Is the immobility of advanced dementia a form of lorazepam-responsive catatonia?

Patients with end-stage dementia typically are very immobilized. Could this state actually be a form of lorazepam-responsive catatonia? Catatonia has been documented following cerebrovascular accidents, head injury, HIV encephalitis, brain tumors, and multiple sclerosis. Identified anatomical substrates include frontal lobes, parietal lobes, limbic system, diencephalon, and basal ganglia. Given that Alzheimer's disease, vascular dementia, Lewy body dementia, corticobasal degeneration, frontotemporal dementia, and Parkinsonian dementia often have degeneration in some of the same areas, dramatic awakenings might be possible by giving lorazepam challenges to locked-in dementia patients. If even a small percentage were lorazepam responders, the impact worldwide would be tremendous. Serious consideration should be given to undertaking large-scale clinical trials.