Differential Diagnosis for Demyelinating Type with Evidence of Chronic Motor Axonal Damage on EMG

• Single Most Likely Diagnosis
  • Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): This condition is characterized by demyelination and can present with evidence of chronic motor axonal damage, making it a strong candidate given the EMG findings.
• Other Likely Diagnoses
  • Multifocal Motor Neuropathy (MMN): This condition primarily affects motor nerves and can show demyelination on EMG, with some cases having axonal involvement over time.
  • Diabetic Amyotrophy: Although primarily a metabolic disorder, diabetes can cause a mix of demyelinating and axonal damage, especially in the context of amyotrophy.
  • Charcot-Marie-Tooth Disease (CMT): A hereditary motor and sensory neuropathy that can present with demyelination and, over time, axonal damage, though the latter is more typical of certain subtypes.
• Do Not Miss Diagnoses
  • Guillain-Barré Syndrome (GBS): Although typically an acute condition, some variants or incomplete recovery can mimic chronic conditions. Missing GBS could lead to delayed treatment with potentially severe consequences.
  • Lyme Disease: Neuroborreliosis can cause neuropathy with demyelinating features, and missing this diagnosis could lead to untreated infection.
  • Vasculitic Neuropathy: Conditions like ANCA-associated vasculitis can cause neuropathy with mixed features, including demyelination and axonal damage. Missing this could lead to untreated systemic disease.
• Rare Diagnoses
  • POEMS Syndrome: A paraproteinemia characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes. The neuropathy is typically demyelinating.
  • Neuropathy associated with Paraproteinemias: Conditions like Waldenström's macroglobulinemia can cause demyelinating neuropathy.
  • Toxic Neuropathies: Certain toxins (e.g., heavy metals, some industrial chemicals) can cause mixed neuropathies with demyelinating and axonal features, though these are less common and depend on exposure history.