Peripheral neuropathy

Differential Diagnosis

• Mononeuropathy
  • Compression/injury
  • Infiltration
  • Mononeuritis
• Mononeuritis multiplex
  • Vasculitis
  • Diabetes
• Polyneuropathy
  • Axonal injury
    • Neoplasm: carcinoma, lymphoma, MGUS
    • Infection: sepsis, chronic HIV, Lyme disease
    • Metabolic: diabetes, uremia
    • Vitamin deficiency: malabsorption
    • Drugs: cisplatin, taxanes, vincristine, isoniazid, nucleoside analogues
  • Demyelinating
    • Guillain-Barré syndrome
    • Neoplasm: carcinoma, lymphoma, MGUS-IgM
    • Drugs: taxanes
    • Chronic inflammatory demyelinating polyradiculoneuropaty (CIDP)
• Amyloid polyneuropathy
• Charcot-Marie-Tooth disease
• Critical illness neuropathy
• Hypothyroidism

Investigations

• Labs
  • CBC, lytes, creatinine, glucose, ESR/CRP, SPEP, vitamin B12, ANA, TSH, urinalysis
  • Based on presentation
    • EMG and nerve conduction
    • Nerve or muscle biopsy
    • LP
    • Lyme serology, HIV test, RPR/VDRL, HBV/HCV serology