11 492 · 11 Blood Supply and Vascular Disorders of the Central Nervous System
(Continued) Fig. 11.37 Spinal arteriovenous (AV) fistula. c This axial T2-weighted image of the spinal cord, obtained just above the level of the conus medullaris, reveals intramedullary edema sparing the ventral portion of the cord. This is an important criterion for the differential diagnosis of AV fistula versus arterial ischemia, in addition to the patient’s clinical manifestations and the dilated epimedullary veins that were seen in the other MR images (above).
c
with necrosis of the anterior horns converts the spastic paraparesis into a flaccid paraparesis.
Diagnostic evaluation. MRI reveals dilated epimedullary veins and edema of the spinal cord. The fistula itself cannot be seen. It may also be very difficult to demonstrate by angiography, because the shunt volume may be very low, and the clinical manifestations of congestive myelopathy may be mainly due to impaired venous drainage.
Even today, arteriovenous fistulas causing congestive myelopathy are often not recognized before the appearance of irreversible neurological deficits. This is regrettable, because such fistulas are a potentially treatable cause of progressive paraparesis.
Treatment. The treatment consists of operative obliteration of the fistula after it has been localized by angiography.
Spinal Cord Hemorrhage and Hematoma
Hematomyelia—a hematoma within the spinal cord—is usually of traumatic origin, and is only rarely due to an aneurysm or vascular malformation. Because thebloodusuallytrackslongitudinally(i.e.,upanddown)inthespinalgraymatter, a clinical syndrome resembling that of syringomyelia results (cf. p. 74).
Spinal epidural hematoma usually occurs at thoracic levels, producing acute radicular pain at the level of the hematoma, as well as a subacute spinal cord transection syndrome that begins with paresthesiae, sensory deficits, and weaknessinthefeetandtoes,andthenrapidlyascendstothelevelofthehematoma. Symptomatic spinal epidural hematoma is an acute neurosurgical emergency: it must be evacuated immediately to prevent irreversible paraplegia.
Baehr, Duus' Topical Diagnosis in Neurology © 2005 Thieme
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