Authors :
Presenting Author: Adam Dickey, MD, PhD – Emory University
Robert Gross, MD, PhD – Emory University; Leonardo Bonilha, MD, PhD – Emory University; Daniel Drane, PHD – Emory University
Rationale:
Laser interstitial thermal therapy (LITT) is an attractive option for treating medial temporal lobe epilepsy (MTLE). Patients with evidence of mesial temporal sclerosis (MTS) on MRI have better odds of seizure freedom after LITT targeting the medial temporal lobe, known as stereotactic laser amygdalo-hippocampotomy (SLAH). MTS is associated with hippocampal atrophy, but it is unknown whether atrophy of other brain regions predicts seizure freedom after SLAH. We compared two statistical approaches by correlating brain region asymmetry with (1) seizure freedom after SLAH, and (2) the number of clinical features concordant with medial temporal lobe epilepsy (MTLE).
Methods:
We analyzed a dataset of 108 patients who underwent SLAH and had 1-year surgical outcomes, classified as free of disabling seizures (Engel I) or not. Volumetric analysis was performed using the Computational Anatomy Toolbox (CAT12) add-on to Statistical Parametric Mapping (SPM12) software. T1 images were deformed to an MNI-152 template. Brain parcellation was done using the Automated Anatomical Labelling atlas (AAL3). Asymmetry indexes were computed between 80 brain regions.
Each patient was given a 0 to 7-point MTLE score, awarding one point for (1) presence of MTS, (2) unitemporal interictal epileptiform discharges (IEDs), (3) absence of generalized tonic-clonic seizures, (4) history of febrile seizures, (5) onset of epilepsy < = 16 years, (6) absence of an auditory, visual or vertiginous aura, (7) unitemporal ictal onset. We previously showed that a higher score predicts better odds of seizure freedom after SLAH.