Article of the Month

Phenomenology of the subtypes of delirium: phenomenological differences between hyperactive and hypoactive delirium

Boetteger, S and Breitbart, W

Palliative and Supportive Care 2011; 9: 129-135

Delirium is a neuropsychiatric disorder characterized by cognitive alterations, attention and perception disturbances. Delirium is frequent in advanced stages of disease and the symptoms are distressing to both the patients and for their caregivers.

Delirium is classified into subtypes characterized by their psychomotor behaviors: the hypoactive type is characterized by decreased reactivity, motor and speech retardation, amimic facial expression; the hyperactive type presents with symptoms like agitation, hyperactivity, delusions, aggressiveness, and perceptual disturbances.

The authors examined the difference in phenomenology between hypoactive and hyperactive subtypes of delirium and determined the comparative prevalence of perceptual disturbances (e.g., hallucinations) and delusions in the two subtypes of delirium in patients referred for delirium management to the Memorial Sloan-Kettering Cancer Center (MSKCC) and who also met the DSM-IV criteria for delirium. Data were recorded in an Institutional Review Board which included serial ratings of the Memorial Delirium Assessment Scale (MDAS), cause of delirium, type and dosages of medications used for delirium-related symptom control.

One hundred patients (79% metastatic, 5 % terminal, mean KPS score 35.5, 53% with Hypoactive delirium, 51.5% male, mean age 59 years, range 19-89,) were evaluated from the data base. Most of patients had lung cancer (21%) and only 3% had brain cancer. However 24% of the patients had brain metastasis and 18% of the total sample had a history of dementia. The main causes of delirium were opioids (63.4%), infections (41%), corticosteroids (30%), hypoxia (28%), dehydration (13%), and others (13%). No significant differences were found between delirium subtypes based on age or gender, MDAS total scores (deliriu m diagnosis and severity) or KPS.

Hallucinations were more frequent in patients with hyperactive delirium compared to hypoactive delirium -- 70% vs 51% (p<0.05) and 79% vs 43% (p<0.001). Hallucinations and delusions were more frequent in patients with hyperactive delirium vs hypoactive one (p<0.001 and p<0.05 respectively) but only when MDAS items were of moderate to severe intensity.

The intensity of hallucinations and delusions were correlated with the intensity of cognitive impairment such as reduced consciousness (p<0.01) and impaired attention (p<0.05).

Hypoactive and hyperactive delirium subtypes were significantly different in the severity of perceptual disturbances (p<0.01) and delusions (p<0.001) and were both more severe in the hyperactive deliriumand in the severity of psychomotor activity (p<0.001). The severity of hallucinations and delusions are independent of delirium severity in both delirium subtypes.

Why I choose this article

Delirium is present in the majority of patients with advanced stages of cancer and is considered a prognostic indicator of survival and in some cases of impending death.

The presence of either hypoactive or hyperactive delirium subtypes is able to create distress in patients, their health caregivers and their family members. Many papers have been written on the assessment and the management of delirium and the related symptoms, however it not easy to provide adequate treatment.

The authors were able to explain, through a revision of the data collected, the differences in phenomenology between hypoactive and hyperactive subtypes of delirium which helps us in our daily clinical practice.

Reviewed by Dr. Carla Ripamonti (Italy). Dr. Ripamonti is a member of the IAHPC Board and her bio may be viewed at http://www.hospicecare.com/Bio/c_ripamonti.htm