Nerve ultrasound characterizes AMN polyneuropathy as inhomogeneous and focal hypertrophic

Tim W. Rattay,
Jennifer Just,
Benjamin Röben,
Holger Hengel,
Rebecca Schüle,
Matthis Synofzik,
Anne S. Söhn,
Natalie Winter,
Nele Dammeier,
Ludger SchölsEmail author and
Alexander Grimm

Orphanet Journal of Rare Diseases201813:194

https://doi.org/10.1186/s13023-018-0939-7

Received: 4 July 2018
Accepted: 22 October 2018
Published: 3 November 2018

Abstract

Objective

High-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.

Methods

Thirteen 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.

Results

UPSS 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.

Conclusion

HRUS 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.