Nerve ultrasound in a case of multifocal motor neuropathy without conduction block

Abstract

Introduction: Multifocal nerve enlargements and ultrastructural changes either corresponding or not to sites of existing conduction blocks have been described in demyelinating polyneuropathies using multiple imaging techniques. Methods: Using the emerging technique of peripheral nerve ultrasonography we investigated the peripheral nerves of a patient with multifocal motor neuropathy (MMN) without conduction block. Results: In this case of MMN without conduction blocks we found multifocal nerve enlargements in the ultrasonography and electrodiagnostic signs of acute and chronic denervation associated with positive anti-GM1 IgM antibodies. Conclusions: This case shows that nerve ultrasound can be a complementary tool for diagnosing multifocal motor neuropathy without typical electrodiagnostic features.