Friday, July 31, 2015

PANDAS presenting as a conversion disorder

In November, 2012, I wrote:  An 11 1/2 yo boy presented with complaints of dizziness, meaning light-headedness and occipital discomfort, associated with marked dysequilibrium. His presentation to several pediatric neurologists, including myself, is that of astasia-abasia. Psychiatry consultation finds him to have features consistent with conversion disorder. The imaging and laboratory studies that one might consider reasonable have been done with negative findings. He did, however have an ASO titer of 431 (0-240) and a streptococcal antibody titer of 798 (less than 376). Throat streptococcal culture was negative.
So, is this PANDAS or PANS or whatever the nom du jour might be?  If streptococcus or mycoplasma or whatever can cause OCD, why not conversion disorder?  Maybe a unifying hypothesis for the girls of Leroy would be that they had an autoimmune disorder which, in turn, caused conversion disorder?
A colleague replied:   Regarding the case of boy with conversion disorders and elevated ASO and some other streptococcal titer (was that anti-DNAase B?). Those titers imply NOTHING about etiology. All they mean is that the boy has likely had a strep infection in the past several weeks or months. Ed Kaplan did a study years ago showing that the average 3rd grader has 3 strep infection per year - most asymptomatic. Thus, the elevated titers are not surprising given his age. While I can't say it's impossible that immune / inflammatory mechanisms are involved in conversion disorder, I think it is unlikely. The Leroy girls had a "mass psychogenic illness" and have mostly recovered. In that situation, it is incredibly unlikely that 15 girls from the same high school all developed an autoimmune disorder within weeks of each other with identical symptoms.
Colleague 2 came to my aid:  I assume that Galen's comments were "tongue in cheek" and not serious since an elevated ASO is common in the pediatric population.

Colleague 3 wrote:   Why not, indeed? Like a lot of other people, I wrestle with the whole PANDAS business. But functional imaging studies can demonstrate transient abnormalities even with typical conversion. Ultimately, all normal and abnormal neurological function is brain-mediated, including conversion.

I replied to Colleague 3:  Indeed, I would suggest that the link between streptococcal titers and cultures and conversion disorder may be no less or more than that thus far established for tics and OCD. If I could come to believe the latter, then the former might be plausible, as well. It would seem a little oxymoronic, would it not, to have an identified "organic" cause for a conversion disorder? 

I replied to Colleague 1:  Where is your sense of humor?  Yes, it was anti-DNAase B.  As an antiPANDAS person, my point was that if you want to blame the standard tics and OCD on streptococcal cultures and serology, which I do not, then why not by the same criteria assert that streptococcal infection is in some way causing conversion disorder.
Colleague 1 replied to me:  My sense of humor about "PANDAS" is seriously lacking. I see at least one patient a month referred from someone who has diagnosed "PANDAS" based on a single elevated ASO titer, treated the child with 21 days of some antibiotic (usually an expensive alternative to Pen VK) and doesn't know what more to do.  3 or 4 times a year the diagnosis has been made by a child neurologist.
I replied to Colleague 1, in turn:  I was attempting a reductio ad absurdum using the type of reasoning you describe.
My comment to Colleague 2:  As you indicate, the 11/23 submission, "PANDAS manifesting as conversion disorder", was made with my tongue firmly inserted into my cheek. 
A further comment:  I would want to emphasize, though, that this is a real patient with real laboratory data where there was a request for consultation "to rule out PANDAS".

See: Maybe one day I'll see one June 10, 2015

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