Multifocal motor neuropathy with conduction block with sensory fibre involvement in a diabetic patient. Case report

Multifocal motor neuropathy with conduction block (MMNcb) is a relatively rare disease characterized clinically by asymmetric limb weakness with spared sensation and electrophysiologically by persistent focal motor conduction block. We present the case of a 40-year-old male patient with six-year history of progressive, asymmetric weakness of upper and lower extremities without sensory symptoms. Electroneurography revealed definite or probable motor conduction block in several nerves. However, features of axonal lesion of sensory fibres were also found. Laboratory studies were unremarkable apart from an abnormal glucose tolerance test, and type 2 diabetes was diagnosed. In the presented case the differential diagnosis should take into consideration MMNcb with coexisting diabetic sensory polyneuropathy and multifocal acquired demyelinating sensory and motor neuropathy (MADSAM).