I am Dr. Arun and will be helping you today.
I am sorry that your question was unanswered for long.
Neuropathy of polyneuropathy can be a possibility of the diagnosis.
Following investigations are done for ascertainment of the diagnosis (some of which had been done for you);
1) Electromyography/nerve conduction studies (EMG/NCS)
2) MRI of the spine and brain
3) blood glucose and glycosylated hemoglobin
4) serum B12 level with methylmalonic acid (with or without homocysteine),
5) serum protein electrophoresis
6) Anti-nuclear antibody
7) Lyme testing
8) Rheumatoid factor
9) Sjogren's syndrome testing (Anti-Ro, Anti-La Antibodies)
10) Serum thiamine (vitamin B 1 ) level
11) Pyridoxine (vitamin B 6 ) level
12) Serum folate levels .
13) Urinary excretion of N -methylnicotinamide
14) Cyanocobalamin (vitamin B 12 ) level
15) Pantothenic acid: Excretion is less than 1 mg/d.
16) The serum α -tocopherol (vitamin E) level
17) Serum phosphate level
18) Biotinidase levels
19) Aminolevulinic acid synthase in urine (porphyria)
20) Arylsulfatase A and B (leukodystrophies)
22) Urine oxalate levels
23) Serum lactate, ammonia, and pyruvate
24) Urine myoglobin
25) Muscle histochemistry
26) Enzyme assays of muscle, blood, and fibroblast
27) Leukocyte glycogen levels to detect acid maltase deficiency
28) Leukocyte, DNA analyses (McArdle disease)
Skin and nerve biopsy are recommended after the results of these investigations.
This is likely to give the diagnosis and guidelines for the management.
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