| These criteria are applied by testing the median, ulnar (stimulated below the elbow), peroneal (stimulated below the fibular head), and tibial nerves on one side of the body. During testing, limb temperature should be no less than 33°C (91°F) at the palm and no less than 30°C (86°F) at the external malleolus. |
| Motor nerve conduction criteria |
| At least one of the following demyelinating parameters are necessary: |
- ≥50% prolongation of motor distal latency above the ULN in two nerves
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- ≥30% reduction of motor conduction velocity below the LLN in two nerves
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- ≥20% prolongation of F-wave latency above the ULN in two nerves, or >50% if the amplitude of the distal negative peak CMAP is <80% of the LLN
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- Absence of F waves in two nerves, if these nerves have amplitudes of distal negative peak CMAPs ≥20% of the LLN, plus at least one other demyelinating parameter (meeting any of the definite criteria) in at least one other nerve
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- Partial motor conduction block, defined by a ≥30% amplitude reduction of the proximal negative peak CMAP relative to distal, if distal negative peak CMAP is ≥20% of the LLN, in two nerves, or in one nerve plus at least one other demyelinating parameter (meeting any of the definite criteria) in at least one other nerve
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- Abnormal temporal dispersion, defined by a >30% duration increase between the proximal and distal negative peak CMAP in at least two nerves
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- Distal CMAP duration (interval between onset of the first negative peak and return to baseline of the last negative peak) increase in at least one nerve plus at least one other demyelinating parameter (meeting any of the definite criteria) in at least one other nerve
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| Sensory nerve conduction criteria |
| Prolonged distal latency, reduced SNAP amplitude, or slowed conduction velocities in at least two nerves |
