# Active Epilepsy as Indicator of Neurocysticercosis in Rural Northwest India

Authors: Sunil Kumar Raina; Sushil Razdan; K. K. Pandita; Rajesh Sharma; V. P. Gupta; Shiveta Razdan
Journal: Epilepsy Research and Treatment
 (2012)

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## Abstract

Objective. To determine the contribution of neurocysticercosis as a cause for active epilepsy and to establish Neurocysticercosis as major definable risk of epilepsy in our setup. Methods. We conducted a door-to-door survey of 2,209 individuals of Bhore Pind and Bhore Kullian villages in Chattah zone of district Jammu (Jumma and Kashmir, Northwest India) to identify patients with symptomatic epilepsy. Patients with active epilepsy were investigated with neuroimaging techniques to establish diagnosis of NCC (neurocysticercosis). Results. Among 25 patients with epilepsy 10(40%) had CT/MR evidence of past or recent NCC infection. This gave us the point prevalence of 4.5/1000 for Neurocysticercosis in our study population. Interpretation. The study shows a high prevalence of NCC accounting for symptomatic epilepsy in our part of India.


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## Body

## 1. Introduction

Neurocysticercosis (NCC) is a frequent cause of neurological disorders in many developing countries and is a predominant cause of epilepsy in India [1–4]. NCC is the cause of seizures in about 37% of otherwise healthy children >3 years of age. The prevalence of human cysticercosis has been estimated between 3% (based on autopsy studies) [5] and 9% (based on immunological data) [6]. However its true prevalence and association with neurological disorders at community level is largely unknown. The association of NCC with high prevalence of epilepsy in developing countries is mostly based on hospital studies [7–9].NCC was found to cause nearly one-third of all cases of active epilepsy in both the urban and rural regions as per a study conducted in Vellore district of Tamil Nadu [10].


## 2.  Material and Methods

The study was conducted in 2,209 individuals of 6 villages of Chattah zone of Jammu district, the winter capital city of Jammu and Kashmir state of India. The villages were randomly selected by simple random technique from  a  total of  36  villages of  Chattah  zone with  a  total population of  30,975.  Chattah was chosen because of the presence of known cases of NCC as recorded by our Neurology Department. This choice  was  helped  further  by  the  willingness of  community  members  to  participate  in  operational research project.Majority  (60%)  of  population of  Chattah is  directly  or  indirectly  involved  with  transport  business. Villagers in Chattah take mixed diet (both vegetarian and non-vegetarian).A door-to-door survey, covering a sample population of 2,209, was performed by a team of interns with the help of clinical epidemiologist from the Department of Community Medicine. A register was set up with one record for each family, containing data on age, gender, occupation, education, and number of family members.  During  a  follow-up  visit  WHO protocol for  assessing  presence  of  neurological disorders was initiated [11]. This tool was used to quantify headaches, epilepsy, cerebrovascular disorders, extra pyramidal syndromes, and peripheral neuropathies and consisted of a structured interview and a task-based selective neurological examination [12, 13].The interview was conducted by a second group of internship students  with  the  help  of  clinical  epidemiologist  and  medical  officer in Chattah. A Hindi questionnaire translated from WHO protocol, containing 12 questions and 10 tasks for individuals >7 years, was used. The version for children <7 yrs contained 16 question and no tasks. For those who did not understand spoken  Hindi,  an  intern (bilingual  member)  from  the  survey  team  was  trained  for  translation.  The protocol thus developed was first tested in another village (Bhore Camp) of Chattah zone on a sample population of 40 families selected randomly.The study was completed in three stages. In stage 1, each individual eligible for inclusion in the survey was visited by a team of clinical epidemiologists and medical officers in Chattah. Individuals absent from their homes  were  asked  to  visit  the  medical  officer  on  the  subsequent day.  Written informed consent for participation in all stages of study was obtained from each individual.In  stage  2, all  individuals  who  responded  to  WHO protocol  positively were  invited  to  undergo examination  by  a  neurologist  and a  physician,  under  standard  conditions. In stage 3 all individuals suspected  to  be  cases  of active epilepsy on  the basis of  history  by  neurologist  were listed for further study.A prevalent case of active epilepsy was defined as a person who has had at least one epilepsy seizure in the  previous  5  years,  regardless  of  antiepileptic  drug  (AED)  treatment,  as  has  been established  in previous  community-based studies [14]  &  conforming  to  the  recommendations  of  the  International League against Epilepsy [15].Children with febrile seizures were excluded for further evaluation. The complimentary examination systematically included a CT and or MRI.  16 of the 25 individuals in the study had already undergone a complimentary examination in the form of neuroimaging. The remaining individuals were investigated with a contrast-enhanced CT after obtaining a written informed consent.The diagnosis on CT∖MRI was ready by a radiologist independent of the survey team.  A diagnosis of NCC was made on the basis of criteria described by del Brutto et al. [16].Calcification was seen  on CT∖MRI  as  small,  round  or elongated, high-density lesions in  the parenchyma; single  or multiple cysts were described as rounded low-density lesion & the encephalitic phase was referred to as a low density  irregular  area  on  plain  CT  which,  after  contrast  infusion,  displayed  a  nodularity/ring enhancement [17].Single calcification was ascribed to possible neurocysticercosis after other types of granulomatous disease, mainly tuberculosis, were ruled out clinically.50  individuals,  chosen  randomly from  amongst  those screened  negative in  stage  1,  were examined  by the neurologists. No epilepsy was found in any of them.


## 3. Results

The  distribution  by  age  & sex  of  the  studied  population was  typical  of  developing  communities  with young population under 20 yrs of age comprising about 46% of the total. Information was obtained from individuals living in two villages of Chattah block.  At  the  end  of  stage  1,  402  individual  had  tested positive  for  neurological  disorder  with  headache  being  the  most  common.  All these people were evaluated by the neurologist & physician trained in neurology at the Chattah Health Facility. There was no loss of participants between stage 1 & stage 2. At the end of stage 2, 25 individuals were confirmed as suffering from active epilepsy, as already defined  [15, 16].The point prevalence, thus calculated, was 11.31/1000. The prevalence ratio for men was more than double in comparison to women. Prevalence ratio dropped at the extremes of age. The number of cases & prevalence ratio by age & sex of 25 patients are shown in Table1.Table 1
Prevalence and prevalence ratios (/1000) by age and sex of epilepsy, Chattah, Jammu.
Age (yrs)
Males
Females
Total
No.
Pre/1000
No.
Pre/1000
No.
Pre/1000
0–9
3
10.86
0
—
3
5.82
10–19
7
26.51
1
4.36
8
16.12
20–29
3
15.62
0
—
3
7.69
30–39
4
25.64
2
14.81
6
20.61
40–49
1
9.25
1
11.36
2
10.20
50–59
0
—
2
32.25
2
14.9
60 and above
0
—
1
12.04
1
5.32
Total
18
15.35
7
6.75
25
11.31
Prevalence ratio for sex = 1.35.Table2 shows the classification of these cases according to seizure type.  Seizures in  6  patients  were classified  as generalized  &  in  19  as  partial.  16 out of 25 patients had undergone CT∖MRI.  Remaining number of individuals were invited for further examination by radiologist.Table 2
Percentage of cases according to seizure type Chattah, Jammu.
Type of seizure
No. of cases
%
Generalized seizures
6
24
Partial seizures
0
0
Simple Partial
3
12
Complex partial
3
12
Partial with sec. generalization
13
52
Total
25
100Among 25 patients with epilepsy 10 (40%) had CT evidence of past or recent NCC infection, using criteria described  by  del  Brutto et  al. (Absolute  criteria  or  two  major,  one minor,  and  an  epidemiological criteria) [18] (Table 3).Table 3
Summary of CT findings in 25 patients with epilepsy.
CT/MRI findings
No. of patients
%
Single intracranial calcification
4
16
Multiple intracranial calcification
2
8
Single cyst/ring enhanced lesion
3
12
Multiply cyst/calcification
1
4
Tuberculoma
2
8
Atrophic lesions
2
8
AVM
1
4
Normal
10
40
Total
25This gave us the point prevalence of 4.5/1000 for Neurocysticercosis in our study population.In a large percentage (40) radiological findings were normal.Two  patients  listed  as  suffering  from  active  epilepsy  were  on  antitubercular  medication  and  had systemic evidence of pulmonary tuberculosis.


## 4. Discussion

The present study is the only study using neuroepidemiological and neuroimaging procedures to assess the  prevalence  of  NCC  on  community-based  approach  from  our  part  of  India.  It might have methodological  inadequacies  for  establishing diagnosis,  but  this  is  the  closest  we  could  reach  to establish etiological basis for epilepsy, in our setup.  The  study  shows  a  high  prevalence  of  NCC  accounting  for  epilepsy.  This is in confirmation with few studies on NCC in our part of world. In a study in Uttaranchal region of India 3.94% of 15,000 patients reporting to hospitals, screened showed neurocysticercosis [18].Prevalence  rate for epilepsy in  a study conducted  in  Kashmir valley  (Jumma and kashmir)  is  lower  (2.47/1000)  than  our  study [19]. Pork  consumption  is  not allowed  for  religious  reasons  in  Kashmir  valley,  making  area  free  of  human  taeniasis,  which is a cause  for development  of NCC.  This  comparison explains  the  high  prevalence of epilepsy  in  our  part  of  Jumma and kashmir  and contribution of NCC in it.In  a  major  community-based  study  conducted  in  Vellore  district  of  Tamil  Nadu,  covering  a  large population  base,  NCC  was  a  major cause  of  active  epilepsy in  both  urban  and  rural  regions.  34% of patients with active epilepsy had a definitive or probable NCC as the cause of their seizures [10].In comparison our study shows a higher prevalence of NCC accounting for epilepsy probably because of the factors favoring development of human cysticercosis.Human  cysticercosis  is  human-to-human  infection  acquired  faeco-orally,   usually  in  areas  with deficient sanitation & improper stool disposal, factors prevalent in Chattah block. The risk is enhanced by an easy availability of pig meat in poor sanitary conditions.Although the number of epilepsy cases is not large, it seems that men become ill in higher proportions probably due to outdoor eating habits prevalent in Chattah. Patients with NCC typically present with partial seizures with secondary generalization in our study. Only  a  few  reported  studies [20–22] have  used  neuroimaging to  estimate  the  prevalence  of  NCC  in  a community.  In  a  study  of  2,273  residents  of  an  Ecuadorian rural  community,  the  prevalence  rate  of active epilepsy was 11.4 per 1,000 (20) which is almost similar to our study. Of the 31 people with AE, 26 had a plain CT scan examination, and a diagnosis of NCC was made in 14(53.8%) which is slightly higher than our study.  Because  only  a  plain CT  was  done, enhancing  cysticercal  lesions  such  as  granulomas would not have been detected.In a random sample of 118 people without seizures from same community, CT showed evidence of NCC in 17(14%).In a community-based CT study [21] involving 2,415 residents of Atahualpa, Ecuador, 24 patients were found to have AE, giving a prevalence rate of 9.9 per 1,000. CT scan showed NCC lesions in five (26.3%) of the 19 patients who accepted the examination. The Salama study [22] conducted in a rural Honduras reported the results of a survey among 6,473 residents.  The  prevalence  rate  of  AE  was reported  to  be  15.4  per  1,000.  A  CT scan performed in 90 (90%) of the 100 patients with AE showed evidence of NCC in 36.6% of patients. The above studies suggest that NCC is the cause of 26.3% to 53.8% of all cases of AE. NCC was the cause of AE in 40% of our patients, suggesting that NCC is as much of a problem in India as in Latin America.  It is  interesting  to note  that  the  prevalence of AE in the  Kashmir division of Jumma and kashmir state of India, a region that is thought to be free of cysticercosis because of its Muslim majority  population, was  only  2.47  per  1000 [11].So with the same state we have a highly comparable data as far as the prevalence of NCC is concerned. The study underlies a need to identify areas of focus as far as public health initiatives to tackle NCC are concerned.  The  radiological data  presented  confirmed  that NCC  is  the major  definable  risk of  epilepsy  in our setup. It is preventable & treatable. Concerted multidisciplinary efforts focusing on the risk factors can help to decrease substantially the burden attributable to epilepsy.



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*Source: 802747-2012-06-13.xml*