Kg. Davies et al., NAMING DECLINE AFTER LEFT ANTERIOR TEMPORAL LOBECTOMY CORRELATES WITHPATHOLOGICAL STATUS OF RESECTED HIPPOCAMPUS, Epilepsia, 39(4), 1998, pp. 407-419
Purpose: To evaluate the determinants of postoperative change in visua
l confrontation naming ability and the differential sensitivity of two
common tests of confrontation naming. Methods: In a group of 99 patie
nts undergoing lobectomy of the left, language-dominant anterior tempo
ral lobe, we examined naming ability using two measures: the 60 item B
oston Naming Test (BNT), and the Visual Naming (VN) subtest of the Mul
tilingual Aphasia Examination (MAE). ATL entailed resection of lateral
temporal lobe followed by microsurgical complete removal of hippocamp
us. Language mapping was not performed. The status of the resected hip
pocampus was graded on a scale 0-4 of hippocampal sclerosis (HS). A di
chotomous grouping HS- (grades 0 and 1, n = 34) and HS+ (grades 3 and
4, n = 61) was effected. Age at surgery, age of epilepsy onset, sex, e
xtent of lateral temporal resection, Full-Scale IQ (FSIQ), and preoper
ative naming scores were also examined as potential predictors of pre-
versus postoperative naming change. Results: Preoperative BNT and VN s
cores were significantly worse for HS+ than for HS- (BNT, p < 0.05; VN
, p = 0.001). Postoperatively, BNT and VN scores significantly decline
d for HS-as compared with HS+ patients (p < 0.001). For individual ris
k, the 90th centile of reliable change index (RCI) was used. By this c
riterion, of the total sample, 39% evidenced decline on the BNT and 17
% evidenced decline on the VN. Logistic regression analysis with backw
ard elimination showed HS to be the only predictor of decline in BNT a
nd HS and sex to be the only predictors of VN decline. Males were more
at risk than females. Age, age at onset, extent of lateral resection,
preoperative scores, and FSIQ were not predictors. Using age at onset
as a proxy for HS+/HS- we calculated probabilities for naming decline
for given onset age. Conclusions: Both preoperative and postoperative
change in naming ability are associated with the pathological status
of the hippocampus. The potential interpretations and implications of
these findings are discussed.