This is the current release of the guideline.

Definition

Multifocal motor neuropathy is a disease of lower motor neurons in adults that produces asymmetrical muscle weakness, often in association with fasciculations and cramping.

The diagnosis of multifocal motor neuropathy is a difficult one. Until further research clarifies the issue, the criteria for definitive and probable multifocal neuropathy listed below are proposed to serve as a guide for diagnosing this disease.

Criteria for the Diagnosis of Multifocal Motor Neuropathy

Criteria for Definite Multifocal Motor Neuropathy

1. Weakness without objective sensory loss in the distribution of two or more of the following nerves: median, ulnar, radial, peroneal, and tibial. During the early stages of symptomatic weakness, the historical or physical finding of diffuse, symmetric weakness excludes multifocal motor neuropathy.
2. Definite conduction block (for criteria for partial conduction block, see Table 1 in the original guideline document) is present in two or more nerves outside of common entrapment sites (median nerve at wrist; ulnar nerve at elbow or wrist; peroneal nerve at fibular head).
3. Normal sensory nerve conduction velocity across the same segments with demonstrated motor conduction block.
4. Normal results for sensory nerve conduction studies on all tested nerves, with a minimum of three nerves tested.
The absence of each of the following upper motor neuron signs: spastic tone, clonus, extensor plantar response, and pseudobulbar palsy.

Criteria for Probable Multifocal Motor Neuropathy

1. Weakness without objective sensory loss in the distribution of two or more of the following nerves: median, ulnar, radial, peroneal, and tibial. During the initial weeks of symptomatic weakness, the presence of diffuse, symmetric weakness excludes multifocal motor neuropathy.
2. The presence of either:
   1. Probable conduction block in two or more motor nerve segments that are not common entrapment sites or
   2. Definite conduction block in one motor nerve segment and probable conduction block in a different motor nerve segment, neither of which segments are common entrapment sites.
3. Normal sensory nerve conduction velocity across the same segments with demonstrated motor conduction block, when this segment is technically feasible for study (that is, this is not required for segments proximal to axilla or popliteal fossa).
4. Normal results for sensory nerve conduction studies on all tested nerves, with a minimum of three nerves tested.
5. The absence of each of the following upper motor neuron signs: spastic tone, clonus, extensor plantar response, and pseudobulbar palsy.

None provided

The type of supporting evidence is not specifically stated for each recommendation.

Not applicable: Guideline was not adapted from another source.

2003 Jan

American Association of Neuromuscular and Electrodiagnostic Medicine - Medical Specialty Society

American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM)

Not stated

Primary Authors Richard K. Olney, MD; Richard A. Lewis, MD; Timothy O. Putnam, MD; Joseph V. Campellone, Jr., MD

Not stated

This is the current release of the guideline.

None available

None available

This NGC summary was completed by ECRI on December 1, 2003.