Parkinsonism associated with multiple sclerosis: A report of eight new cases and a review on the literature

Background: Multiple sclerosis (MS) is an autoimmune inflammatory disease that affects the central nervous system. Except tremor, other movement disorders such as Parkinsonism are less frequent in MS. However, some investigations have shown inflammatory and autoimmune aspects of Parkinson's disease. In this study, we report eight new cases of MS who present Parkinson's disease. Methods: This retrospective population-based study was carried out on Isfahan MS society between April 2003 and July 2012. A total of 3792 patients with MS were surveyed for Parkinson's disease. Parkinson's disease was approved according to "UK Parkinson disease Brain Bank" criteria. Eligible cases were invited to have an interview with a neurologist. MRI was carried out according to the baseline. Results: We identified eight patients (three men and five women) who present MS and Parkinson's disease. The mean (+/- SD) age of onset was 33.3 +/- 6.5 (range: 24-42) years for MS and 39.5 +/- 8.6 (range: 30-55) years for Parkinson's disease patients. In all patients, MS was preceded Parkinson's disease. Parkinson's disease was developed within mean duration of 6.1 +/- 3.4 (range 2-13) years after MS. Focal lesions was shown in six cases, lesions of basal ganglia (BG) in four, lesions of the thalamus in two and lesions of mid-brain in five of cases. In four cases, Parkinsonism occurred before age 40 that is considered as Young-Onset Parkinson's disease. Conclusion: We reported eight patients with MS and Parkinson's disease. To the best of our knowledge, 34 cases of Parkinsonism associating with MS are reported so far. Parkinsonism is a movement disorder, defines as deep gray matter disorder which lead to dopamine deficiency in BG. Investigations have shown that MS could affect deep gray matter structures. Demyelinated lesions in MS and consequence axonal loss in BG and/or nigrostriatal pathway may be responsible for Parkinsonism manifestations in such cases.