A 70-year-old gentleman presented with a 12-month history of progressive bilateral lower limb weakness and numbness. He also developed constipation and urinary retention over the two weeks preceding presentation. There was no history of fever, backache, trauma, weight loss, or cough. Medical history was significant for type-2 diabetes mellitus and hypertension. For these symptoms, he consulted multiple physicians at different hospitals and underwent three magnetic resonance imaging (MRI) of the spine, which the radiologists reported as cervical spondylosis, transverse myelitis, and cervical syrinx, respectively. He was managed with high-dose intravenous steroids (methylprednisolone 1000 mg daily for five days) with tapering oral steroids, multivitamins, and coenzyme Q but his weakness gradually worsened.\nOn neurological examination, higher mental functions were intact. Cranial nerves examination was within normal limits. Pupils were bilateral 3 mm in diameter with normal pupillary reflex to light and accommodation. The fundus examination was unremarkable. Muscle bulk and muscle tone were normal in all four limbs. Muscle strength was normal in upper limbs while it was reduced in the lower limbs bilaterally, with the Medical Research Council (MRC) grade of 3/5 in both proximal and distal muscle groups. Deep tendon reflexes were normal in all four limbs except the ankle reflexes, which were reduced (1+) bilaterally. Babinski’s reflex was present bilaterally. Pinprick sensations were reduced below the level of T7. Proprioception testing was abnormal in lower limbs bilaterally.\nAnother MRI of the spine was performed (Figure ). The T2-weighted MRI images revealed patchy edema in the spinal cord extending from the C4 vertebral body up to the conus along with vessel flow voids dorsally. These findings were suggestive of spinal dural arteriovenous fistula (SDAVF). Although these findings were also present in the previous MRI scans, they were missed on reporting.\nThe diagnosis of SDAVF was subsequently confirmed on digital subtraction angiography (Figure ) and the fistula was embolized using histoacryl glue and lipoidal mixture. He was stable post-procedure and his weakness improved (MRC grade 4/5) within the next 48 hours.
A 36 year-old male with a history of dizziness and suspected cerebrovascular pathology was referred to our center for angiographic evaluation of carotid and vertebral arteries. He underwent multidetector 64-row computed tomography (MDCT) angiography. (GE: Optima660,2011, Tokyo, Japan60). Eighty-five milliliter of nonionic iohexolcontrast (Omnipaque, 350 mg I/ml, GE Healthcare, Shanghai, China) was injected at a rate of 5 ml/s by a power injector through the antecubital vein. The acquired images (slice thickness 0.625 mm) were further analyzed in a work station (GE: AW Volume Share 4) to generate volume-rendered (VR) and maximum intensity projection (MIP) images.\nThe left vertebral artery (LVA) had two separate limbs of origin []. The medial limb (2.2 mm in diameter at its origin) originated directly from the aortic arch in between the origins of left common carotid (LCCA) and left subclavian arteries (LSA) []. The lateral limb (2.4 mm in diameter at its origin) emanated from the LSA in its orthodox position and entered the foramen transversarium of C6 vertebra. Both the limbs united to form a single trunk at C5-C6 interval and the single trunk (3.2 mm in diameter) then entered C5 transverse foramen [Figures and ]. Both the limbs of the right vertebral artery (RVA) originated from the right subclavian artery (RSA) []. The medial limb (3.9 mm in diameter at its origin) originated from its orthodox position, whereas the lateral limb (2.4 mm in diameter at its origin) arose more posteriorly close to the origin of thyrocervical trunk. The lateral limb entered the C6 transverse foramen, but the medial limb entered the carotid space lying posteromedial to right common carotid artery (CCA) []. At the interval between the C4 and C5 vertebrae, both the limbs fused to form a single trunk (4.4 mm in diameter) which entered the C4 transverse foramen [Figures and ]. Further distal course of both vertebral arteries was normal and no cerebrovascular pathology could be detected.