[Neurosurgical management of dystonias]

Dystonia is not a rare condition and there are more than 10 patients per 100,000 general population. In recent years various neurosurgical interventions have been proven to be effective for various types of dystonias. For example, generalized dystonia involving whole the body and resulting in bed-ridden state can be dramatically improved with stereotactic chronic deep brain stimulation of the globus pallidum interna. Cervical dystonia is the most common among dystonias and exhibits symptoms of spasmodic torticollis. The first treatment of choice is local injection of botulinum toxin. But if the symptoms are refractory to the conservative treatment, selective peripheral denervation of the involved muscles is a well-established safe and effective surgical method. Task-specific focal hand dystonia, often called as writer's cramp, is no longer a psychogenic condition. Ventrooralis thalamotomy interrupting the oscillatory hyperactive cortico-pallido-thalamic circuit results in excellent relief of the symptom. of writer's cramp. Thus, in the modern era of functional neurosurgery, we neurosurgeons should regard most dystonias as a definite neurosurgical condition. In this review, we describe the current state of neurosurgical treatment for dystonias.