Neurol Sci DOI 10.1007/s10072-015-2222-1
LETTER TO THE EDITOR
Hirayama disease: the importance of adequate flexion MRI for diagnosis Marinos Kontzialis1 • Noushin Yahyavi-Firouz-Abadi1 • Carlos A. Zamora1
Received: 16 February 2015 / Accepted: 15 April 2015 Ó Springer-Verlag Italia 2015
Keywords Hirayama disease Flexion MRI Myelopathy Cervical Dear Editor, We read with great interest the recent correspondence by Cortese et al. [1], who described the importance of an early diagnosis of Hirayama disease (HD) in a patient who underwent conservative therapy. Herein, we stress the critical role of adequate flexion during dynamic MRI in the diagnosis of HD based on our recent experience. HD is a benign self-limiting disease that causes distal upper limb weakness and atrophy, which progresses over 2–4 years, followed by spontaneous arrest usually within
& Marinos Kontzialis [email protected]; [email protected] 1
Division of Neuroradiology, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps B-112, Baltimore, MD 21287, USA
5 years. HD is thought to occur secondary to spinal cord compression by the posterior dural sac during neck flexion leading to ischemic damage to the anterior horns. The dynamic anterior shift of the dural sac is considered indicative of early progressive disease [2]. Imaging findings on neutral position MRI that should alert the physician include loss of normal cervical spine lordosis, loss of attachment between the posterior dural sac and subjacent lamina, lower cervical cord atrophy, and spinal cord T2 hyperintensity without evidence of extrinsic cord compression [3]. Flexion MRI is the appropriate next diagnostic step in suspected cases. An otherwise healthy 20-year-old male presented with a 2-year history of progressive right hand weakness and right upper extremity atrophy below the elbow. On clinical examination, there was no evidence of fasciculations, spasticity, or sensory deficits, and the atrophic changes spared the brachioradialis muscle. Needle electromyography showed chronic neurogenic changes in the form of fastfiring high-amplitude motor units. HD was suspected, and MRI of the cervical spine with flexion was ordered, which showed abnormal cord signal and segmental volume loss at C5–C6 (Fig. 1a). However, inadequate flexion with a tucked chin failed to demonstrate the expected anterior displacement of the posterior dural sac on the initial scan (Fig. 1b). Given the high clinical suspicion, MRI of the cervical spine was repeated in 3 months, when adequate flexion reproduced unequivocal imaging findings (Fig. 1c). Axial T2-weighted images in neutral position and flexion demonstrated abnormal cord signal, cord deformity and loss of attachment of the dural sac from the subjacent lamina (Fig. 2). HD is a slow progressive disease that can have good prognosis if detected and treated at an early stage and this case highlights the importance of adequate flexion MRI in
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Neurol Sci
Fig. 1 The importance of adequate flexion MRI in the diagnosis of Hirayama disease. a Sagittal T2-weighted image in neutral position demonstrates cord atrophy and abnormal cord signal at C5–C6 (arrow). There is loss of the normal cervical spine lordosis, which is a common but nonspecific finding in HD. b Sagittal T2-weighted image in mild flexion with tucked chin. There is redemonstration of
hyperintense cord signal and atrophy (arrow) without evidence of abnormal anterior motion of the dura. c Sagittal T2-weighted image in adequate flexion with a rolled blanket behind the patient’s head. There is loss of attachment of the dura (arrows) from the posterior elements, which results in cord compression worse at the C5 and C6 level
Fig. 2 Neutral position and flexion axial T2-weighted images. a Axial T2-weighted image in neutral position at C4–C5 shows prominent abnormal hyperintense T2 signal in the right central aspect of the cord, and partial loss of attachment of the dural sac from the subjacent lamina bilaterally (arrows). b Axial T2-weighted image in neutral position at C5–C6 demonstrates mild symmetric flattening of
the cord with patchy T2 hyperintense signal most prominent in its right posterolateral aspect (arrow). c Axial T2-weighted image in adequate flexion demonstrates complete loss of attachment of the dural sac from the subjacent lamina (arrows) resulting in compression and flattening of the cord
suspected cases. Suboptimal flexion MRI may result in under-recognition of this entity and failure to institute appropriate therapy early during the course of the disease.
2. Huang YL, Chen CJ (2011) Hirayama disease. Neuroimaging Clin N Am 21(4):939–950. doi:10.1016/j.nic.2011.07.009 3. Chen CJ, Hsu HL, Tseng YC, Lyu RK, Chen CM, Huang YC, Wang LJ, Wong YC, See LC (2004) Hirayama flexion myelopathy: neutral-position MR imaging findings—importance of loss of attachment. Radiology 231(1):39–44. doi:10.1148/radiol. 2311030004
Conflict of interest
None declared.
References 1. Cortese R, Gerevini S, Dicuonzo F, Zoccolella S, Simone IL (2015) Hirayama disease: the importance of an early diagnosis. Neurol Sci. doi:10.1007/s10072-015-2080-x
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LETTER TO THE EDITOR
Hirayama disease: the importance of adequate flexion MRI for diagnosis Marinos Kontzialis1 • Noushin Yahyavi-Firouz-Abadi1 • Carlos A. Zamora1
Received: 16 February 2015 / Accepted: 15 April 2015 Ó Springer-Verlag Italia 2015
Keywords Hirayama disease Flexion MRI Myelopathy Cervical Dear Editor, We read with great interest the recent correspondence by Cortese et al. [1], who described the importance of an early diagnosis of Hirayama disease (HD) in a patient who underwent conservative therapy. Herein, we stress the critical role of adequate flexion during dynamic MRI in the diagnosis of HD based on our recent experience. HD is a benign self-limiting disease that causes distal upper limb weakness and atrophy, which progresses over 2–4 years, followed by spontaneous arrest usually within
& Marinos Kontzialis [email protected]; [email protected] 1
Division of Neuroradiology, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Phipps B-112, Baltimore, MD 21287, USA
5 years. HD is thought to occur secondary to spinal cord compression by the posterior dural sac during neck flexion leading to ischemic damage to the anterior horns. The dynamic anterior shift of the dural sac is considered indicative of early progressive disease [2]. Imaging findings on neutral position MRI that should alert the physician include loss of normal cervical spine lordosis, loss of attachment between the posterior dural sac and subjacent lamina, lower cervical cord atrophy, and spinal cord T2 hyperintensity without evidence of extrinsic cord compression [3]. Flexion MRI is the appropriate next diagnostic step in suspected cases. An otherwise healthy 20-year-old male presented with a 2-year history of progressive right hand weakness and right upper extremity atrophy below the elbow. On clinical examination, there was no evidence of fasciculations, spasticity, or sensory deficits, and the atrophic changes spared the brachioradialis muscle. Needle electromyography showed chronic neurogenic changes in the form of fastfiring high-amplitude motor units. HD was suspected, and MRI of the cervical spine with flexion was ordered, which showed abnormal cord signal and segmental volume loss at C5–C6 (Fig. 1a). However, inadequate flexion with a tucked chin failed to demonstrate the expected anterior displacement of the posterior dural sac on the initial scan (Fig. 1b). Given the high clinical suspicion, MRI of the cervical spine was repeated in 3 months, when adequate flexion reproduced unequivocal imaging findings (Fig. 1c). Axial T2-weighted images in neutral position and flexion demonstrated abnormal cord signal, cord deformity and loss of attachment of the dural sac from the subjacent lamina (Fig. 2). HD is a slow progressive disease that can have good prognosis if detected and treated at an early stage and this case highlights the importance of adequate flexion MRI in
123
Neurol Sci
Fig. 1 The importance of adequate flexion MRI in the diagnosis of Hirayama disease. a Sagittal T2-weighted image in neutral position demonstrates cord atrophy and abnormal cord signal at C5–C6 (arrow). There is loss of the normal cervical spine lordosis, which is a common but nonspecific finding in HD. b Sagittal T2-weighted image in mild flexion with tucked chin. There is redemonstration of
hyperintense cord signal and atrophy (arrow) without evidence of abnormal anterior motion of the dura. c Sagittal T2-weighted image in adequate flexion with a rolled blanket behind the patient’s head. There is loss of attachment of the dura (arrows) from the posterior elements, which results in cord compression worse at the C5 and C6 level
Fig. 2 Neutral position and flexion axial T2-weighted images. a Axial T2-weighted image in neutral position at C4–C5 shows prominent abnormal hyperintense T2 signal in the right central aspect of the cord, and partial loss of attachment of the dural sac from the subjacent lamina bilaterally (arrows). b Axial T2-weighted image in neutral position at C5–C6 demonstrates mild symmetric flattening of
the cord with patchy T2 hyperintense signal most prominent in its right posterolateral aspect (arrow). c Axial T2-weighted image in adequate flexion demonstrates complete loss of attachment of the dural sac from the subjacent lamina (arrows) resulting in compression and flattening of the cord
suspected cases. Suboptimal flexion MRI may result in under-recognition of this entity and failure to institute appropriate therapy early during the course of the disease.
2. Huang YL, Chen CJ (2011) Hirayama disease. Neuroimaging Clin N Am 21(4):939–950. doi:10.1016/j.nic.2011.07.009 3. Chen CJ, Hsu HL, Tseng YC, Lyu RK, Chen CM, Huang YC, Wang LJ, Wong YC, See LC (2004) Hirayama flexion myelopathy: neutral-position MR imaging findings—importance of loss of attachment. Radiology 231(1):39–44. doi:10.1148/radiol. 2311030004
Conflict of interest
None declared.
References 1. Cortese R, Gerevini S, Dicuonzo F, Zoccolella S, Simone IL (2015) Hirayama disease: the importance of an early diagnosis. Neurol Sci. doi:10.1007/s10072-015-2080-x
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