Tools
Monomelic Amyotrophy (Hirayama Disease)
Introduction
Monomelic amyotrophy, previously known as Hirayama disease, is a rare, nonfamilial neurologic disorder first described by Hirayama in 1959.[1] Classical findings include unilateral or bilateral muscle atrophy and weakness of the forearms and hands without sensory loss. This condition usually progresses for 1 or 2 years before plateauing, eventually showing an abrupt arrest.[2][3] Monomelic amyotrophy is caused by chronic ischemic changes to the anterior horn cells of the cervical spine secondary to a limited dural sac laxity. The disorder is predominantly a lower motor neuron pattern of the lesion.[4]
Although often considered a nonprogressive and self-limiting disease, some individuals experience significant disability. Early intervention has been shown to limit the progression of the disease and minimize disability. Other names to describe this entity include benign juvenile brachial spinal muscular atrophy, juvenile asymmetric segmental spinal muscular atrophy, juvenile muscular atrophy of the distal upper extremity, Hirayama disease, and oblique amyotrophy.[5][6][7][8]
Etiology
Register For Free And Read The Full Article
Search engine and full access to all medical articles- 10 free questions in your specialty
- Free CME/CE Activities
- Free daily question in your email
- Save favorite articles to your dashboard
- Emails offering discounts
Learn more about a Subscription to StatPearls Point-of-Care
Etiology
Many theories have been postulated in the pathogenesis of this entity.[9] The contact pressure theory, inferred from cadaveric studies in 1960, postulated that degenerative spurs during flexion compress the cord. The tight dural canal theory in flexion was proposed in 1987. This theory is the most commonly accepted and describes an increased laxity of the dura mater from its superior anchors on the dorsal surfaces of C2 and C3, harbingering forward cord movement during cervical flexion. Increased laxity allows the spinal cord to shift forward, leading to repeated subclinical trauma and microischemia in the anterior horn during cervical flexion. Trauma and microischemia eventually lead to myelopathy and degeneration, as evidenced by asymmetric lower cervical cord thinning within the C7 and C8.
A growth imbalance between the vertebral column and the dural canal has been suggested to cause this laxity. This imbalance, especially evident during growth spurts, may result in increased laxity that permits anterior displacement of the posterior dura. Dural displacement decreases as growth slows down or stops, causing a plateau in the disease process.
Another theory is based on the posterior longitudinal ligament structure. Two cellular matrices have been described, one with fine elastic ligaments and the other with larger ones. Surgical and cadaveric studies suggest that these ligaments designed to secure the posterior dura mater are unequally dispersed, allowing only part of the cord to have anterior displacement.[10][11][12] Hirayama postulated that increased intramedullary pressure during neck flexion causes posterior epidural venous plexus stagnation, causing cord compression. Loss of dorsal dural attachment from the pedicle due to immunological abnormalities of the dura and the posterior ligaments has also been implicated in the pathogenesis.[13]
Epidemiology
Monomelic amyotrophy has been noted to have a male preponderance. The highest prevalence is observed in Asian populations, with most cases reported in Japan, China, Taiwan, Malaysia, India, and Sri Lanka. A few cases have been documented in Europe and North America. The prevalence of the entity in a Japanese survey was observed to be 1 in every 30,000 people.[14] Similarly, the 10-year prevalence rate in South Korea was reported to be 5.54 per 100,000.[15]
Insidious unilateral weakness typically begins at puberty, during the early to midteens. Peak onset age occurs about 2 years later than the growth curve peak for juvenile boys in Japan.[16] Following this onset, a plateau generally occurs 1 to 4 years later, though this plateau occasionally extends into the early 20s. Most reported cases, with a ratio of 2.8 cases to 1, show greater involvement of the right upper limb regardless of hand dominance. However, the few cases of bilateral upper limb involvement in this age group are considered the most severe clinical subtypes of the condition.
Pathophysiology
Autopsy findings demonstrate a greater than 50% reduction in the anterior-posterior diameter of the cervical cord, central necrosis, and diminished large and small nerve cells without macrophage infiltration at the C7-to-C8 levels, correlating well with reported symptoms and indicative of a chronic ischemic process. Loss of elastin within the dura is evident. Recurrent, flexion-induced chronic microcirculatory insufficiency of the anterior spinal artery results in the necrosis of alpha motor neurons.[17][18] This injury occurs due to the "Poisson effect," leading to gliosis and localized spinal cord atrophy, particularly in the lower cervical regions.[19] Kikuchi postulated disproportionate growth between the cord and the vertebral bony column, most often observed within the juvenile growth spurt, resulting in a tight dural sac.[20]
The loss of postural dural sac attachment to the subjacent lamina may limit compensatory increment in its length during neck flexion, displacing the cord anteriorly and compressing it against the posterior margin of the vertebral bodies. Venous congestion during neck flexion due to impaired jugular vein drainage may also exacerbate cord ischemia. Compression may also result from vein dilation within the posterior cord aspect.
Histopathology
Autopsy studies demonstrate monomelic amyotrophy to be marked by loss of elastin within the dura. This loss may contribute to the pathophysiology of the disease by compromising the dura's structural integrity.
History and Physical
Monomelic amyotrophy is characterized by the insidious onset of pubertal weakness, distal upper extremity atrophy, and gradual progression over 3 to 5 years. Patients often report a progressive decline in function, especially in the right hand, with a 3:1 ratio.[21] This decline stems from decreased strength and reduced dexterity, affecting daily activities that require fine motor skills, such as eating, dressing, and grooming. Patients may also experience increased fatigue and have a history of atopy or allergies.[22]
Some report "cold paresis," where weakness worsens in cold temperatures. Depending on the progression, initial complaints may focus on deformities from muscle atrophy. Sensory changes are rare, and pain usually does not arise until atrophy spreads to the upper arm and shoulder girdle in more severe cases. These symptoms often lead to reduced participation in sports and other social activities, causing patients to become socially withdrawn.
Appearance
A common presentation is unilateral atrophy in the distal upper limb. Most atrophy occurs in the thenar, intrinsic hand muscles, hypothenar, and forearms. Patients may also have limb length discrepancies, depending on disease severity. Asymmetric atrophy in the hand and forearm is characteristic due to the sparing of the brachioradialis, which is innervated by C6 (oblique amyotrophy). Bilateral asymmetric or symmetric amyotrophy and monomelic amyotrophy involving the lower limb are rare.
Strength
The preferential involvement of the C8-T1 segmental myotomes causes weakness most profound in the flexors and extensors of the wrist and digits. Fine motor activities, including pinch and grasp, are limited. The contralateral hand and digits exhibit full strength and dexterity. Elbow flexion, extension, pronation, and supination are typically unaffected. Proximal muscle groups are also mostly spared.
Neurologic Examination
The sensory examination findings for vibration, temperature, sharp, dull, and light touch modalities on all extremities are often unremarkable. The Hoffman and Holman test results are noncontributory. Pyramidal and autonomic involvement are rare.[23] Polyminimyoclonus, a low-amplitude, intermittent, and arrhythmic movement in extended hands, is also characteristic.[24][25]
Cardiovascular Examination
Pulses are normal. The limbs are warm, and the capillary refill is good.
Clinical Diagnostic Criteria for Monomelic Amyotrophy
The diagnostic criteria for monomelic amyotrophy include distal upper limb muscle weakness and atrophy, typically with onset between the ages of 10 and 20. The pattern is usually unilateral or predominantly asymmetric. Symptoms develop insidiously, with gradual progression followed by eventual stabilization. The absence of pyramidal signs or sensory disturbances is a key feature, and the diagnosis is made by excluding other conditions that present with similar symptoms.
Evaluation
Radiological imaging, electromyogram, and nerve conduction studies help differentiate monomeric amyotrophy from similar conditions. Key radiological features include loss of cervical lordosis, lower cervical cord atrophy, intramedullary signal changes, asymmetric cord flattening, an enlarged laminodural space, anterior displacement of the dorsal dura, prominent epidural flow voids, and an enhanced posterior crescentic region on flexion magnetic resonance imaging (MRI). Routine blood work typically does not contribute much to the diagnosis. Some cases show elevated serum immunoglobulin E, but the clinical relevance of such findings remains unclear. Traditional x-rays and fluoroscopy usually only reveal loss of cervical lordosis.
Magnetic Resonance Imaging
MRI commonly reveals a crescent-shaped lesion in the posterior epidural space of the lower cervical cord, atrophic spinal cord changes, mild asymmetric cord flattening, and increased signal intensity. Postcontrast neutral and flexion (30°-40°) MRI is the gold diagnosis standard.[26] The dynamic imaging features demonstrate a sensitivity of 70% and a specificity of 100%. These MRIs reveal a distinct anterior shift of the cervical dural sac from the lamina in the region of C4 to C7, leading to chronic microtrauma. Corresponding postcontrast enhancement of the posterior epidural venous plexus indicates ischemia.[27] Other characteristic findings include crescent-shaped postcontrast enhancement and prominent epidural flow voids due to venous dilatation during flexion.[28][29]
Advanced MRI techniques like 3-dimensional constructive interference in steady state and fast imaging employing steady-state acquisition cycled phases are recommended to eliminate the need for contrast studies. The "snake eye" sign correlates with a poor clinical outcome. Fractional anisotropy from tractography studies shows no link between pyramidal signs and cord atrophy.[30] However, diffusion imaging correlates with the flexion Cobb angle and degree of cord atrophy, serving as a surrogate marker for predicting outcomes.[31] Longitudinal separation range is an important MRI marker to determine "loss of attachment" and the need for long-segment fixation.[32] MRI also reveals reduced cross-sectional areas of the neck flexors and extensors, contributing to cervical spine instability and evidence of sagittal imbalance.[33][34]
Computed Tomography Venogram
Computed tomography venography provides detailed visualization of venous structures, allowing for the assessment of venous compromise and potential contributions to symptoms associated with monomelic amyotrophy. This modality helps precisely predict the required levels of spinal decompression.
Electromyogram and Nerve Conduction Studies
An electromyogram and nerve conduction study showed significant findings in the muscles innervated by C7, C8, and T1. Predominantly, C5-C7 involvement is observed in the Western population. A diminished compound muscle action potential (CMAP) amplitude is most noticeable in the median and ulnar nerves, with only a slight increase in latencies noted. Conduction velocities and sensory nerve conduction studies remain within the normal range. Electromyogram findings indicate chronic denervation, characterized by high-amplitude action potentials with prolonged durations, and may also show signs of active denervation, such as positive sharp waves or fibrillation potentials. These findings tend to be more pronounced at lower temperatures. Somatosensory evoked potentials are not considered a marker for the disease. A progressive decline and loss of the F wave indicate the progression of the lesion.
Motor neuron disease is widely involved in neurophysiological studies. The presence of "reverse split hand syndrome," characterized by decreased or absent CMAP amplitude in the abductor digit minimi while preservation occurs in the abductor pollicis brevis, aids in differentiating it from amyotrophic lateral sclerosis, which presents with "reverse hand syndrome."
Treatment / Management
Although considered a self-limited condition, the long-term effects of monomelic amyotrophy warrant treatment. The guidelines for diagnosis and treatment based on the modified Delphi technique have also been formatted. The Huashan classification system aids in the diagnosis and treatment of monomelic amyotrophy and includes the following categories:
- Type 1: Characterized by atrophy of the hand and forearm muscles or asymmetric bilateral atrophy in the upper limbs, with subtypes 1a (stable) and 1b (progressive)
- Type 2: Involves atrophy accompanied by pyramidal tract damage
- Type 3: Considered atypical, featuring atrophy of proximal upper limb muscles, symmetric upper limbs, or sensory dysfunction
A conservative approach is initially recommended for types 1 and 3, while surgery is advised for patients with type 2 disease.[35] The first-line treatment is a cervical collar designed to limit cervical movement and prevent neck flexion. The recommendation for using a cervical collar along with cervical decompression and fusion or fixation is based on the contact pressure theory. Patients are advised to wear the collar for 3 to 4 years until growth spurts are complete or until a plateau in the condition is observed. This approach aims to limit the progression of symptoms. Additionally, physiotherapy to strengthen the posterior cervical extensors proves beneficial by enhancing cervical sagittal alignment.[36]
The indications for surgical treatment in monomelic amyotrophy include failure of conservative management, noncompliance to the use of the cervical collar for a longer duration, and the presence of advanced, severe, or rapidly progressive neurological deficits. Various surgical approaches, both anterior and posterior, have been described, such as laminectomy, duraplasty, corpectomy, discectomy, decompression alone, and fusion. The major drawback of these approaches is the risk of restricted neck movements and concurrent surgical morbidities. A meta-analysis found equivocal clinical improvement between the anterior and posterior approaches.
Surgeries typically involve anterior cervical discectomy with fusion (ACDF) and plating, which have demonstrated the best outcomes. Maintaining the physiological local lordosis angle prevents adjacent segment disease following ACDF.[37] This technique is preferred over fusion because it reduces the risk of adjacent segment disease, allowing for removal once the disease stabilizes, in contrast to corpectomy.
Laminectomy and coagulation of engorged veins alone, without fusion, yield equivocal results. The rationale for coagulating the posterior epidural venous plexus stems from principles established by Hirayama himself. However, this approach carries an increased risk of bleeding and meningitis.
Open-book laminoplasty with tented duraplasty is also described.[38] This procedure is based on the tight dural canal theory in flexion. Open-book laminoplasty has an improved success rate and prognosis.[39] The procedure's immediate effects may be noted with intraoperative ultrasound, demonstrating decreased spinal cord pulsation and increased amplitude of conductive spinal cord potentials after dural incision. Tailored procedures to improve hand functioning include tendon transfers (thumb opposition, grasp, anti-claw), interphalangeal joint arthrodeses, and tenodeses. These interventions aim to restore mobility and enhance the overall dexterity of the hand in affected individuals.(B2)
Intraoperative anesthetic considerations should include the following:
- Flexible fiberoptic intubation to prevent neck flexion
- Maintenance of spinal cord perfusion above 90 mm Hg to avoid hypotension after anesthetic induction and reduce aspiration risk from gastroparesis due to autonomic dysfunction
- Avoidance of drugs that release histamine
- Facilitation of early recovery through bispectral index and neuromuscular monitoring
Physical therapy has shown varying degrees of improvement.[40][41] Leisure time physical activity promotes rehabilitation.[42](B2)
Differential Diagnosis
The differential diagnosis of monomelic amyotrophy includes the following:
- Motor neuron diseases like young onset amyotrophic lateral sclerosis (rare in young patients), multifocal motor neuropathy, and spinal muscular atrophy
- Syringomyelia
- Myotonic dystrophy
- This is an autosomal dominant genetic disorder commonly seen in middle-aged men and traditionally identified with a tonic contraction of muscles in the upper limbs. This condition is associated with systemic changes, including cataracts, pulmonary dysfunction, endocrine pathology, infertility, and cardiac conduction changes. Myotonic dystrophy is distinguished from monomelic amyotrophy by systemic involvement and muscle biopsy characteristics.
- Tephromalacie anterieure
- This condition involves anterior horn infarction, which causes muscle wasting in the distal upper limbs due to spinal artery occlusion; this commonly affects middle-aged adults and is linked to arteriosclerosis, presenting bilaterally.
- Intrinsic cord lesions, including spinal cord tumors, cervical spondylotic myelopathy, and ossification of the posterior longitudinal ligament
- Cervical vertebral abnormalities
- Lhermitte phenomenon or barber chair phenomenon
- Pronator syndrome
- This typically presents unilaterally and is associated with chronic injury, with symptoms worsening during specific activities. Associated pain is a key hallmark of the condition.
- Peripheral nerve entrapment syndrome
- High ulnar neuropathy
- Lower trunk brachial plexopathy
- C8-T1 radiculopathy [43][44]
A thorough clinical evaluation and judicious diagnostic examination can differentiate monomelic amyotrophy accurately and guide treatment.
Prognosis
Although monomelic amyotrophy has a self-limiting course over the long term, the weakness can progress from 1 month to 5 years. Almost 95% of cases stabilize within 5 years of the disease process. In general, the prognosis of monomelic amyotrophy is thought to be better than that of other motor neuron disorders, with more prolonged survival and lesser morbidity. Cervical collar use alone is effective in almost 58% of cases. However, residual symptoms may last for decades. Approximately 70% of patients experience mild disability.[45] Low self-esteem, depression, and anxiety harbinger inactive lifestyles among these cohorts, further complicating the disease and the management strategies.[46] Quality of life may also be affected.[47]
Nerve conduction testing and electromyograms may help determine the extent of nerve injury and reinnervation. In some cases, neurophysiological involvement may surpass the clinical symptoms expected at the time of presentation.[48] These features may help clinicians dichotomize the prognosis.
The proximal variant, characterized by longer segments and greater loss of spinal curvature, tends to have a poorer prognosis.[49] Higher fractional anisotropy and lower apparent diffusion coefficient values observed in preoperative diffusion tensor imaging (DTI) indicate better surgical outcomes.[50] Additionally, motor unit number estimation and DTI reveal a positive correlation between loss of cervical sagittal alignment and motor impairments. Restoring cervical lordosis is essential for preventing motor unit loss.[51]
Based on results from a study of 126 patients, anterior cervical discectomy with fusion achieved 55% excellent and 40% satisfactory outcomes.[52] Stabilization alone via the anterior approach shows a greater likelihood of clinical improvement than posterior or staged procedures. Neurologic function in the hand improves significantly, and finger extension tremors also lessen. However, muscle atrophy does not show significant improvement.[53] Prolonged illness duration and an early age at disease onset are associated with a poorer prognosis.
Complications
The complications associated with monomelic amyotrophy are primarily due to chronic motor deficits. These complications include weakness in the hand, forearm, or arm functions, which may produce chronic disuse atrophy and permanent contractures. Spasticity may be observed, or the disease may recur despite many years of stability. Respiratory failure may result from monomelic amyotrophy affecting the C4-C6 regions.[54]
Deterrence and Patient Education
Education regarding the prognosis and prevention of chronic motor complications can facilitate informed decisions by patients regarding their personal and professional lives. Proper counseling empowers individuals to take proactive steps in managing their condition and encourages adherence to treatment plans, ultimately improving their quality of life.
Enhancing Healthcare Team Outcomes
Juvenile asymmetric distal upper limb oblique amyotrophy, lower cervical cord atrophy, and crescent-shaped enhancement in the posterior epidural space on flexion MRI are hallmark features of this condition. Although primarily viewed as self-limiting with a subsequent plateau, certain subsets within this cohort necessitate an interprofessional approach, including surgical and occupational therapy, to develop adaptive strategies for achieving functional independence and social participation. Severe, rapidly progressive, and refractory cases require early neurosurgical consultation to assess the need for surgical fixation or functional restorative hand surgeries.[55] Long-term follow-up is essential, as neurological deterioration has been observed despite many years in a stationary phase.
References
Bohara S, Garg K, Mishra S, Tandon V, Chandra PS, Kale SS. Impact of various cervical surgical interventions in patients with Hirayama's disease-a narrative review and meta-analysis. Neurosurgical review. 2021 Dec:44(6):3229-3247. doi: 10.1007/s10143-021-01540-2. Epub 2021 Apr 21 [PubMed PMID: 33884522]
Level 3 (low-level) evidenceHayden ME, Kim J, Arányi Z, Wolfe SW. Outcome of Tendon Transfer for Monomelic Amyotrophy (Hirayama Disease). The Journal of hand surgery. 2023 Jan:48(1):90.e1-90.e5. doi: 10.1016/j.jhsa.2021.11.012. Epub 2022 Jan 22 [PubMed PMID: 35078694]
Mishra SC, Singh V, Singh AK, Sharma S, Tyagi I. Late Presentation of Hirayama Disease With "Snake Eye Sign": A Case Report. Cureus. 2022 Jan:14(1):e21557. doi: 10.7759/cureus.21557. Epub 2022 Jan 24 [PubMed PMID: 35223326]
Lyu F, Zheng C, Wang H, Nie C, Ma X, Xia X, Zhu W, Jin X, Hu Y, Sun Y, Zhu Y, Kuwabara S, Cortese R, Maqbool Hassan K, Takai K, Paredes I, Webere R, Turk M, Kimura J, Jiang J. Establishment of a clinician-led guideline on the diagnosis and treatment of Hirayama disease using a modified Delphi technique. Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 2020 Jun:131(6):1311-1319. doi: 10.1016/j.clinph.2020.02.022. Epub 2020 Mar 16 [PubMed PMID: 32311591]
Iacono S, Di Stefano V, Gagliardo A, Cannella R, Virzì V, Pagano S, Lupica A, Romano M, Brighina F. Hirayama disease: Nosological classification and neuroimaging clues for diagnosis. Journal of neuroimaging : official journal of the American Society of Neuroimaging. 2022 Jul:32(4):596-603. doi: 10.1111/jon.12995. Epub 2022 Apr 8 [PubMed PMID: 35394668]
Wang H, Tian Y, Wu J, Luo S, Zheng C, Sun C, Nie C, Xia X, Ma X, Lyu F, Jiang J, Wang H. Update on the Pathogenesis, Clinical Diagnosis, and Treatment of Hirayama Disease. Frontiers in neurology. 2021:12():811943. doi: 10.3389/fneur.2021.811943. Epub 2022 Feb 1 [PubMed PMID: 35178023]
Tashiro K, Kikuchi S, Itoyama Y, Tokumaru Y, Sobue G, Mukai E, Akiguchi I, Nakashima K, Kira J, Hirayama K. Nationwide survey of juvenile muscular atrophy of distal upper extremity (Hirayama disease) in Japan. Amyotrophic lateral sclerosis : official publication of the World Federation of Neurology Research Group on Motor Neuron Diseases. 2006 Mar:7(1):38-45 [PubMed PMID: 16546758]
Level 3 (low-level) evidenceFoster E, Tsang BK, Kam A, Storey E, Day B, Hill A. Hirayama disease. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. 2015 Jun:22(6):951-4. doi: 10.1016/j.jocn.2014.11.025. Epub 2015 Mar 9 [PubMed PMID: 25766368]
Level 3 (low-level) evidenceHirayama K, Tomonaga M, Kitano K, Yamada T, Kojima S, Arai K. Focal cervical poliopathy causing juvenile muscular atrophy of distal upper extremity: a pathological study. Journal of neurology, neurosurgery, and psychiatry. 1987 Mar:50(3):285-90 [PubMed PMID: 3559609]
Level 3 (low-level) evidenceVerma R, Lalla R, Patil TB, Gupta A. Hirayama disease: a frequently undiagnosed condition with simple inexpensive treatment. BMJ case reports. 2012 Dec 6:2012():. doi: 10.1136/bcr-2012-007076. Epub 2012 Dec 6 [PubMed PMID: 23220833]
Level 3 (low-level) evidenceChiba S, Yonekura K, Nonaka M, Imai T, Matumoto H, Wada T. Advanced Hirayama disease with successful improvement of activities of daily living by operative reconstruction. Internal medicine (Tokyo, Japan). 2004 Jan:43(1):79-81 [PubMed PMID: 14964585]
Level 3 (low-level) evidenceHirayama K. [Juvenile muscular atrophy of unilateral upper extremity (Hirayama disease)--half-century progress and establishment since its discovery]. Brain and nerve = Shinkei kenkyu no shinpo. 2008 Jan:60(1):17-29 [PubMed PMID: 18232329]
Fukutake T. [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]. Brain and nerve = Shinkei kenkyu no shinpo. 2020 Dec:72(12):1371-1381. doi: 10.11477/mf.1416201695. Epub [PubMed PMID: 33293471]
Sharma DN, Yerramneni VK, Yerragunta T, Gaikwad GB, Rangan VS, Akurati S. Venous pathology targeted surgical management in Hirayama disease: A comprehensive case series of nine cases exploring this potential etiology. Journal of craniovertebral junction & spine. 2024 Jan-Mar:15(1):37-44. doi: 10.4103/jcvjs.jcvjs_179_23. Epub 2024 Mar 13 [PubMed PMID: 38644914]
Level 2 (mid-level) evidenceKim KE, Kim EJ, Kim K, Park J, Jung C, Yun JH, Son K. Prevalence of Neuromuscular Diseases in Young South Korean Males; A Korean Military Manpower Administration and Medical Command Data-Based Study. Journal of clinical neurology (Seoul, Korea). 2023 Nov:19(6):565-572. doi: 10.3988/jcn.2022.0261. Epub 2023 Jun 1 [PubMed PMID: 37455505]
Al-Hashel JY, Abdelnabi EA, Ibrahim Ismail I. Monomelic Amyotrophy (Hirayama Disease): A Rare Case Report and Literature Review. Case reports in neurology. 2020 Sep-Dec:12(3):291-298. doi: 10.1159/000508994. Epub 2020 Sep 17 [PubMed PMID: 33082767]
Level 3 (low-level) evidenceChappell AG, Spinner RJ, Bishop AT, Shin AY. Hirayama Disease: Surgical Restoration of Hand Function. The Journal of hand surgery. 2024 Aug 8:():. pii: S0363-5023(24)00306-X. doi: 10.1016/j.jhsa.2024.06.010. Epub 2024 Aug 8 [PubMed PMID: 39127956]
Ranabhat K, Bhattarai S, Shrestha R, Maharjan AMS, Bishokarma S, Pudasaini A, Thapa LJ. Clinical profile and dynamic magnetic resonance imaging in Hirayama disease: a single-centered cross-sectional study in Nepal. Annals of medicine and surgery (2012). 2023 May:85(5):1750-1754. doi: 10.1097/MS9.0000000000000664. Epub 2023 Apr 14 [PubMed PMID: 37229052]
Level 2 (mid-level) evidenceMonteiro JN, Bedekar UP, Sankhe M, Nandkumar S. Anesthetic considerations in Hirayama disease: Primum non noncere. Journal of anaesthesiology, clinical pharmacology. 2023 Jan-Mar:39(1):160-161. doi: 10.4103/joacp.JOACP_273_21. Epub 2022 Aug 16 [PubMed PMID: 37250243]
Kaira P, Kaira V, Verma SR, Kumar S. Hirayama Disease: Neutral and Flexion Magnetic Resonance Imaging Manifestations and Single Tertiary Care Center Analysis on 3T Scanner. Annals of Indian Academy of Neurology. 2024 Jul 1:27(4):364-370. doi: 10.4103/aian.aian_236_24. Epub 2024 Aug 21 [PubMed PMID: 39167476]
Yun JH, Jung C, Kim EJ, Park J, Yeom J, Jung JS, Kim KE. Characteristics of Hirayama Disease in Young South Korean Soldiers. Journal of clinical neurology (Seoul, Korea). 2024 May:20(3):293-299. doi: 10.3988/jcn.2023.0244. Epub 2024 Feb 5 [PubMed PMID: 38330418]
Fustes OH, Kay CSK, Lorenzoni PJ, Ducci RD, Werneck LC, Scola RH. Somatosensory evoked potentials in Hirayama disease: A Brazilian study. Surgical neurology international. 2020:11():464. doi: 10.25259/SNI_861_2020. Epub 2020 Dec 22 [PubMed PMID: 33408949]
Oommen AT, Vengalil S, Baskar D, Thomas A, Kulanthaivelu K, Bardhan M, Bhargava SS, Nalini A. Classical Hirayama Disease Presenting as Progressive Spastic Quadriparesis. Annals of Indian Academy of Neurology. 2023 May-Jun:26(3):308-310. doi: 10.4103/aian.aian_922_22. Epub 2023 Feb 23 [PubMed PMID: 37538421]
Reddy A, Varma P, Barik AK, Narayan V. Anesthetic challenges in a patient with Hirayama disease with quadriparesis and autonomic dysfunction undergoing cervical spine surgery. Journal of neurosciences in rural practice. 2024 Jan-Mar:15(1):137-139. doi: 10.25259/JNRP_224_2023. Epub 2023 Jul 4 [PubMed PMID: 38476430]
Oprea E, Elosegi JA. Minipolymyoclonus revealing Hirayama disease. Revue neurologique. 2024 Sep:180(7):704-705. doi: 10.1016/j.neurol.2024.02.391. Epub 2024 Apr 10 [PubMed PMID: 38604891]
Buturoiu MM, Weber MA, Prudlo J. Dynamic examinations in MRI scanners crucial in diagnosing cervical flexion myelopathy (Hirayama Disease). RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin. 2024 Jul 8:():. doi: 10.1055/a-2338-3445. Epub 2024 Jul 8 [PubMed PMID: 38977013]
Paladi B, Amin D, Yarlagadda J, Jadav S, Jabeen SA. Role of Dynamic Magnetic Resonance Imaging in Hirayama Disease, a Rare Motor Neuron Disease. Cureus. 2022 Nov:14(11):e31099. doi: 10.7759/cureus.31099. Epub 2022 Nov 4 [PubMed PMID: 36475209]
Macey MB, Ho DT, Parres CM, Small JE. Spinal Epidural Venous Plexus Pathology in Hirayama Disease. Journal of clinical neuromuscular disease. 2019 Sep:21(1):47-51. doi: 10.1097/CND.0000000000000243. Epub [PubMed PMID: 31453855]
Kalekar T, Prabhu AS, M S. Cervical Spine Magnetic Resonance Imaging Findings in Hirayama Disease. Cureus. 2023 Jun:15(6):e40015. doi: 10.7759/cureus.40015. Epub 2023 Jun 5 [PubMed PMID: 37425510]
Kalita J, Rahi SK, Kumar S, Naik S, Bhoi SK, Misra UK. A Study of Diffusion Tensor Imaging in Hirayama Disease. Neurology India. 2021 Jul-Aug:69(4):889-893. doi: 10.4103/0028-3886.325338. Epub [PubMed PMID: 34507407]
Gao Y, Sun C, Zhou S, Zhang F, Jiang J, Zhang J, Wang H. Correlation Study Between Spinal Cord Function, Spinal Cord Morphology and Cervical Spine Alignments in Patients With Hirayama Disease. Global spine journal. 2023 Jun 7:():21925682231181871. doi: 10.1177/21925682231181871. Epub 2023 Jun 7 [PubMed PMID: 37282502]
Yu Q, Tang S, Jiang J, Jin X, Lyu F, Ma X, Xia X. The Influence of "Loss of Attachment" on the Outcome of Anterior Cervical Fusion Procedures in Patients With Hirayama Disease. Orthopedics. 2021 Jan 1:44(1):30-37. doi: 10.3928/01477447-20201202-01. Epub 2020 Dec 7 [PubMed PMID: 33284981]
Li Z, Zhang W, Wu W, Wei C, Chen X, Lin J. Is there cervical spine muscle weakness in patients with Hirayama disease? A morphological study about cross-sectional areas of muscles on MRI. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2020 May:29(5):1022-1028. doi: 10.1007/s00586-020-06290-1. Epub 2020 Jan 16 [PubMed PMID: 31950351]
Level 2 (mid-level) evidenceSong J, Cui ZY, Chen ZH, Jiang JY. Analysis of the Effect of Surgical Treatment for the Patients with Hirayama Disease from the Perspective of Cervical Spine Sagittal Alignment. World neurosurgery. 2020 Jan:133():e342-e347. doi: 10.1016/j.wneu.2019.09.025. Epub 2019 Sep 25 [PubMed PMID: 31562968]
Level 3 (low-level) evidenceSun C, Xu G, Zhang Y, Cui Z, Liu D, Yang Y, Wang X, Ma X, Lu F, Jiang J, Wang H. Interobserver and Intraobserver Reproducibility and Reliability of the Huashan Clinical Classification System for Hirayama Disease. Frontiers in neurology. 2021:12():779438. doi: 10.3389/fneur.2021.779438. Epub 2021 Dec 3 [PubMed PMID: 34925218]
Tian Y, Xie L, Jiang J, Wang H. Why the patients with Hirayama disease have abnormal cervical sagittal alignment? A radiological measurement analysis of posterior cervical extensors. Journal of orthopaedic surgery and research. 2022 Jan 15:17(1):19. doi: 10.1186/s13018-021-02905-5. Epub 2022 Jan 15 [PubMed PMID: 35033149]
Lu X, Zou F, Lu F, Ma X, Xia X, Jiang J. How to reconstruct the lordosis of cervical spine in patients with Hirayama disease? A finite element analysis of biomechanical changes focusing on adjacent segments after anterior cervical discectomy and fusion. Journal of orthopaedic surgery and research. 2022 Feb 16:17(1):101. doi: 10.1186/s13018-022-02984-y. Epub 2022 Feb 16 [PubMed PMID: 35172873]
Knafo S, Aghakhani N, Parker F. Laminoplasty with tented duraplasty for Hirayama disease. Acta neurochirurgica. 2024 Jan 12:166(1):5. doi: 10.1007/s00701-024-05893-7. Epub 2024 Jan 12 [PubMed PMID: 38214785]
Thakar S, Arun AA, Rajagopal N, Aryan S, Mohan D, Vijayan JE, Hegde AS. Outcomes after Cervical Duraplasty for Monomelic Amyotrophy (Hirayama Disease): Results of a Case-Control Study of 60 Patients. Journal of neurosciences in rural practice. 2021 Oct:12(4):642-651. doi: 10.1055/s-0041-1735248. Epub 2021 Sep 22 [PubMed PMID: 34737497]
Level 2 (mid-level) evidenceHui T, Chang ZB, Han F, Rui Y. Benign monomelic amyotrophy with lower limb involvement in an adult: A case report. Medicine. 2018 Jun:97(23):e10774. doi: 10.1097/MD.0000000000010774. Epub [PubMed PMID: 29879014]
Level 3 (low-level) evidenceArooj S, Mubarak F, Azeemuddin M, Sajjad Z, Jilani W. Hirayama disease, a rare cause of posture related cord compression: a case report from radiological perspective. JPMA. The Journal of the Pakistan Medical Association. 2013 Nov:63(11):1435-8 [PubMed PMID: 24392537]
Level 3 (low-level) evidenceChen K, Yang Y, Wang X, Zhu Y, Lyu F, Jiang J, Xia X, Zheng C. The role of leisure-time physical activity in maintaining cervical lordosis after anterior cervical fusion and its impact on the motor function in patients with hirayama disease: a retrospective cohort analysis. BMC musculoskeletal disorders. 2023 Nov 21:24(1):903. doi: 10.1186/s12891-023-07038-w. Epub 2023 Nov 21 [PubMed PMID: 37990179]
Level 2 (mid-level) evidenceVydra DG, Rayi A. Myotonic Dystrophy. StatPearls. 2024 Jan:(): [PubMed PMID: 32491378]
Shenoy VS, Munakomi S, Sampath R. Syringomyelia. StatPearls. 2024 Jan:(): [PubMed PMID: 30725795]
Aundhakar SC, Mahajan SK, Chhapra DA. Hirayama's Disease: A Rare Clinical Variant of Amyotrophic Lateral Sclerosis. Advanced biomedical research. 2017:6():95. doi: 10.4103/2277-9175.211797. Epub 2017 Jul 28 [PubMed PMID: 28828346]
Chen K, Gao T, Yang S, Zhu Y, Lyu F, Jiang J, Xia X, Zheng C. Changes in Self-Esteem in Patients with Hirayama Disease and its Association with Prognosis After Anterior Cervical Fusion Procedures. World neurosurgery. 2023 Oct:178():e802-e818. doi: 10.1016/j.wneu.2023.08.014. Epub 2023 Aug 10 [PubMed PMID: 37572833]
Zubair AS, Mustafa R, Crum B. Long term quality of life follow-up and functional impairment study in patients with Hirayama disease. Journal of the neurological sciences. 2024 Apr 15:459():122952. doi: 10.1016/j.jns.2024.122952. Epub 2024 Mar 11 [PubMed PMID: 38484554]
Level 2 (mid-level) evidenceGuo XM, Qin XY, Huang C. Neuroelectrophysiological characteristics of Hirayama disease: report of 14 cases. Chinese medical journal. 2012 Jul:125(14):2440-3 [PubMed PMID: 22882918]
Level 2 (mid-level) evidenceWang H, Tian Y, Wu J, Sun C, Nie C, Zheng C, Zou F, Xia X, Ma X, Lyu F, Jiang J, Wang H. The radiological and electrophysiological characteristics of Hirayama disease with proximal involvement: A retrospective study. Frontiers in neurology. 2022:13():969484. doi: 10.3389/fneur.2022.969484. Epub 2022 Aug 11 [PubMed PMID: 36034284]
Level 2 (mid-level) evidenceGao Y, Sun C, Zhou S, Ma X, Xia X, Lu F, Zhang J, Wang H, Jiang J. Can preoperative cervical spinal diffusion tensor imaging (DTI) indices predict surgical outcomes in patients with Hirayama disease? A retrospective cohort study. Frontiers in neurology. 2022:13():982404. doi: 10.3389/fneur.2022.982404. Epub 2022 Sep 30 [PubMed PMID: 36247750]
Level 2 (mid-level) evidenceChen K, Yang Y, Sun C, Zhu Y, Wang H, Lyu F, Jiang J, Zheng C. Loss of cervical sagittal alignment worsens the cervical spinal lesions in patients with Hirayama disease. Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. 2023 Jun:44(6):2103-2111. doi: 10.1007/s10072-023-06621-2. Epub 2023 Jan 26 [PubMed PMID: 36697854]
Vengalil S, Pruthi N, Bhat D, Uppar AM, Polavarapu K, Preethish-Kumar V, Nashi S, Rajesh S, Aswini NS, Behera BP, Vandhiyadevan GD, Prasad C, Baskar D, Kulanthaivelu K, Saravanan A, Kandavel T, Nishadham V, Huddar A, Unnikrishnan G, Thomas A, Keerthipriya MS, Sanka SB, Manjunath N, Valasani RK, Bardhan M, Nalini A. Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients. World neurosurgery. 2024 Mar:183():e88-e97. doi: 10.1016/j.wneu.2023.11.087. Epub 2023 Nov 23 [PubMed PMID: 38006932]
Liu H, Zhang Z, Li S, Hou Y, Tong X, Yu Y, Wu H. Clinical Outcomes of Anterior Cervical Decompression and Fusion Therapy for Patients With Hirayama Disease. World neurosurgery. 2024 Jun:186():e75-e80. doi: 10.1016/j.wneu.2024.02.145. Epub 2024 Mar 5 [PubMed PMID: 38447739]
Level 2 (mid-level) evidenceSol N, Hartman J, Ten Kate M, van Kempen Z, van der Kooi A, Vandertop P, Tuinman PR, van Oosten B. Successful treatment of respiratory failure in Hirayama disease. The American journal of emergency medicine. 2024 Feb:76():272.e3-272.e5. doi: 10.1016/j.ajem.2023.11.049. Epub 2023 Dec 2 [PubMed PMID: 38072732]
Lynch BT, Slingerland AL, Robson CD, Ghosh PS, Hedequist DJ, Proctor MR, Fehnel KP. Single-institution Series of Hirayama Disease in North America. Clinical spine surgery. 2024 Feb 1:37(1):9-14. doi: 10.1097/BSD.0000000000001492. Epub 2023 Jul 24 [PubMed PMID: 37491712]