Autoimmune atypical parkinsonism - A group of treatable parkinsonism

Background: Immunological causes of atypical parkinsonism/Parkinson plus syndromes are rare. Objective: To study the clinical and laboratory features and treatment outcome of autoimmune atypical parkinsonism. Methods: Retrospective case series. Patients with atypical parkinsonism and positive antibodies were identified retrospectively. Those who received immunotherapy (intravenous methyl prednisolone 1 g daily for five days followed by mycophenylate mofetil 2 g daily or azathioprine 2-3 mg/kg/day) and consented for publication of non-anonymized videos were included. Results: There were ten cases (nine males, age range 49-75 years, disease duration 2 months to 13 years, followup 1-7 months) of atypical parkinsonism [probable multiple system atrophy (MSA)-2, possible progressive supranuclear palsy (PSP)-1, probable PSP-3]. Eight had new uncharacterized neuronal antibodies, leucine rich glioma associated protein 1 (LGI1) antibody in one, and the other had another uncharacterized neuronal antibody along with LGI1 antibody. Four had abnormal CSF. There was a prompt, dramatic improvement in terms of Unified Parkinson Disease Rating Scale motor scale and or modified Rankin Scale as well as improvement in eye movement, postural instability, cerebellar, autonomic and non-motor symptoms. Two had reappearance of symptoms on discontinuing steroids and improvement on restarting. One died of infection despite good recovery of encephalopathy and parkinsonism. Conclusion: Autoimmune atypical parkinsonism is characterized by atypical parkinsonism with neuronal specific antibodies, sometimes associated with abnormal CSF and significant response to immunotherapy. (C) 2016 Elsevier B.V. All rights reserved.