Re: What would cause this demyelination?

Posted By leg on March 09, 1999 at 20:52:29:

In Reply to: What would cause this demyelination? posted by CCF Neurology W6 MD on March 09, 1999 at 20:46:19:






: I recently had a new emg done of my upper left arm, both legs and lower back.  They shocked all of them, and put the needle in the r leg and r back.  Here are the abnormal results: Ulnar ab.elb-wrist 78.6 m/s velocity (l arm), peroneal ankle-edb, latency 5.9 m/s (r leg), tibial knee-ankle amplitude 2.3 m/v (r leg), f-wave latency 66.0 m/s (r leg), tibial h-reflex 37.0 m/s (l leg) and tibial h-reflex absent (r leg).  This is the needle part.  Right medial gastocnemius normal insertional activity, no spontaneous activity, simple configuration w/some increased duration and stable motor units, mildly reduced interference pattern.  Right short head of biceps femoris: normal insertional activity, no spontaneous activity, increased duration 20-22 m/s many complex, few unstable, on satellite with fast firing motor units, mildly reduced interference pattern.  Right gluteus medius, normal insertional activity, no spontaneous activity, few complex and serrated motor unit potentials at the lower lumbar levels.  Summary NCS conduction studies demonstrate normal l median and ulnar motor and sensory parameters. The r peroneal distal motor latnecy is mildly prolonged with normal cmap amplitudes and conduction velocity, but an unobtainable f wave respons.  The r tibial motor responses are normal except for the prolongation of the f wave latency and presence of an axon reflex at 48.3 m/s.  The r sural and superficial peroneal sensory responses are normal.  The h-reflex of the tibial nerve is of normal latency on the left, but the response is absent on the right.  Concentric needle emg demonstrates reinnervation changes in the other L5-S1 myotomes.  Abnormal study.  There is electrophysiologic evidence of chronic r L5-S1 radiculopathy.  Mild demyelinating changes are noted in the motor nerves of the r lower extremity.    My ana test was negative in sep. 98, is now positive 1.40 speckled.  Reflexes have changed some from 2+ in upper to 1+ supinator, trace in biceps, 1+ in triceps, knees are trace, r ankle 0, l ankle 1+, toes are downgoing.  Gait is cautious.  There are mild disc bulges on spine mri with no nerve impingement.  Decreased sensation in rt face, numbness in l thoracic spine, buttocks, both lower legs and feet.  Do you have any idea what this may represent.  What would cause lower limb demyelination?
Thank you for your time.
Leg

Hi Leg,
I think I saw your earlier posting,
but there are a lot of causes of demyelination on the lower limb
A variety of neuropathy can cause demylination (infection such as diptheria, heavy metal toxicity such as gold, etc). I don't think MS is likely in your case in light of normal brain MRI and borderline findings on your evoked potential. EP is very much lab dependent, so it's probably is abnormal but is it clinically significant? I don't know.
So far the only thing that make sense from EMG, clinical history, and physical examination (reflex changes) is the L5-S1 radiculopathy on the right as I mentioned previously
Good luck to you.





prolonged p37 ssep, 8.3 m/s diff in p100, 8. m/s diff in n75 on vep, all values w/in normal limits of ver w/ highest 99 on p100. Negative brain mri
Thank you for your time in advance




Dear Doctor,
Is there any signifiicance in the ana being negative and then  becoming positive 5 mos later?
Thank you