Dorsal Root Entry Zone (DREZ) Lesioning

Dorsal roots carry nerve signals, including pain, from your limbs and body to the spinal cord and brain. The area where dorsal roots pass through the outer layer of the spinal cord into the inner layer is called the dorsal root entry zone or DREZ.

When an injury damages these roots, nerve cells in the DREZ can become chronically overactive –- firing spontaneously and generating severe pain. DREZ lesioning reduces pain in the arm by disconnecting these overactive nerve cells using radiofrequency energy or tiny surgical cuts called micro-lesions.

Pain relief typically develops over weeks to months as your nervous system adjusts.

You may be eligible for the DREZ procedure if you meet the following criteria:

• You experience severe shoulder, arm, or hand pain that significantly impairs your quality of life
• Your pain is due to a confirmed brachial plexus or spinal cord injury 
• Other treatments, like medications, injections, and other non-surgical therapies, have not sufficiently reduced pain

Doctors will also consider:

• Your overall health and readiness for surgery
• The type and severity of your injury
• Your unique anatomy 
• Imaging results (MRI, CT scan, or a myelogram) to inspect your spine in detail and evaluate its strength and stability

Neurosurgeons, spine surgeons, neurologists, and pain specialists will work together to determine whether DREZ lesioning is right for you.

Combined Procedures

If your injury involves the upper spine, neurosurgeons and spine surgeons can collaborate to perform spine stabilization or spinal fusion at the same time as your DREZ procedure.

DREZ lesioning requires general anesthesia and typically lasts between five to seven hours. (It may take longer if spine surgery is performed simultaneously.)

1. Laminotomy or laminectomy: Surgeons create an opening to the spine and remove a small portion of it (this is called a laminotomy or laminectomy) to provide direct access to the spinal cord.
    
2. Opening the dura and locating nerve roots: Surgeons carefully open the dura, a protective membrane that covers the spinal cord, to visualize the nerve roots. They identify the injured nerve roots as well as the closest intact, healthy nerve root, which serves as a landmark for precise lesion placement.
    
3. Micro-lesioning the DREZ: Using radiofrequency energy to deliver heat or using tiny cuts, surgeons create dozens of precisely spaced lesions about one millimeter apart along the DREZ. This disrupts to overactive nerve cells, silencing their pain signals while preserving surrounding cells.

Intraoperative Neuromonitoring

Throughout the operation, experts use advanced intraoperative neuromonitoring tools to protect important nerves and ensure the procedure is safe and effective.