Multiple system atrophy (MSA) is a rare, fatal, neurodegenerative disease of the adulthood presenting with progressive autonomic failure, parkinsonian, cerebellar and pyramidal features in various combinations.
Distinguishing the Parkinson-variant of MSA (MSA-P) from Parkinson’s disease (PD) is often difficult due to overlapping clinical features. This is a major drawback for counselling of patients and timely enrollment into disease-modifying clinical trials.
However, some clinical features, which belong to advanced stages of PD, develop much earlier in MSA and may support an early differential diagnosis. One recent study showed that the presence within the first 2 years of disease of 2 or more features out of:
1. postural instability
2. orthostatic hypotension
3. symptoms of overactive bladder (urinary urge or incontinence)
4. urinary retention (urine post-void residual volume >100 mL)
yields a good diagnostic accuracy for early MSA-P. This simple 4-points score represents a bedside, cost- and time-effective tool for screening parkinsonian patients with low or absent MSA-risk (0-1 point), from those with high MSA-risk (2-4 points), who may benefit from referral to specialized movement disorder centers and, ultimately, recruitment in ongoing neuroprotective studies.
By contrast, neither OH nor symptoms of overactive bladder distinguish MSA-P from PD at moderately advanced stages, because they are frequent and oftentimes severe in both conditions. Only urinary retention remains highly distinctive of MSA-P throughout its course. Urine post-void residual volume should be therefore always measured, if MSA is suspected.
A panel of experts recently reviewed the current diagnostic criteria for MSA and pinpointed several aspects possibly associated with their suboptimal diagnostic accuracy. These are being addressed in the ongoing revision of MSA diagnostic criteria lead by G. K. Wenning and H. Kaufmann under the auspices of the International Parkinson and Movement Disorder Society.
The new criteria will ideally allow an earlier and more accurate diagnosis of MSA based on the recent advances in neuroimaging and biomarker research.
3-5 key points:
- Postural instability and multidomain autonomic failure within the first 2 years of disease distinguish MSA-P from PD.
- At moderately advanced disease stages, the only MSA-specific autonomic feature is urinary retention.
- A revision of MSA diagnostic criteria is ongoing.
References:
Stankovic I, Quinn N, Vignatelli L, Antonini A, Berg D, Coon E, Cortelli P, Fanciulli A, Ferreira JJ, Freeman R, Halliday G, Höglinger GU, Iodice V, Kaufmann H, Klockgether T, Kostic V, Krismer F, Lang A, Levin J, Low P, Mathias C, Meissner WG, Kaufmann LN, Palma JA, Panicker JN, Pellecchia MT, Sakakibara R, Schmahmann J, Scholz SW, Singer W, Stamelou M, Tolosa E, Tsuji S, Seppi K, Poewe W, Wenning GK; Movement Disorder Society Multiple System Atrophy Study Group. A critique of the second consensus criteria for multiple system atrophy. Mov Disord. 2019 Jul;34(7):975-984. https://www.ncbi.nlm.nih.gov/pubmed/31034671
Fanciulli A, Goebel G, Lazzeri G, Scherfler C, Gizewski ER, Granata R, Kiss G, Strano S, Colosimo C, Pontieri FE, Kaufmann H, Seppi K, Poewe W, Wenning GK. Early distinction of Parkinson-variant multiple system atrophy from Parkinson's disease. Mov Disord. 2019 Mar;34(3):440-441. https://www.ncbi.nlm.nih.gov/pubmed/30788854
Fanciulli A, Goebel G, Lazzeri G, Granata R, Kiss G, Strano S, Colosimo C, Pontieri FE, Kaufmann H, Seppi K, Poewe W, Wenning GK. Urinary retention discriminates multiple system atrophy from Parkinson's disease. Mov Disord. 2019 Nov 11. doi: 10.1002/mds.27917. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31710392