Hirayama Disease with Proximal Involvement

Characteristics of Hirayama Disease in Young South Korean Soldiers

BACKGROUND AND PURPOSE

The purpose of this study was to describe the clinical presentation and features in electrodiagnostic and imaging investigations of young South Korean males diagnosed with Hirayama disease (HD).

METHODS

We reviewed the electronic medical records of South Korean enlisted soldiers who were diagnosed with HD and discharged from military service during 2011-2021. We investigated the clinical characteristics and results of electrodiagnostic and magnetic resonance imaging (MRI) investigations. We analyzed laterality and identified the involved muscles using needle electromyography (EMG). Loss of lordosis, localized cervical cord atrophy, loss of attachment between the posterior dura and subjacent lamina, asymmetric flattening of the cord, crescent-shaped mass in the posterior epidural space, and noncompressive intramedullary T2-weighted high signal intensity were investigated using neutral- or flexion-position MRI.

RESULTS

Forty-two male patients aged 20.2±0.8 years (mean±standard deviation) were identified. All patients complained of hand weakness, and 10 complained of hand tremor (23.8%). Four patients (9.5%) had symptoms in both upper limbs, and five (11.9%) had sensory disturbances. Needle EMG revealed that muscles in the C7-T1 myotome were commonly involved, and C5-C6 involvement of the deltoid (10.5%) and biceps brachii (12.5%) was also observed. In cervical MRI, localized cord atrophy (90.0%) was the most characteristic finding, and cord atrophy was most severe at the C5-C6 level (58.3%).

CONCLUSIONS

This is the first description of a large number of patients with HD in South Korea. The clinical presentation and features found in electrodiagnostic and imaging investigations will improve the understanding of HD in the young South Korean male population.

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

Purpose

Hirayama 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.

Methods

Baseline 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.

Results

In 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.

Conclusion

The 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.

Magnetic resonance imaging features of "Proximal" hirayama disease: Case report and literature review

Background:

Proximal “Hirayama” disease (PHD) is characterized by proximal upper extremity atrophy. It is a rare variant of Hirayama disease (HD) which involves the proximal upper limb. Recognition of PHD’s unique magnetic resonance (MR) findings is critical as the treatment options differ versus classical HD.

Case Description:

A 17-year-old male presented with gradual progressive upper extremity weakness and atrophy. On MR, PHD was demonstrated by C4-C5 kyphosis with a posterior epidural soft-tissue mass compressing the C4-C5 cord resulting in gliosis. As the patient declined surgery, he was followed for 1 year with a cervical collar during which time his deficit stabilized.

Conclusion:

PHD, characterized by proximal upper extremity weakness and atrophy, has characteristic MR findings of kyphosis associated with cord compression and ischemia/gliosis. Select patients as the one we described who decline surgery may stabilize radiographically and clinically with the protracted utilization of a cervical collar.

Quantitative assessment of motor impairment and surgical outcome in Hirayama disease with proximal involvement using motor unit number index

OBJECTIVE

To assess the feasibility of motor unit number index (MUNIX) in quantitatively evaluating Hirayama disease (HD) with proximal involvement and to identify the effectiveness of anterior cervical fusion (ACF) in treating atypical HD with proximal involvement.

METHODS

This study included 28 atypical HD patients with proximal involvement (proximal-distal vs. distal-proximal groups: 5 vs. 23) and 41 healthy controls. All patients underwent pre- and postoperative 1-year MUNIX tests on abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB) and deltoid (Del). The disabilities of arm, shoulder and hand (DASH) and Medical Research Council (MRC) scales were also performed in these patients before and one year after operation.

RESULTS

Preoperatively, the patients in the distal-proximal group showed reduced compound muscle action potential (CMAP), decreased MUNIX and increased motor unit size index (MUSIX) in bilateral distal muscles and symptomatic-side proximal muscles (P < 0.05), and similar abnormalities were also observed in ADM, BB and Del on the symptomatic side in the proximal-distal groups (P < 0.05). Postoperative follow-up analysis identified increased MUNIX in the symptomatic-side proximal muscles with improved motor function in the proximal-distal groups (P < 0.05), and distal-proximal group patients showed an increase in both CMAP and MUSIX in the symptomatic-side proximal muscles (P < 0.05).

CONCLUSIONS

MUNIX may serve as an available supplementary test to quantitatively evaluate the motor dysfunction and treatment outcome in HD with proximal involvement. ACF procedures can effectively treat these atypical HD patients, especially for those whose symptoms started in proximal muscles.

Somatosensory evoked potentials in Hirayama disease: A Brazilian study

Background:

Hirayama’s disease (HD) is characterized by an insidious onset asymmetric weakness and atrophy of the forearm and hand. Taking as a premise, the etiopathogenesis of the disease is attributed to forward displacement of posterior wall of lower cervical dural canal in neck flexion causing marked compression and flattening of lower spinal cord. This may result in compression of the posterior column of the spinal cord and seems likely to result in somatosensory evoked potentials (SSEPs) abnormalities. In the present study, we studied the possible involvement of the lemniscal dorsal pathway in patients with HD.

Methods:

SSEPs in upper and lower extremities were prospectively performed in eight patients with HD. All the patients were recruited from the outpatient clinic of a neuromuscular disorder center from South Brazil. SSEPs were obtained by transcutaneous electrical stimulation of the median and posterior tibial nerves, on both sides. We collected the amplitude and the latency of the different components obtained in each channel. The interpretation was based on Brazilian study standards.

Results:

We evaluated seven men and one woman (mean age 27). The data obtained were compared to a control group consisting of eight patients with spondylotic cervical myelopathy, 6 men and 2 women with mean age of 59 years. The measurements of obtained by the SSEP were also compared between the groups and no significant difference was found for any of them.

Conclusion:

SSEP did not turn out to be an electrophysiological marker in our HD patients.

A 34-Year-Old Female Patient with Hirayama Disease Complicated by Severe Spinal Cord Injury

BACKGROUND

Hirayama disease (HD), characterized by insidiously progressive muscular atrophy of forearms and hands, is a self-limited cervical myelopathy that predominantly affects male adolescents, with female patients, especially middle-aged women, rarely affected. We present a rare case of HD with severe spinal cord injury in a 34-year-old woman.

CASE DESCRIPTION

A 34-year-old woman presented with progressive weakness of both hands and forearms for a duration of 6 years and spastic gait for 1 year. The patient worked as a teacher and experienced long-term and repetitive neck flexion while writing at a desk, potentially causing cervical loading. Examination showed weakness and muscular atrophy of the bilateral upper limbs and pyramidal signs, including Hoffmann sign and hyperreflexia of the lower limbs. Radiologic studies revealed midcervical kyphosis and spinal cord compression by forward displacement of the dura mater with neck flexion. The clinical presentation and radiologic characteristics confirmed the diagnosis of HD. Anterior cervical corpectomy and fusion was performed owing to severe spinal cord injury, and the patient experienced satisfactory improvement.

CONCLUSIONS

The present case clarified the potential involvement of cervical kyphosis and cervical loading-related exercise in the onset and progression of HD. Anterior cervical corpectomy and fusion could serve as a promising treatment of HD with severe spinal cord injury.

Benign monomelic amyotrophy with lower limb involvement in an adult: A case report

RATIONALE

Monomelic amyotrophy (MMA) is a benign motor neuron disease with bilateral muscular atrophy in asymmetry and abnormal in the electromyography (EMG). However, we report a case by the muscle biopsy which shows symptoms of slowly progressive amyotrophy despite having a normal EMG.

PATIENT CONCERNS

A 51-year-old male was diagnosed with a lower limb amyotrophy, insidious at the onset and located in the distal thigh and the proximal crus near the knee, slowly progressive weakness, and wasting of his right gastrocnemius muscle for the last 20 years.

DIAGNOSES

He was diagnosed with MMA by the clinical profile, natural history, examinations, and the biopsy.

INTERVENTIONS

We perform dynamic physical therapy for the patient in this case.

OUTCOMES

The positive effects of dynamic physical therapy in this case with MMA were shown in this report.

LESSONS

The outcome of physical therapy is satisfactory.

Risk Factors for Surgical Results of Hirayama Disease: A Retrospective Analysis of a Large Cohort

OBJECTIVE

To explore risk factors affecting surgical results of Hirayama disease.

METHODS

A retrospective analysis of 210 patients was performed to identify risk factors affecting surgical results of Hirayama disease by using univariate and multivariate analyses. A receiver operating characteristic curve and area under the curve were applied to evaluate the significant results of the multivariate analysis and the optimal reference value.

RESULTS

The mean follow-up period was 27.3 months (range, 14-45 months), and 194 patients with clinical and radiographic data completed the final follow-up. Multivariate analysis identified age of patients (cutoff value 22.5 years), duration of the disease (cutoff value 33 months), physiologic reflex, and pathologic reflex as independent risk factors for surgical results of Hirayama disease. The receiver operating characteristic curve analysis and area under the curve showed that good reference value was obtained for the risk factors.

CONCLUSIONS

Age of patient, duration of the disease, physiologic reflex, and pathologic reflex are the main risk factors affecting surgical results of Hirayama disease. Receiver operating characteristic analysis shows that good reference value was obtained for the risk factors.