The surgical treatment of choice for movement disorders

Movement disorder is a group of neurodegenerative diseases that primarily affects the motor and movement processes. The most common disorders include Parkinson’s disease (PD), Essential tremor (ET) and Dystonia.

Medications can be effective in the early treatment of these movement disorders. However, with the progression of disease, medications alone become ineffective. In PD, long-term management is often complicated with development of motor fluctuation and dyskinesia (involuntary dance like movement). In theses patient dyskinesias can be even more disabling then PD symptoms. Approximately 50 % of these patients will develop motor fluctuation and dyskinesia after 5 years of treatment with medication. Furthermore, only 50 % of tremor may respond to medication.
Surgical treatment for PD and ET has been around since the 1950’s. Early surgical intervention involved ablation of specific basal ganglia nuclei. However, lesioning became less effective with progression of the disease and bilateral lesions were often associated with severe complication involving speech, balance and walking. With further research, it was found that stimulation of these nuclei simulates the effects of a lesion without permanent destruction of tissue. In addition, the process is reversible and more importantly the stimulation is adjustable as the disease progresses. Therefore, Deep Brain Stimulation (DBS) has become the surgical treatment of choice for movement disorders.

DBS surgery is preformed in several stages using either the Frame or Frameless approach. The frameless approach uses infrared optics to achieve submillimeter accuracy needed in placement of the leads. The small stereotaxic frameless frame mounts on the skull over a small burr hole opening. This allows patients complete freedom to move their head and body on the operating table and thereby making it a comfortable experience. The DBS electrode is stereotaxically placed into the target nuclei. The patients are awake during this part of the surgery and intraoperative testing is preformed with stimulation of the electrode to ensure excellent response without any adverse side effects. The final stage of the procedure involves connection of the electrode leads to the implantable pulse generator (IPG), which is placed under the skin of the chest or abdomen. The IPG can be programmed to deliver electric stimulation to achieve desired results.

DBS is certainly not a cure for these neurodegenerative disorders by any means. However, it certainly gives us an incredible tool to modulate neuronal activity and thereby preserving function and quality of life for many of these patients with disabling symptoms.



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