Nerve ultrasound characterizes AMN polyneuropathy as inhomogeneous and focal hypertrophic

Abstract

ObjectiveHigh-resolution nerve ultrasound (HRUS) is a painless tool to quickly evaluate peripheral nerve morphology in vivo. This study set out to characterize peripheral nerve involvement in X-linked adrenomyeloneuropathy (AMN) by HRUS.MethodsThirteen adults with genetically proven AMN were examined using the Ultrasound pattern sum score (UPSS) to evaluate morphological abnormalities of peripheral nerves, vagal nerves, as well as cervical nerve roots. Ultrasound results were correlated with clinical findings and nerve conduction studies.ResultsUPSS was increased in six out of 13 patients. Nerve enlargement was mostly inhomogeneous and regional. The median, ulnar, and vagal nerves presented with more prominent alterations than nerves of the lower limbs. The proximal-to-distal ratio was significantly enlarged for the median nerve. HRUS findings matched nerve conduction studies, but identified one patient with enlarged nerves and yet normal conduction velocities. Sonographic findings did not correlate with disease duration or disease severity as assessed by the spastic paraplegia rating scale.ConclusionHRUS reveals significant multifocal regional nerve swellings with reduced echo intensity as the morphological equivalent of electrophysiological peripheral nerve affection in AMN patients. Ultrasound and NCS characteristics in AMN seem to differ from other demyelinating neuropathies like CIDP or CMT1a.Trial registrationGerman clinical-trial-register (DRKS) (DRKS-ID 00005253) Registered 15 October 2013.Electronic supplementary materialThe online version of this article (10.1186/s13023-018-0939-7) contains supplementary material, which is available to authorized users.

Normative Observational Nerve Ultrasound Values in School-Age Children and Adolescents and Their Application to Hereditary Neuropathies

“…Children/adolescents with inflammatory neuropathies seem also to reveal proximal predominant nerve enlargement in chronic radiculoneuritis and root/vagus predominant nerve enlargement in acute inflammatory radiculoneuritis. This pattern is even quite similar to that described in adults and is in line with our limited knowledge of nerve imaging in children and adolescents (12)(13)(14). Finally, some patients with very rare neuropathy types, e.g., lysosomal storage diseases [MLD, M. Krabbe, sulfatase deficiency] haven been examined.…”

“…They even exhibited nerve enlargement, which might be a sign of intraneural accumulation of metabolites (20,21). This finding is very promising, as it opens new doors to non-invasive diagnosis of rarer neuropathies in children/adolescents; so far, not much is known yet about lysosomal storage disease-associated neuropathies except for related disorders, e.g., adrenoleukodystrophy (14) or one case report of MLD (22), and further studies will thus be promising for the future. Children/adolescents without neuropathy had, overall, no CSA enlargement, which emphasizes the power of ultrasound to exclude neuropathies.…”

“…Nerve ultrasounds were carried out by CS and ASG blinded to each other by the use of a high resolution linear transducer (14 MHz, Mindray TE7, Ultrasound systems, Darmstadt, Germany). The authors were orientated on protocols, and they had previously performed other studies involving adults (9,(11)(12)(13)(14). In all children, arm and leg nerves of the right side were examined at several locations: the median and ulnar nerve (MN, UN) at the mid-upper arm, the elbow, and the mid-forearm as well as the MN at the wrist.…”

Nerve Ultrasound as Helpful Tool in Polyneuropathies

“…Growing data are available concerning rare storage diseases, for example metachromatic leucodystrophies, adrenoleucodystrophies, xantochromatosis or glucocerebrosidosis [ 27 , 145 , 146 , 147 ]. Until now, even though only limited data exist, most of the patients with storage diseases show nerve enlargement, possibly due to accumulation of intermediate metabolites within the myelin sheets, according to demyelinating NCS in most of these cases.…”

Defining diagnostic cutoffs in neurological patients for serum very long chain fatty acids (VLCFA) in genetically confirmed X-Adrenoleukodystrophy

“…about one-third of cases, young boys present with signs and symptoms that are due to the onset of cerebral ALD. Nerve conduction studies often reveal multifocal demyelination 4 with detectable peripheral nerve abnormalities by high-resolution ultrasound 5 . The AMN phenotype is an important differential diagnosis to hereditary spastic paraplegias (HSP) 6 , 7 , which are clinically and genetically very heterogeneous (80+ genes are described—see 8 ).…”