Brain sagging syndrome: Occult cerebrospinal fluid leakage as a cause of failed brain expansion after removal of bilateral chronic subdural hematomas.

Background: Patients with chronic subdural hematoma (CSDH), particularly bilateral hematomas, do not infrequently present with cognitive impairments. While those impairments are usually caused by brain compression by CSDH, other underlying causes may also be responsible for the impairments.

Case descriptions: A healthy 74-year-old man visited a local hospital with cognitive impairments of subacute onset. He denied the presence of a headache. A brain computed tomography (CT) revealed bilateral CSDH compressing the cerebral hemispheres. After an emergency bilateral burr hole drainage, his symptoms improved only partially, and recurrence of the CSDH occurred within 14 days of the first surgery. A search for the underlying cause of the cognitive impairments was implemented. A CT myelography revealed cerebrospinal fluid (CSF) leakage at the lumbar spine, and after an epidural autologous blood patch therapy, his cognitive impairments resolved quickly and fully.

Conclusion: In the case of bilateral CSDH with early postoperative recurrence, a search for the presence of occult CSF leakage may be warranted. The term "brain sagging syndrome" or "brain sagging dementia" has been proposed to describe cognitive impairments due both to the brain compression by the CSDH and to the brain sagging by the CSF leakage. The absence of orthostatic headache may not necessarily exclude the presence of CSF leakage.