The purpose of this study is to determine the safe and effective levels of optical stimulation in peripheral nerves of humans otherwise undergoing nerve lesioning in surgery.

The purpose of this study is to determine the safe and effective levels of optical stimulation in peripheral nerves of humans otherwise undergoing nerve lesioning in surgery, namely children undergoing selective rhizotomy for treatment of medically refractory spasticity.

Inclusion Criteria:

• Children over the age of 3 and younger than 17 years
• Children who have failed appropriate medical therapy and are recommended for selective rhizotomy to treat spasticity by the pediatric neurosurgeon
• Children who would normally undergo electrodiagnostic testing including EMG monitoring for physiologic testing during surgery
• Surgery must be performed at the Vanderbilt University Children's Hospital

Exclusion Criteria:

• Patients in which a segment of the nerve (up to 2cm) cannot likely be identified at the time of surgery as determined by the pediatric neurosurgeon
• Children not undergoing routine selective rhizotomy for medically refractory spasticity as determined by the pediatric neurosurgeon
• Children who are medically unstable to tolerate an additional 20 minutes of experimental testing during the surgery
• Women who are pregnant will be excluded from this study

Children over the age of 3 and younger than 17 years who have failed appropriate medical therapy for spasticity and are recommended for Rhizotomy surgery