Cognitive Failure

(Delirium, Temporary and Permanent Cognitive Impairment)

Cognitive decline, including poor memory, attention, and problem solving or even frank dementia and delirium, has long been recognized in patients with end-stage disease. 

As many as one-third of patients admitted to palliative care units show significant cognitive impairment (Power et al., 1993), and the percentage is much higher for patients in the last week or two of life. From 25 to 85 percent of patients with advanced cancer show confusion (Breitbart, 1995) and delirium is the second most common psychiatric diagnosis among hospitalized elderly cancer patients (Stiefel and Holland, 1991). Confusion, which affects decisionmaking and may interfere with a patient’s recognition and reporting of other symptoms, is underreported, undertreated, and rarely studied in palliative care (Breitbart, 1995; Pereira et al., 1997). It can also affect patients’ families and is often a deterrent to home terminal care (Minagawa et al., 1996).

A number of treatments are in use for patients with cancer-related cognitive impairment, despite a relative lack of reliable evidence regarding their effects. Neuroleptics and benzodiazepines are used to manage delirium (Bruera and Neumann, 1998). Haloperidol may be given in combination with lorazepam for patients with delirium who are experiencing agitation. Diazepam is frequently prescribed, but may cause cognitive impairment or worsen dementia. Opioid rotation (switching drugs when side effects occur or pain is not relieved) and mild hydration may reduce delirium in some patients with advanced disease (Bruera et al., 1995). Stimulant therapy may reverse some of the cognitive impairment (problems with memory, attention, and reasoning) shown by cancer patients. In a study of patients with malignant glioma who developed cognitive deficits, Meyers et al. (1998) found that methylphenidate (10mg twice daily) significantly improved gait, stamina, and cognitive function in half of the subjects despite progressive neurologic injury as documented by magnetic resonance imaging (MRI).

Patients with cognitive impairment often exhibit a generalized slowing on electroencephalograph readings and impaired function of the brain stem