Differential effects of temporal pole resection with amygdalohippocampectomy versus selective amygdalohippocampectomy on material-specific memory in patients with mesial temporal lobe epilepsy.
OBJECTIVE
In the surgical treatment of mesial temporal lobe epilepsy, there is converging evidence that individually tailored or selective approaches have a favorable cognitive outcome compared to standard resections. There is, however, also evidence that due to collateral damage, selective surgery can be less selective than suggested. As part of a prospective transregional research project the present study evaluated the outcome in memory and nonmemory functions, following two selective approaches: a combined temporal pole resection with amygdalohippocampectomy (TPR+) and transsylvian selective amygdalohippocampectomy (SAH).


METHODS
One year after surgery, cognitive outcomes of postoperatively seizure-free patients with mesial TLE and hippocampal sclerosis, who underwent either TPR+ (N = 35) or SAH (N = 62) in two German epilepsy centers (Bonn/Berlin), were compared.


RESULTS
Repeated measurement MANOVA and separate post hoc testing indicated a double dissociation of verbal/figural memory outcome as dependent on side and type of surgery. Verbal memory outcome was worse after left-sided operation, but especially for SAH, whereas figural memory outcome was worse after right-sided operation, preferentially for TPR+. Attention improved independent of side or type of surgery, and language functions showed some improvement after right-sided surgeries.


CONCLUSIONS
The results indicate a differential effect of left/right SAH versus TPR+ on material-specific memory insofar as transsylvian SAH appears to be favorable in right and TPR+ in left MTLE. The different outcomes are discussed in terms of a different surgical affection of the temporal pole and stem, and different roles of these structures for verbal and figural memory.
Helmstaedter
Christoph
C
Department of Epileptology, University of Bonn, Germany. christoph.helmstaedter@ukb.uni-bonn.de
Richter
Sabine
S
Röske
Sandra
S
Oltmanns
Frank
F
Schramm
Johannes
J
Lehmann
Thomas-Nicolas
TN
D000328:Adult; D000679:Amygdala / Q000601:surgery*; D038481:Anterior Temporal Lobectomy / Q000379:methods; D001288:Attention / Q000502:physiology; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology*; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology*; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000502:physiology; D012598:Sclerosis; D013238:Stereotaxic Techniques; D013702:Temporal Lobe / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome