A 51-year-old man with no significant past medical history was admitted to our hospital because of gait disturbance and dysuria. He had a 2-year history of low back pain and numbness in both legs. His symptoms worsened 1 week earlier and he suddenly developed gait disturbance associated with bilateral leg weakness. On admission, manual muscle testing revealed paresis with distal dominance. Patellar tendon and Achilles tendon reflexes were not exaggerated. He had urinary retention and his lumbar Japanese Orthopedic Association (JOA) score was only 2/29, indicating severe physical impairment (the lower the score, the more severe the impairment). MRI of the spine revealed a spinal lipoma at the L5 level and a flow void dorsal to the spinal cord at approximately the level of the conus medullaris (Fig. ). MRA revealed tortuous blood vessels within the spinal lipoma (Fig. ). Subsequent angiography showed an arteriovenous shunt from the right lateral sacral artery. The feeding artery entered from the dorsal aspect into the lipoma, and then passed the shun zone, and entered the spinal canal primarily via the juxtamedullary vein (Fig. ).\nDiagnosis was a sAVF within a spinal lipoma, and the patient underwent ligation of the draining vein combined with embolization. Under general anesthesia, a catheter was inserted into the lateral sacral artery and advanced to just before the shunt of the fistula. Because a provocation test with lidocaine hydrochloride (hereafter, xylocaine test) showed depression of the motor-evoked potentials (MEP) in the left anterior tibial and anal muscles, embolization using any liquid embolic agent was deemed to be high risk and, we performed only proximal artery occlusion with a coil. Angiography of the internal iliac artery after embolization revealed slight remaining density in the shunt. Therefore, ligation of the draining vein was additionally performed under microscopic view, with transection of two draining veins in the lipoma. Postoperative angiography confirmed there was no remaining shunt.\nPostoperatively, bilateral lower limb muscle strength was slightly improved, but there was no appreciable improvement in vesico–rectal disturbances. At 1 month after surgery, his lumbar JOA score had improved to 10/29, but angiography revealed an arteriovenous shunt via a collateral route from the right lateral sacral artery (Fig. ). The patient experienced no aggravation of symptoms thereafter. Although his low back pain, leg numbness, and bladder dysfunction persisted, intermittent claudication, muscle weakness, and the ADL score were improved at 1 year after surgery. His lumbar JOA score was further improved to 13/29.
A 51-year-old male, with a medical history of hypertension and diabetes mellitus, was admitted to the local hospital due to intermittent acute exacerbation of myelopathy for 3 months. One year earlier, he had developed gait disturbance and difficulty in balancing. There was no history of trauma. Nine months later, the patient had acute onset of paraparesis after waking up in the morning. He collapsed on the ground and could not stand up for a while. After 30 min, he could raise his legs and walk as baseline. He complained of minimal back pain and denied numbness. Two months before hospitalization, he could not stand up after having dinner in the evening. After 30 min later, his symptoms improved. He had occasionally numbness on his left leg. After this event, he had a limitation on ambulation and was unable to walk more than about 50–100 m without stopping to rest. No bowel or bladder involvement was complained. Three weeks before admission, the patient had the same symptoms and rest for about 30 min then improved. MRI of whole spine was performed and was interpreted of a long segment T2 hyperintense cord lesion extending from the level of T4 to the conus medullaris. Lumbar puncture was performed due to the putative diagnosis of transverse myelitis. Cerebrospinal fluid pressure, cell count, and chemistries were within normal limits. The patient was transferred to Prasat Neurological Institute for definite diagnosis and proper management. The physical examination revealed bilateral lower extremity weakness (muscle strength 4/5) without paresthesia. Hyperreflexia was noted in the lower extremities. Babinski's sign was also positive. By counting vertebrae from whole spine screening, there was a degenerative bulging disc at the level of L4–L5 with spinal canal stenosis and compression of bilateral L5 traversing roots []. MRI of the thoracolumbar spine showed the spinal cord congestion at the level of T4 to the conus medullaris with subtle perimedullary flow voids along ventral and dorsal cord surfaces [Figure and ]. Furthermore, there was a curvilinear intradural flow void on T2-weighted image, identified below the conus medullaris. Contrast-enhanced MRA of the thoracolumbar spine demonstrated an enlarged intradural vessel in the midline location extending from the lower lumbar level to the conus medullaris, probably the vein of the filum terminale [], corresponding with the curvilinear flow void on MRI. Spinal angiography demonstrated SDAVF at the level of L4–L5, probably located on the right L5 nerve root sleeve, which is supplied by the right iliolumbar artery originating from the internal iliac artery with cranial drainage into the dilated vein of the filum terminale. The artery of Adamkiewicz arose from the right T8 intercostal artery. Endovascular treatment with NBCA through the right iliolumbar artery was successfully performed to fill in the arterial feeder and fistulous site but fail to reach the proximal vein []. Postembolization angiography of the internal iliac and iliolumbar arteries revealed complete obliteration of the fistula. The patient had gradually improved and was sent back to the local hospital for further physiotherapy. Four months later, he returned and was readmitted to our institution with gait disturbance with the deterioration of clinical symptoms. Follow-up MRI and MRA of the lumbosacral spine revealed unchanged long segment of spinal cord congestion with the presence of SDAVF at the same level. One week later, the patient underwent decompressive laminectomy with obliteration of the intradural draining vein. The patient had significantly improved until being the ability to walk independently 2 weeks later. Spinal angiography, obtained 2 weeks after surgery, confirmed complete obliteration of the fistula []. MRI of the thoracolumbar spine, obtained 4 months after surgery, confirmed the resolution of spinal cord congestion [].