Table 4.

Diagnostic criteria for definite or probable MMN⁸

Definite	Probable	or	Probable
Clinical
• All core criteria (1,2)	• All core criteria (1,2)		• All core criteria (1,2)
• All exclusion criteria (8–11)	• All exclusion criteria (8–11)		• All exclusion criteria (8–11)
Electrophysiologic
• Definite CB criteria, one nerve	• Probable CB criteria, two nerves		• Probable CB criteria, one nerve
• Normal SNAP conduction in motor nerve(s) with CB	• Normal SNAP conduction in motor nerve(s) with CB		• Normal SNAP conduction in motor nerve(s) with CB
Laboratory/supportive
• Supportive only (not necessary)	• Supportive only (not necessary)		Two of the following:
			• Elevated IgM antiganglioside GM1 antibodies
			• Increased CSF protein (<1 g/dL)
			• Increased T2-signal intensity on MRI of brachial plexus with diffuse nerve swelling
			• Objective clinical improvement following IVIg treatment

Note: Copyright © 2010 Peripheral Nerve Society. Reproduced with permission from John Wiley & Sons, Inc. Joint Task Force of the EFNS and the PNS. European Federation of Neurological Societies/Peripheral Nerve Society guideline on management of multifocal motor neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society – first revision. J Peripher Nerv Syst. 2010;15(4):295–301.

Abbreviations: CB, conduction block; CSF, cerebrospinal fluid; IgM, immunoglobulin M; IVIg, intravenous immunoglobulin; MMN, multifocal motor neuropathy; MRI, magnetic resonance imaging; SNAP, sensory nerve action potential.