Sensory problems and MRI

[Tim__0]

Posted by Tim on July 01, 1999 at 09:58:50
In Jan. '99 I began experiencing transient paraesthesia in both legs.  GP ordered an MRI of lower spine which showed slight bulge in L5 disk.  So, he attributed my sensations to this bulge and said it should get better on its own.  It did not, and by the end of March, the burning sensations (both legs, mainly front and inside thighs) were at their worst.  
I was finally able to get a referral to a neurologist, who saw me in early April.  He looked at the old MRI and quickly dismissed the disk bulge as cause of my paraesthesia.  He gave me a thorough exam which was normal.  He then ordered a second MRI of lower spine (with contrast), C-spine MRI and brain MRI.  He also ordered lots of bloodwork over this period.
All tests normal except C-spine MRI, which showed very small ("pin-head sized dots") lesions on cord.  He said these appeared to be areas of demyelination, but were not the size of typical (classic) MS lesions.  He then ordered a lumbar puncture (May 20) which gave normal results.
So, he said my lesions were probably the result of a viral infection (autoimmune reation) and my symptoms would go away with time (monophasic). He did not feel it is MS.  He scheduled a follow-up C-spine MRI in early August.  He believes the lesions will probably be gone by then.
I like and trust my neuro, but I don't believe he's an MS specialist.  What do you think about my situation?  Do you agree with him?  Can the lesions (or symptoms) go away with time?  And, should I get a second opinion even though I have no symptoms involving other areas of CNS?  
I'd have to say I believe my symptoms have improved (very slowly), although I do take 50mg of Elavil a day since seeing him.  I also have problems with anxiety, which may or may not be a factor.    
My neuro does not believe my peripheral nerves are causing this.  And, all 3 neuro exams in his office were normal.
Your thoughts and advice are greatly appreciated.   Tim

Posted by CCF Neuro MD msf on July 02, 1999 at 15:12:55
Dear Tim,
Thank you for your question. Firstly, I would agree with your neurologist that a disc bulge, without any compression of the nervous system, does not explain paresthesias in your legs. Is it possible that you have MS ? Certainly, MS can cause paresthesias in the legs, that fluctuate over time. However, your neurologist did not find anything abnormal on examination, and (as you appropriately pointed out) you don't have any other symptoms suggesting involvement of several parts of the central nervous system. Also, your brain MRI was normal, and the cervical spine MRI showed only punctuate abnormalities. finally, the spinal tap was negative. For all these reasons, I would say that MS cannot be totally ruled out at this point, but is less likely. The only other test that could be useful is sensory evoked potentials, which consist in giving a sensory stimulus in the legs, and recording the signal that goes up to the brain. If positive, it could confirm that there is a problem within the sensory pathways, but would still not make a diagnosis of MS. If negative, it wouldn't change anything to the current situation. I think it is a very reasonable option at this point to treat your symptoms for themselves, and to monitor their evolution over time. It is likely that you will continue to get better. Even if you finally developed other problems and were diagnosed with MS, the delay in diagnosing it would not cause any prejudice, because I would not recommend any other treatment currently even if you were currently diagnosed with MS. I hope my explanations were clear. To summarize, the "wait and see" approach appears reasonable at this point. It is not equivalent to doing nothing, because your status will be monitored over time, which allows to make appropriate decisions (tests, treatments) if necessary.