High-resolution ultrasound in patients with Wartenberg's migrant sensory neuritis, a case-control study.

Objective: Wartenberg's migrant sensory neuritis (WMSN) is a rare, patchy, pure sensory neuropathy of unknown etiology. High-resolution ultrasonography (HRUS) is an emerging diagnostic technique for neuropathies, but it has not been applied in WMSN. In this study we aimed to determine HRUS abnormalities in WMSN.

Methods: We performed a case-control study of 8 newly diagnosed patients with WMSN and 22 treatment-naive disease controls (16 patients with pure sensory axonal neuropathy and 6 with pure sensory chronic inflammatory demyelinating polyneuropathy (CIDP) or Lewis-Sumner syndrome (LSS)). All patients underwent routine diagnostic evaluations and a predefined HRUS protocol.

Results: We found multifocal nerve enlargement in all 8 WMSN patients. The median nerve in the upper arm and the sural nerve were significantly larger in WMSN than in axonal controls (p = 0.01 and p = 0.04). In CIDP/LSS, sonographic enlargement was more extensive. Furthermore we found brachial plexus involvement in 3 of 8 (38%) WMSN patients.

Conclusion: HRUS showed enlargement of multiple nerves in all WMSN patients even if clinical testing and NCS were normal.

Significance: The feature of multifocal nerve enlargement may be of additional value in establishing the diagnosis of WMSN and may support the suggestion of an auto-immune etiology.