Delirium and Dementia – Untangling the Facts
Delirium and dementia – are they different? Indeed, delirium and dementia are very different and have different diagnostic criteria, although just to muddle the discussion, these syndromes can occur concurrently.
The word ‘delirium’ is derived from the Latin term delirare meaning ‘off the track’. Delirium is not a disease, but rather a syndrome that manifests as a change in mental state. It is often referred to as an acute confusional state; ‘acute’, meaning of rapid onset and short duration. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the Canadian Mental Health Association, symptoms include:
· Problems with attention, memory and thinking
· Disturbances in consciousness and perception
· Disorientation to time
· Disruption of the sleep-wake cycle
Delirium is considered a medical emergency and it is important that the cause is investigated thoroughly. Metabolic disorders (e.g. organ failure, diabetes, hyperthyroidism, dehydration and vitamin deficiencies) are the single most prevalent cause of delirium.
Statistics suggest that 15% of older persons admitted to hospital have delirium and over 50% of older persons may develop delirium while in hospital.
Dementia is not a specific disease, but rather a clinical syndrome accompanying disorders that affect the brain. Unlike delirium, which occurs over the span of minutes or hours, dementia is a chronic, usually progressive, degenerative and often irreversible decline in mental status. Symptoms of dementia include:
· Loss of memory
· Confusion and disorientation
· Language impairment and problems with judgment and reasoning
· Disruptive and inappropriate behaviour
Dementia is an umbrella term. There are over 100 types of dementia, the most common of which is Alzheimer’s disease, which, according to the Alzheimer Society of Canada, accounts for over 64% of all dementias in Canada. Other related dementias are attributed to Parkinson’s disease, acquired brain injury, Huntington’s disease, multiple strokes, chronic drug use and long-term alcohol abuse.
Initial findings of the study, “Rising Tide: The Impact of Dementia on Canadian Society” (Alzheimer Society, 2009) indicate that approximately 500,000 Canadians are living with dementia, 71,000 of whom are under the age of 65. The study estimates that within the next five years, an additional 250,000 Canadians could develop Alzheimer’s disease or a related dementia. The number of Canadians with dementia is expected to triple between 1991 and 2031.
Jennifer Hartman, Guest Blogger