Vascular events after transsylvian selective amygdalohippocampectomy and impact on epilepsy outcome

Abstract

SUMMARYObjective: Epilepsy surgery is a standard treatment option for medically intractable temporal lobe epilepsy. Selective amygdalohippocampectomy (SAH) and anterior temporal lobectomy (ATL) are two of the standard surgical procedures in these cases. We conducted a retrospective analysis of patients treated with SAH via a modified transsylvian approach in our epilepsy center between 2008 and 2011, and we analyzed the impact of adjacent procedure-related infarctions on seizure outcome in these patients. Methods: Infarctions were detected by magnetic resonance imaging (MRI) within the first week postoperatively and by a second MRI 9 months after surgical intervention. Neuropsychological testing was performed preoperatively. Evaluation of seizure outcome and postoperative neuropsychological testing were conducted approximately 1 year after epilepsy surgery. Correlative clinical data were analyzed by retrospective chart review. Results: The postoperative MRI revealed temporal infarctions in 47.9% (n = 23/48) and frontal infarctions in 10.4% (n = 5/48) of the patients. These vascular events were asymptomatic in terms of focal neurologic deficits. Of the patients, 68.5% (n = 37/54) were free of disabling seizures (Engel class I) 1 year after the procedure. Patients with temporal infarctions were significantly more often free of disabling seizures (Engel class I, p = 0.046) than patients without temporal infarctions. Neuropsychological testing indicated a deterioration in verbal memory after SAH in patients with infarctions on the language-lateralized hemisphere compared to patients without infarction (p = 0.011). All other tested neuropsychological categories showed no significant differences between patients with or without infarctions. Significance: Our results indicate a surprisingly high number of procedure-related temporal infarctions after transsylvian SAH. Hence, the volume of nonfunctional "eliminated" tissue is enlarged unintentionally, which is a possible explanation for better seizure outcome in these patients. This result supports the notion that ATL is the favorable procedure for temporal lobe epilepsy compared to SAH in the nondominant hemisphere, as neuropsychological deficits are rarely to be expected.

Neuropsychological performance and seizure control after subsequent anteromesial temporal lobe resection following selective amygdalohippocampectomy

“…[7][8][9] Because clinical predictors for seizure control after surgery are weak, determining the extent of resection preoperatively remains challenging in temporal lobe epilepsies. 16,17 If the first resection does not lead to seizure freedom, a second surgery aiming for a complete resection of the epileptogenic focus is one option suggested in literature. [11][12][13][14][15] Moreover, accidental brain lesions after sAHE seem to have a positive impact on seizure freedom, but increased cognitive impairment cannot be precluded.…”

Neuropsychological outcome after subtemporal versus transsylvian approach for selective amygdalohippocampectomy in patients with mesial temporal lobe epilepsy: a randomised prospective clinical trial

“…This is of interest because it had been discussed in the past that the dissection of the temporal stem as a formation which propagates seizure is mandatory for achievement of seizure control in MTLE 15. Although the transsylvian approach preserves the temporal neocortex, it bears a considerable risk for vascular events due to spasms or injury of blood vessels in the sylvian fissure 42. In this regard, small infarctions were found on MRI in five transsylvian patients.…”

Minimally invasive subfrontal route for the resection of medial temporal region intrinsic tumors

“…We have used it for low and anaplastic gliomas, cavernous angiomas, and cortical dysplasia. Its major advantage over other approaches (transcortical, trans-insular, transsylvian-transcisternal, and sub-temporal approaches) is the possibility of completely sparing not only the temporal cortex but also the temporal stem and limen insulae [2,4,6,8] (Fig. 3).…”