RUSSELLS ADAPTATION OF THE WECHSLER MEMORY SCALE AS AN INDEX OF HIPPOCAMPAL PATHOLOGY

Fifty-nine patients with temporal lobe epilepsy (28 left, 31 right) completed the Visual Reproduction Subtest of the Wechsler Memory Scale before surgery. Patients with right temporal seizure foci were significantly more impaired than those with left seizure foci in their performance on the Immediate Recall measure. Group differences were not found on the measures of Delayed Recall and Percent Retention. After surgical removal of the mesial temporal lobe structures, two blinded observers established volumetric cell densities for hippocampal subfields CA1, CA2, CA3, the hilar area, and the granule cell layer of the area dentata. No statistically significant correlations existed between Visual Reproduction Subtest scores and hippocampal neuronal density. These findings were discussed in combination with those of a prior study concerning the correlation of hippocampal neuron loss and impairment on the Logical Memory Subtest. The authors conclude that when testing patients with epilepsy, the Immediate Recall and Delayed Recall scores of the Logical Memory and Visual Reproduction Subtests should not be considered indices of hippocampal injury or disease. Logical Memory Percent Retention may be an index of left hippocampal injury or disease.