Vision after trans-sylvian or temporobasal selective amygdalohippocampectomy: a prospective randomised trial.
Selective amygdalohippocampectomy (SAH) is an accepted surgical procedure for treatment of pharmacoresistant mesial temporal lobe epilepsy, but it may lead to postoperative visual field deficits (VFDs). Here we present a prospective randomised trial comparing the postoperative VFDs after either a trans-sylvian or temporobasal approach for SAH.



Forty-eight patients were randomly assigned to trans-sylvian (n = 24) or temporobasal (n = 24) SAH. Postoperative VFD were quantitatively evaluated using automated static and kinetic perimetry. In 24 cases, diffusion tensor imaging-based deterministic fibre-tracking of the optic radiation was performed. The primary endpoint was absence of postoperative VFD. The secondary endpoint was seizure outcome and driving ability.



Three patients (13 %) from the trans-sylvian group showed no VFD, compared to 11 patients (46 %) from the temporobasal group without VFD (p = 0.01, RR = 3.7; CI = 1.2-11.5). Fifteen patients from each group (63 %) became completely seizure-free (ILAE1). Among those seizure-free cases, five trans-sylvian (33 %) and ten temporobasal (66 %) patients could apply for a driving licence (NNT = 3) when VFDs were considered. Although the trans-sylvian group experienced more frequent VFDs, the mean functional visual impairment showed a tendency to be less pronounced compared with the temporobasal group. DTI-based tracking of the optic radiation revealed that a lower distance of optic radiation to the temporal base correlated with increased rate of VFD in the temporobasal group.



Temporobasal SAH shows significantly fewer VFDs and equal seizure-free rate compared with the trans-sylvian SAH. However, in patients in whom the optic radiation is close to the temporal base, the trans-sylvian approach may be a preferred alternative.
Department of Neurosurgery, University of Bonn, University Medical Centre, Bonn, Germany. delev.daniel@gmail.com.|Department of Neurosurgery, University Medical Centre, Freiburg, Germany. delev.daniel@gmail.com.
Daniel
D
Delev
Department of Ophthalmology, University of Bonn, University Medical Centre, Bonn, Germany.
Bettina
B
Wabbels
Medical Faculty, University of Bonn, University Medical Centre, Bonn, Germany.
Johannes
J
Schramm
Department of Neuroradiology, University of Bonn, University Medical Centre, Bonn, Germany.
Michael
M
Nelles
Department of Epileptology, University of Bonn, University Medical Centre, Bonn, Germany.
Christian E
CE
Elger
Department of Neurosurgery, University of Bonn, University Medical Centre, Bonn, Germany.|Department of Neurosurgery, University Hospital Bochum, Bochum, Germany.
Marec
M
von Lehe
Department of Neurosurgery, University of Bonn, University Medical Centre, Bonn, Germany.|Department of Neurosurgery, RWTH Aachen University, Aachen, Germany.
Hans
H
Clusmann
Department of Neurosurgery, University of Bonn, University Medical Centre, Bonn, Germany.|Department of Neurosurgery, Evangelisches Krankenhaus Bielefeld, Bielefeld, Germany.
Alexander
A
Grote
D000328:Adult; D000679:Amygdala / Q000601:surgery*; D000069279:Drug Resistant Epilepsy / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000601:surgery*; D005260:Female; D006624:Hippocampus / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects* / Q000379:methods; D011446:Prospective Studies; D014786:Vision Disorders / Q000209:etiology*; D014794:Visual Fields / Q000502:physiology*
Amygdalohippocampectomy; Approach; Epilepsy surgery; Temporobasal; Trans-sylvian; Visual field deficits