The Study of Cognitive Functions and Neuropsychiatric Comorbidities among Intractable Epilepsy Patients in a Tertiary Care Hospital

Introduction: People suffering with epilepsy often present with cognitive dysfunction, neuropsychiatric comorbidities, such as cognitive impairment, depression, anxiety, and other behavioral problems. These illnesses may aggravate the epileptic manifestations in intractable epilepsy patients. The cognitive dysfunction and psychiatric comorbidities may be due to the intractable seizure itself, structural damage to the brain, and antiepileptic drugs. There is lack of studies in Indian context regarding the cognitive functions and neuropsychiatric comorbidities in intractable epilepsy patients.

Aim: To study the cognitive functions (IQ, MQ, visuoperceptual functions) and neuropsychiatric comorbidities (anxiety and depression) in intractable epilepsy patients.

Methods: Around 600 patients who fulfilled the criteria of drug-resistant epilepsy (ILAE, 2010) were included in the study. Only 506 patients underwent detailed history and neurological examination, radiological investigations, neuropsychological evaluation, educational, occupational status assessment, and quality of life assessment. Neuropsychological evaluations (intelligent quotient [IQ], the mental quotient [MQ], Bender–Gestalt test [BGT], anxiety and depression scales) were performed within 2 to 3 months after the radiological investigation.

Results: Out of 506 patients with intractable epilepsy, 147 patients (29.05%) had mental retardation (< 69) score in Wechsler intelligence scale. 20% (n = 104) of them had dull normal intelligence. Two hundred and fifty-five patients (50%) of them had average intelligence. Wechsler's memory quotient scores were low (< 70) in 194 patients (38.34%) and showed memory dysfunction. BGT revealed abnormal visuoperceptual gestalt functions in 218 patients (43.08%). Multiphasic personality questionnaire to assess anxiety and depression could not be administered in 147 patients who had mental retardation. Multiphasic personality questionnaire administered to patients without mental retardation showed anxiety in 161 patients (31.82%), depression in 142 patients (28.06%), and mixed anxiety and depression in 126 patients (24.90%). Pearson's Chi-square test did not reveal any significant difference between the IQ, MQ, BGT, anxiety, depression and quality of life scores between the generalized and partial seizures. Abnormal IQ scores (below average), MQ scores, BGT Results were strongly associated (p < 0.01) with MTS. Significant proportion of patients with intractable epilepsy who had no structural abnormalities had normal IQ scores, MQ scores, and BGT Results. A significant proportion of patients with MTS had anxiety and depression. Also, a significant proportion of patients without any structural abnormalities did not show any signs of anxiety or depression. Another significant proportion of patients with MTS had combined symptoms of anxiety and depression (p < 0.05).

Conclusion: The present study highlights that patients with intractable epilepsy are often associated with neuropsychological manifestations, such as cognitive impairment (mental retardation: 29.05%, memory impairment: 38.34%, abnormal visuoperceptual gestalt functions: 43.08%), anxiety (31.82%), depression (28.06%), and mixed anxiety–depression (24.90%). Hence, diagnosing these conditions is very important among the intractable epilepsy patient and treating them effectively with drugs as well as counseling.