Myoclonus rarely seen in PSP

The most interesting part of this case report is that myoclonus (involuntary jerky movements) is rarely seen in progressive supranuclear palsy (PSP).  The abstract mentions that myoclonus “can be seen as part of later stage Parkinson’s disease and in multiple system atrophy.”  It is also seen in LBD (Lewy body dementia) and CBD (corticobasal degeneration).  Myoclonus is often a part of the differential diagnosis in PSP vs. CBD — since it doesn’t occur in PSP but does occur in CBD.

The case report is about a man with a clinical diagnosis of PSP who develops myoclonus after taking amantadine.  The myoclonus goes away when the medication is removed.

Here are the “key point” of the case report:

* “Myoclonus is a hyperkinetic movement disorder that can be described as a brief shock-like movement.”

* “Myoclonus can be seen in some parkinsonian disorders but is rare in progressive supranuclear palsy (PSP).”

* “Neuropsychiatric medications can precipitate myoclonus, and here we report amantadine-induced myoclonus in a patient with PSP.”

The abstract is copied below.



Age and Ageing. 2012 Mar 15. [Epub ahead of print]

Amantadine-induced myoclonus in a patient with progressive supranuclear palsy.

Yarnall AJ, Burn DJ.
Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK.

Progressive supranuclear palsy (PSP) is a tauopathy that generally results in a hypokinetic disorder. Treatment is largely symptomatic, with some small studies indicating a benefit with dopaminergic therapy. Myoclonus is a hyperkinetic disorder that can be seen as part of later stage Parkinson’s disease and in multiple system atrophy, but is rarely seen in PSP. Here we report a case of myoclonus precipitated by amantadine in a patient with PSP.

PMID:  #22421702  (see for this abstract only)