Adding nerve ultrasound to nerve conduction studies improves detection of chronic inflammatory neuropathies in patients with suspected chronic inflammatory neuropathy, a study in Neurology suggests.
Although nerve ultrasound has been found to be an emerging tool for the diagnostic workup of polyneuropathies, the diagnostic performance of nerve ultrasound has not been fully studied in an unbiased approach. The goal of this study was to establish the clinical value of a previously published sonographic protocol in an incident cohort of consecutive patients with a clinical suspicion of chronic inflammatory neuropathy. Researchers also assessed whether nerve ultrasound could improve the identification of treatment-responsive patients compared with nerve conduction studies.
The study enrolled a total of 100 consecutive incident patients who presented to an outpatient clinic at a tertiary referral center in the Netherlands with a clinical suspicion of chronic inflammatory neuropathy. Patients underwent nerve ultrasound, standardized 90-minute nerve conduction studies, and magnetic resonance imaging of the brachial plexus, lumbar puncture, and several different diagnostic questionnaires.
Chronic inflammatory neuropathy was diagnosed when nerve conduction studies fulfilled demyelination criteria of the European Federation of Neurological Societies/Peripheral Nerve Society or abnormalities on nerve ultrasound combined with treatment response.
A total of 38 of 100 patients included in this study had an established diagnosis of chronic inflammatory neuropathy, including chronic inflammatory demyelinating polyneuropathy (n=20), Lewis Sumner syndrome (n=4), and multifocal motor neuropathy (n=14). For nerve ultrasound, the sensitivity and specificity of the test diagnosing chronic inflammatory neuropathy were 97.4% and 69.4%, respectively.
The sensitivity and specificity of nerve conduction studies were 76.9% and 93.5%, respectively. These findings demonstrated that each diagnostic test complemented one another for diagnosing chronic inflammatory neuropathy. The addition of nerve ultrasound to nerve conduction studies accurately detected an additional 21.1% (n=8) of patients with the condition.
This study’s findings may have been limited by a variation in physicians’ treatment decisions, resulting in small differences in patients’ treatment protocols.
These findings show that nerve ultrasound is a useful tool for the diagnosis of chronic inflammatory neuropathy and can improve identification of patients who may respond to treatment. Although nerve ultrasound and nerve conduction studies test characteristics differ, the study authors concluded that these investigations should be considered “complementary rather than comparable techniques in the diagnostic workup of chronic inflammatory neuropathy.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Herraets IJT, Goedee HS, Telleman JA, et al. Nerve ultrasound improves detection of treatment-responsive chronic inflammatory neuropathies [published online January 20, 2020]. Neurology. doi: 10.1212/WNL.0000000000008978.