diagnosis assitance with possible neuromuscular disorder

[Mike10]

Hello,

I have a history of possible neuromuscular disease (details below).  I was evaluated at Mass General in the early 1980’s and diagnosed with a possible metabolic myopathy of indeterminate origin.  Recent testing at IEEM in Dallas, Texas showed no evidence for glycolytic or mitochondrial disorder via exercise testing.  Current symptoms are muscle pain and aches, fatigue, mild asymmetric intermittent ptosis, intermittent irritability/inability to focus, prolonged recovery time after exercise, and occasional cramping. No weakness detected in exams.  Symptoms are intermittent and worsen greatly with fasting, lack of sleep, fever or other minor illness, exercise in warm weather, etc.  At times I can still tolerate some moderate exercise, other times none at all. (I am a former competitive athlete, these symptoms were sufficient to prevent my participation in intercollegiate athletics).  The current levels of symptoms are now impacting my ability to consistently maintain my work schedule (I am a research scientist in a nonmedical  field).   Any suggestions about possible new avenues to explore beyond metabolic myopathy or experts to consult would be most appreciated.

43 yr old male, history of muscle cramping on moderate exercise, muscle pain, and fatigue dating back 25 years.  Three muscle biopsies over this period (1983, 1999, 2007) showing only mild irregularities: 1983: many myofibers contained large collections of mitochondria in the subsarcolemmal regions, several myofibers were small and atrophoic, one example of ringbinden.  Mitochondria were normal in size and appearance.  1999: Histochemistry was normal.  Myoglobinuria Myopathy Profile and Glycogen Storage Myopathy A panel from Athena Diagnostics were normal.  Mitochondrial enzyme profile were normal except for an increased level of citrate synthase (20.21 vs a reference range of 7.33-12.43).  2007: esterase stain revealed scattered angular fibers with abnormally dark staining sarcoplasm, consistent with recent denervation. Incidence of denervated fibers was “rare”. All other factors normal. Ischemic forearm test and MAX cycle exercise testing essentially normal (may have had slight elevation in lactate and depression in ammonia). CK levels 200-250 range. No evidence of rhabdomyolysis.

Other potentially pertinent health conditions include multinodular goiter (diagnosed at age 35, treated with synthroid), and low HDL (20-25 mg/dl) and high triglycerides (200-500) prior to treatment with Niaspan. Recent work up revealed a low FSH (0.8 mIU/ml) and low-normal testosterone (335 ng/dl). Treatment with clomiphene has raised testosterone level, and also resulted in some improvement in muscle function/decrease in symptoms.  

Thank you for your time and consideration.

[Mike10]

Thank you for the comment back. It is very helpful.  I actually have always had very prominent calf muscles, as well as large lower body muscles in general.  My neuro also speculated that the problem could be some form of MD (after the testing I had at IEEM did not reveal a glycolitic or mitochonridal defect as was suspected). but as I do not show clinical signs of weakness we have held off on further testing for this avenue.

Does your brother have any symptoms similar to what I described, or does he have clinical weakness?  If I do have some form of MD I suspect it is pretty mild given my level of functioning.

I will definitely do some reading in this area, find out the symptom severity range, diagnostic tests, etc.

Thanks again!

[ampky]

By any chance, are your calf muscles abnormally large?  The reason for my asking is that my brother has Becker's MD.  It first focuses on the calfs (which are large because of fat deposits, not muscle) first.  It affects only males and is similar to Duchenne MD, but Becker's usually starts in late teens/early twenties whereas Duchenne's begins at birth.
Not a doc, just trying to help.

[Mike10]

Both sides for fatigue/pain.  Usually leg muscles fatigue first, occasionally shoulders/back first.  

[ampky]

Is your muscle fatigue on both sides or is favored on one side?  Are the muscles in your legs fatigued first or is it all around?

[Mike10]

Anyone have any thoughts?  Also forgot to add, my emg has essentially been normal, checked several times over past 25 years, although one done in 1983 showed cramping with no EMG activity.  

Thanks you.

Mike10