Peripheral Neuropathy Workup
Nerve conduction studies, small fiber vs large fiber, and metabolic causes.
Initial Laboratory Workup
For distal symmetric polyneuropathy, standard initial labs include:
- Fasting blood glucose and HbA1c
- Vitamin B12 and methylmalonic acid
- Serum protein electrophoresis (SPEP) with immunofixation
Nerve Conduction Studies (NCS)
Used to differentiate axonal from demyelinating polyneuropathies.
- Axonal: Reduced amplitudes with relatively preserved conduction velocities.
- Demyelinating: Markedly slowed conduction velocities, prolonged latencies, and conduction block (e.g., in CIDP).
Common Clinical Mistakes
- Premature anchoring on common diagnoses without evaluating red flags.
- Over-reliance on neuroimaging while neglecting detailed physical exams.
- Suboptimal dosing of first-line agents before declaring treatment failure.
Frequently Asked Questions
- When is immediate specialist referral required?
- Urgent referral is indicated for sudden onset of severe symptoms, rapidly progressive deficits, or when standard therapies fail.
- What are the primary outcome measures in recent clinical trials?
- Most contemporary trials focus on slowing disease progression (e.g., EDSS in MS, UPDRS in Parkinson's) and reducing relapse/event rates.
- How does this condition impact patient life expectancy?
- While highly variable, modern disease-modifying therapies have significantly improved long-term survival rates across neurodegenerative and neuroimmunological disorders.