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Year : 2018  |  Volume : 66  |  Issue : 4  |  Page : 1094--1099

Hirayama disease/cervical flexion-induced myelopathy progressing to spastic paraparesis: A report on three cases with literature review

Veeramani Preethish-Kumar1, Kiran Polavarapu1, Saraswati Nashi2, Kajari Bhattacharya3, Jitender Saini3, Seena Vengalil2, Nupur Pruthi4, Dhananjay I Bhat4, Atchayaram Nalini2,  
1 Department of Neurology; Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
2 Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
3 Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India
4 Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India

Correspondence Address:
Dr. Atchayaram Nalini
Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru - 560 029, Karnataka


Hirayama disease (HD)/cervical flexion-induced myelopathy (CFIM) is a lower motor neuron disease conventionally affecting a single upper extremity. We describe three men progressing after a long stable period to develop severe spastic paraparesis and bladder disturbances as a protracted implication of HD. The age at onset was 20, 24, and 15 years, while the age at presentation was 27, 41, and 57 years, respectively. The second phase of disease progression occurred after 4, 13, and 28 years of stationary period. All had CFIM with characteristic magnetic resonance imaging features as observed during progressive stages. The anterior dural shift extended variably from C4 to D4 levels with a median value of 5 mm and was maximum at C6 to C7 levels, pushing the cord anteriorly causing compression. This study emphasizes the need to recognize this unusual subgroup of HD and mandates long-term follow-up with timely intervention in arresting the progression/improving the deficits.

How to cite this article:
Preethish-Kumar V, Polavarapu K, Nashi S, Bhattacharya K, Saini J, Vengalil S, Pruthi N, Bhat DI, Nalini A. Hirayama disease/cervical flexion-induced myelopathy progressing to spastic paraparesis: A report on three cases with literature review.Neurol India 2018;66:1094-1099

How to cite this URL:
Preethish-Kumar V, Polavarapu K, Nashi S, Bhattacharya K, Saini J, Vengalil S, Pruthi N, Bhat DI, Nalini A. Hirayama disease/cervical flexion-induced myelopathy progressing to spastic paraparesis: A report on three cases with literature review. Neurol India [serial online] 2018 [cited 2020 May 27 ];66:1094-1099
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Full Text

Hirayama disease (HD) is a distinct disorder with distal upper limb wasting and weakness [1] and commonly progresses over 3–5 years before attaining a stable course. Traditionally, HD is thought to spare the descending tracts;[1] however, there is now convincing evidence that HD is secondary to dynamic compression of the cord during neck flexion leading to arterial and/or venous ischemic damage to anterior horn cells and other descending tracts.[2] There exist a few reports on HD progressing to manifest signs of pyramidal tract and bladder dysfunction. Here we describe three men with HD who after several years of stable course developed progressive spastic paraparesis and sphincter disturbances.

Written informed consent was obtained and the study was approved by Institutional Ethics Committee. Muscle strength was assessed according to the Medical Research Council (MRC) grading. Standard procedures were followed for nerve conduction studies and electromyography. Magnetic resonance (MR) imaging of the cervical spine was performed with neck in neutral and fully flexed position. The transverse and antero-posterior cord diameters were measured in T2 axial images from C3 to T1 mid-vertebral levels. The cervical curvature was measured as described by Chen et al.[3] The range of motion was measured by the extent of kyphosis in flexion and lordosis in extension, between the lower border of C2 and C7 vertebrae on lateral cervical spine X-ray image.

 Case Reports

Case 1

A 27-year old man presented with asymmetrical onset weakness and wasting of distal upper limbs, tremulousness of fingers, and cold paresis from 20 years of age. The deficits progressed for 3 years and attained a stable course. From 26 years of age, he developed progressive stiffness of lower limbs, hesitancy and urgency of micturition with constipation, and mild paresthesias in lower limbs. Examination revealed severe wasting and weakness of the hand and forearm muscles with sparing of brachioradialis and prominent spasticity of lower limbs. According to MRC grading of muscle strength, shoulder girdles and biceps muscles were grade 5, elbow extension = 3+, wrist = 2+, small muscles and fingers = 0–1, hips = 4, knees = 4+, ankles = 4, and toes = 3+ [Figure 1]. The tendon reflexes were exaggerated, and Babinski's sign was positive and there was prominent spastic gait.{Figure 1}

Case 2

A man aged 41 years, presented with progressive weakness and wasting of small muscles of the hands and forearms associated with severe cold paresis from 24 years of age. The illness progressed over 4–5 years and had attained a stable course but with severe motor disability. From 39 years of age, he developed progressive symmetrical stiffness of lower limbs, and 1 year later, noticed hesitancy in micturition. His examination revealed bilateral mini-polymyoclonus, severe wasting of small muscles of hand and forearm muscles, partial sparing of brachioradialis, and spasticity of lower limbs [Figure 1]. The muscle strength was grade 4 at the shoulders and arms, 2+ distally, 4+ at the hips and thighs, and 5 at the foot. The tendon reflexes were exaggerated, Babinski's sign was positive and he had a spastic gait. Sensory, cerebellar, and extrapyramidal systems were normal.

Case 3

A man aged 57 years, had progressive weakness and wasting of both hands and forearms with severe cold paresis from 15 years of age. The deficits progressed over 4–5 years and attained a stable course. From 47 years of age, he noticed progressive stiffness of both lower limbs and urgency of micturition. Examination revealed moderate asymmetrical wasting of small muscles of the hands and forearm with partial sparing of brachioradialis, severe weakness of small muscles of hands, grade 4 weakness of wrist extensors and grade 3 weakness of triceps, spasticity of lower limbs with exaggerated tendon reflexes, and positive Babinski's sign [Figure 1]. All three patients demonstrated evidence of chronic denervation with re-innervation potentials in the wasted muscles. Motor conductions evoked severely reduced compound muscle action potential (CMAP) amplitudes in atrophic muscles and normal CMAPs from lower limbs. The clinical and imaging characteristics of the cases are summarized in [Table 1] and [Figure 2], [Figure 3], [Figure 4].{Table 1}{Figure 2}{Figure 3}{Figure 4}


HD is considered to be a focal degenerative motor neuron disease affecting the cervical cord.[1],[2] The most common conditions mimicking HD are primary cervical canal stenosis, intrinsic cord lesions, juvenile amyotrophic lateral sclerosis, distal spinal muscular atrophy, spondylotic myelopathy, and multi-focal motor neuropathy with conduction block. Currently, it is well established that HD is a form of cervical flexion-induced myelopathy (CFIM)[2],[3] amenable to surgical decompressive therapy, resulting in stability/improvement in the neurological deficits and disability.[4] Studies on different surgical methods implemented in HD are summarized in [Table 2]. There has been less focus on the disease course/progression after several years of stabilization period and also the involvement of descending tracts of the cord. In an early report from Japan, the authors describe proximal muscle atrophy and weakness with features of cervical spondylotic amyotrophy in a patient with HD after a stable period of 20 years.[5] This was followed by a few case reports on these rare extended forms of HD having long tract signs/other additional clinical features [Table 3].[6],[7],[8] The commonest theory proposed for HD is the “over-stretch theory,” with disproportionate growth between the spine and the cord, making the cord relatively short compared with the spine. During flexion, therefore, the cord and dura get stretched by 17.6% between the C2 and T1 levels at maximum.[9] The cord takes the shortest pathway through the spinal canal, and this results in the cord being stretched and pressed onto the posterior wall of the vertebrae. Some authors have proposed the tight dural canal theory for HD, where an inelastic dural membrane compresses the spinal cord onto the vertebrae. This is supported by demonstrating loss of both elastic fibers and the normal wavy structure of the dura.[10] The majority of HD patients have a self-limiting course, but certain patients may develop advanced myelopathy, as was observed in our cases. Thus, a longitudinal follow-up is recommended in HD to consider surgical treatment for prevention of progression and disability.{Table 2}{Table 3}

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


1Hirayama K, Tsubaki T, Toyokura Y, Okinaka S. Juvenile muscular atrophy of unilateral upper extremity. Neurology 1963;13:373-80.
2Hirayama K, Tokumaru Y. Cervical dural sac and spinal cord in juvenile muscular atrophy of distal upper extremity. Neurology 2000;54:1922-6.
3Chen CJ, Hsu HL, Tseng YC, Lyu RK, Chen CM, Huang YC, et al. Hirayama flexion myelopathy: Neutral-position MR imaging findings-importance of loss of attachment. Radiology 2004;231:39-44.
4Lu F, Wang H, Jiang J, Chen W, Ma X, Ma X, et al. Efficacy of anterior cervical decompression and fusion procedures for monomelic amyotrophy treatment: A prospective randomized controlled trial: Clinical article. J Neurosurg Spine 2013;19:412-9.
5Hashiguchi S, Ogasawara N, Watanabe A, Kawachi Y, Miki N. Cervical spondylotic amyotrophy associated with Hirayama's disease. Intern Med 1997;36:647-50.
6Kameyama T, Ando T, Mimatsu K, Sobue G. Delayed exacerbation of cervical myelopathy in a case of juvenile muscular atrophy of unilateral distal upper extremity. Rinsho Shinkeigaku 1997;37:60-3.
7Fujimori T, Tamura A, Miwa T, Iwasaki M, Oda T. Severe cervical flexion myelopathy with long tract signs: A case report and a review of literature. Spinal Cord Ser Cases 2017;3:17016.
8Sakai K, Ono K, Okamoto Y, Murakami H, Yamada M. Cervical flexion myelopathy in a patient showing apparent long tract signs: A severe form of Hirayama disease. Joint Bone Spine 2011;78:316-8.
9Breig A, El-Nadi AF. Biomechanics of the cervical spinal cord: Relief of contact pressure on and overstretching of the spinal cord. Acta Radiol Diagn (Stockh) 1966;4:602-24.
10Yoshiyama Y, Tokumaru Y, Arai K. Flexion-induced cervical myelopathy associated with fewer elastic fibers and thickening in the posterior dura mater. J Neurol 2010;257:149-51.