CLINICAL OUTCOMES: EPILEPSY Deep Brain Stimulation

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• Effectiveness Results
• High Patient Satisfaction
• Safety Results

SANTE (Stimulation of the Anterior Nucleus of the Thalamus in Epilepsy) was a multicenter, prospective, randomized, double-blind, parallel groups study intended to evaluate the safety and efficacy of bilateral stimulation of the anterior nucleus of the thalamus (ANT) as adjunctive therapy for the treatment of medically refractory epilepsy, characterized by partial-onset (focal) seizures, with or without secondary generalization.

The study was conducted at 17 centers in the United States. The study enrolled 157 adult subjects, of which 110 were implanted.

The SANTE trial provides Level 1 Clinical Evidence for Medtronic Deep Brain Stimulation for Epilepsy. The study's outcomes demonstrated the safety, effectiveness and long-term benefits of Deep Brain Stimulation therapy for medically refractory partial-onset (focal) seizures in adults.^6,7

EFFECTIVENESS RESULTS⁷

Reduced Seizure Frequency

DBS for Epilepsy was shown to reduce median seizure frequency, and these results improved over time. Our therapy benefits were consistent and sustained over time.

Freedom From Seizures

In the seven years after implant, twenty patients in the SANTE study (18%) reported a seizure-free interval of at least six months. Nine patients were seizure-free for over two straight years during that time.

SUSTAINED INCREASE IN RESPONDER RATES

For patients receiving Medtronic Deep Brain Stimulation Therapy for Epilepsy in the SANTE study, the responder rate (percentage of subjects with ≥50% seizure reduction) was 43% (n=99) at one year and 74% (n=50) at year seven.

Increase in rate of ANT DBS-treated patients who met the responder criteria over 7 years (≥50% reduction in seizures for at least 6 months: all randomised patients in the SANTE trail with at least 70 days of diary in the 3 months prior to the annual follow-up visit) (Adapted from Salanova 2015⁸, Sandok 2016⁹)

SUBGROUPS SEIZURE REDUCTION

Significant seizure reductions were observed for specific subgroups, including those with temporal seizure origin and those with or without prior Vagus Nerve Stimulation (VNS) at seven years compared to baseline.

FEWER SEIZURE-RELATED INJURIES

During the blinded phase, DBS was shown to significantly reduce patients' most severe seizures, complex partial seizures, and incidence of epilepsy-related injury.

IMPROVED QUALITY OF LIFE

The SANTE study showed a significant increase in quality of life for patients with epilepsy. After seven years, 43% of patients experienced a clinically meaningful improvement in quality of life.

HIGH PATIENT SATISFACTION⁷

After 7 years, 84% of patients (54 out of 64) said they were satisfied or greatly satisfied with the results.

Safety Results⁷

• Lead(s) not within target requiring replacement (8.2%)
• Implant site infection (10.9%; 9 subjects required partial or full system explant)
• All other SAEs were reported in 1.8% or fewer subjects

No symptomatic hemorrhage events were associated with lead implant or replacements. Of eight intracranial hemorrhage events, one SAE in the long-term follow-up resulted in clinical symptoms and was attributed to a head injury after two seizure related falls. The event resolved without sequelae or surgical intervention.

The most frequent device-related adverse events were:

• Implant site pain in 31.8% total post implant (30.9% in 7 years)
• Paresthesia in 23.6% total post implant (23.6% in 7 years)

There were no unanticipated adverse device effects reported in the study.

Device-related adverse event reported through 9 years by ant-dbs-treated patients in the sante study trial (all randomised patients)⁸

SUSTAINED NEUROPSYCHOLOGICAL TEST SCORES

Neuropsychological test scores for mood and cognition were stable acutely during the blinded phase and long-term through seven years. No subject discontinued the study due to depression or memory impairment. However, self-reports of depression and memory impairment were higher in the active group during the blinded phase.

Adverse event rates reported through 7 years by ANT DBS-treated patients in the SANTE trial (all randomised patients)⁸

MEMORY

Memory impairment was reported in 30.9% of subjects at any time after implant (30.0% at 7 years). Of the 34 subjects who reported memory impairment, 38.2% had a history of memory impairment.

DEPRESSION

Depression was reported in 39.1% of subjects at any time after implant (37.3% in 7 years). Three events in three subjects were device related. Of the 43 subjects who reported depression, 65.1% had a prior history of depression.

SUICIDALITY

Twelve subjects (10.9%) reported 15 suicidality events after DBS implant. Nine of the 15 events were serious in seven subjects (6.4%). There was one completed suicide four years after implantation (not device related). Of seven subjects reporting suicidality SAEs, six had a medical history of depression or suicide attempt.

STATUS EPILEPTICUS

Status epilepticus was reported in seven subjects (6.4%) at the time of database cutoff:

• 4 events were nonconvulsive
• 6 subjects required hospitalization
• 3 events occurred in subjects who were not receiving stimulation

SUDDEN UNEXPLAINED DEATH IN EPILEPSY (SUDEP)

There were seven deaths that occurred at the time of the database cutoff:

• 1 probable SUDEP prior to device implantation
• 2 definite SUDEP
• 1 possible SUDEP

Including pilot studies, SUDEP rate (definite/probable) was 2.5 per 1,000 patient years including all follow-up.⁷ Published SUDEP rate for epilepsy surgery candidates is 9.3 per 1,000 patient years.¹ The three other deaths were attributed to completed suicide, cardiorespiratory arrest, and liver cancer.⁷

Brief Statement:

See the device manual for detailed information regarding the instructions for use, indications, contraindications, warnings, precautions, and potential adverse events. For further information, contact your local Medtronic representative and/or consult the Medtronic website at medtronic.eu.