I ran across an interesting medical journal article today that provides a guide for neurologists on how to diagnose three atypical parkinsonism disorders — PSP (progressive supranuclear palsy), CBD (corticobasal degeneration), and MSA (multiple system atrophy.
The full article is available online for a fee. See:
“Atypical Parkinsonism: Diagnosis and Treatment”
Maria Stamelou, MD, PhD and Kailash P. Bhatia, FRCP
Neurologic Clinics 33 (2015) 39-56
Here’s a short overview of MSA from the article:
“MSA is a neurodegenerative disorder characterized by autonomic failure and parkinsonism and/or cerebellar signs. MSA-parkinsonism (MSA-P) is characterized predominantly by parkinsonism and autonomic failure at presentation, whereas in MSA-cerebellar type (MSA-C), cerebellar signs occur with autonomic failure. However, during disease progression, cerebellar signs often develop in patients with MSA-P and parkinsonism in MSA-C. The prevalence is about 4 per 100,000. Typical age at onset is 53 to 55 and onset before age 30 has never been reported. Men and women are equally affected, and mean survival time is 9 years from symptom onset.”
The authors ask the question – why is it so hard to diagnose these atypical parkinsonian disorders accurately during life? Their answers:
“[The] early differential diagnosis is complicated by patients with pathologically proven PSP, CBD, or MSA that may present clinically with phenotypes other than the classic ones. Conversely, patients with the classic AP [atypical parkinsonism] phenotypes may turn out to have other pathologic abnormalities.”
So, basically, it’s really hard to tell all of these disorders apart.
The authors ask: “if it’s not PSP, CBD, or MSA, what could it be?” One disorder it could be is Parkinson’s Disease (PD). What else could it be if it’s not PD? Very commonly, it’s one of the other atypical parkinsonian disorders — PSP, CBD, MSA, and DLB (Dementia with Lewy Bodies).
What else could it be if it’s not one of the other atypical parkinsonism disorders? For MSA, it’s vascular parkinsonism or primary progressive MS (multiple sclerosis).
I recommend shelling out some money on this article.