Cervical collar therapy for juvenile muscular atrophy of distal upper extremity (Hirayama disease): results from 38 cases]

BACKGROUND: Juvenile muscular atrophy of distal upper extremity is a peculiar type of cervical myelopathy affecting young people characterized by localized amyotrophy in the forearm and hand that is initially progressive, and then stabilized in a few years. The anterior horn cell damage may be induced by forward displacement of the lower cervical dural sac and spinal cord on neck flexion. We proposed that the forward displacement was one of pathogenic factors, and reported that therapeutic intervention using a cervical collar in order to minimize neck flexion halted the progressive weakness in some patients. OBJECTIVE: To examine effectiveness of cervical collar treatment for this disease and to investigate clinical and radiological profiles that predict a favorable outcome before treatment. METHODS: Thirty-eight patients who had progressive illness within 5 years after onset underwent cervical collar therapy (treatment group). Forty-five patients in a previous case series without any therapeutic intervention made up a control group. The duration of progressive phase of illness was compared between the two groups. In the treatment group, the time interval from onset and the measurements of cervical cord atrophy and its flattening on neck flexion at the introduction of treatment by CT-myelography or MRI were analyzed with respect to prognosis. RESULTS: All the patients in the treatment group showed no further progression after introduction of treatment. The duration of the progressive period was shorter in the treatment group (mean 1.8 +/- 1.2 years) than in the control group (mean 3.2 +/- 2.3 years) (p < 0.005). In the treatment group, 15 of 31 patients within 2.5 years after the onset showed not only stabilization but also improvement of muscular weakness or cold paresis. Five of 7 patients who had no or mild cord atrophy at the introduction showed improvement after treatment. CONCLUSION: Cervical collar therapy induces a premature arrest of this disease. Improvement is expected in patients who have shorter duration of illness and have mild cord atrophy in a neutral neck position. Early diagnosis and therapeutic intervention may minimize the functional disability of young patients.     

A case of Hirayama's disease successfully treated by anterior cervical decompression and fusion]

The authors report the case of a 16-year-old boy with Hirayama's disease(juvenile muscular atrophy of unilateral upper extremity). The present history began about 6 months previously, when he noticed slowly progressive weakness with atrophy of the left hand and forearm. Neurological examination on admission revealed diffuse distribution of muscular atrophy including the left hypothenar, thenar, forearm, and triceps muscles. However, EMG studies identified neurogenic changes in both upper extremities. There was no long tract sign of objective sensory impairment. Plain spinal radiograms showed abnormal kyphosis of the cervical vertebrae. Cervical MR images in the neutral position demonstrated focal atrophy of the cervical cord at the C 5-6 vertebral levels. When the neck was flexed, the cervical cord was displaced anteriorly and was compressed over the posterior surface of the C 5-6 vertebral bodies. He was diagnosed to have Hirayama's disease(cervical flexion myelopathy). Via an anterior approach, he underwent a C 5 vertebrectomy followed by fixation of C 4-6 vertebral bodies using iliac bone and plate system. He recovered from surgery without any complications and has been well for the past 6 months with remarkable improvement of muscle strength. Application of cervical collar for 3 to 4 years has been generally advocated for the treatment of Hirayama's disease because progression of signs and symptoms is usually expected to cease within several years. However, some patients were reported not to response to conservative treatment for more than 5 years after their onsets. To these patients surgery seems to be beneficial, because it can give rise to permanent stable fixation with much shorter period of external cervical immobilization compared with cervical collar therapy, in which long-term application is frequently unbearable in many patients. In conclusion, the present case emphasizes the importance of surgical treatment in Hirayama's disease not only to improve neurological deficits but regain better quality of life.     

A case of Hirayama disease

We report a male patient with Hirayama disease aged 13. The disease was insidiously progressive and he had severe disability of the right hand at presentation. He had muscular atrophy in the intrinsic muscles of the right hand and in the distal muscles of the right forearm. The atrophy was pronounced on the ulnar side. Cold paresis was also noticed. There was no sensory disturbance. On Electromyography, neurogenic changes were recorded in several atrophic muscles. Motor and sensory nerve conduction was normal. MR images of the spinal cord were normal when it was performed with a conventional method (i.e., without neck flexion). However, characteristic MR findings were obtained when the patient lay with maximum neck flexion. The posterior wall of the cervical dural canal was shifted anteriorly at the C3-7 vertebral level, which caused cord compression at the lower cervical spinal canal. The epidural space was crescent-shaped and showed high signal intensity on T2-weighted imaging. These clinical features are typical of Hirayama disease. Pediatrician should be aware of this disease and treat it as soon as possible in order to prevent progression of the atrophy.     

Cervical dural sac and spinal cord in juvenile muscular atrophy of distal upper extremity

OBJECTIVE: To investigate specificity and significance of dynamic changes of the cervical dural sac and spinal cord during neck flexion in juvenile muscular atrophy of the distal upper extremity. BACKGROUND: The disorder affects young people-predominantly men-and is progressive for several years. One autopsy case showed ischemic necrosis of the cervical anterior horn, suggesting that the disorder is a type of cervical myelopathy. Some authors classify it as monomelic amyotrophy, implying that it is a focal motor neuron disease. METHODS: Neuroradiologic examinations including myelography, CT myelography, and MRI in a fully flexed neck position were performed on 73 patients with this disorder and on 20 disease control subjects. RESULTS: A distinctive finding in the disorder was forward displacement of the cervical dural sac and compressive flattening of the lower cervical cord during neck flexion. The forward displacement was significantly greater in patients with disease duration less than 10 years than in age-matched control subjects and patients in a late, nonprogressive stage. CONCLUSIONS: Radiologic abnormalities of the lower cervical dural sac and spinal cord support the hypothesis that this disorder is a type of cervical myelopathy.     

Is juvenile spinal muscular atrophy of the distal upper limbs due to cervical flexion myelopathy? A case report

A 22-year-old woman developed a slowly progressive symmetric weakness and muscular atrophy of distal upper limbs at the age of 17. Radiography during anteflexion and retroflexion showed a hypermobile cervical spine with a maximum at the C5/6 disc level. Cervical myelography and postmyelographic computed tomography (CT) of the lower cervical spine demonstrated a remarkable anterior shift of the dural sac during anteflexion resulting in anteroposterior compression of the lower spinal cord. Postmyelographic CT and magnetic resonance imaging (MRI) revealed atrophy of the lower spinal cord with bilateral cystic lesions. We suppose that repetitive straining and compression of the lower cervical cord during neck flexion of the hypermobile cervical spine caused selective necrosis of anterior horn cells with secondary cystic transformation. Mechanically induced flexion myelopathy should be considered in all young patients presenting with muscular atrophy of the distal upper limb. Functional CT myelography or dynamic MRI of the cervical spine are appropriate to demonstrate lower spinal cord compression during flexion.     

Anterior shift of posterior lower cervical dura mater in patients with juvenile muscular atrophy of unilateral upper extremity

Myelography was performed in 16 male patients with juvenile muscular atrophy of unilateral upper extremity. The age at onset ranged from 11 to 19 years (average, 16 years), and the age at study ranged from 15 to 38 years (average, 25 years). The most remarkable finding was an anterior shift of lower cervical dural canal during neck flexion, particularly of its posterior wall at around 6th vertebral level. The above finding was clearly shown in 12 patients whose duration of illness was under 20 years but not in 4 patients whose duration of illness was 20 years or over. And the rates of anterior shift of posterior lower cervical dura mater was inversely proportional to the duration of illness. There was a tendency that the greater the degree of the anterior dural shift and compression of the spinal cord, the greater the severity of the disease. We thought that the anterior shift of the posterior lower cervical dura mater provides the clue to understanding of its etiology and methods of arresting the progression of the disease.     

A case of monomelic amyotrophy of the upper limb: MRI findings and the implication on its pathogenesis

Monomelic amyotrophy of the upper limb or Hirayama disease is mostly considered as an anterior horn disorder resulting from local ischemia, triggered by arterial compression from an anterior shifting of the posterior cervical dura upon neck flexion. However, such a dural shifting is not universally seen. We report on a Caucasian male patient who developed a slowly progressive unilateral distal hand weakness in his teens. His clinical and electromyographic findings were consistent with Hirayama disease. Local anterior cervical cord atrophy was observed without dural shifting on the dynamic magnetic resonance imaging. Axial magnetic resonance imaging demonstrated signal changes of "snake-eye" appearance in the cervical anterior horn region, similar to ischemic myelopathies caused by various etiologies. This case illustrated that even without dural shifting, a mechanism of anterior spinal cord ischemia could still be responsible for the pathogenesis of Hirayama disease.     

MRI findings in Hirayama’s disease: flexion-induced cervical myelopathy or intrinsic motor neuron disease?

Hirayama’s disease is a benign juvenile form of focal amyotrophy affecting the upper limbs. Previous studies have suggested that the disorder is a neck flexion induced cervical myelopathy. We report clinical and magnetic resonance imaging findings in nine patients with Hirayama’s disease. Cervical imaging of seven patients revealed spinal cord changes consisting of focal atrophy and foci of signal alterations. On neck flexion a forward movement and mild reduction in the anteroposterior diameter of the lower cervical cord against the vertebral bodies was noted in affected individuals as well as in five normal controls. In contrast to earlier reports, none of our patients showed complete obliteration of the posterior subarachnoid space. Measurement of the anteroposterior spinal cord diameter in each vertebral segment (C4–C7) revealed no significant differences in the degree of spinal cord flattening between the two groups. Furthermore, two of our patients had significant degenerative changes in the cervical spine (disc herniation, retrospondylosis) contralateral to the clinically affected side. These degenerative changes resulted in a marked cord compression on neck flexion but were not associated with ipsilateral clinical abnormalities or spinal cord alterations. Our results argue against a flexion-induced cervical myelopathy and support the view that Hirayama’s disease is an intrinsic motor neuron disease. Received: 15 March 1999 Received in revised form: 25 May 1999 Accepted: 1 June 1999     

Juvenile muscular atrophy of distal upper extremity (Hirayama disease): Focal cervical ischemic poliomyelopathy

Hirayama disease is characterized by an initially progressive muscular weakness and atrophy of the distal upper limb(s) in adolescence, occurring predominantly in males, followed by spontaneous arrest within several years. Although the disease could be separated from motor neuron disease, some authors considered the illness to be a variant of degenerative motor neuron disease until the first autopsy case was reported which showed focal ischemic changes in the anterior horn of the lower cervical cord. Since then, many in Japan have recognized the disease as cervical ischemic poliomyelopathy; however, several authors in foreign countries did not or do not appreciate the pathologic findings of the disease, and still consider the illness a degenerative motor neuron disease. The pathology of the disease prompted neuroradiologic investigations, which have revealed dynamic changes of the cervical dural sac and spinal cord induced by neck flexion. The cause of these dynamic changes is unknown. However, as the number of patients is exceedingly large in Japan, there may be an ethnic factor.     

Hirayama disease

Hirayama disease (juvenile muscular atrophy of distal upper extremity) is a cervical myelopathy. Predominantly affecting male adolescents, it is characterized by progressive muscular weakness and atrophy of distal upper limbs, followed by spontaneous arrest within several years. Although the cause of cervical myelopathy remains unclear, neuropathologic and neuroradiologic findings suggest a forward displacement of the posterior cervical dural sac during neck flexion, causing compression of the cervical cord, and results in atrophic and ischemic changes in the anterior horn. A good understanding of Hirayama disease is essential because early recognition and management can effectively halt the progressive deterioration.     

Demyelinating lesions in the cervical cord in multiple sclerosis 10 years after onset of the disease. Correlation between MRI parameters and clinical course

BACKGROUND AND PURPOSE: Demyelinating lesions in spinal cord in multiple sclerosis (MS) are found in magnetic resonance imaging (MRI) in 47-90% of patients; spinal cord atrophy, however, which is a measure of axonal loss and correlates with disability, is found in 13-41% of patients. Presence and character of lesions depend on the duration and progression of the disease. The aim of this study was to estimate the presence, character and location of lesions and cervical cord atrophy in MRI performed 10 years after the onset of MS in relation to the clinical course. MATERIAL AND METHODS: 60 patients (41 females and 19 males) with definite MS according to McDonald's criteria were studied. The age of patients ranged from 29 to 62 years and disease duration ranged from 11 to 40 years. The MS group comprised 20 patients with secondary progressive MS (SPMS), 20 patients with primary progressive MS (PPMS) and 20 patients with benign form of MS (BMS). Spinal cord MRI was performed in conventional T1 and T2-weighted sequences. RESULTS: Demyelinating lesions were found in 62% of patients (50% of patients with BMS, 60% with PPMS and 75% with SPMS). 42 intrinsic focal lesions were identified in 18 patients and diffuse lesions of spinal cord were noted in 19 patients. Focal lesions were seen in patients with BMS, whereas SPMS patients had diffuse cervical cord abnormalities, and PPMS patients exhibited both forms of changes. 60% of intrinsic focal lesions were located at C3-C5 levels. Medium-sized lesions prevailed in BMS form; in PPMS form small and medium-size lesions, and in SPMS form large lesions (>10 mm) were more frequent. The spinal cord was atrophic in 8% of patients (10% of patients with PPMS and 15% with SPMS). In BMS no atrophy of the cervical cord was observed. We did not find focal demyelinating lesions in the cervical segment of patients with spinal cord atrophy. CONCLUSIONS: Presence and character of demyelinating lesions in cervical cord ten years after onset of MS is significantly related to the clinical form of the disease. The mid-cervical region of the spinal cord appeared to be the commonest location of the focal lesions. Cervical cord atrophy was more frequent in patients with PPMS and SPMS, but it was not accompanied with intrinsic focal cord lesions.     

Two patients with cervical diastematomyelia

Two patients with cervical diastematomyelia are reported here. A nineteen year-old-man (patient 1) admitted to our hospital because of muscular weakness of right upper limb. He noted muscular atrophy of right upper limb at 16 years old, and then paresthesia was gradually aggravated in the ulnar side of the right hand. Physical examination showed muscular atrophy of right upper limb and hypesthesia in the right eight cervical and first thoracic dermatomes. The deep tendon reflexes were decreased in the right upper limb and were increased in the lower limb without pathological reflexes. In electromyographic examination, neurogenic motor units were observed in the upper right limb, dominantly in 1st interosseous muscle (between the fourth cervical and the first thoracic dermatome). Metrizamide computed tomographic (CT) myelography revealed sagittal splitting of the spinal cord from the third to the sixth cervical vertebra, producing two asymmetrical hemicords. A osseous or fibrous septum were not seen. The right hemicord was smaller than the left one. Patient 2 was a twenty-four-year-old woman. She visited our hospital because of muscular weakness of the right upper limb. In physical examination, there were the muscular atrophy of right hand and hypesthesia in the right eighth and first thoracic dermatomes. The deep tendon reflexes were decreased in the right upper limb and were increased in the right lower limb without pathological reflexes. The EMG studies revealed the neurogenic NMU in the right upper limb (between the fourth cervical and the first thoracic dermatome). Magnetic resonance imaging showed marked narrowing of the dural sac in flexion of the neck.(ABSTRACT TRUNCATED AT 250 WORDS)     

The phenomenon of disproportionate antecollis in Parkinson's disease and multiple system atrophy.

We sought to explore the phenomenon of disproportionate antecollis in multiple system atrophy (MSA) and Parkinson's disease (PD). The etiology is much debated and the main issue is whether it represents a primary myopathy or is secondary to the underlying motor disorder. The clinical, electrophysiological, and biopsy data of MSA or PD patients with antecollis were reviewed. We reviewed 16 patients (7 MSA and 9 PD) who developed antecollis during the course of their disease. The interval between onset of motor symptoms and of antecollis was shorter in the MSA group (4.6 +/- 1.7 years vs. 10.5 +/- 7.0 years). In 6 patients, the antecollis developed subacutely, and in 2 the abnormal neck flexion was initially an off-period phenomenon. Two additional patients also showed some dopa-responsiveness. Clinically, the antecollis was characterized by a forward flexion and anterior shift of the neck, with prominent cervical paraspinal and levator scapulae muscles, usually without weakness of residual neck extension. Electromyography of cervical paraspinal muscles showed mixed myopathic, normal, and neurogenic units, without early recruitment. Cervical paraspinal muscle biopsy in 2 patients disclosed fibrosis and nonspecific myopathic changes. We suggest that, in the context of MSA or PD, the initiating event in antecollis could be a disproportionately increased tone in anterior neck muscles that leads to secondary fibrotic and myopathic changes. However, a primary but yet unexplained neck extensor myopathy still remains the alternative possibility and longitudinal studies are necessary to settle this issue.     

平山病患者的临床电生理及颈磁共振成像研究

目的 研究平山病(HD)患者的临床特征、肌电生理及颈磁共振成像(MRD特点.方法 观察15例HD患者的特殊临床表现.检测双侧上肢远端及下肢常规肌电图及周围神经传导速度.行颈部自然位、过屈位及过伸位MRI扫描,观察低位颈髓有无萎缩及颈椎曲线情况.结果 15例患者均为男性,青春期起病.病变均表现为上肢远端肌肉、骨间肌、鱼际肌萎缩和双手厥冷无力.肌电图检查示患者受累侧远端肌运动单位平均时限宽,多相波增多,波幅显著增高(巨大电位),主要位于C7、C8及T1节段.颈自然位MRI示9例患者低位颈髓萎缩,主要在C5、C6节段.所有患者过屈位时颈髓前移、变扁平,变扁节段以C6为主.结论 HD主要发生在青春期,以男性多见,临床表现和肌电图检查提示局限于下位颈髓的前角病变,颈部自然位和过屈位MRJ不同的特点可协助诊断.     

Angiographically proven cervical venous engorgement: a possible concurrent cause in the pathophysiology of Hirayama’s myelopathy

The objective of this study is to discuss the possible role of cervical posterior epidural plexus engorgement during cervical flexion in the pathogenesis of Hirayama myelopathy. In Hirayama disease, MRI during neck flexion often shows that the posterior dura detaches from the posterior arches compressing the spinal cord. Autopsies demonstrated asymmetric changes in the anterior horns consistent with chronic ischemic damage, attributed to arterial insufficiency during flexion or to microcirculatory changes due to compression by the tight dura. In a 15-year-old patient with 5-year history of distal upper limbs weakness, MRI demonstrated marked venous engorgement of the posterior epidural plexus in cervical flexion, confirmed by angiography. Laminectomy from C3 to C6 with duraplasty was performed. At one-year follow-up, the clinical condition of the patient remained stable. In Hirayama myelopathy, compression of the spinal cord by the tight dura is probably the most important pathogenetic factor. However, venous congestion in flexion might play an additional role in determining spinal cord ischemic changes.     

Amyotrophic cervical myelopathy in adolescence.

The clinical and radiological features in seven patients who had asymmetric muscular atrophy of the hand and forearm when young are reported and a new hypothesis for its aetiology is proposed. Investigation of body growth curves (a surrogate for velocity of arm growth) showed close relation between (a) the age when the body height increased most rapidly and the onset age of this disorder, and (b) the age when the rapid body growth period ended and the age when symptom progression ceased. Cervical radiological evidence is provided showing asymmetric anterior cord atrophy, disappearance of slackness of dorsal roots in neck extension, and anterior and lateral displacement of the lower cervical cord against the posterior aspects of the vertebral bodies during neck flexion. These results suggest that disproportionate shortening of the dorsal roots is further accentuated during the juvenile growth spurt, which determines the onset and self limited course of the condition, and that repeated neck flexion causes micro-trauma and relative ischaemia of anterior horn cells, which finally results in atrophy of the muscles innervated by motoneurons with long axons. Predisposing anatomical factors are a straight neck due to lack of physiological cervical lordosis and the presence of foreshortened dorsal roots.     

Flexion myelopathy due to tic of neck

A 22-year-old male developed a tic of neck-flexion at the age of 14. The tic occurred 40 to 50 times per minute on its peak at age 16. Since then he noticed the atrophy and weakness of his both upper limbs. His right leg became weak at age 22. On admission, neurological examination revealed tic of lip and neck, severe muscle atrophy and weakness of bilateral upper limbs, mild muscle weakness and spasticity of right lower limb and hyperreflexia in four limbs. Needle EMG studies revealed fibrillation, positive sharp wave and giant MUP in the biceps, triceps and first interossei muscles. There were no abnormal findings suggesting cervical spondylosis or disc herniation on neck roentgenogram and neck MRI in neutral position. Neck MRI in the ventro-flexed position showed a flattening of the lower cervical cord and a band-like isointensity lesion in the posterior epidural space at C4-6. This isointensity lesion was considered to represent a congestion of the internal vertebral venous plexus. These findings suggest that frequent neck flexion by itself causes the injury of the lower cervical cord through (1) over-stretching of the cord, (2) compression of the cord by dural sac, (3) arterior ischemia, and/or (4) stagnant hypoxia due to venous congestion. Flexion myelopathy may represent one of the most important mechanisms of cervical cord injury accompanied with involuntary movement of neck.     

Juvenile muscular atrophy of the distal upper limb (Hirayama disease) associated with atopy

Juvenile muscular atrophy of the distal upper limb (Hirayama disease) is a rare disease predominantly affecting the anterior horn cells of the cervical spinal cord in young men. Although the disease is considered to be a type of cervical myelopathy, the mechanism remains unknown. An immunological study of five consecutive patients with this disorder who were examined in the neurology clinic at Kyushu University Hospital during the past 2 years were performed. All developed distal muscular atrophy and weakness of one or both upper limbs in the second decade, and showed forward displacement of the dural sac and passive dilatation of the posterior venus plexus at the lower cervical portion on MRI during neck flexion. Four of the five patients had one or more coexistent airway allergies, such as allergic rhinitis, pollinosis, and asthma, and all five patients had a family history of atopic or allergic disorders in close relatives. Four of the five patients had mild eosinophilia. All five patients commonly had IgE specific to two mite antigens, Dermatophagoides pteronyssinus and Dermatophagoides farinae, whereas three of them also showed a raised total serum IgE concentration. The frequency of mite antigen specific IgE was significantly higher in the present patients with Hirayama disease than in 82 healthy controls (26/82, p<0.005). These findings suggest that atopy may be one of the contributing factors for Hirayama disease.     

Lewis–sumner syndrome of pure upper‐limb onset: Diagnostic,prognostic, and therapeutic features

We studied two 16‐year‐old males with juvenile muscular atrophy of the distal arm, “Hirayama disease,” resulting in asymmetric atrophy and weakness of the distal upper extremities. Pathogenic theories include a compressive myelopathy with or without ischemia, and occasional cases are accounted for by genetic mutations. To specifically address the ischemia hypothesis we performed spinal angiography and epidural venography. Neck flexion during spinal angiography showed a forward shift of a nonoccluded anterior spinal artery without impedance to blood flow. Epidural venography demonstrated engorgement of the posterior epidural venous plexus without obstruction to venous flow. The findings do not support large vessel obstruction as a contributory factor. The Hirayama hypothesis continues to best explain the disease pathogenesis: neck flexion causes tightening of the dura and intramedullary microcirculatory compromise with resultant nerve cell damage. The age‐related factor can most likely be accounted for by a growth imbalance between the vertebral column and the cord/dural elements. Resolution of progression is associated with cessation of body growth, after which the symptoms plateau or modestly improve. Muscle Nerve 40: 206–212, 2009     

A rare anterior spinal epidural cyst mimicking Hirayama disease

Introduction: Hirayama disease is a rare focal motor neuron disorder that manifests as slowly progressive unilateral or bilateral hand weakness and atrophy. Methods: The case report of a young man who presented with the phenotype of Hirayama disease indicated an extensive anterior cervical epidural arachnoid cyst. Results: A 34‐year‐old man presented with a 5‐year history of slowly progressive hand and forearm weakness and atrophy. Nerve conduction studies demonstrated low median and ulnar motor amplitudes, and EMG demonstrated fibrillation potentials and long‐duration, high‐amplitude motor unit potentials in C6–T4‐innervated muscles. MRI demonstrated a longitudinally extensive anterior spinal epidural cyst extending from C2 to L1. The patient had improved hand strength after surgery. Conclusions: Anterior cervical epidural spinal cysts should be considered in the differential diagnosis in patients who present with slowly progressive hand weakness. Muscle Nerve, 2012