Neuromuscular ultrasound in polyneuropathies and motor neuron disease.

Current standards for diagnosing polyneuropathies (PN) and motor neuron disease (MND) sometimes lack early sensitivity and result in delayed diagnosis and treatment. Neuromuscular ultrasound (NMUS), already established in the diagnosis of entrapment neuropathies, may offer another means of diagnosis and monitoring response to therapy. This review of current evidence discusses diffuse nerve hypertrophy in hereditary demyelinating neuropathies, multifocal nerve enlargement in acquired demyelinating PN and the lack of readily apparent structural change in axonal neuropathies. NMUS detection of fasciculations and muscular change in MND is also reviewed, along with the need for further research to better define the role of nerve imaging in patients with PN.