The Spine Journal 15 (2015) 1484–1485
Snake eyes A 25-year-old college student presented with insidious onset and gradually progressive wasting and weakness of both upper limbs for the past 2 years. There was no history of bulbar dysfunction or lower limb involvement. On examination, he had hypotonia and severe wasting of upper limbs both proximally and distally. He had Grade 2 power proximally and small muscles of the hands were weak. Tongue was normal without any fasciculations or atrophy. There was no sensory loss or cranial nerve palsies. Diffuse fasciculations were present on both arms and forearms. Deep tendon reflexes were absent in upper limbs and normal in lower limbs. Lower limbs had Grade 5 power with normal bulk and tone. There was no bladder or autonomic involvement. No significant family history was present. Hemogram, chest X-ray, biochemical parameters, and viral markers (human immunodeficiency virus, hepatitis B virus, hepatitis C virus) were negative. Electrophysiologic studies showed evidence of denervation and reinnervation in both
upper limbs and normal studies in lower limbs, paraspinal muscles, and tongue. Magnetic resonance imaging of cervical spine showed longitudinally extending T2W hyperintensities in the anterior spinal cord from C4 to C8 spinal segments without any contrast enhancement (Figure, Left). T2-axial images showed hyperintensities in bilateral anterior horn cells with characteristic owl eye or snake eye appearance (Figure, Right). In view of clinical features, flail arm variant of amyotrophic lateral sclerosis was diagnosed and Riluzole 50 mg twice daily was started along with regular physiotherapy. He had no significant worsening till the last follow-up of 1 year. Flail arm variant of motor neuron disease usually presents with progressive weakness and wasting of upper limbs, which is symmetric and proximal, without any significant involvement of bulbar muscles or lower limbs . The prognosis is better than limb onset and bulbar onset motor neuron disease . The snake eyes or owl eye appearance is because of the degeneration of anterior horn cells. It is also described in anterior spinal cord infarction , cervical spondylotic amyotrophy, Hirayama disease, and ossification
Figure. (Left) Magnetic resonance imaging of cervical spine showed longitudinally extending T2W hyperintensities in the anterior spinal cord from C4 to C8 spinal segments without any contrast enhancement. (Top Right and Bottom Right) T2-axial images showed hyperintensities in bilateral anterior horn cells with characteristic owl eye or snake eye appearance. http://dx.doi.org/10.1016/j.spinee.2015.02.020 1529-9430/Ó 2015 Elsevier Inc. All rights reserved.
V.Y. Vishnu et al. / The Spine Journal 15 (2015) 1484–1485
of posterior longitudinal ligament. Snake-eye appearance in compressive myelopathy may be the result of cystic necrosis because of mechanical compression and venous infarction and is a poor prognostic factor for the recovery of upperextremity motor weakness . References  Hu MT, Ellis CM, Al-Chalabi A, Leigh PN, Shaw CE. Flail arm syndrome: distinctive variant of amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 1998;65:950–1.  Wijesekera LC, Mathers S, Talman P, Galtrey C, Parkinson MH, Ganesalingam J, et al. Natural history and clinical features of the flail arm and flail leg ALS variants. Neurology 2009;72:1087–94.  Trebst C, Raab P, Voss EV, Rommer P, Abu-Mugheisib M, Zettl UK, et al. Longitudinal extensive transverse myelitisdit’s not all neuromyelitis optica. Nat Rev Neurol 2011;7:688–98.  Mizuno J, Nakagawa H, Inoue T, Hashizume Y. Clinicopathological study of ‘‘snake-eye appearance’’ in compressive myelopathy of the cervical spinal cord. J Neurosurg 2003;99(2 Suppl):162–8.
Venugopalan Y. Vishnu, MD (Medicine) Pulikottil Wilson Vinny, MD (Medicine) Manish Modi, MD (Medicine), DM (Neurology) Manoj Kumar Goyal, MD (Medicine), DM (Neurology) Department of Neurology Post Graduate Institute of Medical Education and Research Sector 12, Chandigarh India 160012 FDA device/drug status: Not applicable. Author disclosures: VYV: Nothing to disclose. PWV: Nothing to disclose. MM: Nothing to disclose. MKG: Nothing to disclose. Contributors statement: VYV: Data collection, drafting of manuscript, and review of literature; PWV: Review of literature; MM: Revision of manuscript; MKG: Concept and revision of manuscript. Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. There were no competing interests.