HIPPOCAMPUS ANATOMY HISTOLOGY SUBIICULUM FREE

Of the nine patients, four (44%) were seizure free at 18 months. Five patients were randomized to an initial 1-month, double-blind period without stimulation to investigate possible implantation effects. Bipolar stimulation was usually delivered to the head of the hippocampus or the amygdalohippocampal junction, with 1-minute trains of square wave pulses at 130вЂЇHz, 450-Вµsec duration, and 300-в™љ amplitude, followed by 4-minute stimulation-free intervals (alternating side-to-side in bilateral cases). Four patients underwent bilateral implantation, three on the left and two on the right. Four of these patients had bilateral independent onset, three had onset on the dominant side associated with preserved verbal memory, one had right-sided onset with occasional left-sided epileptiform discharges, and another did not undergo resection because of magnetic resonance imaging (MRI) evidence of bilateral hippocampal sclerosis. 23,36,80,81 Velasco and colleagues performed the first human study in a pilot study of stimulation before temporal lobectomy in 10 patients, 28 and more recently reported the findings after 18-month follow-up of nine patients with MTLE 82 (see Table 79-2). Studies in hippocampal slices and rodent models provided preclinical support for electrical neuromodulation of the hippocampus. The hippocampus is an appealing target for stereotactic neuromodulation techniques, being a frequent target for stereotactic implantation of recording depth electrodes by epilepsy surgeons. 79 Thus, availability of a treatment that can decrease seizure frequency in MTLE to a similar degree as ablative or resective procedures but that preserves interictal function would represent a major advance in the surgical treatment of epilepsy. In fact, open resection is associated with a high rate of lateral temporal lobe dysfunction regardless of approach, such as naming or object recognition deficits. However, hippocampal resection or ablation may be contraindicated in patients with dominant-onset MTLE with preserved verbal memory and/or dominant temporal lobe function, patients with bilateral mesial temporal onset, or those with recurrent MTLE contralateral to a prior resection. Patients with mesial temporal lobe epilepsy (MTLE), the most common form of drug-resistant epilepsy, have a high rate of seizure freedom 75 after amygdalohippocampal resection, 3,5,8,76 whether by anterior temporal lobectomy (approximately 75%) or selective amygdalohippocampectomy (approximately 72%), or by stereotactic ablation (radiofrequency or laser 77,78). Richard Winn MD, in Youmans and Winn Neurological Surgery, 2017 Hippocampus

Hippocampus anatomy histology subiiculum