Phenytoin Induced Cognitive Impairment in Patients with Epilepsy

Epilepsy is a common episodic neurological condition characterized by seizures. WHO estimates that 4 to 10 per 1000 worldwide have this disease. It is not clearly established whether cognitive impairment is due to either seizure or anti-epileptic drugs. Previous studies already reported the relationship between homocysteine and cognitive status. The present study aimed to investigate the mechanisms involved in the cognitive impairment in patients with epilepsy on phenytoin monotherapy. A prospective case-control study was carried out in a hospital in India. Newly diagnosed epilepsy patients were the controls; Whereas, Epilepsy patients on phenytoin monotherapy were the cases. Key finding suggests that cases have mild hyperhomocysteinemia when compared with controls. Homocysteine has significant negative correlation (P<0.05) with cognitive status among the cases. The present study recommends the routine assessment of homocysteine level in epilepsy patients on phenytoin monotherapy in order to protect this population from severe cognitive impairment which may ultimately progress to Alzheimer's disease.