Dementia is an umbrella term used to describe a group of symptoms that impact memory, communication abilities and activities of daily activities. Alzheimer’s is the most common cause of dementia, affecting between 60% and 80% of the people with dementia.
Alzheimer’s is a specific disease. Dementia is a syndrome or category.
While symptoms of Alzheimer’s and dementia do overlap, they should be treated as separate entities to best address the conditions medically.
Alzheimer’s typically develops in persons age 65 and older. Dementia symptoms can result from other causes that develop earlier in life, such as Huntington’s disease, Parkinson’s disease and Creutzfeldt-Jakob disease, which can show up in middle age or earlier.
Both dementia and Alzheimer's cause memory impairment, language difficulties and cognitive decline.
Symptoms associated with Alzheimer’s would include difficulty remembering recent events and conversations; depression; personality and behavioral changes; impaired judgment; difficulty speaking; and confusion and disorientation. Some causes of dementia will share these symptoms, but they include or exclude other symptoms, which can assist in making a differential diagnosis. For example, the symptoms of Lewy body dementia, though having the same later symptoms as Alzheimer’s, include paranoia and visual hallucinations as well as difficulties with balance and sleep disturbances.
Alzheimer’s disease is degenerative, incurable and irreversible and is the only one of the top 10 causes of death that has no prevention, maintenance or cure.
About 20% of the causes of dementia can be reversed with the right diagnosis and treatment. Such reversible conditions include vitamin deficiency or metabolic disorder; normal pressure hydrocephalus; alcohol or drug abuse; brain tumors; or HIV-associated neurocognitive disorders.
The process and assessments to determine a diagnosis of Alzheimer’s disease are typically more involved than other forms of dementia. A detailed medical history is taken as well as a ruling out of other conditions that may be causing the symptoms. Brain imaging scans may indicate pronounced brain cell death that is associated with Alzheimer’s disease.
Alzheimer’s disease can only be 100% confirmed after someone dies. An autopsy will reveal the plaques and tangles associated with the disease and also rule out other causes.