[Analysis of the clinical and electrophysiological characteristics of multifocal motor neuropathy]

Ten patients diagnosed with multifocal motor neuropathy (MMN) were recruited in the Department of Neurology at Chinese PLA General Hospital from January 1, 2009 to August 31, 2015. The clinical and electrophysiological features were analyzed retrospectively. All patients complained of progressive asymmetric limb weakness, which was more severe in distal than in proximal. Five presented muscle atrophy. None had sensory disturbances. All suffered diminished or disappeared tendon reflex, whereas Babinski signs were negative. Multi-focal conduction block (CB) was confirmed by nerve conduction studies (NCS) in all patients and 7 showed spontaneous potentials in needle electrode electromyography. Abnormal sensory nerve conduction was seen in 3 patients. Laboratory test revealed anti-ganglioside GM1 antibody in cerebrospinal fluid (CSF) in 6 cases and elevated CSF protein in 7 cases. Limb weakness alleviated greatly in 9 cases after intravenous immunoglobulin (IVIg) treatment. But the other one reported poor response, who had long course of disease, serious limb weakness and obvious muscle atrophy. Motor nerve damage is the most important manifestation of MMN and sensory nerve damage may also appear. NCS is essential to the diagnosis of this disease, with CB as the characteristic electrophysiological feature. IVIg is an effective treatment.