平山病4例临床和影像学分析

目的探讨平山病的临床特征、影像学特点及发病机制。方法对4例患者的临床、神经电生理、影像学资料进行分析。颈部屈曲位,采用平卧位时骨盆下放置一个定制的楔形物而获得。结果4例均为青春期男性。主要表现为局限于手和前臂的肌萎缩,尺侧肌肉萎缩较重,上肢呈斜坡样。4例手指伸展时出现震颤;3例伴寒冷麻痹。常规颈MR均可见颈髓下段轻度萎缩,均未发现髓内异常信号。屈颈MR均见下段颈髓前移、变平,硬脊膜向前移位;硬脊膜外间隙增宽;硬脊膜外间隙内半月形信号影,在T1加权像与脊髓的信号相同,在T2加权像呈高信号,其中有一些弧线形或圆形的血管流空信号。结论屈颈位MR,出现下颈髓及其硬膜囊的异常表现是平山病的一个显著特点,当遇到青少年(尤其是男性)出现手及前臂不对称的肌无力和萎缩时,应进一步行屈颈MR检查。     

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.     

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.     

平山病发病机制的研究进展

平山病(Hirayama disease)是由日本学者平山惠造(Keizo Hirayama)于1959年首次报道,又称青少年上肢远端肌萎缩症 (juvenile muscular atrophy of distal upper extremity),是一种良性自限性下运动神经元疾病。大部分病例在日本及印度报     

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.     

单肢肌萎缩/平山病:41例患者临床、电生理和颈椎MRI特征分析

目的 探讨单肢肌萎缩(MMA)/平山病患者的临床、肌电图及颈椎MRI特征。方法 2009年5月至2014年5月就诊本科,符合诊断标准的患者,连续登记并详细记录及分析人口学资料、临床、电生理和颈椎自然位和屈曲位MRI资料。结果(1)共41例,男39例、女2例,发病年龄14～24岁、平均年龄(16.87±2.62)岁。病程1～121月、平均病程(22.13±26.25)月。双上肢均有临床症状者6例(14.6%),症状局限单侧者35例(85.4%); 单侧者左12例(29.3%)、右23例(56.1%)。冷麻痹22例,指震颤9例,手麻木4例; 41例均有手固有肌萎缩,均无感觉障碍;(2)症状侧尺和正中神经运动潜伏期延长,小指展肌、拇短展肌运动波幅减低,小指展肌/拇短展肌波幅比值减小;(3)症状侧针肌电图显示异常自发活动者的出现率,在第一骨间肌和小指展肌为100%、拇短伸肌90.1%、拇短展肌86.3%、肱桡肌16.8%、肱二头肌13.8%; 在仅限于单侧症状的35例患者中,无症状侧手固有肌也显示异常自发活动者占51.4%;(4)32例患者完成颈椎MRI检查。自然位时32例均显示颈2-颈7椎体后方下缘连线与椎体相交; 均显示下段颈髓萎缩变扁平,其中位于C5-C7节段14例,C5-C6节段6例,C6-C7节段7例,C5-T1节段5例; 屈颈位时15例显示硬膜腔后壁前移,移位的硬膜后方可见硬膜外占位,内有流空信号,恢复自然位后占位消失。9例显示髓内可疑T₂异常高信号。结论 MMA/平山病主要见于青少年男性; 电生理表现为低位颈髓前角细胞病变,且无症状侧可显示临床下神经源性损害; 小指展肌/拇短展肌波幅比值减小,是有鉴别意义的电生理指标; 屈颈位颈椎MRI对于诊断很重要。结合临床、神经电生理及影像表现,有助于更全面认识本病。     

A clinical study of Hirayama disease in Taiwan

The purpose of this study was to review the clinical manifestations of 40 patients who fulfilled the clinical criteria for Hirayama disease (juvenile muscular atrophy of distal upper extremities), identified in our neuromuscular clinic between February 1995 and December 2005. Of these 40 patients, 87.5% were male. The mean age at onset was 16.8 years, which was 4.5 years later than the peak age of the normal growth curve. Progressive muscle weakness and wasting were characteristic and occurred predominantly in the distal part of the right upper limb. Neurogenic symptoms ceased to progress within 5 years in most patients (92.5%). About one third of patients had participated frequently in heavy physical activity before onset of muscle symptoms. Reduced amplitude of the compound muscle action potential of the ulnar nerve was the most prominent finding in nerve conduction studies. Electromyography showed acute or chronic neurogenic changes, most frequently in muscles supplied by the C7-T1 segments. Magnetic resonance imaging showed anterior shifting of the posterior dura and engorged posterior venous plexus at the cervical level in 95% of patients. Our results support the belief that Hirayama disease is a self-limited, focal lower motor neuron disease involving the lower cervical segments. Disproportionate growth between the vertebral column and the contents of the spinal canal may be the underlying cause, and strenuous physical activity may be a precipitating factor.     

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.     

Carotid cavernous fistula with cervical myelopathy

We report a patient with carotid cavernous fistula (CCF) presenting with cervical myelopathy. The patient initially presented with ocular pain accompanied by binocular diplopia and was diagnosed with Tolosa-Hunt syndrome at another institution. This patient experienced long-standing venous hypertension due to the delay in diagnosis. Posterior venous drainage from the CCF caused venous congestion in the brainstem and cervical spinal cord causing cervical myelopathy. Glue embolization using n-butyl-2-cyanoacrylate was attempted, but only partial embolization was possible because access to feeding arteries was limited. Stereotactic gamma-knife radiosurgery was performed as an alternative treatment, and effectively obliterated the CCF. However, the patient remained disabled due to cervical cord atrophy associated with long-standing venous hypertension.     

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.     

Significance of increased signal intensity on MRI in prognosis after surgical intervention for cervical spondylotic myelopathy

We aimed to examine whether increased signal intensity (ISI) on T2-weighted MRI can be used to predict the surgical outcome of patients with cervical spondylotic myelopathy (CSM). ISI on T2-weighted MRI are frequently observed but the relevance of this finding remains controversial in patients with CSM. Between September 2007 and February 2009, 52 patients with CSM who underwent surgery were studied prospectively. Preoperative and postoperative functional status was evaluated using the modified Japanese Orthopaedic Association (JOA) scoring system, and the recovery rate was calculated using the Hirabayashi method. An MRI was performed on all patients. For those with ISI on T2-weighted MRI, the ratio of the signal intensity on T2-weighted to T1-weighted MRI (T2:T1 ratio) at the same spinal cord level and of similar area was calculated. Although the clinical outcome of all patients had improved at final follow-up, there was a significant difference between patients with ISI and those without ISI in age, duration of symptoms, preoperative and postoperative JOA scores, and recovery rate. The preoperative and postoperative JOA scores and the recovery rate differed significantly (p < 0.05) between the three groups: patients without a T2-weighted ISI, and those with different levels of a T2:T1 ratio. Patients with an ISI usually had a low preoperative JOA score and experienced less improvement in neurologic function after surgery. The T2:T1 ratio can be used to help predict surgical outcomes.     

Bilateral familial Hirayama disease in a father and daughter

We are reporting a case of bilateral familial Hirayama disease where a father and daughter are the affected members of the family with the similar distribution of their weakness and wasting. To the best of our knowledge, bilateral familial Hirayama disease has not been described in father and daughter.     

Degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) frequently leads to severe neurologic disability but is still frequently underdiagnosed. One explanation may be the variability of the symptoms presented by the patients, from paresthesia to quadriplegia, making it another great masquerader. What do we know? How can we manage better these patients? We will review the keys points concerning its challenging diagnosis (clinical and radiologic), some of the recent discoveries about DCM, notably the underlying genetic mutations identified, linked to its pathophysiology, before addressing the consensual points concerning its management and the major evolutive risk: acute decompensation.     

显微外科治疗脊髓型颈椎病的临床研究

目的评价脊髓型颈椎病前入路显微手术减压及内固定的疗效。方法对38例脊髓型颈椎病患者采用经颈前入路显微手术减压,12例取自体髂骨、26例用钛质网笼行植骨及钢板内固定。根据日本骨科协会(JOA)评分对神经功能恢复进行评价,并观察植骨融合率、融合节段椎间高度、颈椎生理曲度维持以及内植入物情况。结果随访32例,随访时间3~24个月,平均18个月,JOA评分由术前平均10.1分提高到术后平均14.8分,平均改善率为86%。32例单节段和两节段病变者以及6例三节段病变者术后3个月内形成骨性融合,融合率为100%;全部病例术后椎间高度和生理曲度维持满意;全部植入物无脱落或移位。结论采用显微手术方式,术野照明良好,经显微镜放大后解剖层次清晰,能准确识别各种病理损害,不但能使脊髓减压彻底而且能增加手术的安全性。     

Clinical and radiological profile of Hirayama disease: A flexion myelopathy due to tight cervical dural canal amenable to collar therapy

Background:

Hirayama disease (HD) is benign focal amyotrophy of the distal upper limbs, often misdiagnosed as motor neuron disease. Routine magnetic resonance imaging (MRI) is often reported normal.

Objective:

To study the clinicoradiological profile of hand wasting in young males.

Materials and Methods:

Patients presenting with insidious-onset hand wasting from March 2008 to May 2011 were evaluated electrophysiologically. Cervical MRI in neutral position was done in 11 patients and flexion contrast imaging was done in 10 patients.

Results:

All patients were males less than 25 years of age, with median age 23 years, except one patient who was 50 years old. Duration of illness was 3 months to 3 years. All (100%) had oblique amyotrophy, four (36%) cold paresis, 10 (91%) minipolymyoclonus and three (27%) had fasciculations. Regional reflexes were variably absent. Two patients (18%) had brisk reflexes of lower limbs with flexor plantars. Electromyography (EMG) showed chronic denervation in the C7-T1 myotomes. Neutral position MRI showed loss of cervical lordosis in 10/11 (91%), localized lower cervical cord atrophy in 9/11 (82%), asymmetric cord flattening in 11/11 (100%) and intramedullary hyperintensity in 2/11 (18%); flexion study showed loss of dural attachment, anterior displacement of dorsal dura, epidural flow voids in 9/10 (90%) and enhancing epidural crescent in 10/10 (100%). Clinical profile, imaging and electrophysiological findings of the patient aged 50 years will be described in detail as presentation at this age is exceptional. Collar therapy slowed progression in most cases.

Conclusion:

Clinical features of HD corroborated well with electrophysiological diagnosis of anterior horn cell disease of lower cervical cord. While dynamic contrast MRI is characteristic, routine studies have a high predictive value for diagnosis. Prompt diagnosis is important to institute early collar therapy.     

A meta-analysis showing that high signal intensity on T2-weighted MRI is associated with poor prognosis for patients with cervical spondylotic myelopathy

We used PubMed, Medline, and EMBASE to conduct a meta-analysis to determine the significance of high signal intensity on T2-weighted MRI for predicting postoperative prognosis in patients with cervical spondylotic myelopathy (CSM). Although patients with CSM with high signal intensity on T2-weighted MRI usually had a poor prognosis even after undergoing surgery, some researchers have argued recently that high-intensity signals are not associated with postoperative prognosis. Data consistent with the inclusion criteria of this study were cited for meta-analysis using Review Manager 5 Software. The postoperative recovery ratio specified by the Japanese Orthopedic Association (JOA) was assessed using the weighted mean difference (WMD) method. Five articles (one prospective; four retrospective) involving 309 patients with CSM were included. The aggregate WMD with regard to the postoperative JOA recovery ratio between the T2-weighted high signal intensity positive (+) group and the T2-weighted high signal intensity negative (-) group was -6.56, and the 95% confidence interval (CI) was -12.15 to -0.97 (p=0.02). Thus, we concluded that in patients with CSM, the postoperative JOA recovery ratio in the T2-weighted (+) group was lower than that in the T2-weighted (-) group.     

Hirayama disease: description of an Italian case

Hirayama disease is slowly progressive, usually monolateral, distal upper limb amyotrophy occurring mainly in young men. It is usually considered a kind of cervical myelopathy related to flexing movements of the neck. Several patients have been reported in Japan; we describe an Italian case.     

Hirayama disease with juvenile myoclonic epilepsy: A case report

Hirayama disease (HD) is rare, but benign anterior horn cell disease, predominantly affecting young men. One of the symptoms, besides weakness, is abnormal movement in the hand. Juvenile myoclonic epilepsy (JME) is one of the most common types of generalized epilepsies and can be recognized by a myoclonic jerk and electroencephalography (EEG) features. We report the case of a 19-year-old male who had HD, with unilateral abnormal movement in the hand, which was diagnosed as JME. We should consider performing an EEG in patients with HD, who present with atypical hand movements, in order to differentiate it from seizure.     

Operative fusion of multilevel cervical spondylotic myelopathy: Impact of patient demographics

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in patients older than age 55, with operative management being a widely adopted approach. Previous work has shown that private insurance status, gender and patient race are predictive of the operative approach patients receive (anterior-only, posterior-only, combined anterior–posterior). The Nationwide Inpatient Sample from 2001 to 2010 was used to assess the potential role of multilevel CSM as a contributing factor in determining which operative approach CSM patients receive, as it is rare for an anterior-only approach to be sufficient for CSM patients requiring fusion of four or more involved levels. Multivariate analyses revealed that female sex (OR = 3.78; 95% CI = 2.08–6.89; p < 0.0001), private insurance (OR = 5.02; 95% CI = 2.26–11.12; p < 0.0001), and elective admission type (OR = 4.12; 95% CI = 1.65–10.32; p = 0.0025) were predictive of increased receipt of a 3+ level fusion in CSM. No other variables, including patient age, race, income, or admission source were predictive of either increased or decreased likelihood of receiving fusion of at least three levels for CSM. In conclusion, female sex, private insurance status, and elective admission type are each independent predictors in CSM for receipt of a 3+ level fusion, while patient age, race and income are not. Given the propensity of fusions greater than three levels to require posterior approaches and the association between posterior CSM approaches and increased morbidity/mortality, these findings may prove useful as to which patient demographics are predictive of increased morbidity and mortality in operative treatment of CSM.