Why the patients with Hirayama disease have abnormal cervical sagittal alignment? A radiological measurement analysis of posterior cervical extensors

Purpose To explore the relationship between the strength of posterior cervical extensors (PCEs) and cervical sagittal alignment in Hirayama disease (HD) patients. Methods We analyzed the (magnetic resonance imaging) MRI T2WI and X-rays of 60 HD patients who visited Huashan Hospital from June 2017 to February 2020. Symptoms of these patients include adolescent onset, manifestation of unilateral upper limb muscle weakness and muscle atrophy of the forearm and hand. MRI images were used to measure (the cross-sectional area) CSA of cervical PCEs. The ratio of muscle CSA to vertebral body areas at the same level is defined as R-CSA. Cervical sagittal alignment includes the C2–7 Cobb angle, T1 slope and C2–7 sagittal vertical axis (SVA). The geometric center of the C3–6 vertebral body was determined using the line connecting the C2 inferior endplate and the C7 upper endplate. When located behind the line, it is defined as a “local kyphotic deformity.” The number of vertebral bodies involved in kyphotic deformity was determined by measuring the local kyphosis angle (LKA). Spearman correlation analysis (α = 0.05) was used to determine the relationship between R-CSA and sagittal parameters. ROC curves were used to analyze the sensitivity and specificity of relevant variables. Results Spearman correlation test revealed that R-CSA negatively correlated with T1S (S = 0.34, r = 0.34, p = 0.01) and LKA (S = 0.44, r = 0.5, p = 0.01), but did not correlate with the C2-C7 Cobb angle (S = 0.20, p = 0.12) or C2-C7 SVA (S = − 0.17, p = 0.46). (p < 0.05). ROC curve analysis showed that the areas under the curve (AUCs) of the T1 slope and LKA was 0.6696 and 0.7646, respectively. T1 slope, cutoff value: 17.2°; sensitivity: 0.5806; specificity: 0.7241; p < 0.05. LKA: cutoff value: − 14°; sensitivity: 1; specificity: 0.5333; p < 0.05. Conclusions In patients with Hirayama disease, the strength of posterior cervical extensors and cervical sagittal alignment are closely related. The local kyphosis angle can be used as a reference for the strength of posterior cervical extensors. These results indicate the weakness of PCEs, which may predispose the cervical spine of HD patients to a less stable situation. Therefore, patients with Hirayama disease should strengthen the exercise of the PCEs.

Hirayama disease. Clinical cases

Hirayama disease, or monomelic amyotrophy, is a rare neurological pathology manifested by unilateral or bilateral asymmetric paresis with atrophy of the distal upper extremities. The development of this disease is associated with the forward displacement of the posterior dural sac during neck flexion, which leads to compression of the spinal cord and venous stasis. The diagnosis of monomelic amyotrophy is based on the clinical picture and the results of magnetic resonance imaging of the cervical spine with flexion, showing segmental atrophy of the anterior horns of the spinal cord at C7 — Th1, detachment of the posterior dura mater and venous stasis. Most of the cases described in the literature are from India and Japan, with isolated cases diagnosed in North America and Europe. This article presents two clinical cases of progressive hand weakness in young men. The clinical picture of the disease and the results of additional examination methods are presented, which is necessary to establish a diagnosis of Hirayama’s disease.

Supercharged End-to-Side Anterior Interosseous to Ulnar Motor Nerve Transfer for Hirayama Disease: A Case Report

Hirayama disease is a rare condition of cervical myelopathy. Its early identification and correction can optimize functional outcomes. However, late presentation and some more severe cases may be associated with loss of hand function. Among the cases described, there are no reports of nerve transfers for this condition. We presented the first case report of a Hirayama disease of isolated ulnar nerve impairment managed with nerve transfer. Electroneuromyography showed isolated preganglionic involvement of C7, C8, and T1, with no sensory changes. The patient underwent nerve transfer with anterior interosseous nerve to ulnar nerve supercharge end-to-side, recovering hand function in 7 months.

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.

Interobserver and Intraobserver Reproducibility and Reliability of the Huashan Clinical Classification System for Hirayama Disease

Purpose: The Huashan clinical classification system for Hirayama disease has recently been proposed and has been found useful for diagnosis and treatment. So far, however, there has been little in-depth evaluation of its reliability. Thus, this study aimed to assess the reproducibility and reliability of the system.Methods: Patients diagnosed with Hirayama disease between 2019 and 2020 were recruited. Seven spine surgeons from four different institutions, including an experienced group of three and an inexperienced group of four, were trained as observers of the Huashan clinical classification system for Hirayama disease, and these surgeons classified the recruited patients using the system. Then, 2 months later, they repeated the classification on the same patients in a different order. The interobserver and intraobserver agreement between the results was analyzed using percentage agreement and weighted kappa (κ) statistics.Results: A total of 60 patients were included in the analysis. For all the observers, experienced observers, and inexperienced observers, the agreement percentages were, respectively, 78.5% (κ = 0.76), 80.0% (κ = 0.78), and 78.9% (κ = 0.77), indicating substantial interobserver reproducibility. For distinguishing typical (Types I and II) and atypical (Type III) Hirayama disease among the different groups of observers, the percentage agreement ranged from 95.6 to 98.9% (κ = 0.74–0.92), indicating substantial to nearly perfect reproducibility. For suggesting conservative treatment (Types I and III) or surgery (Type II), the percentage agreement ranged from 93.3 to 96.4% (κ = 0.81–0.90), indicating nearly perfect reproducibility. As for intraobserver agreement, the percentage agreement ranged from 68.3 to 81.7% (κ = 0.65–0.79), indicating substantial reliability.Conclusion: The Huashan clinical classification system for Hirayama disease was easy to learn and apply in a clinical environment, showing excellent reproducibility and reliability. Therefore, it would be promising to apply and promote this system for the precise and individualized future treatment of Hirayama disease.

P.205 Association Between Vein of Galen Aneurysmal Malformation and Hirayama Disease: A Clue into Pathophysiology?

Background: Hirayama Disease (HD) is a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. Vein of Galen aneurysmal malformations (VGAMs) are rare congenital cerebral vascular malformations, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders. Methods: 14 years old boy known for VGAM presented with left-sided HD. His cervical MRI revealed enlarged epidural with anterior, left-ward displacement of the posterior dura and spinal cord. He underwent surgical treatment by laminotomies, along with tenting of an autologous duroplasty to the overlying laminae. Results: We decided to combine epidural venous plexus coagulation with posterior duraplasty and dural fixation using tenting suture which led to a favorable clinical outcome has not been previously proposed in the literature. We hypothesize that in this context, an abnormal vasculature could also predispose to posterior epidural venous plexus engorgement, anterior dural displacement in cervical flexion, and microvascular changes in the anterior spinal arterial circulation, leading to the progressive anterior horn cell ischemia that lead to the clinical phenotype of HD. Conclusions: The association between HD and VGAM in this patient may provide clues with regard to the pathophysiology of HD.

Hirayama Disease in a Patient with a History of Late-Onset Symptomatic Vein of Galen Aneurysmal Malformation

<b><i>Introduction:</i></b> The purpose of this report is to present a rare case of Hirayama disease (HD) in a patient with a history of late-onset symptomatic vein of Galen aneurysmal malformation (VGAM). This report may provide new insights into the pathophysiology of HD, a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. These symptoms are believed to result from cervical myelopathy affecting the anterior horn cells due to abnormal compressive forces on the spinal cord from adjacent anatomical structures (i.e., dura and/or epidural veins), but this has not been proven. VGAM is a rare congenital cerebral vascular malformation, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders, which most frequently presents in the early neonatal period with congestive heart failure. <b><i>Case Presentation:</i></b> We report the case of an otherwise healthy boy who presented with heart failure due to VGAM at 7 years and subsequently presented at 14 years with left-sided HD. His cervical MRI with neck flexion revealed enlarged epidural veins at the C5–C6 spinal level with anterior, leftward displacement of the posterior dura and spinal cord as well as left hemicord flattening and/or atrophy at this level. He underwent successful surgical treatment by C5–C6–C7 osteoplastic laminotomies and tenting and expansile autologous duraplasty, during which enlarged, engorged epidural veins were confirmed and coagulated. This halted the progression of his left hand weakness and atrophy and allowed significant functional improvement. Postoperative catheter angiogram showed no anatomical connection between the persistent VGAM and the engorged epidural veins, and genetic testing revealed no genetic predisposition of vascular malformations. <b><i>Discussion/Conclusion:</i></b> In this patient, a combined surgical technique was performed that included epidural venous plexus coagulation with posterior autologous duraplasty and dural fixation using tenting sutures. This combined approach led to a favorable clinical and radiographic outcome with no complications or limitations and has not been previously proposed in the literature, to our knowledge. Although not completely ruled out, we found no angiographic connection or genetic predisposition to suggest there is a pathophysiological link between HD and VGAM.

The Relationship Between Preoperative Cervical Sagittal Balance and Clinical Outcome of Patients With Hirayama Disease Treated With Anterior Cervical Discectomy and Fusion

Objective: Anterior cervical discectomy and fusion (ACDF) is a common surgical method used to treat patients with Hirayama disease. And sagittal balance indexes have been revealed to be predictors of clinical outcomes in patients with cervical diseases, but their relationships with ACDF-treated Hirayama disease outcomes remain unknown. The purpose of this study is to evaluate the relationship of preoperative cervical sagittal balance indexes and clinical outcomes in ACDF-treated Hirayama disease patients.Methods: Eighty patients with Hirayama disease treated by ACDF were reviewed retrospectively. Six cervical sagittal balance parameters were collected including Cobb angle, T1 slope, C1–7 sagittal vertical axis (SVA), C2–7 SVA, center of gravity of the head (CGH)-C7 SVA, range of motion. The recovery outcomes of the patients were divided into 2 groups by Odom score and the differences in recovery between the 2 groups were confirmed by electromyography. The correlation between imaging parameters and postoperative outcome was evaluated with logistic regression. The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to evaluate the significant result of logistic regression and the optimal diagnostic value.Results: Only 2 parameters, Cobb angle and CGH-C7 SVA, showed statistical correlation with the postoperative outcome assessment by logistic regression. AUC of Cobb angle and CGH-C7 SVA were 0.559 and 0.702 respectively. The optimal predictive threshold was 1.50° and 5.40 mm, respectively.Conclusion: A larger Cobb angle and smaller CGH-C7 SVA seemed to correlate with a better postoperative outcome. These 2 factors could be used to predict the outcome of surgical treatment of Hirayama disease preoperatively.