Parkinsonism secondary to neurosyphilis

✍ Scribed by Jonathan Carr

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 85 KB
• Volume: 24
• Category: Article
• ISSN: 0885-3185
• DOI: 10.1002/mds.22615

✦ Synopsis

I read with interest the letter concerning Parkinsonism related to neurosyphilis by Spitz et al. 1 However, their proposal that neurosyphilis may cause Parkinsonism, is, at best, contentious, and is more likely to represent a spurious association.

The usual approach required to establish causation in such a case would be to apply Koch's postulates to assess the relationship, if any, between a disease and an infectious organism, but none of these postulates was met. Alternatively, one can examine pre-existing evidence for such a relationship. Despite the authors' statement that in the past neurosyphilis was a relatively common infectious cause of Parkinsonism, there are probably less than five case reports published in the last century. 2 Similarly, major textbooks published during the pre-antibiotic era do not refer to such an entity, and, indeed, actively dispute it. 3,4 Encephalitic illnesses resulting in Parkinsonism are well known, and it would not be surprising for there to be some evidence of basal ganglia dysfunction in a patient with tertiary neurosyphilis affecting the brain. However, the fact that this patient was significantly levodopa responsive would be highly atypical for an encephalitic illness in general and for neurosyphilis in particular. It seems entirely reasonable to propose that Parkinson's disease would be worsened by an acute encephalitis, such as parenchymal neurosyphilis. It would be useful in future if case reports of this nature be accompanied by imaging of the dopaminergic systems, to assess whether the striatum or nigrostriatal pathways are involved.