Stereotactic Laser Ablation for Temporal Lobe Epilepsy

The purpose of the study is to evaluate the safety and efficacy of the Visualase MRI-guided
laser ablation system for necrotization or coagulation of epileptogenic foci in patients with
intractable mesial temporal lobe epilepsy.

The study will include approximately 150 adult patients with drug-resistant MTLE treated at
selected epilepsy centers across the United States. After the Visualase procedure, patients
will be followed for 12 months and evaluated for freedom from seizures, quality of life,
adverse events, and neuropsychological outcomes.

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