Thread by @EricLawson90

#Tweetorial! Join me on a saga through history and the fields of #Neurology #Neurosurgery and #Pathology! This was prompted by Neuropathology rounds today with @StewartGNeill

"Foix-Alajouanine Syndrome"

@MedTweetorials #MedEd
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"Gesundheit" was my first thought when @StewartGNeill said "Foix-Alajouanine" but some reading turned up some interesting facts about this eponym..

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Charles Foix was a French internist and neurologist. A student of Pierre Marie (who was an assistant to Jean-Martin Charcot) at Salpêtrière, Foix later taught alongside Georges Guillain.

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Théophile Alajouanine was also a French neurologist who was a student of Joseph Dejerine and worked alongside Foix and Georges Guillain.

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While Foix and Alajouanine were learning from legends in #Neurology they published a report in 1926 "La Myélite nécrotique subaiguë" describing clinical and pathological characteristics of 2 cases progressive myelopathy that later became known as Foix-Alajouanine Syndrome
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What did their cases show?
Both patients had a progressive and fatal myelopathy. Autopsy showed tortuous vessels and pathology showed "endomesovasculitis" with vessel wall thickening.

Important to note that dural arteriovenous fistulas had not yet been discovered...
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Since their original report "Foix-Alajouanine Syndrome" has commonly been associated with intradural venous thrombosis... BUT their original report excludes thrombosis and subsequent studies point to the likelihood of their patients having dural AVFs.
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So what is a dural AVF?

It is the most common spinal vascular malformation that is an abnormal connection between radicular artery and vein in the dura of a nerve root sleeve.
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This abnormal connection results in progressive pain, LE weakness, and sensory symptoms occurring over the course of years due to intramedullary edema and eventual ischemia and infarction.
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MRI will show cord enlargement with multisegmental cord signal changes from edema with prominent intradural extramedullary flow voids on T2 sequences.

Conventional angiogram is typically the next step as it allows for diagnosis and treatment with embolization.
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So why not use Foix-Alajouanine Syndrome to describe what it was originally misinterpreted to be: a progressive spinal cord venous thrombosis?

Well, this isn't what their report described and a spinal cord venous thrombosis does not have the therapeutic options of a sdAVF
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Ok so who else is confused on what exactly Foix-Alajounine Syndrome is then?

You can describe it as a subacute to chronic progressive myelopathy due to intradural arteriovenous malformations (such as dural AVFs) that leads to a congestive myelopathy without hemorrhage.
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Clinically your Foix-Alajounine patients will have an initially spastic paraplegia with subsequent flacid paraplegia, urinary incontinence, and ascending spinal sensory level
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So since this all started with #Neuropathology what does the pathology actually show? a cavitary cord parenchyma (from the edema), old infarctions with micro hemorrhages, thickened hyalinized small vessels (pictured below)
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And small vascular "collagen tubes" within a background of necrotic cord.

Pathology images courtesy of this great case!
path.upmc.edu/cases/case543.…
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So why did I take you on this round about journey to essentially tell you Foix-Alajouanine Syndrome is a misnomer for spinal-dural ateriovenous malformations?

Because on average it takes !!24months!! to diagnose patients with spinal dAVFs!
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For more reading on Foix-Alajouanine Syndrome check out these great articles:

thejns-org.proxy.library.emory.edu/view/journals/…

ncbi.nlm.nih.gov/pmc/articles/P…

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Always welcome corrections if I made mistakes (I am learning too!), and especially welcome additional teaching points, hopefully from many disciplines on this #tweetorial @YoungNIR @NeuroIntervener @RyanBPetersonMD @DiogoHaussen @AlAlBayati1 imaging/treatment of spinal dAVFs
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@StewartGNeill knows the #Pathology. Any comments on recognizing spinal dural AVFs clinically welcome as well @Tracey1milligan @MonicaDhakar @AaronLBerkowitz @Nirav_r_bhatt @DineshJillella @VJeanneretl @SitaraKoneru @MedTweetorials
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