A 61-year-old woman first experienced sudden lower back and right leg
pain 3 years prior to surgery. At this time, MRI showed an intramedullary
cavernous angioma at Th10-11 with central T2 high and peripheral T2 low signal intensity. However, she completely recovered in two weeks. Four days prior to the present admission (day of the second
hemorrhage), she again experienced severe lower back and right leg
pain, followed by complete
paralysis of the right leg. Despite vigorous medical treatment including administration of
steroid,
hemostatics and
glycerol, her condition became aggravated with complete
paraplegia and loss of sphincter control by the 4th hospital day. MRI taken two days after the second
hemorrhage showed an increase of peritumoral T2 hypointensity and another area of T2 hypointensity in the lumbar spinal cord at L1-Th12 with cord swelling. MRI 13 days after the second
hemorrhage showed that these areas of T2 hypointensity had changed to T1 and T2 hyperintensity suggesting conversion of
deoxyhemoglobin to
methemoglobin. Subsequent MRI showed longitudinal punctuate propagation of
methemoglobin from the
angioma down to the lumbar enlargement and into the conus medullaris, where a 30 x 6 mm spindle-shaped area of T1 and T2 hyperintensity indicating
hematomyelia had formed. Total removal of the
angioma was followed by gradual recovery and decrease in the size and signal intensity of the
hematomyelia. Histopathological examination demonstrated the typical features of
cavernous angioma with deposition of
hematoidin. Propagation of extravasated blood from the ruptured thoracic cavernoma to the conus medullaris, with splitting of spinal cord nerve fibers, was demonstrated by MRI.