Ped w/ Periph Neuro and Mito?

[jvaughn]

01/04 - active 12y.o. son’s hands swelled. Occurred 2x past 5 years, resolved 12 hours and no docs concerned. New ped suspected lyme. Hist - frequent "growing pains."

01/06 - clinical mito dis diag with addl + lyme & catscratch titers (lyme resolved). 3 mos. IV Rosephin (2004) ceased with worsening sympts. Progress. worse exer. intol (1-grade teacher yells at him “slow runner”– he “sucked it up” muscles felt like “pouring acid”). Current pattern - keep up with gym classes followed w/ unable to walk 1-2x/per month. Severe cramps fold calf skin. Skeletal muscle pains. Some migr, myalgia, chest pains, etc. Chrondroma (elbow) removed (2005). Growing back. “4 or 5” muscle pain. **NORMAL: CSF, Spine/Brain MRIs (incl spectro); Birth-2 – 70% height, now 22% (normal?), Gen evals normal,  **NOTED: o EMG w/muscle and nerve involvement, mild demyl  o Stock/Glove Periph. Neuro  o Single retinal spot – TBD w/ 12-month follow-up  o Sural nerve -demylineation with OMFs, and RRF (“inconclusive”, damaged sample)  o Skin punch (arm) (“normal”?)- Complex II & III 10.9 mU/mg ptn low on range 11.6-19.6   o Muscle bio “inconclusive”, single angular atrophic fiber, with COX IV 35.6 low on range 57.3-373.0  o Hearing Tinnitus w/ mild to moderate U/Level loss

Q?s:

• Neuro “frustrated” with no specific diagnosis and want addt’l nerve and muscle samples. Patient(and mom)resist. Are there less invasive tests recco?
• If this (or part of it) is mito, is he harming himself by “overdoing it”?
• Does this sound like a specific class of mito disease or something else?

[CCF-Neuro-M.D.-PW]

Its difficult for me to interpret the extensive testing your son has had with the above information.

I will make a few comments though -  I wonder was electron microscopy of the skin or muscle biopsy done? sometimes some metabolic or mitochondrial disorder may be more apparent on electron microsopy of the tissue sample (a very high powered microscope able to look even at individual cells)

Other enzymes can be tested in the muscle biopsy sepcimen which disorder of can give exercise related cramps, discolored urine etc - myophoshorylase or adenylyl cyclase are some examples. Other muscle disorders can be diagnosed from the muscle biopsy such as muscular dystrophy

If the urine changes color to red during excercise or the CK level is elevated after exercise, then this indicates some muscle breakdown and strenuous exercise should be avoided until a diagnosis is made.

The combination of different systems affected - muscle, hearing, nerves could suggest a mitochondrial disorder. I am not sure what a 'single retinal spot' mean, but some mito disorder are associated with retinitis pigmentosa usually lots of spots on the retina, paricularly in the periphery of the retina - a full ophthalmological exam should be done, a bedside fundoscope is not enough as you cannot see the periphery. There are some specific genes for mitochondrial disease that can be tested on a blood sample, but the ordering doctor must know what is the more likely mitochondrial disorder before ordering them - a good pediatric neurologist should be able to tell you this.

The pediatric neuromuscular neurology department at the Cleveland Clinic (Dr. Neil Friedman) or another major center could help sort out the diagnosis if needed

[WARRIORMOM]

I might be just throwing out something here, but this case sounds like a demyelination problem. There is a whole strain of them, and I do not know if there is a test available yet for them.  Have they ruled out adrenoleukodystrophy? With the hearing problems and extreme muscle problems it may benefit to check out.

[vega1318]

There are many muscle diseases, some mitochondrial, some not -- that can result in with various forms of exercise induced myopathies.  You need to go to an experienced neuromuscular specialist or myologist who will order the right panel of tests -- unfortunately, another muscle biopsy may also be necessary.  

Depending where you are, you can contact a major department's head of Neuromuscular diseases to suggest someone experienced in your area.  Columbia in NYC has a specialist by the name of Salvatore DiMauro who could be of help.