Globus pallidus internus deep brain stimulation for dystonia

Scenario

A 14-year-old female is referred to discuss deep brain stimulation surgery for idiopathic generalized dystonia. She is of Ashkenazi Jewish descent and presented in early childhood with dystonic movements of one leg, which later generalized. Multiple oral medications as well as botox injections were tried with limited relief over a period of several years and with different physicians. Genetic analysis revealed the Dopa-responsive dystonia (DYT)-1 mutation.

• Variation : Non-DYT1 dystonia and differential diagnosis -- A series of other genetic mutations, often labeled by numeric DYT designations 1–21 (though other nomenclatures exist), have been identified, and successful use of deep brain stimulation (DBS) for dystonias of differing etiologies has been reported in dystonias of varying genetic origin. DYT5 , which presents with gait difficulty, is remarkably responsive to oral levodopa and should be ruled out prior to surgery as it often does well with medications alone.

• Variation : Secondary dystonias -- While DBS is effective in most cases of idiopathic primary dystonia, it has been used in secondary dystonias of a variety of etiologies, including cerebral palsy as well as tardive dystonia, and can be considered in cases of secondary dystonia in patients refractory to medical therapy, although with the caveat that the results are less predictable than those for primary generalized dystonia.