Movement disorders secondary to craniocerebral trauma.

Over the past few decades it has been recognized that traumatic brain injury may result in various movement disorders. In survivors of severe head injury, post-traumatic movement disorders were reported in about 20%, and they persisted in about 10% of patients. The most frequent persisting movement disorder in this population is kinetic cerebellar outflow tremor in about 9%, followed by dystonia in about 4%. While tremor is associated most frequently with cerebellar or mesencephalic lesions, patients with dystonia frequently have basal ganglia or thalamic lesions. Moderate or mild traumatic brain injury only rarely causes persistent post-traumatic movement disorders. It appears that the frequency of post-traumatic movement disorders overall has been declining which most likely is secondary to improved treatment of brain injury. In patients with disabling post-traumatic movement disorders which are refractory to medical treatment, stereotactic neurosurgery can provide long-lasting benefit. While in the past the primary option for severe kinetic tremor was thalamotomy and for dystonia thalamotomy or pallidotomy, today deep brain stimulation has become the preferred treatment. Parkinsonism is a rare consequence of single head injury, but repeated head injury such as seen in boxing can result in chronic encephalopathy with parkinsonian features. While there is still controversy whether or not head injury is a risk factor for the development of Parkinson's disease, recent studies indicate that genetic susceptibility might be relevant.