Etiological and Symptomatological Differences Between Hyperactive and Hypoactive Delirium Subtypes

Abstract

The processes of ageing and the related impairment of maintaining homeostasis, understood as the loss of adaptive abilities, lead to an increased susceptibility to developing delirium among the elderly. The pathophysiological process of delirium development is dependent on the presence of causative and predisposing factors; for example, neurotransmission process disorders (cholinergic, serotonin and dopaminergic regulation), resulting in metabolic inefficiency of the brain. The symptoms of delirium differ in duration and severity; there are 3 clinical subtypes of delirium: hypoactive, hyperactive and mixed. Moreover, subsequent evaluations using methodological tools have made it possible to distinguish an additional subtype of delirium - the no-motor subtype. Recognizing the delirium subtype is essential - it identifies high-risk patients, has an effect on the procedures, treatment and further prognosis. Medical personnel working with elderly patients ought to be well familiar with the predisposing factors, non-pharmacological procedures, treatment and prognosis of delirium; they also are required to know how to differentiate between each delirium subtype. Physicians should be aware that the hypoactive subtype of delirium indicates a much worse prognosis for patients.