Tehran University of Medical Sciences Current Journal of Neurology 2717-011X 13 2 2014 06 15 88 93 Masoud Etemadifar Department of Neurology, School of Medicine, Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Farshid Afshar Department of Medical Sciences, School of Medicine, Medical Students' Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Zahra Nasr Department of Medical Sciences, School of Medicine, Medical Students' Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Mohsen Kheradmand Department of Medical Sciences, School of Medicine, Medical Students' Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. 2015 10 14 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. (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 Parki sonism manifestations  in such cases. https://ijnl.tums.ac.ir/index.php/ijnl/article/view/616 https://ijnl.tums.ac.ir/index.php/ijnl/article/download/616/186