Journal of the International Neuropsychological Society



Extratemporal quantitative MR volumetrics and neuropsychological status in temporal lobe epilepsy


BRUCE  HERMANN  a1 c1, MICHAEL  SEIDENBERG  a3, BRIAN  BELL  a1, PAUL  RUTECKI  a1 a5, RAJ D.  SHETH  a1, GARY  WENDT  a2, DANIEL  O'LEARY  a4 and VINCE  MAGNOTTA  a4
a1 Department of Neurology, University of Wisconsin, Madison
a2 Department of Radiology, University of Wisconsin, Madison
a3 Department of Psychology, Chicago Medical School, North Chicago
a4 Department of Psychiatry, University of Iowa, Iowa City
a5 Middleton VA Medical Center, Madison

Abstract

Neuropsychological studies of temporal lobe epilepsy have focused heavily on the nature and extent of memory dysfunction and its relationship to the neuropathological status of the hippocampus and related mesial temporal lobe structures. In this study, we examined whole brain and lobar quantitative MRI volumes and comprehensive neuropsychological performance in 58 patients with temporal lobe epilepsy and 62 healthy controls in order to determine (1) the nature and degree of extratemporal structural abnormalities in localization-related temporal lobe epilepsy; (2) the nature and degree of cognitive abnormalities outside of anterograde memory function; and (3) the relationship of volumetric abnormalities to neuropsychological status. Temporal lobe epilepsy patients exhibited significant reduction in the volume of adjusted (age, gender, height) total cerebral tissue (−5.8%), more evident in white (−9.8%) compared to gray matter (−3.0%) tissue volumes. Significant volumetric reductions were evident across frontal, temporal and parietal but not occipital lobe regions. Subarachnoid but not total ventricular CSF was significantly increased in epilepsy patients. Neuropsychological abnormality was generalized in nature, consistent with the generalized nature of the morphometric abnormalities, and reductions in cerebral tissue volumes were directly associated with poorer cognitive performance. In summary, patients with temporal lobe epilepsy exhibited clinically significant structural and functional abnormalities that extended outside the epileptogenic temporal lobe. The degree to which these structural and cognitive abnormalities are due to factors that cause the epilepsy, as opposed to reflecting the consequences of chronic epilepsy (e.g., duration and severity of epilepsy), remain to be determined. (JINS, 2003, 9, 353–362.)

(Received June 4 2001)
(Revised March 21 2002)
(Accepted March 25 2002)


Key Words: Temporal lobe epilepsy; MRI; Neuropsychology; Complex partial seizures.

Correspondence:
c1 Reprint requests to: Bruce Hermann, Ph.D., Department of Neurology, University of Wisconsin, 600 N. Highland Ave., Madison WI 53792. E-mail: hermann@neurology.wisc.edu