A case of convexity subarachnoid haemorrhage from intracranial hypotension treated with epidural blood patch

The majority of subarachnoid haemorrhages (SAH) are of aneurysmal origin, and nontraumatic convexity SAH is rare. We describe one patient who had a convexity SAH caused by cortical veins thrombosis (CVT) secondary to intracranial hypotension (IH). We discuss possible pathophysiologic mechanisms and its treatment. A 52-year-old female presented with left hemiparesis and tonic-clonic seizures, following lumbar epidural injections of local anaesthetics and steroids because of chronic low back. Brain CT showed right fronto-parietal convexity SAH. Brain MRI revealed diffuse pachymeningeal enhancement and confirmed the SAH. Cerebral angiography showed no/low flow signal in few frontal and parietal cortical veins in the correspondence of the SAH. A restoration of flow signal in this area was revealed after 2 months. The patient was treated with lumbar epidural blood patch with recovery. Convexity SAH caused by CVT from IH may be treated only with lumbar epidural blood patch which eliminates by itself the determinants of CVT (vein dilatation and slow vein drainage).