Study On Cognitive Dysfunction In Primary Epileptic Patients With Different Seizure Types

Background:The majority of Neuropsychological studies have con- firmed that the patients with epilepsy exhibited general cognitive dys- function; the contents and severity of cognitive dysfunction were affected by epilepsy itself, treatment-related factors and psychosocial factors. Now, at home and abroad there are many studies on cognitive function of epilepsy, but most of them do not exclude the impact of primary intracranial lesions on cognitive function. Especially, there are fewer studies on the impact of primary epilepsy in comparison with the three main types on cognitive function.Objective:To explore the features and severity of cognitive dys- function in Primary epileptic patients with Different seizure types, to find the law of cognitive dysfunction in epileptic patients, to explore the me- chanisms, and to provide assistance for the diagnosis and therapy of pati- ents with epilepsy.Methods:The subjects were 18-45 year-old patients with primary epi- lepsy. According to the amendment proposal which was proposed in 1981 by International League Against Epilepsy's classified and named Committee, the subjects were grouped by seizure types: Complex partial seizures group (Group A), Partial seizures evolving to secondarily generalized seizures group (Group B), Generalized seizures group (Group C). The Full Intel- ligence Quotient (FIQ), Verbal Intelligence Quotient (VIQ), Performance Intelligence Quotient (PIQ) and sub-test scores were calculated by means of Wechsler Intelligence Scale for Adult-Chinese Revised (WAIS-RC). P3 was elicited from Cz by auditory"oddball paradigm"and its peak latency and amplitude were measured. Results:1. The FIQ, VIQ, PIQ in the 3 epileptic patients groups were significantly lower than that in the control group. The FIQ in group B was significantly lower than that in group C. The VIQ in group B was significantly lower than that in group A and C.2. Except the Digit span, all the subtests'scores of the Verbal scale in the 3 epileptic patients groups were significantly lower than that in the control group; the Digit span subtests'scores in Group A and B were significantly lower than that in the control group. The Arithmetic subtests'score in Group B was significantly lower than that in Group A and C. The Digit span subtests'score in Group B was significantly lower than that in Group C.3. The subtests'scores of the Verbal scale: the Picture Completion, Block Design, Object Assembly subtests'scores in the 3 epileptic patients groups were significantly lower than that in the control group; the Digit Symbol subtest's score in Group B was significantly lower than that in the control group; the Picture Arrangement subtest'scores in Group A and B were significantly lower than that in the control group; the Picture Completion subtest's score in Group B was significantly lower than that in Group C.4. The three factors A, B, C in the 3 epileptic patients groups were sig- nificantly longer than that in the control group; The factor C in Group B was significantly lower than that in Group A and C.5. The latency of P3 in the 3 epileptic patients groups was significantly lower than that in the control group.6. The FIQ is negatively correlated with the latency of P3.Conclusion:1. The patients with primary epilepsy exhibited general cognitive dys- function; especially the verbal comprehension (factor A) is seriously da- maged.2. Cognitive dysfunction in epileptic patients with different seizure types vary in severity: Partial seizures evolving to secondarily generalized seizures have significantly more impact on the Full Intelligence Quotient than on the other two groups, especially the attention / memory (factor C) is seriously damaged.3. The latency of Cz point's P3 in the primary epileptic patients groups were significantly longer than that in the control group. 4. The FIQ is negatively correlated with the latency of P3.