I'm male, age 51. About 5 months ago, after (voluntarily) losing 30 pounds on a low-carb, hi protein diet, I started awakening with numb / tingling fingers. Since then, it's progressed to regular (but intermittent) sensory loss in parts of all four distal limbs, with slight muscular weakening, plus some muscular and joint soreness (especially shoulders / upper arms). My health is fine otherwise.
After arm EMG/NCVs, a neurologist diagnosed mononeuritis multiplex (both wrists & elbows). Lab tests all normal -- Chest X-Ray, CBC, Differential, HbA1C, Blood Glucose, Blood B12, Glycohemoglobin, Sed rate, BUN, ANA, C3 & C4 complement, rheumatoid factor, Hep B antigen, protein electrophoresis, Lyme disease, ANCA, C-Reactive, immunoglobulin GAM, creatinine. Also been examined by a rheumatologist.
My neurologist says it is "most likely" HPNN, with some chance of still-undetected vasculitis. He wants to wait to see what happens for another month, then possibly do a nerve biopsy. He recommends against the genetic test for HPNN, saying it is not that reliable. He also declined to do MRIs (cranial or spinal) or a lumbar puncture because he says the problems aren't in the CNS.
I'm not happy just waiting to see what happens, as my symptoms are definitely progressing.
Questions:
(1) What addition tests (including HPNN genetic, MRI, LP, or others) would you recommend now?
(2) Is the HPNN test reliable?
(3) Is HPNN likely to present as almost-simultaneously appearing symptoms in multiple limbs?
(4) Suggestions for other possible diagnoses?
Thanks!