Abstracts

Pharmacoresistant temporal lobe epilepsy(TLE) has been associated with interictal cognitive and mood deficits subserved by neuronal networks extending beyond the temporal lobe, but motor function has not been included in most prior investigations . We therefore evaluated manual dexterity in refractory TLE patients, and correlated motor deficits with fluoro-deoxy-glucose(FDG) uptake on basal positron emission tomography (PET)., Subjects were patients with refractory TLE(n=34) who underwent neuropsychological(NP) testing and basal FDG-PET of brain obtained with eyes closed in the resting state. NP testing included the Grooved Pegboard(GPB) with right and left hand tested separately. Patients were split into low score subgroup and high score subgroup (cut score of -1.5 S.D) for completion of GPB and the PET scans of the low score subgroup were compared to PET scans of the high score subgroup. The data were analyzed using MATLAB 1 and SPM 2(Wellcome Department of Imaging Neuroscience, University College London, UK). We used minimum statistical thresholds of p[lt]0.001 and a voxel extent threshold of at least 50 voxels for the correlation of PET scans with the GPB scores., The mean score for right hand GPB was 1.26 standard deviations (s.d.) below the established normal mean for age and the mean for left hand GPB was 1.19 s.d. below. We found that the left supplementary sensorimotor area(SSMA) had a significantly higher FDG uptake(Fig. 1), whereas there was a relatively decreased FDG-uptake in the right insula, transverse and superior temporal gyri in the low scoring group when compared to the high scoring group. No between group differences were found in PET metabolism for the left GPB. Multivariate analysis confirmed that the results were not affected by mono versus polytherapy, duration of epilepsy, verbal IQ or depression., Interictal deficits in TLE inlcude fine motor impairment in a substantial proportion of patients. The pathophysiological significance of this observation is supported by the finding of increased basal glucose metabolism in the dominant SSMA in patients with poorer right GPB performance, similar to other disorders of movement such as Parkinson[apos]s disease. Additional investigation of the clinical significance of interictal motor dysfunction seems necessary, as well as the potential need for intervention.[figure1], (Supported by NIH grant NS047551.)