Evaluation of the Percutaneous SCS Trial Using the DSSEP Collision Testing

The SCS trial leads will be placed as per standard of care, using fluoroscopic guidance and
leads will be checked for proper positioning. Leads will be tested for appropriate
paresthesia coverage of the patient's painful area(s), using multiple electrode
configurations and lead positions (dependent on the location of the pain). After the leads
are secured, the patient will be sent to the recovery room where the DSSEP test will be
performed. A technologist will glue/tape recording electrodes to the patient's head, neck,
back or legs. One or two stimulating electrodes are also placed on the patient's leg. Each
electrode is checked with a meter to ensure proper functioning. Pulsing stimulus will start
in one of the stimulating electrodes. Each time a different area is tested, the pulsing will
be started again. Each area tested will take 10-15 minutes. The painful dermatomal
distribution area, specific to each patient will be used for dermatomal SSEP stimulation.
Placement will be correlated with nerve roots involved with the corresponding dermatomes.
Measurements will be obtained to determine collision criteria.

Inclusion Criteria

A subject will be eligible for inclusion in this study only if all the following criteria
apply:

A. Subject understands the procedures, agrees to participate in the study, and has signed
and dated the informed consent form prior to the initiation of any study-related
activities.

B. Subjects are male or female greater than 18 years old at the time of screening visit.

C. Pain in one or both lower extremities. D. Pain is not responding to conservative
treatment such as physical therapy or medications.

E. Average pain rating of at least 4 on a scale 0 to 10, on average, prior to enrollment in
the study.

F. Patient is mentally competent to make decisions.

Exclusion Criteria

A subject will not be eligible for inclusion in this study if any of the following criteria
apply:

A. Female subject with childbearing potential (a premenopausal female, who is not
surgically sterile).

B. Subjects who poorly cooperate or have any cognitive impairment. C. Patient with severe
concomitant depression. D. Inability to communicate adequately with physician and /or study
coordinator.

E. Patient is diagnosed with a psychiatric condition that will likely interfere with
diagnostic accuracy of the workup protocol or with recovery following the anticipated
procedure