Bradykinesia and dystonia

Background: Bradykinesia has been reported in patients with dystonia. Despite this, the pathophysiological mechanisms of bradykinesia in dystonia remain largely unknown. Methods: We here performed a comprehensive literature search and reviewed clinical and experimental studies on bradykinesia in patients with dystonia. Results: Many studies have documented the presence of bradykinesia in patients with idiopathic and inherited isolated dystonia, regardless of the presence of parkinsonism. In addition, bradykinesia has been observed as a side effect in dystonic patients who have undergone deep brain stimulation, in those with functional dystonia as well as in those with combined dystonia, e.g., dystonia-parkinsonism. These clinical and experimental findings support the hypothesis that dysfunction in a brain network involving the basal ganglia, primary sensorimotor cortex, and cerebellum may play a key role in the pathophysiology of both bradykinesia and dystonia. Conclusion: Bradykinesia is frequently observed in dystonia. We may gain insights into the pathophysiological underpinnings of two distinct movement disorders by investigating this issue. Furthermore, a deeper understanding of bradykinesia in dystonia may have terminological implications in this field.