Steroid-responsive Multifocal Motor Neuropathy with Cranial Manifestations

Abstract

The typical presentation of multifocal motor neuropathy (MMN) is progressive asymmetric limb weakness. Cranial neuropathy is rare. We report a 28-year-old woman with cranial and bulbar palsies but with typical electrophysiological features of MMN by multifocal motor conduction blocks and serological markers of anti-ganglioside GM1 antibodies. The previous consensus on the treatment of MMN is intravenous immunoglobulins, but our patient responded to oral steroids and had clinical and electrophysiological improvement under continuous low-dose prednisolone treatment. In summary, MMN is a treatable chronic inflammatory disease of peripheral nerves. Cranial neuropathies can be its initial presentation. Electromyography studies are crucial for MMN diagnosis and helpful in monitoring disease activity and treatment responses. Although the previous guideline did not suggest using steroids for MMN, with careful patient selection, low-dose oral steroids can be an effective treatment in patients with relatively minor symptoms.