Movement disorders are a collection of conditions characterised by abnormalities of the initiation, regulation or coordination of posture or movement. They have in common dysfunction of the basal ganglia (central deep nuclei) of the brain.
Essential tremor is the most common movement disorder and affects up to 4% of the population. There is often a family history and the tremor, either unilateral or bilateral is worst with posture and action. The tremor tends to worsen with time. Medication is often tried but often ineffective or produces side effects. Neurosurgical treatment with either thalamotomy or deep brain stimulation can be very effective.
Parkinson’s disease is characterised by tremor, slowness of movement, stiffness and gait difficulties. Depletion of dopamine in the basal ganglia leads to abnormal regulation of neural circuits important to motor function. Dopamine is often effective in the initial stages of this progressive disease but with time patients may develop side effects. Neurosurgical procedures including thalamotomy, pallidotomy and deep brain stimulation can be helpful in improving these symptoms for some patients.
Dystonia is a rare condition characterised by abnormal posture secondary to abnormal contraction of opposing muscles for example writers cramp. Medical treatment is often effective however deep brain stimulation may be helpful.