Hyperacute extensive spinal cord infarction and negative spine magnetic resonance imaging: a case report and review of the literature.

Spinal cord infarction (SCI) accounts for only 1% to 2% of all ischemic strokes and 5% to 8% of acute myelopathies. Magnetic resonance imaging (MRI) holds a role in ruling out non-ischemic etiologies, but the diagnostic accuracy of this procedure may be low in confirming the diagnosis, even when extensive cord lesions are present. Indeed, T2 changes on MRI can develop over hours to days, thus accounting for the low sensitivity in the hyperacute setting (ie, within 6 hours from symptom onset). For these reasons, SCI remains a clinical diagnosis. Despite extensive diagnostic work-up, up to 20% to 40% of SCI cases are classified as cryptogenic. Here, we describe a case of cryptogenic longitudinally extensive transverse myelopathy due to SCI, with negative MRI and diffusion-weighted imaging at 9 hours after symptom onset. A 51-year-old woman presented to our Emergency Department with acute severe abdominal pain, nausea, vomiting, sudden-onset of bilateral leg weakness with diffuse sensory loss, and paresthesias on the trunk and legs. On neurological examination, she showed severe paraparesis and a D6 sensory level. A 3T spinal cord MRI with gadolinium performed at 9 hours after symptom onset did not detect spinal cord alterations. Due to the persistence of a clinical picture suggestive of an acute myelopathy, a 3T MRI of the spine was repeated after 72 hours showing a hyperintense "pencil-like" signal mainly involving the grey matter from T1 to T6 on T2 sequence, mildly hypointense on T1 and with restricted diffusion. The patient was given salicylic acid (100 mg/d), prophylactic low-molecular-weight heparin, and began neuromotor rehabilitation. Two months later, a follow-up neurological examination revealed a severe spastic paraparesis, no evident sensory level, and poor sphincteric control with distended bladder. Regardless of its relatively low frequency in the general population, SCI should be suspected in every patient presenting with acute and progressive myelopathic symptoms, even in the absence of vascular risk factors. Thus, a clinical presentation consistent with a potential vascular syndrome involving the spinal cord overrides an initially negative MRI and should not delay timely and appropriate management.