Evaluation of the NaviFUS System in Drug Resistant Epilepsy

Inclusion Criteria:

1. Diagnosis of drug resistant temporal lobe epilepsy (TLE)

2. Patients must experience at least six (6) observable seizures over the 60-daybaseline, each on a separate day.

3. Patients have focal-onset seizures with or without secondary generalization.

4. Patients have had at least 24 hours video-electroencephalography (EEG) monitoringand comprehensive epilepsy evaluation confirming TLE.

5. Seizure medication treatment is anticipated to remain stable during the trial,except for rescue medicines or occasional extra doses of ongoing medicines, asrequired.

6. Patients should be capable of and willing to completing assessments andneuropsychological testing in English either alone or with the help of the studypartner (where appropriate), per local guidelines. A study partner is a carer orfamily member of the patient.

7. Patients and study partner (if applicable) who in the Investigator's opinion arereliable and able to use the seizure diary to record seizure throughout the studyand are willing to comply with study procedures and visits.

Exclusion Criteria:

1. Patients who have primary generalized epilepsy or non-epileptic seizures in the lasttwo (2) years.

2. More than two (2) seizure onset zones (foci) (except bitemporal foci) or unknownlikely site of seizure onset, as determined by usual clinical,electroencephalography (EEG) and imaging practice.

3. Patients who have experienced tonic-clonic status epilepticus in the three (3)months leading up to enrollment in the study.

4. Presence of devices including but not limited to cardiac pacemaker, implantablecardioverter-defibrillator (ICD), permanent medication pumps, cochlear implants,responsive neurostimulator (RNS) or deep brain stimulation (DBS). Vagus nervestimulators (VNS) do not represent an exclusion criterion, but settings should bestable throughout the trial.

5. Patients with clips or other metallic implanted objects in the FUS exposure path,except shunts.

6. Patients with more than thirty percent (30%) of the skull area traversed by thesonication pathway covered by scars, scalp disorders (e.g., eczema), or atrophy ofthe scalp at Screening.

7. Patients who have a medical or surgical history of severe systemic disease(s), suchas (but not limited to) coronary artery disease, myocardial infarct, progressiveheart failure, uncontrolled hypertension or abnormal ECG, severe pulmonaryhypertension (pulmonary artery pressure > 90 mmHg), chronic obstructive pulmonarydisease (COPD), adult respiratory distress syndrome, hepatic and renal insufficiency (ALT or AST 3 times above normal range; serum creatinine > 1.3 mg/dL), diabeticpatients with poor control of blood sugar (HbA1c > 8.5 %) at Screening.

8. History of intracranial hemorrhage.

9. History of multiple strokes, or a stroke within the six (6) months prior toScreening.

10. Patients with intracranial aneurysms requiring treatment or arterial venousmalformations (AVMs) requiring treatment at any time.

11. Presence of central nervous system (CNS) disease(s) other than epilepsy includingbut not limited to infections of the CNS (e.g., syphilis, Lyme disease, borreliosis,viral or bacterial meningitis/encephalitis, human immunodeficiency virus [HIV]encephalopathy), cerebral vascular disease, Parkinson's disease, traumatic braininjury, alcoholic encephalopathy within three (3) years prior to Screening.

12. Patients with concurrent major psychiatric disorder, such as schizophrenia orbipolar disorder, severe depression, active suicidal ideation, active psychosis (excluding time-limited postictal psychosis) or psychiatric hospitalization withinone (1) year before Screening.

13. Prior diagnosis of cancer within the past two (2) years and evidence of continuedmalignancy within the past two (2) years (except for adequately treated basal cellor squamous cell skin cancer, in situ cervical cancer, or in situ prostate cancerwith normal prostate-specific antigens post resection).

14. Patients who are not able or willing to tolerate the required prolonged stationarysemi-supine position during treatment.

15. Inability to tolerate MRI procedures or contraindication to MRI (e.g.claustrophobia, too large for MRI scanner), including, but not limited to, presenceof pacemakers (with the exception of MRI-safe pacemakers), aneurysm clips,artificial heart valves, ear implants, or foreign metal objects in the eyes, skin,or other areas of the body that would contraindicate an MRI scan.

16. Patients who had major surgery six (6) weeks before study enrollment or who are notfully recovered from a surgical procedure or with planned surgery during studyperiod or within fourteen (14) days thereafter.

17. Patients who have received radiofrequency thermocoagulation (RFTC) within two (2)months of Screening.