker |
46 |
37 (47.44%) |
9 (40.91%) |
|||
|
Grand total |
100 |
78 (100%) |
22 (100%) |
|||
|
ID=Intellectual disability |
||||||
|
|
|
|
|
|
|
|
In our study, we found that seizure disorder was present in 22% of the intellectually disabled subjects (Figure 1).
Figure 1: Prevalence of seizure disorders in intellectually disabled population.
47.06% of severe intellectually disabled subjects, 20% of the moderately disabled, and 11.9% of the mildly disabled subjects had comorbid seizure disorder. The only subject with profound disability had seizure (100%) (Figure 2 and Table 2A). So, we see here that with the increase in severity of ID, there is an increased prevalence of seizure disorder (Figure 3). This result is highly statistically significant at p=0.0045 (Table 2A). Within the group who had IQ less than 35, 50% of the subjects had comorbid seizure disorder, whereas only 16.67% of the subjects having IQ more than 35 had comorbid seizure disorder. This finding is statistically significant with p-value = 0.0067 (Table 2B).
Figure 2: Prevalence of seizure disorder in different types of ID groups. ID=Intellectual disability
|
Table 2A: Prevalence of seizure disorder according to types of ID |
|||
|
Variable |
Seizure disorder |
||
|
Present |
Absent |
Grand total |
|
|
Mild |
5 (11.9%) |
37 (88.1%) |
42 (100%) |
|
Moderate |
8 (20%) |
32 (80%) |
40 (100%) |
|
Severe |
8 (47.06%) |
9 (52.94%) |
17 (100%) |
|
Profound |
1 (100%) |
0 (%) |
1 (100%) |
|
Grand total |
22 (22%) |
78 (78%) |
100 (100%) |
|
Chi-square was applied: χ2=10.81, df=2, p-value=0.0045. ID=Intellectual disability, df=degree of freedom |
|||
|
Table 2B: Prevalence of seizure disorder according to IQ score |
|||
|
Variable
IQ |
Seizure disorder |
||
|
Present |
Absent |
Grand total |
|
|
1-35 |
8 (50%) |
8 (50%) |
16 (100%) |
|
36-70 |
14 (16.67%) |
70 (83.33%) |
84 (100%) |
|
Grand total |
22 (22%) |
78 (78%) |
100 (100%) |
|
Fisher’s exact t-test was applied: p-value=0.0067, odds ratio=0.2 IQ=Intelligence quotient |
|||
Figure 3: Line diagram showing increase in prevalence of seizure disorder with increase in severity of ID. ID=Intellectual disability
To evaluate the correlations between the various socio-demographic variables and seizure disorder in our study population, we have re-tabulated the data and the correlations obtained are shown in Table 3. Among the various socio-demographic variables, we have found a statistically significant association between the literacy of the study subjects and seizure disorder (p=0.0031).
|
Table 3: Correlation of various important socio-demographic variables and seizure disorder in study subjects |
||||||
|
Variables |
Seizure disorder |
p-value |
Significance |
Odds ratio |
95% CI |
|
|
Absent |
Present |
|||||
|
Age (years) |
||||||
|
<20 |
56 |
18 |
0.4193 |
Not significant |
0.5657 |
0.1720-1.861 |
|
>20 |
22 |
4 |
||||
|
Sex |
||||||
|
Male |
47 |
12 |
0.633 |
Not significant |
0.7915 |
0.3048-2.055 |
|
Female |
31 |
10 |
||||
|
Domicile |
||||||
|
Rural |
41 |
11 |
1.000 |
Not significant |
1.108 |
0.4299-2.856 |
|
Urban/semi-urban |
37 |
11 |
||||
|
Type of family |
||||||
|
Nuclear |
36 |
10 |
1.000 |
Not significant |
1.023 |
0.3977-2.66 |
|
Joint/extended |
42 |
12 |
||||
|
Education of subject |
||||||
|
Illiterate |
40 |
19 |
0.0031 |
Significant |
0.1662 |
0.04546-0.6077 |
|
Literate |
38 |
3 |
||||
|
Education of father |
||||||
|
Illiterate |
24 |
6 |
1.000 |
Not significant |
1.185 |
0.4129-3.402 |
|
Literate |
54 |
16 |
||||
|
Education of mother |
||||||
|
Illiterate |
42 |
10 |
0.6297 |
Not significant |
1.4 |
0.5413-3.621 |
|
Literate |
36 |
12 |
||||
|
Socioeconomic status |
||||||
|
Lower+lower middle |
60 |
16 |
0.7784 |
Not significant |
1.25 |
0.4261-3.667 |
|
Middle+upper middle+upper |
18 |
6 |
||||
|
CI=Confidence interval |
||||||
We were able to identify five types of seizure disorders among our study subjects; those being generalised tonic clonic seizure (GTCS, 50%), absence seizure (23%), complex partial seizure (nine per cent), simple partial seizure (nine per cent), and partial seizure with secondary generalisation (nine per cent) (Figure 4).
Figure 4: Distribution of the types of seizure disorder in intellectually disabled subjects. GTCS=Generalised tonic clonic seizure, CPS=complex partial seizure, SPS=simple partial seizure, PSSG=partial seizure with secondary generalisation
The various socio-demographic data according to the type of seizure disorders is shown in Table 4A. Complex partial seizure, simple partial seizure, and partial seizure secondarily generalised has been grouped together as ‘others’ as the data obtained in these individual category is minimum.
|
Table 4A: The socio-demographic data of the study subjects according to types of seizure disorder |
||||
|
Variables |
Absence |
GTCS |
Others (CPS+SPS+PSSG) |
Total ID patients |
|
Age (years) |
||||
|
1-10 |
3 (60%) |
2 (18.18%) |
2 (33.3%) |
7 (31.82%) |
|
11-20 |
1 (20%) |
7 (63.64%) |
3 (50%) |
11 (50%) |
|
21-30 |
0 |
0 |
1 (16.66%) |
1 (4.55%) |
|
31-40 |
0 |
1 (9.09%) |
0 |
1 (4.55%) |
|
41-50 |
0 |
1 (9.09%) |
0 |
1 (4.55%) |
|
51-60 |
1 (20%) |
0 |
0 |
1 (4.55%) |
|
Grand total |
5 (100%) |
11 (100%) |
6 (100%) |
22 (100%) |
|
Sex |
||||
|
Female |
1 (20%) |
6 (54.55%) |
3 (50%) |
10 (45.45%) |
|
Male |
4 (80%) |
5 (45.45%) |
3 (50%) |
12 (54.55%) |
|
Grand total |
5 (100%) |
11 (100%) |
6 (100%) |
22 (100%) |
|
Socioeconomic status |
||||
|
Lower |
1 (20%) |
3 (27.27%) |
1 (16.66%) |
5 (22.73%) |
|
Lower middle |
3 (60%) |
4 (36.36%) |
4 (66.66%) |
11 (50%) |
|
Middle |
1 (20%) |
3 (27.27%) |
1 (16.66%) |
5 (22.73%) |
|
Upper middle |
0 |
1 (9.09%) |
0 |
1 (4.55%) |
|
Upper |
0 |
0 |
0 |
0 |
|
Grand total |
5 (100%) |
11 (100%) |
6 (100%) |
22 (100%) |
|
Education of subject |
||||
|
Illiterate |
4 (80%) |
10 (90.91%) |
5 (83.33%) |
19 (86.36%) |
|
Primary |
1 (20%) |
1 (9.09%) |
1 (16.66%) |
3 (13.64%) |
|
Grand total |
5 (100%) |
11 (100%) |
6 (100%) |
22 (100%) |
|
Type of family |
||||
|
Extended |
0 |
1 (9.09%) |
0 |
1 (4.55%) |
|
Joint |
3 (60%) |
5 (45.45%) |
3 (50%) |
11 (50%) |
|
Nuclear |
2 (40%) |
5 (45.45%) |
3 (50%) |
10 (45.45%) |
|
Grand total |
5 (100%) |
11 (100%) |
6 (100%) |
22 (100%) |
|
Domicile |
||||
|
Rural |
2 (40%) |
6 (54.55%) |
3 (50%) |
11 (50%) |
|
Semi-urban |
1 (20%) |
3 (27.27%) |
1 (16.66%) |
5 (22.73%) |
|
Urban |
2 (40%) |
2 (18.18%) |
2 (33.33%) |
6 (27.27%) |
|
Grand total |
5 (100%) |
11 (100%) |
6 (100%) |
22 (100%) |
|
GTCS=Generalised tonic clonic seizure, CPS=complex partial seizure, SPS=simple partial seizure, PSSG=partial seizure with secondary generalisation, ID=intellectual disability |
||||
Here, we have found that maximum of the GTCS patients belonged to the age group of 11-20 years (63.64%). Most were female (54.55%), from a lower middle socioeconomic class (36.36%), 90.91% being illiterate, and most were from rural population (54.55%). The subjects with GTCS had come equally from nuclear and joint families.
Table 4B and Figure 5 shows distribution of the types of seizure disorder according to the types of ID. We can see that most of our subjects with GTCS (63.6%) had severe/profound ID, most cases with simple partial seizure (100%) belonged to the moderately intellectually disabled category, whereas most of the absence seizure (60%) belonged to the mild intellectually disabled group. Complex partial seizure and partial seizure with secondary generalisation can be found equally among the mild (50%) and moderate (50%) disability group.
|
Table 4B: Distribution of types of seizure disorder according to types of ID |
|||||
|
|
Mild |
Moderate |
Severe |
Profound |
Grand total |
|
Absence |
3 (60%) |
1 (20%) |
1 (20%) |
0 |
5 (100%) |
|
CPS |
1 (50%) |
1 (50%) |
0 |
0 |
2 (100%) |
|
GTCS |
0 |
3 (27.27%) |
7 (63.6%) |
1 (9.09%) |
11 (100%) |
|
PSSG |
1 (50%) |
1 (50%) |
0 |
0 |
2 (100%) |
|
SPS |
0 |
2 (100%) |
0 |
0 |
2 (100%) |
|
Grand total |
5 (22.7%) |
8 (36.36%) |
8 (36.3%) |
1 (4.55%) |
22 (100%) |
|
ID=Intellectual disability, CPS=complex partial seizure, GTCS=generalised tonic clonic seizure, PSSG=partial seizure with secondary generalisation, SPS=simple partial seizure |
|||||
Figure 5: Distribution of types of seizure disorder according to types of ID. ID=Intellectual disability, CPS=complex partial seizure, GTCS=generalised tonic clonic seizure, PSSG=partial seizure with secondary generalisation, SPS=simple partial seizure
On investigating about the types of seizure disorder and various socio-demographic variables, we have not found any significant association between them (Table 5A). However, we found that among the different types of seizure disorder, GTCS was more among the subjects with low IQ (p=0.001). Odds ratio here is significantly high, i.e. 55.86 (95% confidence interval [CI]: 2.532-1232). Also, the prevalence of GTCS increases with the increasing severity of ID (p-value =0.0042) (Table 5B).
|
Table 5A: Association of various important socio-demographic variables and the types of seizure disorder in subjects |
|||
|
Variable |
Type of seizure disorder (total subjects with seizure disorder=22) |
||
|
GTCS |
Absence |
Others |
|
|
Age |
|||
|
<20 years |
9 (40.9%) |
4 (18.18%) |
5 (22.7%) |
|
>20 years |
2 (9.09%) |
1 (4.54%) |
1 (4.54%) |
|
Sex |
|||
|
Male |
5 (22.7%) |
4 (18.18%) |
3 (13.6%) |
|
Female |
6 (27.2%) |
1 (4.54%) |
3 (13.6%) |
|
Domicile |
|||
|
Rural |
6 (27.2%) |
2 (9.09%) |
3 (13.6%) |
|
Urban/semi-urban |
5 (22.7%) |
3 (13.6%) |
3 (13.6%) |
|
Type of family |
|||
|
Nuclear |
5 (22.7%) |
2 (9.09%) |
3 (13.6%) |
|
Joint+extended |
6 (27.2%) |
3 (13.6%) |
3 (13.6%) |
|
Education of subject |
|||
|
Illiterate |
10 (45.4%) |
4 (18.1%) |
5 (22.7%) |
|
Literate |
1 (4.54%) |
1 (4.54%) |
1 (4.54%) |
|
Socioeconomic status |
|||
|
Lower+lower middle |
7 (31.8%) |
4 (18.18%) |
5 (22.7%) |
|
Middle+upper middle+upper |
4 (18.18%) |
1 (4.54%) |
1 (4.54%) |
|
GTCS=Generalised tonic clonic seizure; ‘others’ include simple partial seizure, complex partial seizure, and partial seizure with secondary generalisation |
|||
|
Table 5B: Association between GTCS and type of ID and IQ score |
|||||
|
Variables |
Seizure disorder (n=22) |
p-value |
OR |
95% CI |
|
|
IQ score |
GTCS |
Non-GTCS |
0.001 |
55.8 |
2.532-1232 |
|
1-35 |
8 (72.7%) |
0 |
|||
|
36-70 |
3 (27.2%) |
11 (100%) |
|||
|
Total |
11 (100%) |
11 (100%) |
|||
|
|
|||||
|
Mild+moderate ID |
3 (27.2%) |
10 (90.9%) |
0.0075 |
0.0375 |
0.003245-0.4334 |
|
Severe+profound ID |
8 (72.7%) |
1 (9.09%) |
|||
|
Total |
11 (100%) |
11 (100%) |
|||
|
GTCS=Generalised tonic clonic seizure, ID=intellectual disability, IQ=intelligence quotient, OR=odds ratio, CI=confidence interval |
|||||
Discussion
Our study is a hospital-based, cross-sectional study on serially taken 100 intellectually disabled subjects who fulfilled the DSM-5 criteria for ID as well as the other inclusion and exclusion criteria as mentioned earlier. We investigated about the prevalence and type of seizure disorders and their socio-demographic association among those subjects. In our study, we found that seizure disorder was present in 22% of the intellectually disabled subjects. As quoted by McGrother et al.[10], “community-based studies of epilepsy in adults with ID show a prevalence of 16-26%”; they also conducted a population-based prevalence study among the English population and found that the prevalence of epilepsy in adults with ID was 26%. As quoted by Deb[11], “epilepsy affects approximately 14 to 24% of patients who are mentally retarded”. Among studies on adults who have mental retardation, Lund[12] found that in 18.2% of a Danish population, there was a history of epilepsy at some point in their life. When we searched for seizure disorder among individual types of ID, we found that 47.06% of severe intellectually disabled subjects, 20% of the moderately disabled, 11.9% of the mildly disabled subjects, and the only subject with profound disability had comorbid seizure disorder. So, here we see that the prevalence of seizure disorder increases with the increase in the severity of ID. This finding is highly significant statistically (p-value=0.0045). Madhavan and Narayan,[13] in their study, also found increased number of seizure disorder cases with the increase in the severity of the retardations. They found 9.6% of the mild, 11.8% of the moderate, 21.9% of the severe, and 33.8% of the profoundly mentally retarded subjects had comorbid seizure disorder. They also mentioned about the similar findings reported by Corbett[14] and Rutter et al.[15] which were quoted by O’Donohoe.[6] Steffenburg et al.[16] conducted a study among 378 children with mental retardation between age six and 13, and found that 15% of those with mild mental retardation and 45% of those with severe mental retardation had epilepsy. Johnson et al.[17] in their study quoted that Shepherd and Hosking[18] also reported similar trend. They found that seven per cent of children with mild mental retardation as opposed to 67% of those with severe mental retardation had epilepsy. There is a variance in the reported rates of epilepsy in people with profound mental retardation. Literatures suggest it varies between 50[19] and 82%.[20]
In our study, we found that the most common type of seizure disorder is GTCS (n=11), which is 50% of all the patients with seizure. Types of seizure found by Steffenburg et al.[16] in their study sample were tonic-clonic, myoclonic, atypical absences, and partial complex seizures. Among the children identified with seizure disorder (n=98), 60% (n=59) had generalised seizure and 20% (n=20) had partial seizure.
In our study, most of the subjects with GTCS (63.6%) had severe ID, most cases with simple partial seizure (100%) belonged to the moderately intellectually disabled category, whereas most of the absence seizure (60%) belonged to the mild intellectually disabled group. Complex partial seizure and partial seizure with secondary generalisation were equally distributed among the mild (60%) and moderate (60%) disability group. We also observed in our study that the association between GTCS and severity of ID was statistically significant (p-value=0.0042). We have also found a significant association between GTCS and low IQ (p=0.001). Odds ratio here is significantly high, i.e. 55.86 (95% CI: 2.532-1232).
In this context, we would like to highlight the fact that a study carried out in the same centre on ‘organic mental disorders’ found maximum number of cases to be of seizure disorder.[21] Chronic illnesses like epilepsy takes a toll not only of the patients but their caregivers as well. When such a condition is comorbid with mental illness, the problem increases manifold. Among persons with epilepsy and schizophrenia, Kumar et al.[22] studied subjective well-being and coping, while Karim et al.[23] studied care burden and social support of caregivers. Moreover, there is a therapeutic aspect to it also. Yadav et al.[24] “found prevalence of seizures and encephalitis of brain was more common in rural and low socioeconomic status patients in all age groups. The patients with seizures in post encephalitis and sequelae were less tolerated to higher doses antiepileptic drugs and its combinations.”
Conclusion
In our study, out of 100 intellectually disabled cases, we found that the prevalence of seizure disorder was 22%, which is supported by most of the national and international studies. Regarding the association between seizure disorder and various socio-demographic variables, we found that seizure was mostly found in the age group of 11-20 years (50%), probably indicating that they are diagnosed much later as compared to developed countries due to poor parental education, poor healthcare services, and many other related factors. There was no significant difference in various religious groups; however, seizure disorder was found to be more in the sample coming from rural areas, which probably reflected the real picture of the society. We did not find any significant differences in distribution of seizure disorder in family type; but, we have found that 86.36% of the seizure disorder subjects were illiterates and also seizure disorders were more in the group of illiterate mothers (45%), from lower middle class socioeconomic strata (50%), and those whose parents works as unskilled workers (40.91%). We have noticed a statistically significant correlation between severity of ID and frequency of seizure disorder; it was also distributed in the same way when correlated with the IQ of the sample. Though statistically we have only found statistical association of seizure disorder with illiteracy of the subjects, findings in relation to other socio-demographic variables were also important from the psychosocial point of view for management. Poor education, poor socioeconomic status, poor healthcare facilities, and poor awareness- all are important psychosocial variables which are strongly associated with ID and seizure disorder as well as their management. In the present study, we have found that 50% of the seizure disorders were GTCS in type, which indicates that this group should be treated and controlled as early as possible to prevent further deterioration. On investigating about the type of seizure disorders and various socio-demographic variables, we have not found any significant association; however, when the types of seizure disorder are compared with types of ID and IQ score, most of the GTCS cases (eight out of 11, 72.7%) were coming from severe/profound ID group and from an IQ range of one to 35.
Our study has got some limitations too. As it was a hospital-based study in a tertiary care centre, these findings may not portray the actual picture prevailing in the society. Also, we have taken only 100 subjects in our sample. If analysis is carried out on a larger sample, more light could be shed on the issue at hand. Our study, however, points towards a need for urgent interventions at psychosocial level to reduce the preventable causes of ID and seizure disorder for better outcome of already affected subjects in our society.
References
1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Association; 2013.
2. Mercadante MT, Evans-Lacko S, Paula CS. Perspectives of intellectual disability in Latin American countries: epidemiology, policy, and services for children and adults. Curr Opin Psychiatry. 2009;22:469-74.
3. Madhavan T, Kalyan M, Naidu S, Peshwaria R, Narayan J, editors. Mental retardation: a manual for psychologists. Secunderabad, AP: National Institute for the Mentally Handicapped (Under the Ministry of Social Justice and Empowerment, Government of India); 1983.
4. International League Against Epilepsy [Internet]. [cited 2015 Nov 5]. Available from:http://www.ilae.org/
5. Gowers WR. Epilepsy and other chronic convulsive diseases: their causes, symptoms & treatment. New York: Dover Publications; 1964.
6. O’Donohoe NV. Epilepsies of childhood. Postgraduate paediatric series. London: Butterworths; 1981:143-6,233.
7. Bhat SR. Achar’s textbook of paediatrics. 4th ed. Hyderabad: Universities Press; 2009.
8. Wechsler D. WAIS-III administration and scoring manual. San Antonio, TX: The Psychological Corporation; 1997.
9. Kumar I, Singh AR, Akhtar S. Social development of children with mental retardation. Ind Psychiatry J. 2009;18:56-9.
10. McGrother CW, Bhaumik S, Thorp CF, Hauck A, Branford D, Watson JM. Epilepsy in adults with intellectual disabilities: prevalence, associations and service implications. Seizure. 2006;15:376-86.
11. Deb S. Mental disorder in adults with mental retardation and epilepsy. Compr Psychiatry. 1997;38:179-84.
12. Lund J. Epilepsy and psychiatric disorder in the mentally retarded adult. Acta Psychiatr Scand. 1985;72:557-62.
13. Madhavan T, Narayan J. Epilepsy and mental retardation. Indian J Psychiatry. 1992;34:12-7.
14. Corbett JA. Epilepsy and mental retardation: In: Reynolds EH, Trimble MR, editors. Epilepsy and psychiatry. London: Churchill; 1981:138-46.
15. Rutter M, Graham P, Yule W. A neuropsychiatric study in childhood. Philadelphia: JB Lippincott; 1970.
16. Steffenburg U, Hagberg G, Kyllerman M. Characteristics of seizures in a population-based series of mentally retarded children with active epilepsy. Epilepsia. 1996;37:850-6.
17. Johnson CR, Lowengrub JA, Lubetsky MJ. Psychiatric and behavior disorders in children with mental retardation and seizure disorder. J Dev Phys Disabil. 1995;7:243-52.
18. Shepherd C, Hosking G. Epilepsy in school children with intellectual impairments in Sheffield: the size and nature of the problem and the implications for service provision. J Ment Defic Res. 1989;33(Pt 6):511-4.
19. Michelucci R, Forti A, Rubboli G, Plasmarti R, Volpi L, Tassinari CA. Mental retardation and behavioral disturbances related to epilepsy: a review. Brain Dysfunction. 1989;2:3-9.
20. Suzuki H, Aihara M, Sugai K. [Severely retarded children in a defined area of Japan--prevalence rate, associated disabilities and causes]. [Article in Japanese] No To Hattatsu. 1991;23:4-8.
21. Nath S, Roy D, Hazarika S, Das S, Nath K. Organic mental disorders: a study among admitted patients of psychiatry department at teaching hospital. Dysphrenia. 2012;3:40-7.
22. Kumar P, Nehra DK, Verma AN. Subjective well-being and coping among people with schizophrenia and epilepsy. Dysphrenia. 2013;4:25-30.
23. Karim N, Ali A, Deuri SP. A comparative study of care burden and social support among caregivers of persons with schizophrenia and epilepsy. Open J Psychiatry Allied Sci. 2015;6:132-7.
24. Yadav JS, Tripathi MN, Kaur S, Singh TB. Comparative efficacy of antiepileptic drugs and lacosamide in patients with epilepsy due to an underlying brain lesion. Dysphrenia. 2013;4:127-31.
Nath K, Naskar S. A clinical study on seizure disorder in intellectually disabled patients in Barak Valley, North-Eastern India. Open J Psychiatry Allied Sci. 2016;7:46-53. doi: 10.5958/2394-2061.2015.00023.3. Epub 2015 Nov 11.
Source of support: Nil. Declaration of interest: None.
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