Sonographic Multifocal Cranial Nerve Enlargement in Multifocal Acquired Demyelinating Sensory and Motor Neuropathy

Abstract

Multifocal enlargements with the alteration of a normal fascicular pattern are considered to be sonographic peripheral nerve features in multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), a subtype of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We herein present the case of an 18-year-old patient with MADSAM in whom intensive sonological assessments revealed multifocal nerve enlargement within clinically affected cranial nerves. Our case demonstrated that, if systematically investigated with ultrasound, morphological changes similar to those in the peripheral nerves may be detected in a large proportion of clinically affected cranial nerves in MADSAM, boosting the future applications of cranial nerve ultrasound in CIDP.

Keywords: CIDP; MADSAM; chronic inflammatory demyelinating polyneuropathy; diagnostic imaging; ultrasonography; ultrasound.

Figure.

(A) A schematic drawing showing the examined portion of the cranial nerve in our cranial nerve ultrasound protocol. (B) Representative nerve conduction study (NCS) results and sonographic images of the left ulnar nerve. Note that the left ulnar nerve became focally enlarged in the upper arm at the site of the conduction block. (C) A representative schematic drawing and sonographic images of the left vagus nerve. Note that the left vagus nerve became focally enlarged at the level just above the branching point of the left recurrent nerve. (D) A Representative NCS results and sonographic images of the facial nerve. Scale bars, 1 mm. CCA: common carotid artery, CSA: cross-sectional area, D: diameter, Lt: left, Rt: right, SCA: subclavian artery