The ExAblate Transcranial system will be used to destroy a small cluster of cells that may be causing the study participant's pain . The ExAblate uses ultrasound to heat a small spot in the brain. The process of ablation is similar to a magnifying glass that uses light to heat a small spot on a piece of paper. Ultrasound passes through the skin and skull and into the brain to focus on a spot the study investigator wants to treat.Once the spot is destroyed, it cannot grow back.