The radiological and electrophysiological characteristics of Hirayama disease with proximal involvement: A retrospective study

Abstract

PurposeHirayama disease (HD) has been largely believed to affect only distal muscles. However, the proximal upper extremities have been affected in some cases, which can be confused with motor neuron diseases.MethodsBaseline data, deep tendon reflex, Hoffmann sign, cervical curvature, sagittal Cobb angle, atrophied spinal cord, high signal intensity, loss of attachment, and affected muscles and segments on electromyography (EMG) were retrospectively obtained and compared between patients with HD with proximal involvement and patients with simple distal HD in one center from September 2007 to April 2022.ResultsIn this study, fifteen patients with proximal HD and 30 patients with simple distal HD were included. The proximal group had a larger proportion of patients with decreased biceps reflex, decreased triceps reflex, brisk or hyperactive knee reflex, positive Hoffmann sign, and cervical kyphosis. The curvatures of the upper part of the cervical spine (C2-4) were lost to a greater degree in the proximal group. More affected segments were observed on magnetic resonance imaging (MRI) and electromyography in the proximal group.ConclusionThe injured segments were longer and the upper curvature of the cervical spine was poorer in patients with HD with proximal involvement. These findings indicated that proximal involvement may indicate more serious HD.

Characteristics of Hirayama Disease in Young South Korean Soldiers

“…However, several studies have found proximal upper extremity involvement in some patients with HD. 3 12 19 20 23 Huang et al 21 documented proximal involvement in 3 of 40 patients (7.5%), while Gourie-Devi and Nalini 24 observed proximal involvement in 4 of 44 patients (2.3%). In our study, none of the 42 patients complained of symptoms involving the proximal upper extremities, but 4 patients (9.5%) showed denervation or reinnervation potentials in the deltoid and biceps muscles in EMG.…”

“…Several studies found that patients with HD exhibit atypical clinical features with pyramidal signs, involvement of the proximal upper extremities, and sensory disturbances. 3 6 11 12 19 20 Pyramidal signs, which refer to upper motor neuron signs, have been reported in 2.4% of Japanese and 10.6% of Chinese patients with HD, predominantly in severe cases. 6 19 None of our subjects showed pyramidal signs.…”

“…In our study, none of the 42 patients complained of symptoms involving the proximal upper extremities, but 4 patients (9.5%) showed denervation or reinnervation potentials in the deltoid and biceps muscles in EMG. According to Wang et al, 3 proximal HD often involves a more-extensive range of cervical spinal segments, affecting both rostral and caudal areas around C5–C7, whereas the simple distal type primarily affects the C7–T1 myotome. Wang et al 3 also reported that proximal HD often presents with a higher incidence of cervical kyphosis.…”

“…According to Wang et al, 3 proximal HD often involves a more-extensive range of cervical spinal segments, affecting both rostral and caudal areas around C5–C7, whereas the simple distal type primarily affects the C7–T1 myotome. Wang et al 3 also reported that proximal HD often presents with a higher incidence of cervical kyphosis. In our study, all four patients with proximal muscle involvement in EMG exhibited kyphosis in MRI, and three of them displayed extensive cord atrophy, including at the C5–C7 levels, which is consistent with previous findings.…”

“… 1 HD is diagnosed based on a combination of distinctive clinical features and electrodiagnostic and cervical magnetic resonance imaging (MRI) findings. 2 3 4 5 6 The clinical presentation of HD includes asymmetric oblique amyotrophy, specifically involving the distal muscles of the hand and forearm, but sparing the brachioradialis. HD primarily affects males and typically manifests during late adolescence or early adulthood.…”