[Electrophysiological evaluation of a case of sensory-motor multifocal acquired demyelinating neuropathy. The effects of immunoglobulin therapy].

INTRODUCTION

Sensory motor multifocal acquired demyelinating neuropathy (SMMADN) is a variant of the chronic multifocal neuropathies. Several reports have been published about the clinical and electrophysiological progression in motor multifocal neuropathy (MMN) prior to and following immunoglobulin (Ig) therapy, but we have found no reports that deal with SMMADN.

AIMS: We describe a case of SMMADN in which we conducted a clinical and electrophysiological evaluation before and after therapy with Ig UNC Hemoderivados.

CASE REPORT: Female, 40 years of age, who presented asymmetrical weakness in all four limbs which she had been suffering for 12 years. We observed distal muscular atrophies, notable weakness and paresthesias in the four limbs. Electrophysiological studies revealed demyelinating neuropathy with secondary axonal involvement. Intravenous Ig was indicated. We observed a clear improvement in muscular strength, and changes in motor and sensory conduction speeds, but not in the amplitudes of the respective potentials.

CONCLUSION

SMMADN is a chronic sensory motor multiple mononeuropathy that begins in the upper limbs and progresses asymmetrically down towards the lower members. The most usual sensory disorders are distal paresthesias. Electrophysiology presents conduction blockages, temporal dispersion, prolongation of the distal latencies, diminished conduction speeds, absence or prolongation of the F wave in one or more motor nerves, and abnormal sensory conduction speed. Accepted treatment is with Ig and, in some cases, with corticoids. In our case, the variations that were obtained could be explained by myelin reconstitution following the immunomodulatory effect of Ig and the axonal involvement that existed due to the secondary sequelae of the inflammatory process.