Last week I saw a patient who was complaining of numbness and weakness in her left leg. She also had a rash. She said, "I got a rash 2 weeks ago, and thats when my leg got weak and I started falling." I thought that was interesting. A rash associated with numbness and weakness? On futher evaluation, I discovered that she had numbness and decreased sensation where the rash was, and that was in a dermatomal pattern. Furthermore, her weakness was in a myotomal pattern of the same level. VEEEEERY Interesting I thought.
WHAT the heck is she saying, you wonder??? Ok, in English, I had a petient who had a rash and numbness in the same area on her leg. That area correlated to a pattern known ad a dermatome. A dermatome is an area of the skin supplied by nerve fibers originating froma certain level of the spinal cord. The dermatomes are named according to the spinal nerve which supplies them. C4, C5, L1, L2 etc. There is an area of skin for every level of your spinal cord. My patient had her rash and her numbness in a specific area defined by a dermatome. She also had weakness in her leg associated with a myotome. A myotome is the muscle or muscles who get their nerve supplies from a particular level in the spinal cord. This patient had muscle weakness associated with the same area of the skin as the rash and the numbness. L3. The third lumbar nerve. As shown by the inner knee/thish area. And Weakness in straightening the knee and lifting the leg.
I was curious. I was stumped. I had heard vaguely of neurological illnesses with a dermatological presentation. But I wasn't sure about them. So I had my student look it up overnight and I looked it up also. I couldn't find anything in my class notes or books, so I did multiple Google and medical searches on the subject. Finally I found it. YA for GOOGLE!!! It was SO simple!!! Shingles. Yup! She had the Chicken Pox! Again.
It threw me off at first because shingles isn't usually associated with numbness and weakness. AND it usually happens on the chest and back, AND it's usually pretty painful! But for the location of her rash pain isn't common, and weakness is.
According to the research I read, (YAY FOR GOOGLE for giving me a TON!) the virus stays in the roots of your spinal cord after chicken pox. And it lays dormant. And any decrease in your immune status can bring it out. Usually happens in the elderly and immunocomprimised. (My patient was in her 80's) And you get a recurrance. But only in the level of the root in which it is laying. USUALLY (95%) that's in the thoracic area, giving the rash in the chest and back with significant pain. But sometimes (5%) it can happen in the cervical (referring to the neck/arm areas) or Lumbar (leg areas) regions of the spinal cord. And when it does, it is often associated not with pain, but with sensory loss and motor weakness.
TA DUM!!! I had figured out the problem. I felt so smart. :) The next day I asked one of the neurologists about the symptoms and he automatically said shingles. TEE HEE!! I was right! I felt all happy that I was able to find the answer. Granted I had to go looking for awhile, but I found it and that was perty rewarding.
So now you know. A rash with numbness and weakness is Chicken pox. And Google kicks bootie for information. When in doubt, search Google.
And then you can feel smart for knowing all that information and figuring out what's wrong with people. :)