OBJECTIVE Brain sagging after craniotomy and clipping of a ruptured aneurysm is a rare complication. Clinical and electrographic changes in patients with a final diagnosis of intracranial hypotension are not well described, and can be mistaken on rare occasions for other entities such as nonconvulsive status epilepticus. There may be resulting delay in the diagnosis and treatment of this potentially life-threatening disorder. METHODS Case report and imaging. RESULTS We present a case of intracranial hypotension in which concerning continuous electroencephalogram (cEEG) and quantitative EEG (qEEG) findings were noted during active sagging of the brain, which resolved with supine positioning. During upright seating, cEEG showed high-amplitude bilateral rhythmic 2-Hz slow-wave activity, and bilateral increase of spectral delta power on qEEG, in association with neurologic decline in function. When placed in supine position, the cEEG and qEEG abnormalities resolved in conjunction with the recovery of neurologic function. CONCLUSIONS Brain sagging can be diagnosed using simple maneuvers such as supine positioning. This case report describes changes seen in cEEG and qEEG monitoring that accompany these maneuvers, which may provide further evidence for the diagnosis of brain sagging. Thus, cEEG and qEEG monitoring may have a role in the early detection and treatment of brain sagging.