Cervical Dystonia - The Bertrand Procedure: Selective Peripheral Denervation

Selective peripheral denervation surgery for cervical dystonia is commonly referred to as the Bertrand procedure. In the 1970s, Dr. Claude Bertrand, with the collaboration of Dr. Pedro Molina-Negro, developed this procedure as a peripheral approach to treat cervical dystonia. The term selective refers to the care taken to identify the muscles of the neck affected by dystonia, and the termdenervationrefers to cutting the nerves that supply those muscles. The purpose of the Bertrand procedure is to reduce abnormal contractions in the affected muscles by severing the nerves to these muscles. The goal of the procedure is to leave intact the supply of nerves to unaffected or less-affected muscles.

This procedure is tailored to address the unique needs and symptoms of each patient. The initial approach is often to denervate the muscles causing the most prominent dystonic movement, knowing that some residual movements may remain from lesser-affected muscles. If the results do not sufficiently alleviate symptoms, a second procedure may be performed. In many cases, the initial surgery is enough to significantly improve the abnormal posture. More aggressive surgeries, in which all cervical muscles involved in the dystonia are denervated in a single operation, may result in excessive weakness in the neck.

An essential part of the procedure is the pre-operative evaluation to properly identify the muscles involved and to assess if the procedure will benefit the individual. Patients who may be eligible for the surgery are observed clinically by the physician and with EMG equipment to monitor muscle activity and pinpoint the muscles affected by the dystonia.

One basic element of the Bertrand procedure is to cut rootlets of the spinal accessory nerve, which supply sternocleidomastoid muscles in the neck, and to spare the nerves to the trapezius muscle. The spinal accessory nerve is one of 12 cranial nerves that originate in the brainstem, which is the junction of the brain and the spinal cord. A second element of the Bertrand procedure is cutting the posterior rami (branch) of one or more spinal nerves along the cervical vertebrae. (This element of the procedure is called posterior ramisectomy.) Spinal nerves are arranged in pairs along the length of the spinal cord and supply muscles and organs. Some research suggests that the ramisectomy increases the improvement in persons who have become resistant to botulinum toxin therapy.

To date over 2,000 cervical dystonia patients have undergone this procedure. Some centers report significant improvement in as many as 88% of cases. Although the procedure may benefit individuals with a range of symptoms, the categories of patients who may have the best results from the Bertrand procedure are individuals in which:
• Symptoms mainly affect the neck
• Symptoms have stabilized for 3 years
• The head turns to one side (rotational torticollis)
• The head is tilted (laterocolis)
• The head turns and is pulled backwards (rotational torticollis with superior retrocollis)
• The head turns and tilts forward (rotational torticollis with superior antecollis)
• The head is pulled back (superior retrocollis)

Dystonia in which the head turns both to the side and either back or forward may have the best outcome. Individuals who respond to botulinum toxin therapy as well as non-responders may be eligible. The procedure may also be an option for a small number of patients with generalized dystonia who have very defined symptoms in the neck.

Side effects may include numbness in the back of the head, tightness at the surgery site, some remaining movements, difficulty swallowing, and lack of benefit. Patients are often able to go home after two or three nights in the hospital.

Studies have demonstrated that the Bertrand procedure can significantly improve the posture of the neck with a better range of motion. Physical therapy following the procedure is very important to preserve range of motion.

Last update: May 2017