Spinal cord infarction is a rare vascular-occlusive disorder of the spinal cord that constitutes only 1% of reported strokes. It is characterized by myelopathy and sensory loss, although atypical symptoms occur.
Spinal cord infarction (SCI) is an ailment that is precipitated by the occlusion of one of the arteries of the spinal vasculature, leading to variable clinical features depending on the affected vessel. Resultant local ischemia of the spinal cord leads to the acute onset of myelopathy [1]. The latter is characterized by sensory and motor deficits below the lesion. Diagnosis of SCI is clinical, and although the condition is abrupt, it may be partially diminished and delayed due to the continued circulation provided by collateral vessels [2]. Individuals who suffer from SCI may have risk factors such as trauma, coagulopathies or prior aortic surgery, although a significant number of cases have no identifiable etiology [3] [4].
One of the most common symptoms is back pain, which occurs in up to 70% of cases [5]. The general findings reported, however, are neurological, and may include loss of fine touch and proprioception (commonly in anterior spinal artery infarcts), vibration, pain and temperature perception. Motor disturbances and flaccid paralysis have also been described. In addition, muscle weakness and loss of reflexes are often experienced [6]. Features of Brown-Sequard syndrome are also documented [7].
Individuals may also present with loss of sphincter tone as well as complaints consistent with a neurogenic bladder. Hyperreflexia may follow initial symptoms, and a positive Babinski reflex may be elicited.
SCI shares feature with other neuropathies and myopathies such as Guillain-Barré syndrome, thus making the diagnosis more difficult [1].
The aim of imaging modalities and laboratory studies is to demonstrate the presence of a spinal cord infarction, and also to rule out alternative etiologies of symptoms such as hypercoagulability and stroke due to cardiac emboli.
Visualization of the spinal cord in the form of magnetic resonance imaging (MRI) scanning may show abnormalities such as the 'owl eye' sign, seen in anterior spinal artery (ASA) involvement [5]. Nevertheless, up to 45% of patients have undetectable changes on MRI while in the acute stages. Additional signs include vertebral body infarction, which may become apparent earlier than SCI [8]. The importance of MRI is emphasized in its ability to exclude conditions such as atriovenous malformations, space occupying lesions and infection [9]. Diffusion-weighted imaging and T2 weighted imaging may be able to detect early infarctions, although artifacts are common in the former [10]. Signs of cord ischemia seen in T2 weighted images include local swelling and hyperintense lesions [1] [2] [10]. Brain abnormalities may also be visible after some hours.
Spinal angiogram to eliminate vascular malformations as the cause may be attempted in young patients, however, this procedure is available at highly specialized institutions and carries a risk of worsening the ischemia.
Cerebrospinal fluid (CSF) analysis can rule out both bacterial and viral infections such as human immunodeficiency virus, herpes simplex virus, Epstein-Barr virus, and syphilis. Polymerase chain reaction and serology are among the tests performed. Screening for autoimmune causes uses both CSF and serum analysis, measuring erythrocyte sedimentation rate, antinuclear antibody, and complement.