Seizure control and cognitive outcome after temporal lobectomy: a comparison of classic Ammon's horn sclerosis, atypical mesial temporal sclerosis, and tumoral pathologies.
OBJECTIVE
Neuropathologic examination of resected tissue after anterior temporal lobectomy (ATL) for treatment of complex partial seizures revealed several distinct histologic substrates. Our study examined the relation between neuropathology, seizure control, and cognition in ATL patients and described preliminary profiles to aid in the prediction of outcome.


METHODS
Of the 149 patients who underwent ATL from 1980 to 1999, long-term follow-up was available for 145. Specimens from 124 of the 145 patients had histologic findings consistent with one of three diagnoses: classic Ammon's horn sclerosis (cAHS; n = 75), atypical mesial sclerosis (Atypical; n = 21), or low-grade tumor (Tumor; n = 28). The other 20 patients had diverse pathologies that were insufficient for analysis. ATL patients underwent a complete preoperative and 68 underwent a postoperative neuropsychological evaluation.


RESULTS
Of the 145 patients, 84% of cAHS, 57% of Tumor, and 29% of Atypical patients had a > or =95% reduction in seizure frequency. Neuropsychological testing suggested that cAHS patients demonstrate more generalized preoperative cognitive impairment than do the Atypical or Tumor patients. The Atypical group recalled significantly less nonverbal material after surgery than did the cAHS or Tumor groups. Stratification by both pathology and surgery side revealed that the right Atypical patients declined more on information processing and set shifting.


CONCLUSIONS
Patients with cAHS or Tumor demonstrated better seizure control and fewer declines in cognitive functioning after ATL than did the Atypical patients, highlighting the need to investigate this group as a distinct entity.
York
Michele K
MK
Department of Neurosurgery, The Baylor Comprehensive Epilepsy Center at The Methodist Hospital Baylor College of Medicine, Houston, Texas 77030, USA. myork@bcm.tmc.edu
Rettig
Gayle M
GM
Grossman
Robert G
RG
Hamilton
Winifred J
WJ
Armstrong
Dawna D
DD
Levin
Harvey S
HS
Mizrahi
Eli M
EM
D000293:Adolescent; D000328:Adult; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis*; D015331:Cohort Studies; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000175:diagnosis*; D012598:Sclerosis; D013702:Temporal Lobe / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome