Follow up for "Peripheral Neuropathy and Amyloidosis" posted on 10/26/98

[Clara__0]

  I had an EMG done today, and I am just a little frustrated. When the neurologist came in to put the needle into the muscle he did not do this to anything but my left leg and my right leg is the one that I have had more numbness in. He said the EMG was negative and that I do not have peripheral neuropathy. When I mentioned to him about the ultrasound of the abdomen and the calcifications noted in the spleen he said it wasn't important. This is not the doctor that I originally went to see. I am supposed to hear from him after he gets the report. If this is not a peripheral neuropathy then why do my feet and hands burn, why do I have numbness and tingling and sharp stabbing pains in my feet and my hands. This is not in my imagination. This wakes me up at night. It is very uncomfortable and sometimes very painful. Are there any answers out there that neurologists agree on? I appreciate the time that you take to answer these questions. Thank you.

[CCF Neuro MD MJD]

I'm not sure if you've posted previously - has a diagnoses of amyloid been established by biopsy in your case?  If so, then here are some answers - First, amyloidosis can cause neuropathy involving the symptoms that you describe - it affects sensation far more than motor strength in the limbs. It tends to affect the smallest nerve fibers. EMG evaluates the larger, heavily coated fibers, and so, though it is generally very good in diagnosing neuropathy, it can miss abnormalities in disorders that affect the smaller fibers in the hands and feet.  Another test which is done at larger centers (Medicare and many insurance companies don't pay for it) is Quantitative Sensory Testing which can be more sensitive (though at times nonspecific) for small-fiber neuropathy.  Although it may help in your diagnosis, if the symptoms are suggestive enough, many neurologists will treat your pain as if you have a neuropathy even if specific diagnosis is difficult.  There are many medications out there which can treat the burning pain of neuropathy. Still, a specific diagnosis of amyloid neuropathy is important and ultimately, a nerve biopsy of a sensory nerve in the foot may be necessary for diagnosis.  Ask your doctor about the possibility of your amyloidosis causing a small fiber neuropathy.  Finally, regarding your question regarding the EMG of one leg - since neuropathies commonly affect both feet symmetrically, it is common practice to only test one leg and spare the person the unnecessary pain and expense of another leg tested; generally, the more affected leg would be the one chosen.