Are Fluctuations in Motor Performance a Diagnostic Sign of Delirium?

Patients with delirium exhibit a pattern of fluctuating motor performance that is chronologically related with the onset and the end of delirium, ie, they decline when delirium develops and improve when delirium ends. This pattern seems to be typical of delirium, as it is appreciable in subjects with dementia developing delirium but not in patients with dementia alone. A fluctuation of motor performance should be considered a diagnostic sign of delirium.