The effect of phenobarbitone on cognition in adult patients with new onset epilepsy: a multi-centric prospective study from India

Objective: In view of the conflicting results of cognitive and behavioral consequences of PB, the present study was planned to analyze its efficacy, serial neuropsychological functions and its impact on psychosocial functioning in adults with epilepsy while on phenobarbitone (PB).

Methodology: This prospective multi-centric study carried out across 4 centers in India included 75 adult patients of ≥18 years (M:F=52:23; age: 27.3 ± 8.5 years) with epilepsy who were prescribed phenobarbitone and underwent serial standardized neuropsychological assessment (NIMHANS battery for adults) at baseline, 1 month, 3 months, 6 months and 12 months. The demographic, seizure details and outcome measures were recorded.

Results: Of the 75 patients, 63 had completed clinical and neuropsychological assessment, i.e. visit 1 (baseline), visit 4 (6 months) and visit 5 (12 months). There was no deterioration rather an improvement during the follow visits in all the neuropsychological functions. The results indicate that 16 neuropsychological variables changed significantly, viz. mental speed (p<0.001), sustained attention (p<0.001), focused attention (p<0.002), planning (p<0.001), concept formation (p<0.05), set shifting (p<0.001), verbal learning (p<0.0001), verbal memory (p<0.0001), visual memory (p<0.0001) and intelligence (p<0.001). The scales measuring the outcome of psychosocial functioning significantly changed during follow up included happiness (p<0.002), Impact of Epilepsy on patient's life (p<0.02), A-B Neuropsychological Assessment (p<0.015), HADS anxiety (p<0.001) and emotional disorder (p<0.006). There was a significant reduction in seizure severity as measured by Liverpool Seizure Severity Scale (p<0.002) and seizure freedom was maintained.

Conclusions: This study demonstrated that phenobarbitone is effective, well tolerated AED and do not have cognitive impairment over one year. There was variable but distinct improvement in cognition and psychosocial functioning, and effective seizure control could be one of the factor for it.