Answers on stroke, epilepsy, neuropathy, and dystonia
Anthony E. Lang, M.D., is director and founder of the Movement Disorders Centre at Toronto Western Hospital.
Q After years of painful symptoms, I've finally been diagnosed with cervical dystonia. What are the latest therapies?
A Cervical dystonia is a movement disorder that causes muscle spasms in the neck and can produce abnormal posture of the head and neck. The spasms can lead to a pulling of the head in one direction or another. Sometimes the person's head will shake from side to side.
It's not unusual for these movements to be accompanied by pain in the affected muscles. In fact, pain can be the predominant symptom.
Although the problem originates in the brain, the current treatment of choice focuses on the neck muscles themselves.
To quiet the jerking or shaking, neurologists inject a low dose of botulinum toxin (Botox) into the spasming muscle or muscles. The toxin leads to a withering of the nerves that causes the spasming, but eventually the nerve will grow back and another injection will be needed.
The majority of patients can be managed with botulinum toxin alone, although some will also need medication, too. Typically this would be a muscle relaxant, an antispasmodic medication, or an anticholinergic medication.
A small percentage of patients develop antibodies to the toxin and become resistant to it. Management of these patients (or those not helped by botulinum toxin in the first place) has been exceedingly difficult since medications generally are only moderately effective at best. In selected patients, surgery directed at severing the affected nerves has been very helpful. There is a long history of brain operations (functional neurosurgery) for cervical dystonia but this had been largely given up until the recent application of deep brain stimulation to other forms of dystonia.
Deep brain stimulation is a technique in which electrodes are implanted into a part of the brain called the globus pallidus, and very preliminary data suggests this can help both the movements and the pain in patients with cervical dystonia. Low-voltage stimulation appears to shortcircuit the abnormal signals going from the brain to the neck muscles.