Ahlskog, J. Eric

Background Parkinsonism following hypoxic ischemic damage of the basal ganglia is an uncommon phenomenon that has been infrequently reported. However, only a few cases have noted improvement of symptoms with dopaminergic therapy. We report the clinical and imaging features of five patients with post-anoxic parkinsonism responsive to dopamine supplementation. Objective To describe a retrospective case series of five cases of dopamine-responsive post-anoxic parkinsonism. Methods We identified all the cases using the Mayo Clinic Data Management System utilizing advanced data explorer search engine for any patients evaluated for post anoxic parkinsonism and its associated acronyms from 2000–2024. Clinical features, neuroimaging, medication trials, and responses were obtained from chart review of identified patients. Results Five patients met the inclusion criteria. All patients underwent anoxic events followed by development of parkinsonism. Patients exhibited parkinsonism described as combinations of bradykinesia, rigidity, tremor, and postural instability. All patients underwent evaluation by a neurologist, MRI imaging, and treatment by dopaminergic agents. Of the five patients, four received carbidopa/levodopa whereas one received a dopamine agonist. All patients were clinically followed for a median of approximately 4 years and showed improvement in parkinsonism. Conclusions Parkinsonism following a hypoxic ischemic insult is a rare occurrence but response to dopaminergic therapy in those cases is even more scarcely described. Our cases series provides important implications for treatment options for patients with post anoxic parkinsonism.