Reversible Parkinsonism caused by Influenza B‐associated encephalitis affecting bilateral basal ganglia: A case report

• Published in: CNS neuroscience & therapeutics Vol. 26; no. 3; pp. 396 - 398
• Main Authors: Zhu, Yue‐Li, Guo, Xiao‐Ming, Qin, Zun‐Bo, Zhou, Zhi‐Jian, Cao, Jin, Wu, Ji‐Min, Pu, Jia‐Li
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.03.2020; John Wiley and Sons Inc
• Subjects: Amantadine; Autoimmune diseases; Autoimmunity; Basal ganglia; Central nervous system diseases; Conflicts of interest; Encephalitis; Gait; HIV; Human immunodeficiency virus; Infections; Influenza; Influenza B; influenza B virus; Intravenous administration; Letter to the Editor; Letters to the Editor; Levodopa; Magnetic resonance imaging; mechanism; Methylprednisolone; Movement disorders; Parkinsonism; Pathogenesis; Patients; Putamen; Viral infections; Viruses; West Nile virus; Parkinsonism; basal ganglia; mechanism; encephalitis; influenza B virus
• ISSN: 1755-5930; 1755-5949
• DOI: 10.1111/cns.13278

Repeated MRI images 3 mo later show lesions with obvious improvement in bilateral caudate head and putamen: (D) hypointensity on T1‐weighted images, (E) hyperintensity on T2‐weighted images, (F) hyperintensity on T2‐weighted fluid‐attenuated inversion recovery sequences The patient was diagnosed with encephalitis of the basal ganglia resulting from influenza B virus, and treated with intravenous methylprednisolone (80 mg/d for 8 days), madopar (each containing 200 mg levodopa and 50 mg benserazide) (62.5 mg TID), and amantadine (0.05 g BID). [...]autoimmunity could be an underlying mechanism, since it has been reported that infectious agents can trigger autoimmune encephalitis. [...]improvement of clinical symptoms will be noted after the discontinuation of cytostatic treatment. Since our patient had a 6‐year history of cytostatic treatment and his symptoms of Parkinsonism improved without withdrawal of the drugs, then this diagnosis was excluded. [...]we report a rare case of reversible Parkinsonism caused by the influenza B virus producing lesions of the basal ganglia, but the mechanism of basal ganglia involvement remains hypothetical.