Neuropsychological characteristics in active epilepsy and its risk factors

Abstract

Objective To assess the neuropsychological characteristics in active epileptic patients and investigate itsrisk factors. Methods Ninety adult epileptic patients included 60 active epileptic patients (two or more unprovoked seizures within 12 months) and 30 age-, sex-, education-, course of disease- and seizure type-matched seizure-free subjects (without epileptic seizure for at least 1 year) . The neuropsychological tests including trail making test,digit symbol test, verbal fluency test,digit span test and hamilton depression scale( HAMD) ,were used to detect mental and motor speed, attention, language, working memory and depression symptoms respectively. The neuropsychological tests were compared between active and seizure-free epileptic patients and identified the risk factors of neuropsychological deficits in active epileptic patients. Results Compared to seizure-free subjects, active epileptic patients had significantly worse scores in digit symbol test, verbal fluency test, digit span test ((47.45 ±18. 812) vs(56.40 ±13. 631), (25. 25 ±8. 163) vs(30.40 ±8. 414), (10. 39 ±2. 228) vs( 11. 80 ± 2.074) respectively) ; more time to accomplish the trail making test A and B((64. 35 ±31.710) vs( 45. 47 ± 16. 309) , ( 133. 18 ± 47. 331 ) vs ( 98. 00 ± 35. 003 ) respectively) ; and higher scores in depressive symptoms ((9.12 ±6.219)vs(3.77 ±3.997) ,all P<0.05). Within active epileptic group,significant predictors of neuropsychological deficits were identified in a stepwise linear regression analysis: advancing age was significantly negatively correlated with digit symbol test(β = -0. 468, P = 0. 000) , digit span test (β = -0. 439, P = 0. 000), trail making test A (β =0.365, P = 0.003) and B(β = 0.346, P=0.002) ; higher scores on depressive symptoms was significantly negatively correlated with digit symbol test (β = -0.244, P = 0.015) ; mental work,high-education level and monotherapy were positively correlated with some of the cognitive function subscales. Conclusion This study suggests that active epilepsy can have a direct adverse effect on cognition and depression symptoms. Multi-drug therapy, severity of depression symptoms, advancing age, low-education level and non-mental work are the predictors of neuropsychological impairment in active epilepsy. In addition, good seizure control even after 1 year can have a beneficial impact on cognitive and depression prognosis. Key words: Epilepsy ; Neuropsychology ; Cognitive impairment ; Depression ; Risk factors ;