Neuromuscular

Demyelinating Neuropathy with anti-MAG Antibodies

Prolonged Distal Latency
Temporal Dispersion
Absent SNAPs
Distal Latency: Prolonged

Sweep speed = 5 ms/div; Sensitivity = 5 mV/div
  • Distal latencies: Prolonged
  • Nerve conduction velocities
    • Moderate slowing
    • Often relatively spared early in disease course
from M. Al-Lozi

Temporal Dispersion of Compound Motor Action Potentials (CMAPs)

Sweep speed = 5 ms/div; Sensitivity = 5 mV/div
  • CMAPs: Proximal nerve stimulation
    • Amplitudes: Reduced
    • Durations: Prolonged (> 30% on proximal stimulation)
    • Areas: Relatively spared
  • Conduction block: Not present
  • Also see: CIDP
from M. Al-Lozi

Absent Sensory Potentials

  • Sensory nerve action potentials (SNAPs) are reduced
      out of proportion to motor potentials.
from M. Al-Lozi

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11/24/2025