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 43-year-old Caucasian man was admitted to the emergency department of our hospital for headache associated with weakness of the left limbs. He had no medical history, he denied even slight trauma of the neck, and his only cardiovascular risk factor was tobacco smoking for 10 years. Neurological examination revealed verbal aphasia and left hemiparesis.\nDuring CT angiography (TK–64-row MDCT scanner, LightSpeed VCT, GE, Waukesha, WI) of the neck and head, segmental dissections of the right internal carotid artery (ICA) at the level of the cranial basis were discovered (Fig. a). The lumen of the ICA was decreased to 4 × 2.5 mm (60 % of normal flow). Cerebral CT showed a recent infarction involving the medial part of the right temporal lobe and deep structures of the right hemisphere including the thalamus, the genu and the posterior limb of the internal capsule (Fig. b).\nCT angiography of the neck and head also showed a duplication of the left vertebral artery (LVA) with two origins, both from the left subclavian artery (Figs. , ). The duplicated segments were fused at level of the C5–6 vertebrae into a single vertebral artery, which then entered the transverse foramen of C5 (Fig. ). All measurements were taken on an Advantage Workstation (GE).\nThe first LVA originated from the left subclavian artery at a distance of 7 mm from the aortic arch. It measured 2.9 and 2.8 mm in diameter at the points of origin and just before fusion, respectively (Fig. ). The course of the artery was 101 mm. The second LVA arose from the left subclavian artery 37 mm distal to the first (44 mm from the aortic arch). It measured 2.4 and 2.2 mm in diameter at the points of origin and just before fusion, respectively (Fig. ), and its course was 89 mm. Both vertebral arteries possessed a regular lumen. The diameter of the LVA after fusion was 3.3 mm (at level C5–6) (Fig. ).\nThe right VA arose as the first branch from the left subclavian artery, 43 mm from the aortic arch. Its course was normal. The diameters of the right VA were 4 mm at the points of origin and 3.8 mm at the C5–C6 vertebrae (Fig. ). Both thyrocervical trunks were seen to originate separately from the subclavian arteries.\nAdditionally, complementary but independent to CT angiography Doppler Sonography B-flow mode (Vivid 7 Pro, GE) of the vertebral arteries also revealed a duplicated LVA (Fig. ).\nAfter all procedures were completed, Ehlers–Danlos syndrome type IV was diagnosed.