I found out ...somewhere (I forget), that it is Rare Disease Day. Of course, as someone who has a few rare diseases, I cannot let that pass, although my head is full of other stuff at the moment.
So the rare disease I want to discuss is Syringomyelia (SM). I bet you weren't expecting that, were you? You were expecting Ehlers Danlos Syndrome, or intractable seizures. Or maybe the plight of the undiagnosed, which is something to which I could devote a month's worth of blogging. Is there an Undiagnosed Day (year)? There should be.
Yes, Syringomyelia: WTF is it, anyway? Well, inside the spinal cord there is a central canal, a little space through which flows Cerebro-Spinal Fluid (CSF). With Syringomyelia, this canal becomes enlarged in one or more locations, creating a cavity called a syrinx, which in turn will push the nervy parts of the spinal cord (technical term) outward, pressing them against the bone and causing major problems for the sufferer -and yes, "sufferer" is the correct term here, because the primary symptom is usually mind-boggling, intractable neuropathic pain.
We are very familiar with what happens in the spinal cord is severed crossways, the person essentially loses sensation and motor control from that point downward. But Syringomyelia(SM) is not like that. In SM, rather than think of the spinal cord as severed, think of it as being slowly ripped apart lengthways. So the nerves are still intact (but very unhappy) and capable of conducting; however the signals can get mightily messed up.
As I mentioned, the main symptom is usually pain. It is not the only symptom: Tremors, spasms, spasticity, numbness/loss of sensation (although still able to feel the PAIN), paralysis, the "MS Hug" , incontinence, and brain fog are all symptoms.
SM is usually progressive, and the cure is ...tricky (will get to that in a bit)
The primary cause of SM is a blockage in the flow of CSF. Most blockages -like 80%, are caused by an Arnold-Chiari Malformation (Chiari, ACM or CM), which is why there are so many Chiari links off this page. Other causes are spinal cysts, tumors, tethered spinal cord, MS lesions and cranial instability or settling due to EDS or other conditions. About 1% of cases are idiopathic, in that a blockage cannot be found.
Here we see a pretty significant Chiari Malformation, which has blocked the CSF flow, and made a sizable syrinx. (the blackish void in the center of the cord, to the right of the vertebral discs). You can see the syrinx has taken up a lot of the available space, which is a huge red flag. This person is probably (but not necessarily) a mess.
I have idiopathic Syringomyelia, which is a 1 in 1.8 million occurrence in the general population (how happy am I?). I think mine, which does not cause me many problems (now) and appears to be slowly self-resolving was caused by a B12 deficiency, but a link between B12 and SM has not been studied.
The treatment for Syringomyelia is surgery. The first course of action is to find the source of the blockage and correct it. In theory, once correct CSF flow is restored, the syrinx will self-resolve. Unfortunately, nerves which have been damaged are unlikely to repair themselves.
In cases where the cause cannot be found, the treatment is pain management (HA!) until the patient is in a wheelchair or at risk of death. Then the surgical team will perform a procedure to place a shunt into the syrinx in an attempt to drain it. The reason they wait so long is that shunt placement requires a surgeon to cut into the spinal cord, thus risking permanent paralysis. Also shunts are tricks and get blocked a lot, requiring additional procedures. Of course, because they usually wait so long to place the shunt in the first place, the nerve damage is usually permanent anyway, so one may question the logic of this approach (and I do).
Like many rare diseases, Syringomyelia and related conditions (ACM and EDS) are quite misunderstood in the medical community and the population at large.
The Big Syringomyelia Myth: A small syrinx does not cause symptoms.
This is not true, unlike the male sex organ, in which size DOES matter (-to me anyway), the size of a syrinx does NOT matter. Small Syringes (note correct plural) can cause humongous symptoms, and humongous ones can sometimes be totally asymptomatic. No-one is totally sure why this is, but there are two theories: firstly that width, rather than length is the most important measurement (and any men with short, fat willies who happen to be reading this right now are doubtless nodding their heads vigorously in favor of this theory). The other theory is that there are probably other factors at play that cause symptoms, such as the underlying blockage and overall CSF pressure (and the men stop nodding).
The other Big Myth, which is related to size and is also applied to diagnosis of Chiari Malformation as well as to other disorders, are those Damn Rules which use absolute measurements as opposed to relative ones. The most widely spread myths are as follows:
- Regardless of symptoms, a tonsillar herniation of <5mm is not a Chiari Malformation
- A syrinx that is short (spans only one or two vertebrae) and/or less than 3-4mm in diameter does not cause symptoms
Here is the problem with those myths -OK let's call a spade a spade- Damn Rules. First off, as mentioned already, the argument that size does not matter if pain and other symptoms are present. Clearly, it matters.
Secondly, people come in all shapes and sizes. Therefore, absolute measurements taken in isolation make NO SENSE. You cannot apply the same rules of measurement to a 20 lb infant that are applied to a six-foot, 200lb man (but they do!). Plus -especially with these conditions, there are often other skeletal abnormalities. Many people with EDS, who have a much higher incidence of Chiari and SM than the general population have abnormally long and thin necks. So the tolerances are tighter in there to begin with. The Chiari Institute in New York does syrinx measurement in a sensible way: Rather than use absolute measurements, they us a percentage of available space; if >50% of available space is taken up or if other criteria are met (rapidly growing syrinx, serious symptoms, good insurance (Sorry. That slipped out. TCI are not my favorite people in the world)) they will do in and operate.
With Syringomyelia as with most rare conditions and diseases, there are very few true specialists in the world, and a LOT more research is needed to find causes, treatments and a cure.
For more information on SM visit this site.