PracticeUpdate

Nerve Ultrasound Improves Diagnosis of Neuromuscular Disorders Nerve ultrasoundmay help improve detection of treatment- responsive chronic neuropathies T he detection of treatment-responsive chronic neuropathies may benefit from the use of nerve ultrasound, reported a retrospective study presented at ICNMD 2018.

H. StephanGoedee, MD, of theUniversityMedical CentreUtrecht, The Netherlands, and colleagues evaluated nerve ultrasound for the identification of treatment-responsive chronic neuropa- thies without nerve conduction abnormalities. Overall, 240 incident individuals with a clinical phenotype compatible with chronic inflammatory demyelinating pol- yneuropathy, Lewis Sumner syndrome, or multifocal motor neuropathy were analyzed. Work-up consisted of routine ancillary investigations rec- ommended in diagnostic consensus guidelines and a

Dr. H. Stephan Goedee

standardized sonographic protocol assessing arm nerves and brachial plexus. All individuals without demyelinating features according to nerve conduction study, but with sonographic abnormalities fitting inflammatory neuropathy, underwent stand- ard treatment with IV immune globulin. The treatment effect was evaluated using routine clinical examination and hand grip or myometry. " Our results showed that nerve ultrasound is a reliable diagnostic tool with important added value in identifying patients with treatable neuropathies. Nerve ultrasound confers advantages over MRI in terms of flexible field of view and objective cut-off values for abnormalities. " A total of 17 (7%) individuals were found to harbor a clinical phenotype compatible with chronic inflammatory demyelinating polyneuropathy (n=10), Lewis Sumner syndrome (n=1), or multifocal motor neuropathy (n=6). Three individuals were positive for anti-GM1 autoantibodies. They were also positive for sonographic nerve enlargement of the proximal median nerve segments and/or cervical (nerve) roots. However, they tested negative on nerve conduction studies (n=2 axonal loss only, n=15 normal). In contrast, MRI of the brachial plexus was normal in 8 out of 17 individuals (47%). The protein content of cerebrospinal fluid was normal in 6 out of 17 individuals (35%). All 17 individuals exhibited objective improvement with IV immune globulin treatment. Dr. Goedee explained that diagnostic consensus criteria for inflammatory neuropa- thies rely primarily on results of nerve conduction studies that indicate multifocal demyelination. However, nerve conduction studies can be inconclusive or even normal in individuals with neuropathies that respond to immune-modulating treatment. Dr. Goedee told Elsevier’s PracticeUpdate , “Our results showed that nerve ultrasound is a reliable diagnostic tool with important added value in identifying patients with treatable neuropathies. Nerve ultrasound confers advantages over MRI in terms of flexible field of view and objective cut-off values for abnormalities. “Future revisions of diagnostic consensus criteria,” he added, “should include nerve ultrasound and MRI more prominently.” www.practiceupdate.com/c/70505

that pose a significant burden on individ- ual sufferers and health care systems. Genetic heterogeneity and the use of a conventional gene-by-gene approach have resulted in little knowledge about molecular etiologies in a significant pro- portion of these individuals. Relatively recently, massive parallel sequencing using next-generation sequencing has emerged as a successful approach to interrogate multiple genes simultaneously. It has proven efficient and cost-effective for accelerating diagnosis. Dr. Natera de Benito concluded that in recent years, next-generation sequencing has transformed the study of neuromus- cular disorders completely. His team’s experience indicates that the cases of approximately half of individuals with suspected neuromuscular disease are solved using next-generation sequencing. Despite this transformation, molecular causes remain unknown in 47% of indi- viduals. Some unsolved cases may, in fact, be attributable to the kind of next-gen- eration sequencing strategy applied, to previously undescribed causative genes, or to unknown genetic variations causative genes, or to unknown genetic variations. www.practiceupdate.com/c/70505

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ICNMD 2018 • PRACTICEUPDATE CONFERENCE SERIES