Ruptured Thoracolumbar Spinal Artery Aneurysm Mimicking an Intradural Vascular Malformation in an Adolescent

A 15-year-old adolescent boy presented after 6 hours of lower back pain, left lateral thigh spasms, and inability to walk.Examination showed left-leg Motor Research Council grade 3 weakness, bilateral lower limb hypertonia, and meningeal signs.Thoracolumbar CT before lumbar puncture revealed a mildly hyperdense intradural lesion (Figure 1A).Bloody CSF showed opening pressure 280 mm H 2 O and red blood cells >20,000 × 10 6 /L.Contrastenhanced thoracolumbar MRI demonstrated a 1.6 × 1.2-cm enhancing intradural nodule posterior to T11 with extensive spinal subarachnoid hemorrhage, suggesting an intradural vascular lesion or hemorrhagic intradural tumor (Figure 2A).Magnetic resonance angiography showed a T12 aneurysm, confirmed by selective spinal digital subtraction angiography, establishing ruptured thoracolumbar spinal artery aneurysm (Figure 2B).Because surgery or embolization risked spinal cord ischemia, conservative blood pressure control and symptomatic treatment were used.At 8 months, he walked without recurrence.Isolated spinal artery aneurysm is rare 1,2 ; magnetic resonance angiography/computed tomographic angiography may suffice in selected cases, whereas digital subtraction angiography defines arterial supply, venous drainage, and treatment feasibility.Figure 1 Prelumbar Puncture Thoracolumbar CT (A) Noncontrast CT showed a mildly hyperdense lesion in the left spinal canal; (B) contrast-enhanced CT showed heterogeneous nodular enhancement.