MULTIPLE SCLEROSIS

The amazing neuro imitator

Multiple Sclerosis (MS) is an autoimmune disease that demyelinates the CNS. The cause is unknown. MS is special in the field of neurology, because it can cause nearly any pattern of neurological symptoms, making it the great imitator of neurology.

What are the different forms?

Relapsing Remitting is most common. There are acute brief flares, but 10% of the flare symptoms become permanent. Here’s an example -- during a flare your right arm becomes totally numb. After the flare cools down, there is still some lingering paresthesias. Neurological symptoms accumulate over time, eventually making it difficult to function. 

How does it work?

It’s an autoimmune attack against Oligodendrocytes. T cells are able to slip past the blood brain barrier every once in a while, where they will kickstart inflammation and produce a flare up. Most of the oligodendrocytes survive (remitting symptoms), but a handful perish (permanent symptoms)

Symptoms?

The classic patient is a white female in her 20s to 40s. She has neurological symptoms that are temporally and regionally separate. She can have any imaginable CNS deficit. Any. But the deficit will resolve, and then a totally new deficit will pop up later, only to resolve after a while. It’s almost like she’s having lots of strokes in different parts of the brain, but we know that that would be highly unlikely, especially in a 25 year old. Odd symptoms involving vision and proprioception are common. That makes sense, because those are the most myelinated fibers (controlling gaze requires extremely rapid coordination). Some symptoms that tend to get mentioned on question stems are painful blurry vision (caused by optic neuritis or CN 2 lesions), vertigo (CN 8 lesions), scanning speech (motor ataxia), Marcus Gunn pupil (light flashed into affected pupil won’t generate constriction in either eye), internuclear ophthalmoplegia (difficulty coordinating eyes together to look laterally), and neurogenic bladder. Optic neuritis hurts more when you move your eyeball around. Lhermitte’s Sign is an electrical sensation that randomly shocks the spine, especially with neck flexion. Uhthoff’s phenomenon is the worsening of MS when hot (in a hot bath for example). 

Diagnosis?

You can diagnose MS with a contrast MRI. The contrast lights up plaques. Plaques are scars replacing dead Oligodendrocytes. If you get an LP, you’ll find oligoclonal IgG bands (oligo refers to how there are lots of different kinds of antibodies, it just means that it’s not cancerous, as monoclonal bands are from a single cancerous predecessor cell or “clone”), WBCs and myelin protein. In reality, the diagnosis of MS is quite complicated, and somewhat controversial. 

Treatment?

Treatment mostly consists of high dose steroids and other weird drugs like Interferon, Glatiramer and Baclofen (for spasms).