Subarachnoid hemorrhage caused by spontaneous intracranial hypotension: two rare cases report

Spontaneous intracranial hypotension (SIH) combined with subarachnoid hemorrhage (SAH) has rarely been reported. Herein, we report two patients with SIH who suffered from diffuse non-aneurysmal SAH and expanded the symptom spectrum of SIH.

(1) A 55-year-old male was diagnosed with SIH based on orthostatic headache and diffuse pachymeningeal enhancement on brain MRI. One more month later, his headache was exacerbated, and brain CT showed diffuse SAH. Lumber puncture showed bloody cerebrospinal fluid (CSF) with a low CSF pressure of 20 mmH₂O after a 30 mL intrathecal injection of saline. The patient was treated with a lumbar epidural blood patch and recovered. (2) A 41-year-old male presented with orthostatic headache and nuchal pain. The brain CT scan confirmed the diagnosis of SAH. Brain MRI revealed diffuse dural thickening and bilateral frontoparietal subdural fluid collection. Lumber puncture showed bloody CSF with low CSF pressure. Then, an epidural blood patch was performed with satisfactory results.

Dilation and rupture of intracranial venous structures might play significant roles in SIH combined with SAH. We should be alert to SIH patients who develop a new persistent severe headache without relief after lying down or a suddenly changed state of consciousness.