Multifocal Acquired Demyelinating Sensory And Motor neuropathy MADSAM

Synonyms:

Lewis Sumner syndrome LSS

Diagnosis:

Clinical features supported by +NCS/EMG

Clinical features:

Chronic, asymmetric, distal, sensorimotor, arms >legs, can affect cranial nerves

Findings on investigations:

NCS/EMG:

  • Multifocal conduction block in affected nerves,
  • Widespread sensory abnormalities: helps distinguish from MMN,
  • Asymmetric, helps distinguish it from CIDP
  • Serum anti-GM1 antibody: negative, helps distinguish from MMN

CSF: raised protein occasionally

Treatment:

Intravenous immunoglobulin IVIg 2 g/kg over 3–5 days once a month for 2 months,
Prednisolone 1 mg/kg/day for 4 weeks then taper for 6 weeks

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