Does a positive EMG rule out MS and point to Neuromuscular disease?

  : Over the last few years I have had many symptoms and as many tests. The symptoms are loss of balance, leg weakness, numbness/tingling in right arm and hand, frequent urination (at least once an hour),fatigue, heat intolerance, memory problems, reduced fine motor function in hand, etc.The tests I have had  include; MRI of the Brain, Cervical Spine and Lumbar spine (all w/o contrast), they were all normal. I've also had Myelogram/CT scan and EMG done twice. The CT revealed mild-moderate osteophytes at c5-6 and c6-7 causing compression of the thecal sac with effacement of the spinal cord. Also, minimal posterior bulging discs at L4-5 and L5-S1 levels. The finding of the EMG was Bilateral Ceervical Radiculopathy at C6,7,8 levels, more pronounced on the right side.
  : Several dr's, including a neurologist and orthopedic surgeon, said that they dont feel that all of my symptoms are coming from these findings.
  : My current neurologist is re-ordering the MRI of the brain this time w/contrast. However, he has stated that if it is still negative I should see a neuromuscular expert. What is your opinion on this? Could a neuromuscular disease be responsible for all of these symtoms (symptoms)?
  : Thanks for you help!
Dear Babet,
Thank you for your question, which is actually two-fold.
In the title of your message, you ask if positive findings on EMG rule out MS and orient the diagnosis towards neuromuscular diseases. It is true that EMG is a test commonly used to diagnose neuromuscular disorders, and that EMG tests are often negative in MS patients. In fact, this is a little bit more complicated. Some patients in whom the diagnosis of MS is certain might have also some co-existing EMG abnormalities, but this does not mean that they cannot have MS. One must consider the "global picture", in order to interprete the results of a test. This leads to your second question.
If I summarize your interrogations, you are wondering which diagnosis is compatible with your symptoms. It is difficult to give very specific answers over the internet, but I can give you pieces of information. Making a neurological diagnosis is a step-by-step process, which requires to take into account many different elements. The evolution of your symptoms over time, and signs oberved by the neurologist during the examination are important elements.
A cervical radiculopathy alone could explain symptoms in your arms only. The symptoms that you describe in your right arm, legs, and bladder could be due to a problem in your cervical spinal cord. Memory problems would orient towards the brain... MS could certainly produce all the symptoms that you describe, but this diagnosis cannot be based only on your symptoms. MRI is currently the best way to diagnose MS in a majority of patients. I think this is a good idea to perform an MRI with Gadolinium (contrast) because this could reveal inflammatory lesions such as the ones seen in MS. A spinal tap, to analyze the cerebrospinal fluid, or evoked potentials, are other tests that can be useful. If you did not have these tests already, you can discuss this with your neurologist.
I hope this helped. Remenber that this information is disclosed only for the purpose of general medical education.