[Two cases of spontaneous intracranial hypotension associated with chronic subdural hematoma only treated with burr hole irrigation of the hematomas].

We reported two cases of spontaneous intracranial hypotension (SIH) associated with bilateral chronic subdural hematoma (CSDH). The patients presented with severe positional headache, aggravated by sitting or standing. Neither spinal surgery nor lumbar-tap had been performed in these patients. They were diagnosed as SIH with bilateral CSDH. Headache was aggravated and CSDHs volume increased despite conservative therapy. However, after a burr hole irrigation of hematoma, not only CSDHs but also the symptoms with SIH were completely resolved and there was no recurrence. We demonstrated that burr hole irrigation for CSDH associated with SIH might completely resolve the SIH symptom in some cases, as in the present report. The mechanism of this phenomenon was discussed.