Unexplained Numbness

[sls334]

Nearly 7 weeks ago, I began having extreme pain in my jaw on the right side.  It was sharp, stabbing, and aching pain.  I had sharp stabbing pains in the top right side of my head, especially when I ate.  This pain continued for weeks, and I sought the help of my dentist 3 times.  X-rays and exams were all normal, and he referred me to my family dr.  I saw my family dr., and he said it was TMJ and I should reduce stress.  Within the next few days, the back right side of my head, my right ear, right jaw, right front and back of my neck, and my right shoulder went numb.  It feels normal until pressed, and then it feels tingly and like pins and needles.  A few days later, my right arm and right leg were numb.  I had difficulty walking, as my right leg felt rigid and clumsy.  I returned to the dr., and he ordered an MRI of the brain.  The next day, my left arm was affected...felt like dead weight, burning and pins and needles sensations, inability to grasp, primarily middle, ring, and pinky fingers.  (I get the same problems with my right arm, too.)  I went to the ER, and they did an MRI of the brain.  It came back normal, and they sent me home.  The numbness and weakness have continued in all areas mentioned, and the neurologist I saw has no answers as to what it may be.  He has ordered an MRI of the spine and said he'd see me in 6 weeks.  In the meantime, I am not functioning very well (walking, grasping, etc).  I have made an appointment with a specialist out of town, but I am looking for more information in the meantime.  Any thoughts?  

Thank you in advance!

[Lama Chahine, MD]

Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.

Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is. However I will try to provide you with some useful information.

Your symptoms are unusual; a normal MRI of the brain does exclude several concerning possibilities. It is difficult to narrow down the possibilities without being able to obtain more information from you, but broadly speaking, 3 possibilities include a problem in the spinal cord itself, a radiculopathy or a neuropathy.

Radiculopathy: The spinal cord is encased by bones called vertebra. Nerves start to form as they come off the spinal cord and exit through holes formed between the vertebra. If a nerve is compressed on as it exits through these holes, particularly in an area called the nerve root, a radiculopathy results. The compression could be due to arthritis of the spine or due to a herniated disc or other lesions. The symptoms include pain at the level of the problem (i.e. neck or back etc) and pain that may radiate down the arm or leg (depending on where the problem is). In more advanced cases, muscle weakness or sensory symptoms such as tingling or numbness may occur. A radiculopathy is often diagnosed based on history, physical examination, and MRI of the spine. A radiculopathy at multiple cervical levels could theoretically affect your head/ear area (if the C2 region of the spine has an abnormality) and your arm if the C5-T1 areas are involved (depending on the exact distribution of your symptoms.

What is unusual in your case is that your symptoms involve both sides of your body, but these can still occur with multi-level bilateral radiculopathy or stenosis of the spinal canal. However, symptoms on both sides of the body occurring over a few days such as in yourself would be concerning for a spinal cord problem; it is good you have an MRI of the spine scheduled. If you begin experiencing urinary incontinence, you need evaluation rapidly.

Finally, and very differently from the above two conditions, your symptoms if your examination does not suggest a spinal cord or spinal column problem and your MRI of your spine is normal, could be due to a neuropathy.

There are 2 types of nerves in our body, large and small. The small nerve endings supply the skin and sweat glands. There are two types of sensory neuropathy: small fiber and large fiber (depending on the size of the nerves affected). With small fiber neuropathies, symptoms including burning or buzzing or other vague symptoms starting in the feet and hands then in some cases spreading to other parts of the body. There are several causes of small fiber neuropathy, including diabetes, vitamin deficiencies, autoimmune problems

The other type of sensory neuropathy is called a large fiber neuropathy. There are several categories of this type of neuropathy, and there are many many causes. Sensory neuropathies can involve just one nerve or several nerves in the body. The symptoms are sensory loss and if motor nerves are involved ,weakness. Some types of sensory neuropathies occur and progress very slowly, others sort of wax and wane (with flare-ups) and some are progressive. One of the most common causes of neuropathy is diabetes, and sometimes only glucose intolerances, or abnormal rises in blood sugar after a glucose load can be the only indication (this is called a oral glucose tolerance test. Other causes include but are not limited to hereditary/genetic causes, autoimmune problems, Vitamin B12 and B6 deficiency, as well as excess vitamin B6, can also cause neuropathy. Some toxins, such as lead, arsenic, and thalium can cause large fiber sensory neuropathy. Other causes include abnormalities of protein metabolism. In many neuropathies, both the sensory and motor nerves (the nerves that supply the muscles) are involved, leading to sensory symptoms as well as weakness.

The diagnosis of large fiber neuropathy is made by findings on a test called EMG/NCS which assess how well the nerve conduct electricity and how well muscles respond. The EMG/nerve conduction studies (NCS) (tests done to check for large fiber neuropathy) will not show an abnormality in small fiber neuropathy, and a definitive diagnosis can only be made with a skin biopsy so that the number of nerve endings can literally be counted. There are other tests of the function of small nerves that can be ordered, such as QSART testing which looks at how much sweat the skin makes, since sweating is in a sense of function of these small nerves. Treatment for neuropathic pain (pain coming from nerves) includes neurontin and lyrica, and medications such as elavil (which is an antidepressant but has actually been found to be helpful with neuropathic pain as well).

I recommend continued evaluation by a neurologist.

Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.