Deep brain stimulation (DBS) is a FDA-approved therapy for some patients with Parkinson’s Disease, essential tremor, and dystonia. The goal of deep brain stimulation is to improve quality of life and improve ability to function.
DBS is a brain stimulation therapy that offers an adjustable, reversible treatment used to manage some of the symptoms of Parkinson’s Disease, essential tremor and dystonia. The therapy uses an implanted medical device, similar to a pacemaker, to deliver electrical stimulation to precisely targeted areas of the brain. Stimulation of these areas enables the brain circuits that control movement to function better. The device is typically implanted near the collarbone. The device will then generate electrical pulses and deliver them through extensions and leads to targeted areas of the brain.
The average patient requires programming 4 to 8 times in the first 6 months following surgery; however, following 6 months post-procedure, adjustments become less frequent.
Dementia and untreated depression are contraindications to deep brain stimulation.
• In Parkinson’s Disease, deep brain stimulation is considered when patients have intolerable wearing-off (the recurrence of parkinsonism from 2 to 4 hours after a dose of levodopa), motor fluctuations (unpredictable motor response to levodopa in patients with chronic Parkinson’s Disease), or dyskinesias (involuntary muscle movements) despite optimal medical management or, medication-refractory tremor. This helps reduce some of the symptoms of Parkinson’s Disease and is used in conjunction with medication.
Not all patients with Parkinson’s Disease are a candidate for this procedure. The best surgical candidates are Parkinson patients who are relatively young, responsive to levodopa, and have predominately tremors or gait disturbance.
DBS is contraindicated in atypical parkinsonian syndrome (eg, progressive supranuclear palsy, multiple system atrophy, dementia with Lewy bodies, corticobasal degeneration, or vascular parkinsonism). These patients typically respond poorly to the DBS.
Additionally, patients with Parkinson’s Disease whose primary goals are to improve speech, breathing, swallowing, postural instability, and freezing are poor candidates for deep brain stimulation. Parkinson patients with mild cognitive impairment, or dementia are also contraindicated.
- Essential Tremoris one of the most commonly encountered movement disorders; it is characterized by an action tremor involving the hands and sometimes the head, chin, or voice. In essential tremor, deep brain stimulation is considered when patients have tremor that is disabling and unresponsive to medical therapies. Unfortunately, only 50% of patients with essential tremor are successfully managed with medication alone.
Although there is no clear contraindication for deep brain stimulation in essential tremor patients, these patients should undergo an adequate medication trial before considering surgery.
• In dystonia, deep brain stimulation is considered in patients with significant disability from their dystonia who have failed medical therapy. Dystonia is a neurological disorder in which muscle contractions cause twisting and repetitive movements or abnormal postures.
There are different forms of dystonia: 1. Primary dystonia – when no identifiable cause or structural abnormality in the central nervous system is found. In many cases it may involve some genetic predisposition. 2. Secondary dystonia refers to dystonia brought on by some identified cause, usually involving brain damage, trauma,certain drugs or as the result of diseases of the nervous system such as Wilson’s disease.
Primary dystonias tend to respond better than secondary dystonias to DBS. Dystonia patients with fixed dystonic postures are not candidates. The FDA approved deep brain stimulation for dystonia under a humanitarian device exemption in 2003.