MSA-P
The Parkinsonian type of multiple system atrophy, previously known as striatonigral degeneration, is a neurodegenerative disease, and one of the manifestations of multiple systemic atrophy (MSA).
Terminology
It is important to note that the current belief that olivopontocerebellar degeneration, Shy-Drager syndrome, and striatonigral degeneration are different manifestations of the same underlying disease, namely multiple systemic atrophy (MSA), is recent, and as such many older publications will describe these as separate entities .
For a discussion of epidemiology and pathology, please refer to multiple systemic atrophy (MSA).
Clinical presentation
Striatonigral degeneration presents predominantly with parkinsonism with mild cerebellar and pyramidal and signs. As such it is classified within the MSA-P subtype of MSA.
Unlike Shy-Drager syndrome and olivopontocerebellar degeneration (OPCD) (the other two manifestations of MSA), autonomic dysfunction and ataxia and bulbar symptoms are less prominent.
Radiographic features
MRI
Putaminal findings in MSA-P :
- reduced volume
- reduced GRE and T2 signal relative to globus pallidus
- reduced GRE and T2 signal relative to the red nucleus
- putaminal rim sign: abnormal high T2 linear rim surrounding the putamen is seen at 1.5 T
- importantly this is a normal finding at 3 T and thus should not be relied upon at a higher field strength