041-22 – Hypothalamic volume alterations of patients with refractory temporal lobe epilepsy before and after amygdalohippocampectomy

Mesial temporal lobe epilepsy is one of the most common intractable epilepsy disorders.
Around a third of patients who receive surgery continue to have seizures. It is therefore of
paramount interest to find biomarkers of surgical outcome. The present study sought to
investigate whether atrophy of pre-surgical hypothalamic volume is associated with mTLE, whether the volume of hypothalamic structures can predict post-surgical seizure outcome and lastly whether there is a difference between pre-surgical hypothalamic volumes and post-surgical hypothalamic volumes. An automated tool was used to segment the hypothalamus from a datatset of MRI images of patients with mTLE who were being considered for amygdalohippocampectomy. The volumetric data from hypothalamic subunits was analysed using multiple analysis of variance models and a t-test. We report that patients with mesial temporal lobe epilepsy (mTLE) show a reduction in hypothalamic volume relative to controls. Additionally, hypothalamic subunits show further reduction in volume after relative to prior to surgical resection. It is suggested that remote deafferentation may explain atrophy of the hypothalamus in patients with mTLE; that deafferentation of hippocampal efferents causes neuronal damage in connected limbic structures, including the hypothalamus. Future research should investigate whether the discussed hypothalamic alterations play a role in HPA-axis dysregulation in refractory epilepsies.