ABSTRACT
Multifocal motor neuropathy (MMN) is an uncommon, asymmetric motor neuropathy. As MMN is a treatable disorder, its differentiation from lower motor neuron disease is important. Evidence of conduction block (CB) or positive IgM anti-GM1 is considered one of important markers for the diagnosis. However, some patients with atypical MMN have no detectable CB or anti-GM1 antibody. We experienced a case of MMN with focal nerve enlargement on ultrasound. Ultrasound can be a valuable tool in supporting the diagnosis of MMN.
Subject(s)
Humans , Diagnosis , Immunoglobulin M , Motor Neuron Disease , Peripheral Nervous System Diseases , UltrasonographyABSTRACT
A 84-year-old woman presented with a two weeks history of dizziness, slurred speech and ataxia. The neurological exam showed spontaneous left beating nystagmus, horizontal gaze evoked nystagmus and limb ataxia. A few weeks earlier, she had an upper airway infection. Brain MRI revealed diffuse leptomeningeal enhancement in the both cerebellar hemisphere and brain single photon emission computed tomography (SPECT) showed hyperperfusion in both cerebellar hemisphere. Extensive laboratory studies with cerebrospinal fluid analysis did not reveal any etiologic factors. She was started on methylprednisolone (1 g/day for 7 days), gradually improved over the weeks. Post infectious cerebellar ataxia is a neurologic complication that occasionally follows systemic viral and bacterial infections. This case demonstrates that cerebellar abnormalities can be detected by brain magnetic resonance imaging and SPECT.