Predictors of refractory epilepsy in north India: a case-control study

The study was done to identify the predictors of refractory epilepsy in the North Indian population attending a tertiary care centre. This case-control study from August 2006 to December 2008 enrolled 200 consecutive patients of intractable epilepsy and 200 age matched controls with well controlled epilepsy. The factors which were significant in univariate analysis were age of onset before fourteen years (OR 7.92), partial seizures (OR 6.27), presence of neurological deficits (OR 19.68), perinatal insult (OR 11.00), delayed milestones (OR 13.93), history of CNS infection (OR 7.45), febrile seizures (4.33), high initial seizure frequency of more than one per month (OR 14.26), non response to first Anti Epileptic Drug (AED) (OR 6.71) and abnormal brain imaging (OR 20.47). On multivariate analysis significant predictors were radiological evidence of structural cerebral abnormality (OR 20.47), non response to first AED (OR 19.21), delayed mile stones (OR 9.09), high initial seizure frequency of more than one per month (OR 6.71), partial seizure type (OR 6.27), febrile seizures (OR 5.66) and age of onset before fourteen years (OR 3.09). It is thus possible to identify a certain profile of patients with epilepsy who are likely to be refractory to medical therapy. These observations would be useful in selecting patients early for evaluation in Northern India where a high surgical treatment gap exists.