Anterior cervical discectomy and fusion for the treatment of pediatric Hirayama disease

PURPOSE

Hirayama disease, a rare cervical myelopathy in children and young adults, leads to progressive upper limb weakness and muscle loss. Non-invasive external cervical orthosis has been shown to prevent further neurologic decline; however, this treatment modality has not been successful at restoring neurologic and motor function, especially in long standing cases with significant weakness. The pathophysiology remains not entirely understood, complicating standardized operative guidelines; however, some studies report favorable outcomes with internal fixation. We report a successful surgically treated case of pediatric Hirayama disease, supplemented by a systematic review and collation of reported cases in the literature.

METHODS

A review of the literature was performed by searching PubMed, Embase, and Web of Science. Full-length articles were included if they reported clinical data regarding the treatment of at least one patient with Hirayama disease and the neurologic outcome of that treatment. Articles were excluded if they did not provide information on treatment outcomes, were abstract-only publications, or were published in languages other than English.

RESULTS

Of the fifteen articles reviewed, 63 patients were described, with 59 undergoing surgery. This encompassed both anterior and posterior spinal procedures and 1 hand tendon transfer. Fifty-five patients, including one from our institution, showed improvement post-treatment. Eleven of these patients were under 18 years old.

CONCLUSION

Hirayama disease is an infrequent yet impactful cervical myelopathy with limited high-quality evidence available for optimal treatment. The current literature supports surgical decompression and stabilization as promising interventions. However, comprehensive research is crucial for evolving diagnosis and treatment paradigms.

Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients

BACKGROUND

Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD.

METHODS

Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire.

RESULTS

Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement.

CONCLUSIONS

ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

Single-institution Series of Hirayama Disease in North America

STUDY DESIGN

A retrospective chart review.

OBJECTIVE

The aims of this study were to review pathophysiology, workup, and treatment for Hirayama disease (HD); and to assess outcomes from a single institution.

SUMMARY OF BACKGROUND DATA

HD is a rare, painless, cervical myelopathy with distal upper extremity weakness, muscle wasting, and spinal cord atrophy. Disease progression-a consequence of repeat flexion injury-occurs up to 5 years from the initial diagnosis.

METHODS

Single-institution review of pediatric HD patients from 2010 to 2020.

RESULTS

Patients (n=10 male, n=2 female) presented in the second decade (14-20 y) with painless progressive distal upper extremity weakness and atrophy without sensory loss. Electromyography (n=12) demonstrated denervation in C7-T1 myotomes and flexion/extension magnetic resonance imaging showed focal cord atrophy and anterior displacement of the posterior dura with epidural enhancement in flexion. Treatment included observation and external orthoses (n=9) and anterior cervical discectomy with fusion (n=3). One of the 9 patients managed conservatively experienced further deterioration; no patient who underwent anterior cervical discectomy with fusion progressed.

CONCLUSIONS

Patients with HD require a multidisciplinary approach to diagnosis and treatment to preserve function. Treatment is preventive and aims to minimize flexion injury by inhibiting motion across involved joints. First-line management is avoidance of neck flexion and use of rigid orthosis; in cases of failed conservative management and/or rapid clinical deterioration, surgical fixation can be offered.

Laminoplasty with tented duraplasty for Hirayama disease

BACKGROUND

Hirayama disease (HD) is a characterized by progressive amyotrophy of the upper limbs due to a forward displacement of the cervical dura during neck flexion.

METHODS

Unlike other treatment options aiming at preventing cervical flexion (e.g., collar or arthrodesis), laminoplasty with tented duraplasty addresses dural dysplasia. Technically, the procedure consists in enlarging the dural sac by performing an expansile duraplasty that is secured to the yellow ligaments, in association with an open-book laminoplasty.

CONCLUSION

Laminoplasty with tented duraplasty is a surgical option addressing the cause of HD to prevent further neurological deterioration while preserving cervical motion.

Spinal Muscular Atrophy Type III Recognized After Delayed Recovery From Neuromuscular Blockade After an Orthognathic Surgery

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by the degeneration of alpha motor neurons in the spinal cord, resulting in progressive proximal muscle weakness and paralysis. SMA is classified into types I-IV based on the age at symptom onset or maximum motor function achieved, and its clinical manifestations vary. SMA affects maxillofacial growth because of muscle dysfunction and results in abnormal maxillofacial morphology. In addition, definitive diagnosis is not often made because of the older onset age and symptoms are rarely severe. Therefore, the possibility of undiagnosed SMA in craniofacial surgeries must be considered. This report described a case of an SMA type III recognized after delayed recovery from the neuromuscular blockade in an orthognathic surgery under general anesthesia.

Procedural sedation for paediatric patients with spinal muscular atrophy undergoing intrathecal treatment

AIMS

Nusinersen is administered intrathecally for treating spinal muscular atrophy (SMA). Procedural sedation is common with intrathecal treatment in children. The purpose of this study is to emphasize that intrathecal treatment of paediatric patients with SMA I, II and III can be tolerated with procedural sedation instead of general anaesthesia.

METHODS

Data were collected the from the anaesthesia charts and electronic medical records of 14 paediatric patients with SMA types I, II and III who underwent procedural sedation for repeated intrathecal treatments for SMA. Intravenous induction was performed, and patients were oxygenated with a face mask or nasal cannula while spontaneous breathing continued.

RESULTS

Fourteen patients were included in the study: one SMA I, eight SMA II and five SMA III. They underwent 88 intrathecal nusinersen injections in total. In the one SMA I patient, of 8 months, the procedure was performed under local anaesthesia. In all other patients, the treatments were performed under procedural sedation. Different combinations of midazolam, ketamine, propofol, fentanyl and remifentanil were used. The mean doses of the agents used were 0.03 mg kg-1 , 0.97 mg kg-1 , 2.71 mg kg-1 , 0.84 μg kg-1 and 0.5 μg kg-1 , respectively. There were no intraoperative or postoperative complications.

CONCLUSION

We found the procedural sedation to be sufficient, safe and effective in SMA II and III paediatric patients who underwent nusinersen treatment intrathecally, provided anaesthetic agents are titrated and administered carefully.

Evolving Surgical Management for Early-Onset Scoliosis in Spinal Muscular Atrophy Type 1 Given Improvements in Survival

CASE

We present a case of an 18-month-old child with early-onset scoliosis in the setting of spinal muscular atrophy (SMA) type 1 whose rapidly progressive scoliosis is successfully managed with magnetic growing rods, the youngest age of implantation in a patient with SMA we are currently aware of. Technical challenges, complications, and outcome are described in this case presentation.

CONCLUSION

Patients with SMA type 1 and early-onset scoliosis can be managed with growing-rod constructs given dramatic improvements in medical care that have expanded life expectancy.

Successful weaning from mechanical ventilation in a patient with SMA type 1 treated with nusinersen

SMA type 1 is the most severe type, characterized by early onset at <6 months of age, and rapid progression resulting in permanent assisted ventilation before 2 years of life. Supportive care was the only treatment until the approval of nusinersen, an antisense oligonucleotide drug that increases functional SMN protein levels. We present a case of successful weaning from permanent ventilation via tracheostomy with nusinersen in an infant who had been diagnosed with SMA type 1 at the age of one month and had become ventilator‐dependent from the age of 3 months.

The Influence of "Loss of Attachment" on the Outcome of Anterior Cervical Fusion Procedures in Patients With Hirayama Disease

The objective of this study was to identify the influence of the measurements of "loss of attachment" on the surgical outcome in Hirayama disease (HD). Forty-two patients with HD underwent neutral and cervical-flexion magnetic resonance imaging (MRI) before surgery, and the cervical-flexion MRI was repeated at the 3-month postoperative visit. The longitudinal separation range (LSR) of loss of attachment, the maximum forward-shifting (MFS) degree in the cervical cord, and the relative morphological changes of the cervical cord were measured on MRI. Additionally, all patients underwent handgrip strength (HGS) testing, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and Medical Research Council scales at the 1-year postoperative visit. Postoperatively, the cervical-flexion X/Y and the LSR decreased significantly at a mean of 94.17±8.65 days (range, 75-110 days) (P<.01), while the cervical-flexion A/B increased (P<.01). Loss of attachment was resolved in fused segments in all 42 patients, but there were 7 instances of residual loss of attachment at adjacent segments. Twenty (47.6%) of the 42 patients' DASH scores decreased at the 1-year postoperative visit. According to the logistic regression analysis, both LSR and MFS were related to the surgical outcomes. Receiver operating characteristic curve analysis found that area under the curve and cutoff values were 0.959 and 4.5, respectively (P<.05) for LSR and 0.782 and 0.215, respectively (P<.05) for MFS. Anterior cervical fusion procedures can effectively improve the abnormal loss of attachment and prevent further progression of HD. The LSR is an important risk factor for the prognosis, and longer fused segments may be required when the LSR is 5 segments or more. [Orthopedics. 2021;44(1):30-37.].

Improvement of Pulmonary Function Measured by Patient-reported Outcomes in Patients With Spinal Muscular Atrophy After Growth-friendly Instrumentation

BACKGROUND

Children with spinal muscular atrophy (SMA) sustain a progressive reduction in pulmonary function (PF) related to both muscular weakness and the concomitant effects of spinal deformity on the thorax. Growth-friendly instrumentation is commonly utilized for younger patients with scoliosis and SMA to halt the progression of spinal curvature, but its effect on PF in these patients has not previously been investigated. Using the change in Early Onset Scoliosis 24-Item Questionnaire (EOSQ-24) PF subdomain scores, the authors will investigate whether PF improves in patients with SMA after a growth-friendly intervention.

METHODS

This was a multicenter retrospective cohort study from 2 international registries of patients with SMA undergoing spinal deformity surgery from 2005 to 2015. Data collected were age, sex, degree of major coronal curve, type of growth-friendly construct, forced vital capacity (FVC), and EOSQ-24 scores at the patient's preoperative, 1-year postoperative, and 2-year postoperative visits. Differences in EOSQ-24 PF scores and FVC between baseline and postoperative assessment were examined by paired tests.

RESULTS

A total of 74 patients were identified (mean age, 7.6±2.3 y, major curve 68.1±22.4 degrees, 51.4% female individuals). The mean EOSQ-24 PF scores improved significantly from 70.6 preoperatively to 83.6 at 1 year (P=0.092) and 86.5 at 2 years postoperatively (P=0.020). The scores in patients with rib-based constructs showed steeper increases at 1-year assessments than those in patients with spine-based constructs. The mean paired FVC value decreased from 63.9% predicted preoperatively, to 57.6% predicted at 1 year postoperatively (P=0.035), and 61.9% predicted preoperatively, to 56.3% predicted at 2 years postoperatively (P=0.178).

CONCLUSIONS

Patients with SMA who received growth-friendly instrumentation did experience improvements in PF as measured by EOSQ-24 assessing the caregivers' perception. Given the uncertain reliability of PFTs in this young population, EOSQ-24 is an important tool for measuring improvements in health-related quality of life.

LEVEL OF EVIDENCE

Level III-retrospective study.

Factors Affecting the Surgical Outcomes of Hirayama Disease: A Retrospective Analysis of Preoperative Magnetic Resonance Imaging Features of the Cervical Spine

OBJECTIVE

We explored the factors affecting the surgical outcomes of Hirayama disease (HD).

METHODS

We enrolled 40 patients with a diagnosis of HD in the present study. Cervical spine magnetic resonance imaging (MRI) was performed before surgery with the neck in the cervical neutral and flexion positions. Fusion surgery was performed at the most severely compressed 2 levels according to the flexion sagittal MRI findings. The patients were divided into improvement and no-improvement groups according to Odom's scale 6 months after surgery. The axial MRI parameters in the neutral and flexion positions at the most severely compressed segment were measured. P values < 0.05 were considered statistically significant.

RESULTS

The average age was 18.4 ± 2.27 years, and the average disease duration was 1.8 ± 1.2 years. The main symptomatic side of HD statistically matched the atrophied side of the spinal cord (P < 0.001). Based on the pathophysiology of spinal cord flattening with flexion, the parameters indicating atrophy of the spinal cord and the ability of the spinal cord to recover from flattening were significantly larger in the improvement group (P < 0.05). Receiver operating characteristic curves showed good prognostic capacity for these parameters (P < 0.05).

CONCLUSIONS

The main side of the symptoms in patients with HD corresponded with ipsilateral spinal cord atrophy found on MRI. Also, atrophy of the spinal cord in the neutral position MRI study and the ability of the spinal cord to recover were significantly related to the surgical outcome. These factors might be used as potential indications for surgery of HD.

Cortical Activation Changes in Hirayama Disease After Anterior Cervical Decompression and Fusion

BACKGROUND

Spinal cord injury may cause cortical reconstruction. We, therefore explored the changes in cortical activation before and after anterior cervical decompression and fusion surgery in patients with Hirayama disease (HD).

METHODS

In total, 17 cases with HD underwent anterior cervical decompression and fusion surgery. Blood oxygenation level-dependent functional magnetic resonance imaging scan was performed preoperatively, 3 months, 6 months, and 1 year after surgery. Activated voxels were compared between both hands after adjusting for head motion, slice timing, spatial normalization, and image smoothing. Grip strength also was tested in both hands.

RESULTS

A retrospective review indicated that the grip strength of the asymptomatic hand was significantly stronger than the symptomatic hand at the time point before the surgery, 3 months after surgery, 6 months after surgery, and 1 year after surgery (P < 0.001). The grip strength of both symptomatic and asymptomatic hands continuously increased within 6 months after surgery (P < 0.05), but it stopped at 1 year after the surgery. The symptomatic limb tends to produce bilateral activation in the primary motor area (M1) during motor tasks. Both contralateral and ipsilateral M1 activation were stronger in symptomatic hand tasks preoperatively (P < 0.05). Both contralateral and ipsilateral activation in M1 during symptomatic hand tasks began to reduce after surgery, and statistical significance was observed 6 months after surgery (P < 0.05). Contralateral activation was relatively even over 6 months of the surgery (P > 0.05).

CONCLUSIONS

After surgery, pathologic reconstruction may have occurred in the primary motor cortex. Recovery of motor function in the symptomatic limb was accompanied by decreased ipsilateral and contralateral M1 activation, as well as symptom improvement. These findings suggested that postoperative cortical activation changes may reflect functional recovery in HD.

[Midterm clinical outcomes and radiological results of surgical treatment for Hirayama disease]

OBJECTIVE

To assess the midterm clinical and radiological outcomes of internal fixation and fusion for the treatment of Hirayama disease and to evaluate the clinical significance and value of this procedure.

METHODS

In the study, 36 patients were treated with anterior cervical internal fixation and fusion. The clinical outcomes including muscle strength and atrophy were recorded. The radiological outcomes including range of motion of cervical spine and the cross-sectional area of spinal cord at each level on MRI scan were measured before and at 3 month, 1 year and 2 years follow-up time points after surgery.

RESULTS

(1) Clinical outcomes: all the patients showed no further progression of symptoms except one patient with mild progression of muscular weakness and atrophy. As the time passed by, the ratio of the patients with muscle strength and atrophy improvement increased. There were 26.5% of patients in 3 months, 36.0% in 1 year and 85.7% in 2 years who experienced muscle strength improvement. 8.8% of patients in 3 months, 24.0% in 1 year and 35.8% in 2 years felt muscle atrophy improvement. And 12 of the 14 patients showed improved muscle strength and atrophy at the end of 2 years period follow-up. (2) Radiological outcomes: the range of motion (ROM) of C2-C7 was significantly decreased after the operation. The ROM of preoperation was 62.25°±2.10° and that of 2 years postoperation was 13.67°±7.51°(P<0.01). The spinal cord was of no compression on flexion MRI. The cross-section area of spinal cord on MRI was significantly increased only at C6 level (P<0.05) at the end of three months follow-up. The level of increased cross-section area rose to C4-C5-C6 levels (P<0.01) in 1 year and to C4-C5-C6-C7 levels at the end of 2 years follow-up (P<0.05). The cross-section area increased 15.60% at C4, 19.08% at C5, 21.60% at C6 and 23.91% at C7 with significant difference (P<0.05) 2 years after the operation.

CONCLUSION

Anterior cervical internal fixation and fusion is an effective surgical treatment for Hirayama disease and may provide preferable midterm clinical and radiological outcomes. This procedure has clinical significance and value in terms of control of the progression and outcome of this disease.

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.

[A clinical study of laryngotracheal separation in spinal muscular atrophy type I patients]

Artificial respiration by tracheostomy is necessary for long-term survival in spinal muscular atrophy (SMA) Type I patients. There are two types of tracheostomy: i )simple tracheostomy and ii) tracheostomy plus aspiration prevention surgery, including laryngotracheal separation. We experienced three cases of SMA type I patients that had good outcomes after undergoing laryngotracheal separation. The patients' ages at onset were 14 days, two months and one and a half months. Laryngotracheal separation was performed at five months, seven months, and 15 years and five months respectively, and the times from diagnosis to surgery were a month, three months and 15 years. The aspiration pneumonia disappeared in all three cases. This study suggests that laryngotracheal separation is an effective surgery to prevent aspiration in SMA type I cases, and also contributes to the improved quality of life of patients and their families.

Strategies for treating scoliosis in children with spinal muscular atrophy

Progressive pulmonary dysfunction is a major complication of spinal muscular atrophy (SMA). Growing constructs are a well-established alternative to spinal arthrodesis to maximize pulmonary growth. We describe patients who demonstrated sustained pulmonary function and improved quality of life following hybrid growing construct implantation. The purpose of this article is to demonstrate a range of approaches for managing scoliosis in children with SMA by utilizing vertical expandable prosthetic titanium rib implantation or growing rods with lateral rib fixation to improve clinical and patient-reported outcomes. Pulmonary compromise and quality of life decline are leading concerns in the SMA population. This case series highlights important surgical strategies that can be utilized to treat scoliosis in patients with SMA.

Advanced Hirayama disease with successful improvement of activities of daily living by operative reconstruction

Juvenile muscular atrophy of the distal upper extremity (Hirayama disease) is a benign and non-progressive motor neuron disease. Application of a cervical collar is believed to prevent progression of symptoms in the early stages, but there is no effective therapy for the advanced disease. We found that tendon transfer improved the activities of daily living (ADL) of a patient with advanced Hirayama disease. An operative reconstruction can be valuable, even in patients with Hirayama disease who have developed impaired ADL due to extensive intrinsic hand muscle atrophy.

One-stage versus two-stage spinal fusion in neuromuscular scolioses

The principles of the operative treatment of neuromuscular scolioses differ from those of idiopathic scolioses. Depending upon the deformity in the frontal and sagittal plane, the amount of pelvic obliquity and especially the etiology of the curve, consideration of a posterior, an anterior or a combined anterior-posterior procedure is necessary. Statistics demonstrate a higher preoperative angle and a higher rate of complications combined with worse corrections in comparison with idiopathic scolioses. The existing deterioration of vital capacity in patients with Duchenne muscular dystrophy, as in patients with spinal muscle atrophy, makes an anterior approach impossible. The correction of a severe pelvic obliquity combined with a rigid lumbar or thoracolumbar scoliosis requires a combined approach in most patients suffering from myelomeningcele (MMC) and cerebral palsy. In neurofibromatosis Recklinghausen associated with an angulated kyphotic curve the anterior approach is mandatory to avoid further deterioration. Multisegmental primary-stable anterior or posterior instrumentations allow postoperative care without external support.