Persistent vegetative state. Extension of the syndrome to include chronic disorders.

Twenty-nine institutionalized patients had the vegetative state as a sequela of chronic progressive neurologic disorders. During three years, the state was persistent; none improved, ten died. Eight similar patients were reviewed retrospectively post mortem. Eight patients with severe dementia, while acutely ill or sedated, temporarily met the criteria for persistent vegetative state (PVS) but improved when the underlying condition was treated. Abnormalities on electroencephalography or computed tomographic scan are not specific for the PVS. Electroencephalograms were normal in three patients with PVS. The computed tomographic scans showed extensive destruction of the brain parenchyma but were not different from those of severely demented patients without the PVS. The PVS is a feature of the terminal phase of several progressive neurologic disorders. Patients should be treated without excessive intervention.