I’ve been neglecting psp-blog.org for the past two weeks in favor of a project to help general neurologists diagnose PSP and other atypical Parkinsonian disorders (APDs) without having to refer to a movement disorders specialist.  I can hear you saying, “Great idea, but why now?”  Here’s how this started:

I’ve told you about CurePSP’s Centers of Care network.  That’s a group of (now) 32 medical school-based movement disorder centers with a special interest and expertise in PSP, CBD and in many cases, MSA as well.  The network’s mission is to improve the quality and availability of care for these disorders.  One of the problems standing in our way is the long wait for an initial appointment with a movement disorders specialist.  A survey among our own 32 centers showed an average wait of about 4 months.  For rapidly progressive disorders, that’s too long.

One partial solution we discussed is to educate general neurologists to make a confident diagnosis themselves and to institute appropriate management.  Then, the referral to a movement disorders specialist could be simply confirmatory.  Of course, making a diagnosis of any disease means looking for evidence against the competing diagnostic possibilities.  In the case of PSP, the main alternatives (a list called the “differential diagnosis”) are Parkinson’s disease, corticobasal degeneration, multiple system atrophy, and dementia with Lewy bodies. 

Then there’s a long list of less likely disorders that can resemble PSP, at least in some ways, at least in some cases, at least in the early stages.  They can be degenerative like PSP and the other four, but also genetic, infectious, autoimmune, nutritional, vascular, toxic, endocrine, psychiatric, neoplastic (directly related to tumors), and paraneoplastic (indirectly related to tumors).  The list includes 24 disorders that, like PSP, are treatable only at a symptomatic level but also, crucially, 31 with specific treatment to slow, halt or reverse progression of the disease.  All of those 55 are pretty rare as causes of a PSP-like picture, but the 31 with specific treatment must not be overlooked. 

We devised a decision algorithm to help the general neurologist navigate this daunting menu of options.  I can’t “publish” the list here just yet, as we want to submit it, along with an explanatory text, to a good, selective journal, and journals don’t like to accept previously published material.  Besides, we should show it to a few experts from outside of our 13-member writing committee, and of course, the peer review process at the journal could result in major changes.  Plus, the raw list of 55 disorders wouldn’t be that useful without the decision algorithm and the sub-lists of diagnostic features and recommended tests.  I’ll pass it along to you when I can in the next couple of months, but in the meantime, my blog post from March of this year on “PSP mimics” covers 30 of the 55 in a useful degree of detail.