The Memory Assessment Scales and lateralized temporal lobe epilepsy

We report Memory Assessment Scales (MAS) performance in 101 patients with unilateral temporal lobe epilepsy (TLE; left, n = 51; right, n = 50) with left cerebral language dominance. A significant multivariate group effect was present for the major summary indices (Verbal Memory, Visual Memory, and Global Memory, p < .04). Univariate analyses revealed no significant differences for either the Global Memory or Verbal Memory summary scores, although a significant group difference was present for Visual Memory (p < .04). The Verbal Memory-Visual Memory discrepancy score was significantly different between right and left TLE groups (p < .004). Verbal Memory scores were at least 14 points lower than Visual Memory scores in 34 patients (left = 20, 59%; right = 14, 41%). Visual Memory scores were at least 14 points lower than Verbal Memory performance in 20 patients (left = 5, 25%; right = 15, 75%). Diagnostic efficiency statistics show higher sensitivity but lower specificity in group classification for left TLE patients. These data suggest that the MAS is sensitive to material-specific memory deficits associated with a unilateral temporal lobe seizure focus. However, over one-third of the patients (19/54) with at least a 14-point Verbal Memory-Visual Memory discrepancy were classified incorrectly. The MAS, like other material-specific memory measures, should be interpreted within the context of other clinical findings.