Miller, Nicholas J.

ABSTRACTIntroduction/AimsPacinian corpuscles are end organs of the sensory nervous system. The size and superficial location of Pacinian corpuscles allows them to be visualized with high‐resolution ultrasound. This pilot study sought to assess the reliability of Pacinian corpuscle counting in the hand using ultrasound.MethodsTwo healthy participants underwent ultrasound evaluation by three ultrasonographers using a scanning protocol developed for this study. The ultrasound protocol used anatomic landmarks to identify and trace digital nerves in the palms and the adjacent Pacinian corpuscles. The ultrasonographers used morphologic features to identify and count Pacinian corpuscles at two sites in each hand for each participant using a 10–22 MHz linear‐array transducer. The procedure was repeated at 2 time points. Inter‐rater and intrarater reliabilities were determined using intraclass correlation coefficients (ICCs).ResultsPacinian corpuscles were identified in the second–third and fourth–fifth intermetacarpal spaces. The ultrasound appearance of Pacinian corpuscles is of a hypoechoic, rounded structure without a hyperechoic rim. A clustered appearance and septate internal structure are distinct features of Pacinian corpuscles, but these features are not always present. The mean number at each site was between 10.71 and 11.71. Inter‐rater and intrarater reliability both resulted in ICC values over 0.8, indicating “good” inter‐rater and intrarater reliabilities.DiscussionPacinian corpuscles can be reliably counted in the hand using high‐resolution ultrasound. The reliability data from this pilot study may facilitate further ultrasound studies of Pacinian corpuscles, which may be decreased in number or undergo other changes in polyneuropathies.

AbstractThe classification of peripheral neuropathies has traditionally been based on etiology, electrodiagnostic findings, or histopathologic features. With the advent of modern imaging, they now can also be characterized based on their varied distribution of imaging findings. We describe the major morphologic patterns of these changes, which include homogeneous enlargement; homogeneous thinning; focal, multifocal, and segmental enlargement; and focal thinning and beading (multifocal thinning). Representative disorders in each of these categories are discussed, along with examples of the more complex imaging manifestations of neuralgic amyotrophy, nerve transection, and hereditary amyloidosis. An appreciation of the diverse morphologic manifestations of neuropathy can help neuromuscular clinicians conduct appropriate imaging studies with ultrasound and, when needed, order suitable investigations with magnetic resonance neurography.