Seizure detection and automatic magnet mode performance study

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 3

Inclusion Criteria

1. Patients with a clinical diagnosis of medically refractory epilepsy
dominated by partial seizures suitable for implantation with the Model 106
VNS Therapy System.
2. Patients with a history of increased heart rate (tachycardia) associated with
seizure onset based on clinical data obtained from medical history,
admission/hospital charts, or prior neurophysiologic evaluations.
3. Patients willing to undergo an EMU evaluation for a period of at least three
days with activation of the AMM feature during that time.
4. Patients having an average of * 6 seizures per month based upon diary or
patient reporting for the 3 months prior to enrolling.
5. Patients must have peak-peak R-wave amplitude greater than or equal to 0.25 mV on ECG measured from the proposed electrode location in the neck to the proposed generator location in the chest via surface ECG electrodes.
6. Patients must be at least 18 years old.
7. Patients must be in good general health and ambulatory.
8. Patient or guardian must be willing and able to complete informed consent.

Exclusion Criteria

1. Patients have had a bilateral or left cervical vagotomy.
2. Patients currently use, or are expected to use, short-wave diathermy,
microwave diathermy, or therapeutic ultrasound diathermy.
3. A VNS Therapy System implant would (in the investigator*s judgment) pose
an unacceptable surgical or medical risk for the patient.
4. Patients expected to require full body magnetic resonance imaging.
5. Patients have a history of VNS Therapy.
6. Patients have a documented history of clinically meaningful bradycardia
(heart rate less than 50 bpm) associated with seizures.
7. Patients with a significant psychiatric disorder, history of depression, or
suicidality as defined by DSM IV-TR that in the investigator*s judgment
would pose an unacceptable risk for the patient or prevent the patient*s
successful completion of the study.
8. Patients with a history of status epilepticus within 3 months of study
enrollment.
9. Patients prescribed drugs specifically for a cardiac or autonomic disorder that in the investigator*s opinion would affect heart rate response unless the patient has ictal tachycardia while taking said drugs. These include, but are not limited to, beta adrenergic antagonists (*beta blockers*).
10. Patients with known clinically meaningful cardiovascular arrhythmias as well as patients with clinically meaningful cardiovascular arrhythmias determined by a 24-hour Holter recording obtained at the baseline visit.
11. Patients dependent on alcohol or narcotic drugs as defined by DSM IV-TR
within the past 2 years.
12. Patients with a history of only psychogenic or pseudo seizures.
13. Women who are pregnant. Women of childbearing age must take a pregnancy
test.
14. Patients currently enrolled in another investigational study.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The purpose of this study is to confirm R-wave detection and to determine<br /><br>whether the SDA and AMM perform in vivo as predicted in silico (i.e. software<br /><br>performance tested by using a library of vEEG/ECG data from multiple patients).<br /><br>Performance analyses are conducted as described below.<br /><br>Primary Performance Objective<br /><br>Sensitivity and potential false positive rate per hour * Using vEEG and<br /><br>ECG recordings from the EMU stay, sensitivity and potential false positive rate<br /><br>per hour will be estimated to confirm the performance of the algorithm*s<br /><br>ability to detect seizures at different SDA settings. </p><br>

Secondary Outcome Measures