Dementia is a general term for memory loss and decline in mental ability that is severe enough to interfere with the activities of daily living. Dementia can result from a variety of causes, which fall into three categories: (1) potentially reversible, (2) non-progressive, and (3) progressive. An estimated 5-15% of all dementias are due to potentially reversible causes, while the remainder are irreversible and most commonly progressive. An early and accurate evaluation is critical to identify any potentially reversible causes of dementia, such as depression, vitamin B12 deficiency, hypothyroidism, side effects from medications, and infections.
Some dementias are non-progressive, characterized by a change in cognition that remains stable over time. The vast majority of dementias, however, are progressive, causing a steady irreversible decline until death. The most common progressive dementia among the elderly is Alzheimer’s disease, which accounts for approximately 70% of all cases. Nearly 47 million people in the world have Alzheimer’s disease, including 5.5 million in the United States. Nearly 600,000 Californians are affected, including an estimated 84,000 individuals in Orange County.
Other neurodegenerative conditions, including vascular dementia, dementia with Lewy bodies, Parkinson’s disease dementia, frontotemporal dementia, Huntington’s disease, and a number of other very rare conditions, account for most other dementia cases.
Just like cancer medications don’t all work for all the various forms of cancers, treatments for the different types of dementia can vary widely, highlighting the need for an accurate diagnosis.