Effects Of Idiopathic And Cryptogenic Epilepsy On Cognitive Function

Objective:To investigate the effect of idiopathic and cryptogenic epilepsy oncognitive function, and analysis the character and the affecting factors ofcognitive function of the two types of epilepsy.Methods:This is a case control study. We recruited35idiopathic andcryptogenic epileptic patients and39matched normal group membersfrom all the patients coming to the department of neurology in the FirstHospital of Jilin University between March2013and February2015,aged16-65. The two groups are matched in age, gender and educationdegree. Their cognitive function are assessed using the Wechsler adultintelligence scale-Chinese revised (WAIS-RC), including11subtests. Fullintelligence quotient (FIQ), verbal intelligence quotient (VIQ),performance intelligence quotient (PIQ) and the scales of11subtests areused for statistical analysis.Results:1. Epilepsy group shows lower FIQ, VIQ and PIQ than the matchednormal control group, with significant difference (P<0.05). The rate of full IQ lower than normal people (FIQ=80~89) in the epilepsy group ishigher than that of the control group (37.1%vs.15.4%，P<0.05).2. Among the11subtests, the scale score of the epilepsy group showsignificant reduction, except the vocabulary and similarity subtests(P<0.05). The more significant differences are shown in the subtests ofinformation, arithmetic, digit span, and picture arrangement (P<0.01).3. Compared among the subgroup of different epileptic seizure typesand the control group, there is a statistically significant different in thescore of VIQ, PIQ, and FIQ (P<0.01), while the scores of secondarilygeneralized tonic-clonic seizure (SGTCS) are the lowest among the fourgroups.4. The rate of FIQ lower than the normal level (FIQ=80~89)in thelong epilepsy duration group is significantly higher than the short group(57.1%vs.23.8%, P<0.05). The rate of people with dysnoesia (FIQ≤69)is higher in the long duration group, without significant differences(21.4%vs.4.8%, P=0.333).5. We define the mental imbalancement as|VIQ PIQ|≥10in thisresearch,22patients suffer mental imbalancement in the epilepsy group.The difference between different sides EEG discharges happened(left/right) do not show a significant impact on the mentalimbalancement (P=0.478). The difference is significant (P<0.05) betweendifferent EEG discharge areas (frontal lobe/temporal lobe).81.8%of patients with mental imbalancement whose VIQ scores are higher sufferparadoxical discharge in frontal lobe, while the rest18.2%discharges intemporal lobe.69.2%of patients with mental imbalancement whose PIQscores are higher suffer paradoxical discharge in temporal lobe, while therest30.8%suffer discharges in the temporal lobe.Conclusions:1. Idiopathic and cryptogenic epilepsy patients may have lowercognition level than the normal population.2. Idiopathic and cryptogenic epilepsy may effect patients’ cognitivefunction widely, especially effect attention, memory, visual motion.3. Different types of idiopathic and cryptogenic epilepsy havedifferent impact on the cognitive function, SGTCS shows wider and moresevere damage.4. The longer epilepsy duration may be a negative effect on thecognitive function.5. The verbal cognition is vulnerable with paradoxical discharge inthe frontal lobe, while the performance cognition is vulnerable withparadoxical discharge in the temporal lobe.