Responsive Neurostimulation (RNS) for the treatment of epilepsy

Daniel Friedman, MDAssistant Professor

NYU Comprehensive Epilepsy CenterApril 27, 2014

The RNS™ System

• Cranially implanted battery powered responsive neurostimulator

• Connected to 2 leads (depth and/or subdural) with 4 electrode contacts each

Stacey WC and Litt B (2008) Technology Insight: neuroengineering and epilepsy—designingdevices for seizure control

Nat Clin Pract Neurol 10.1038/ncpneuro0750

Figure 3 The NeuroPace Responsive Neurostimulator (RNS®) System (Mountain View, CA)

The RNS® System: Responsive Stimulation

Neurostimulatorand Leads

Patient Data Management System

(PDMS) Programmer

Remote Monitor

RNS® System Indication

The RNS® System is an adjunctive therapy for:

• >18 years of age

• partial onset seizures who have undergone diagnostic testing that localized no more than 2 epileptogenic foci

• refractory to two or more antiepileptic medications

• have frequent and disabling seizures (motor partial seizures, complex partial seizures and/or secondarily generalized seizures)

The RNS™ System

Neurostimulator detects and stimulates abnormal brain electrical activity with implanted electrodes

Programmer sets detection and stimulation parameters

Programmer and PatientData Transmitter send

ECoG data to web-based repository for review

RNS® System: Responsive Stimulation

• Physician identifies electrocortico-graphic activity to be detected

• Detection and stimulation settings programmed, then adjusted as needed

• Varied seizure patterns require individualized settings

Patient Data Management System

Caution: InvestigationalDevice. Limited by US Law to Investigational Use Only.Caution: investigational device. Limited by US law to investigational use

only.

Single Patient Seizure Plot: 2009-2014

Red: disabling seizures, Green: auras; Black: total seizures

The NeuroPace Responsive Neurostimulator (RNS®)

System Trial

• 191 patients; 32 centers• Randomized to Treatment vs.

Sham group for 3 months• Need to know localization of

epileptic brain tissue 1- 2 foci• 3 or more disabling seizures

per month

Study Design

Morrell M J Neurology 2011;77:1295-1304

The NeuroPace Responsive Neurostimulator (RNS®) System TRIAL RESULTS

Overall: • 38% Seizure

Reduction in Active Treatment

• 17% Seizure Reduction in Sham Treatment

Other outcomes

• Improved quality of life in treated group• No difference in memory function between

treated and sham groups

Safety

• Bleeding in the brain in 2.3%• Infection of scalp/soft tissue in 5.3% (4 pts had

to have device removed); no brain infection• Other rarer side effects included pain,

abnormal sensations related to stimulation and worsening seizures

Two year seizure reduction in adults with medically intractable partial onset epilepsy treated with ‐responsive neurostimulation: Final results of the RNS System Pivotal trial

EpilepsiaVolume 55, Issue 3, pages 432-441, 22 FEB 2014 DOI: 10.1111/epi.12534http://onlinelibrary.wiley.com/doi/10.1111/epi.12534/full#epi12534-fig-0005

At the end of 2years of treatment, 9% were seizure free during the last 3 mo

- Those with 1 focus were more likely to be seizure-free

~7% had worsening of seizures

Many had improvement in cognitive functioning

Treatment with RNS – Patient perspective

• Localize seizure onset regions using EEG, MRI, PET, MEG, SPECT and/or intracranial EEG

• RNS leads and stimulator implanted & recording activated– Patient uploads data daily

• Post-op visit 10-14 days– Data reviewed, detectors adjusted if necessary, stimulation activated

• Follow up visits ~ 1-3 months– Data reviewed, detectors and stimulation parameters adjusted– Patient continues to upload data every 1-7 days

• Long term follow-up, every 3 months– Continue to upload data– Monitor battery/device function– Adjust parameters as necessary

• Battery change about every 2 years, may be longer/shorter