|LETTER TO THE EDITOR
|Year : 2020 | Volume
| Issue : 2 | Page : 109-110
Owl's eye sign: A rare neuroimaging finding
Abhishek Juneja, Kuljeet Singh Anand, Arpit Agrawal
Department of Neurology, Dr. RML Hospital, New Delhi, India
|Date of Submission||25-Mar-2020|
|Date of Decision||24-Apr-2020|
|Date of Acceptance||24-May-2020|
|Date of Web Publication||07-Jul-2020|
Dr. Abhishek Juneja
A-15, Old Quarters, Ramesh Nagar, New Delhi - 110 015
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Juneja A, Anand KS, Agrawal A. Owl's eye sign: A rare neuroimaging finding. Indian J Med Spec 2020;11:109-10
A 28-year-old male patient presented with complaints of wasting and weakness of the left upper limb for 1 year. He also complained of involuntary muscle twitching over his left arm and forearm. On neurological examination, he had wasting of the left hand and forearm muscles with diffuse fasciculations over the left arm and forearm. He had weak hand grip on the left side along with weak flexion and extension across the left elbow joint. Deep tendon reflexes were exaggerated in all four limbs. Plantar response was bilaterally flexor. The rest of the neurological examination was unremarkable. His routine blood investigations were normal including glycemic and thyroid profile. His serum antinuclear antibody and human immunodeficiency virus tests were negative. His nerve conduction studies were normal. Electromyography done per motor neuron disease protocol revealed spontaneous activity, in the form of diffuse fasciculations in bilateral upper and lower limbs and paraspinal and tongue muscles. Large amplitude giant muscle unit action potentials with reduced interference pattern were noted in most of the sampled muscles. The patient was diagnosed as a case of laboratory-supported probable amyotrophic lateral sclerosis (ALS) as per revised El Escorial criteria. Magnetic resonance (MR) imaging of the cervical spine revealed linear T2 intramedullary hyperintensity in C3–C5 cervical segments, which on axial cuts had the appearance of owl's eyes [Figure 1]. The patient was told the prognosis of his illness and started on tablet riluzole 50 mg twice daily. He was registered in the Department of Physical Medicine and Rehabilitation.
|Figure 1: Magnetic resonance imaging cervical spine T2 sequence showing linear intramedullary hyperintensity at C3–C5 segments (sagittal section) with Owl's eye sign (axial section)|
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The “owl's eye” sign is also known as “snake-eye” sign. It is characterized by bilaterally symmetrical hyperintensity in the anterior horn of the spinal cord in axial T2-weighted MR imaging. It has been reported in various diseases including cervical spondylosis, Hirayama disease, spinal cord infarction, neuromyelitis optica, and flail arm syndrome., It is possibly secondary to cystic necrosis in the central gray matter near the ventrolateral posterior column of the spinal cord. It is regarded as a poor prognostic factor for the recovery of upper-extremity motor weakness as found in our case. It is a rare neuroimaging finding and ALS should be kept in mind, apart from the more common ischemic and mechanical causes, as a differential diagnosis.
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.
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