Hirayama Disease Research Articles

Neuroimage: the crescent moon sign of Hirayama disease.

Neuroimage: the crescent moon sign of Hirayama disease.

A Study of Diffusion Tensor Imaging in Hirayama Disease.

Hirayama disease (HD) is a motor neuron disease and occasionally is associated with lower limb hyper-reflexia. Corticospinal tract dysfunction can be evaluated by diffusion tensor imaging (DTI), but there is paucity of study in HD. We report corticospinal tract functions using DTI in the patients with HD and correlate with clinical findings. The patients with HD diagnosed on the basis of clinical and electromyography findings were included. Their age, duration of illness, side of initial involvement, and progression were noted. Presence of lower limb hyper-reflexia, and cervical spine magnetic resonance imaging (MRI) findings were noted. Cranial MRI was done and DTI findings at internal capsule, cerebral peduncle, pons, and pyramid were noted. In total, 10 patients with HD and 5 matched controls were evaluated. The apparent diffusion coefficient (7.03 ± 0.27 vs 6.83 ± 0.36), fractional anisotropy (0.79 ± 0.04 vs 0.82 ± 0.05), axial diffusivity (5.08 ± 0.08 vs 5.04 ± 0.07), and radial diffusivity (3.79 ± 0.05 vs 3.76 ± 0.05) between HD patients and controls were not different in internal capsule. These values were also not significantly different in cerebral peduncle, pons, and pyramid. These values were also not significantly different between the severe and less severely affected sides. The fractional anisotropy did not correlate with lower limb hyper-reflexia (P = 1.00) and spinal cord atrophy (P = 0.60). DTI study in HD patients did not reveal corticospinal tract involvement in brain.

Hirayama disease: An ayurvedic approach

Introduction: Hirayama disease, also known as Monomelic amyotrophy or benign focal amyotrophy, is a rare motor neuron disease. It is reported to primarily affect males of southeast Asia, particularly India and Japan. Clinical findings and Intervention: A 27 years male patient approached Ayurveda OPD with a known case of Hirayama Disease from last 9 years. Considering this condition, the treatment was planned according to Ayurvedic Medicinal system which included courses of Nasya karma, Basti karma and Shamana aushadi. Outcome: Post treatment, the patient showed considerable clinical improvement, and arrest in disease progression was observed. Conclusion: The present condition is understood under the spectrum of Vata vyadhi and was diagnosed as a case of Viswachi. The treatment was focused upon pacifying vata Dosha and restoring strength and functional capacity.

Diagnosis of Benign Monomelic Amyotrophy

Diagnosis of Benign Monomelic Amyotrophy

Clinical, electrophysiological and MRI profile of Hirayama disease: A case series

Introduction: Hirayama disease (HD) is focal amyotrophy in young adults, and commonly involves distal upper limbs, often misdiagnosed as motor neuron disease and writer’s cramp. This often leads to delay in the diagnosis and results in disease progression. In this study, we have analyzed clinical, radiological and electrophysiological profile of patients presenting with hand wasting and weakness. Materials and Methods: Patients presenting with insidious onset of hand wasting (January 2014 to February 2017) were evaluated clinically and electro physiologically. Cervical MRI in neutral and flexion position was done. Results: All 16 patients were male, were less than 25 years of age, with median age of 22 years. Duration of illness was 3 months to 7 years. All patients presented with insidious onset of progressive weakness and lower motor neuron type of wasting of hands. Nine (56.25%) patients presented with right sided, five (31.25%) with left sided and another two (12.5%) presented with bilateral asymmetric weakness and wasting. None of the patients had neck pain or radicular symptoms. Twelve (75%) had cold paresis, eight (50%) had minipolymyoclonus and five (31.25%) had fasciculations. Electromyography (EMG) showed chronic denervation in the C7T1 myotomes. In MRI, localized lower cervical cord atrophy was seen in 13 (81.25%) cases. Asymmetric cord flattening was noted in 14 (87.5%) cases. Loss of dural attachment in 13 (81.25%), anterior displacement of dorsal dura on flexion in 14 (87.5%) and epidural flow voids were seen in 14 (87.5%) cases. Enhancing epidural crescent in flexion was seen in all 12/16 (75.0%) cases. Intramedullary hyper intensity was seen in 2 (12.5%) patients. Conclusions: 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 differentiate it from other progressive conditions and to institute early therapy.

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.

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.].

Hirayama Disease can be Caused by Loss of Attachment of the Cervical Posterior Dura to the Pedicle due to Immunological Abnormalities of the Dura and Posterior Ligaments: A New Hypothesis

Hirayama disease is a rare and self-limiting cervical myelopathy related to neck flexion in adolescents, predominantly male, originally described by Hirayama in 1959 and until today reported worldwide. It characteristically presents with asymmetric distal upper extremity muscular weakness and atrophy without objective sensory disturbance or lower extremity involvement, which spontaneously halts within 3-5 years after onset with some sequelae. Neuroradiological and autopsy/neuropathological studies have shown that the condition is caused by chronic ischemic changes to the anterior horn cells of the lower cervical cord due to abnormal forward-shifting of the lower cervical posterior dura on neck flexion. Although the true pathomechanism of the dural changes is still unknown, various hypothetical theories have been formulated: "tight dural canal in flexion", "flexion myelopathy", "engorgement of the posterior venous plexus", and "disproportional growth between the vertebral column and the contents of the spinal canal during puberty" (Hirayama). However, rarity of the condition and asymmetric cord involvement cannot be explained with these theories alone. Combination of a "posterior epidural ligament [sparse at C6-C7] factor" proposed by Shinomiya , "loss of dorsal dural attachment from the pedicle even in neutral position in the MRI" pointed out by some neuroradilogists, and "pathological abnormalities of elastic and collagen fibers in the operatively-resected dura" reported by several spinal surgeons suggest that abnormal changes of the dura and posterior ligaments, as well as the existence of "myodural bridge" at C1-C2 described by some neuroanatomists, can cause the dural forward-shifting of the lower cervical cord. In addition to these mechanical factors, immunological abnormalities such as hyperIgEemia and upreguration of some cytokines and chemokines in serum/CSF of patients with Hirayama disease have been reported. Furthermore, immune cells comprise -17% of all cells in the dura in rats. In conclusion, although further immunological studies of the patient's cervical dura and surrounding structures are required, I propose, in addition to Hirayama's theory, a new hypothesis about the pathomechanism of Hirayama disease, "loss of dorsal dural attachment from the pedicle due to immunological abnormalities of the dura and posterior ligaments", which can resolve the remaining problems of the condition. (Received May 25, 2020; Accepted July 2, 2020; Published December 1, 2020).

In Reply to the Letter to the Editor Regarding “Chiari Formation and Syringomyelia Associated with Hirayama Disease”

In Reply to the Letter to the Editor Regarding “Chiari Formation and Syringomyelia Associated with Hirayama Disease”

Letter to the Editor Regarding “Chiari Malformation and Syringomyelia Associated with Hirayama Disease”

Letter to the Editor Regarding “Chiari Malformation and Syringomyelia Associated with Hirayama Disease”

Effect of strengthening exercises in Hirayama disease: a case study

Background/AimsThe effects of strengthening exercises in patients with Hirayama disease are not well documented. This case study examined the effect of strengthening exercises on hand functions in a patient with Hirayama disease.MethodsAn 18-year-old man with weakness in the right hand was given a hand-function strengthening programme consisting of 40 minutes of exercises, which were performed 5 days a week over an 8-week period. The patient used theraputty, a gel ball, finger dexterity board, gym kit and hand grip exerciser. The effects of the programme were evaluated using manual muscle testing, a hand-held dynamometer, pinchometer and the Minnesota Manual Dexterity Test.ResultsThe patient's manual muscle testing grades improved following the strengthening programme. Results from the Dynamometer, pinchometer and Minnesota Manual Dexterity Test objectively exhibited increased muscle strength and improved hand functions.ConclusionsStrengthening exercises are effective in alleviating muscle weakness and improving hand functions associated with Hirayama disease.

An Interesting Case of Bilateral Upper Limb Wasting: Hirayama Disease

AbstractHirayama disease is a rare neurologic disease and is characterized by insidious unilateral or bilateral muscular atrophy and weakness of the forearms and hands without sensory or pyramidal signs. Our patient presented with bilateral upper limb wasting, which is a rarer variant of motor neuron disease. The diagnosis of Hirayama disease is based on dynamic magnetic resonance imaging (MRI). This case displays how dynamic cervical spine MRI can pick up dynamic cord compression and contributes to zero in the diagnosis of Hirayama disease.

Letter to the Editor Regarding “Diffusion Tensor Imaging Characteristics in Hirayama Disease: Case Report and Review of the Literature”

Letter to the Editor Regarding “Diffusion Tensor Imaging Characteristics in Hirayama Disease: Case Report and Review of the Literature”

In Reply to the Letter to the Editor Regarding ‘Diffusion Tensor Imaging Characteristics in Hirayama Disease: Case Report and Review of the Literature’

In Reply to the Letter to the Editor Regarding ‘Diffusion Tensor Imaging Characteristics in Hirayama Disease: Case Report and Review of the Literature’

Polymyoclonus aggravated by neck flexion as the isolated presenting symptom of Hirayama disease: case report

BackgroundWe report a rare case of an 18-year-old male with unilateral hand tremor who was finally diagnosed with Hirayama disease (HD).Case presentationAn 18-year-old male presented with unilateral polymyoclonus that aggravated with neck flexion. The patient did not complain of muscle weakness or muscle atrophy. The needle electromyography showed giant motor unit potentials in right cervical 7 and 8 innervated muscles. The cervical magnetic resonance imaging on supine and flexion state showed prominent forward effacement of posterior dural sac that was compatible with HD.ConclusionsHD usually presents with unilateral distal hand weakness, muscle atrophy and tremor. Although it is a benign and self-limiting disease, early diagnosis may lead to less clinical deterioration. Moreover, electromyography should be completed in the differentiation of young male patients who present with polymyoclonus without hand weakness or atrophy.

The diagnostic quandary of magnetic resonance imaging-negative Hirayama disease: a case report

BackgroundMagnetic resonance imaging (MRI) features are typical findings in Hirayama disease (HD) and are useful diagnostic entities but may not be present in all patients.Case presentationWe present the case of a 22-year-old Nepalese man who presented with insidious onset of weakness of his right upper limb of more than 5 years duration. His weakness was progressive for the first 3 years, and then remained static. On examination, weakness of the interossei, thenar, hypothenar, flexor, and extensor muscles were present in his right upper limb, power was normal in his left upper and bilateral lower limbs. Minipolymyoclonus was present in both upper limbs, less prominent on the left side. Electrophysiological findings showed motor axonal neuropathy in his right upper limb, neurogenic discharges and fibrillations, and fasciculations in both upper limbs. Contrast magnetic resonance imaging (MRI) of his cervical spine in flexion was normal. Our patient was diagnosed with HD based on clinical and electrophysiological findings. Our patient was advised to use a cervical collar and regular physiotherapy and was found to have subjective benefit.ConclusionA normal cervical MRI does not rule out HD and the diagnosis can also be made based on clinical and electrophysiological studies. Progressive distal upper limb weakness or tremor in young patients should be evaluated for HD, because early diagnosis and intervention might halt the progression.

Hirayama Disease: A Report of Two Cases and Review of Imaging Findings

Hirayama Disease: A Report of Two Cases and Review of Imaging Findings

Hirayama disease – Early MRI diagnosis of subacute medullary ischemia: A case report

Background: Hirayama disease (HD) is a rare, benign, and self-limiting motor neuron disorder that results in selective motor impairment of the C7-T1 myotomes. It is characterized by progressive, unilateral, or bilateral asymmetric muscle atrophy of the distal upper extremities and myelopathy.Case Description: A 23-year-old male presented with bilateral atrophy of the thenar/hypothenar eminences/ interosseous muscles, plus left-hand weakness. The cervical MRI documented subacute ischemic damage of the distal cervical cord. To rule out a tumor and reduce questionable cord compression, the patient underwent a C5–C6 anterior cervical discectomy and fusion (ACDF) immediately followed by a laminectomy with durotomy and to obtain a spinal cord biopsy. When the histology confirmed focal cord ischemia consistent with HD, it was clear that both operations were unnecessary.Conclusion: Establishing the diagnosis of HD is based on clinical findings and MRI/flexion MR features which include the demonstration of an increased T2-weighted intramedullary cord signal, enlargement of the posterior epidural space, and segmental spinal cord atrophy. The presence of HD should be recognized as a “nonsurgical entity,” and conservative nonsurgical management should be employed.

Significance of Dynamic Imaging in Diagnosis of Hirayama Disease: A Rare Case Report and Literature Review

Significance of Dynamic Imaging in Diagnosis of Hirayama Disease: A Rare Case Report and Literature Review

Establishment of a clinician-led guideline on the diagnosis and treatment of Hirayama disease using a modified Delphi technique

ObjectiveTo establish a clinician-led guideline for the diagnosis and treatment of Hirayama disease (HD) using a modified Delphi technique. MethodsBased on a combination of a systematic review and opinion of ten experts, a protocol for the consensus of the diagnosis, treatment and follow-up assessment of HD was established. A modified 3-round Delphi survey was then performed by more than 40 panelists from various countries of the world. Both levels of evidence and levels of agreement were derived in all statements of finial guideline. ResultsA total of 47 experts from 6 countries were enrolled in the expert panel in this study. Highly consistent results were achieved during the three Delphi rounds. An expert-led guideline finally constructed includes 24 statements related to diagnosis, treatment and follow-up assessment of HD. ConclusionsThe modified Delphi technique used in this study resulted in an expert-led guideline concerning several clinical aspects of HD. SignificanceThis clinician-led guideline may provide a helpful direction for clinical practice with regard to the diagnosis and treatment of HD.