Abstracts

NEUROPSYCHOLOGICAL FUNCTIONING AMONG 32 PATIENTS WITH TEMPORAL LOBE EPILEPSY AND THEIR DISCORDANT SIBLINGS

Abstract number : 2.167
Submission category :
Year : 2002
Submission ID : 1867
Source : www.aesnet.org
Presentation date : 12/7/2002 12:00:00 AM
Published date : Dec 1, 2002, 06:00 AM

Authors :
Annette Roeschl-Heils, Christoph Bledowski, Christian E. Elger, Armin Heils, Christoph Helmstaedter. Clinic of Epileptology, University of Bonn, Bonn, Germany

RATIONALE: The syndrome of temporal lobe epilepsy (TLE) is associated with an impairment of localization-related neuropsychological functions, mainly dysfunctions of distinct memory performances. This study was conducted to test for the quality and quantity of cognitive dysfunctions in patients with TLE by using results obtained in their unaffected siblings as measures of reference.
METHODS: We obtained results on a broad range of cognitive measures such as intelligence, verbal and nonverbal memory performance, attention, etc. in 32 patients suffering from medically intractable TLE. We also sought for further important information such as those related to academic achievement and career. Since classical case-control studies do not take into account the probands individual normalized range of performance, we conducted a discordant sibling study in which patients were compared with one of their unaffected siblings, thereby minimizing confounding influences of genetic and environmental factors.
RESULTS: Our results showed that clinically unaffected individuals outperformed their affected siblings on almost all measures obtained on a high significance level. Patients differed from their siblings at least by 1 to 2 standard deviations, differences being pronounced with respect to full scale IQ and verbal memory. Regression analysis indicated greater differences in IQ with earlier onset of epilepsy whereas greater differences in memory were rather seen with later onset of epilepsy. The duration of chronic epilepsy however did not explain the observed group differences.
CONCLUSIONS: Our results provide further evidence that the functional impairment associated with TLE exceeds a disturbance of normal temporal lobe function. Instead, dramatic differences between patients and their siblings on a broad range of cognitive functions suggests a profound disturbance of CNS functioning probably manifest at early stages of brain maturation and development. Such point of view may open novel research directions to improve our understanding of the pathological mechanisms underlying TLE.
[Supported by: The German Volkswagen-Stiftung and the Deutsche Forschungsgemeinschaft (DFG)]