Spinal axis imaging in non-aneurysmal subarachnoid hemorrhage: a prospective cohort study

In 15 % of all spontaneous subarachnoid hemorrhages (SAH), no intracranial vascular pathology is found. Those non-aneurysmal hemorrhages are categorized into perimesencephalic SAH (PMSAH) and non-perimesencephalic SAH (NPSAH). Searching for spinal pathology might reveal a cause for the hemorrhage in some patients. Our goal was to assess the yield of magnetic resonance (MR) imaging of the complete spinal axis in search for a spinal origin in non-aneurysmal SAH. In a prospective, observational study at a tertiary SAH referral center, we assessed clinical and radiological characteristics of patients who consecutively presented with spontaneous non-aneurysmal SAH, diagnosed by computed tomography (CT) or lumbar puncture, and negative CT angiography and digital subtraction angiography (DSA). Eligible patients were enrolled for investigation of the complete spinal axis by standard T1- and T2-weighted MR-imaging. Ninety-seven non-aneurysmal SAH patients were included in the study. Baseline characteristics were comparable between PMSAH and NPSAH patients. DSA and spinal MR-imaging were performed in 95 and 91 % of patients, respectively. This revealed one lumbar ependymoma in a 43-year-old male who was diagnosed by LP (yield 1 %). No spinal origin for the SAH was found in 51 PMSAH patients. The yield of MR-imaging of the complete spinal axis in spontaneous non-aneurysmal SAH patients is low. Routine radiological investigation of the spinal axis in non-aneurysmal SAH patients is therefore not recommended.