CLINICAL TRIAL / NCT02844465

Inclusion Criteria: - History of drug-resistant mesial temporal lobe epilepsy (MTLE) - If the subject has a vagus nerve stimulator (VNS), must have failed to achieve sustained seizure freedom with the VNS implanted for at least 6 months - On stable antiepileptic drugs (AEDs) (and/or stable VNS setting, if applicable) and compliant with medication use - An average of at least 1 complex partial or secondarily generalized seizure compatible with MTLE per month - Seizure symptoms and/or auras compatible with MTLE - Video EEG shows evidence of seizures from one temporal lobe consistent with MTLE - MRI has evidence consistent with mesial temporal lobe sclerosis - Willing and able to remain on stable AEDs (and stable VNS setting, if applicable) for 12 months following the Visualase procedure - Willing and able to comply with protocol requirements - Able to complete study assessments in English or Spanish language Exclusion Criteria: - Unwilling or unable to sign the study informed consent form - Pregnant or intends to become pregnant during the course of the study - Currently implanted with a device contraindicating MRI - Progressive brain lesions and/or tumors not associated with epileptic disease state - History of previous intracranial surgery for treatment of epileptic seizures - Persistent extra-temporal or predominant contralateral focal interictal spikes or slowing, or generalized interictal spikes on EEG - Seizures with contralateral or extra-temporal ictal onset on EEG - Aura and/or ictal behavior suggest an extra-temporal focus - MRI evidence of epileptogenic, extra-temporal lesions, dual pathology in the temporal lobe, or contralateral hippocampal MRI increased signal and/or loss of architecture - If additional testing has been performed, results are discordant with the seizure focus scheduled for ablation - Non-compliance with AED requirements - IQ < 70 - Dementia or other progressive neurological disease - Unstable major psychiatric illness, psychogenic non-epileptic seizures, or medical illness that would contraindicate the Visualase procedure or affect the neuropsychological assessments - Participation in other research that may potentially interfere with SLATE endpoint(s) - Allergy to gadolinium