Differences Between Alzheimer's and Dementia

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• Causes of dementia
• Alzheimer's dementia
• Why is the difference between AD and other dementias important?

People have been talking about dementia and Alzheimer's disease (AD) for over 100 years now. Yet, in most cases, the difference between them is not clear. Is there a real difference?

The answer is that AD is just one of the types of dementia, albeit the most common type by far, making up 60 to 80 percent of cases. Dementia refers to a progressive loss of cognitive abilities or a permanent decline in mental function. Dementia is characterized by chronic memory loss, a change in personality, and loss of reasoning and logic. While forgetfulness is often experienced, especially by busy or rushed older people, it is not called dementia unless it is so severe that it disrupts daily living.

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Causes of dementia

Dementia is caused by many conditions other than AD, the second most common cause being vascular dementia. In this case, the brain is slowly destroyed by blood pumping through the arteries at increased pressure, damaging the arterial walls. In many cases, vascular dementia follows the occurrence of a stroke or a series of strokes. The risk factors for vascular dementia include high blood pressure, diabetes, high blood cholesterol, and atrial fibrillation, all of which also increase the risk of stroke.

Some other causes of dementia include:

• Alcohol-related dementia is caused by a long-term intake of excessive alcohol, which damages the brain cells, leading to cognitive loss.
• Parkinson's dementia is seen in Parkinson's disease, a progressive motor condition associated with the loss of dopamine-secreting neurons in certain parts of the brain.
• Frontotemporal dementia is caused by a group of brain diseases termed frontotemporal lobar degeneration. It is more common in middle-aged adults, unlike other forms of dementia. It is a type of dementia associated with progressive degeneration of the brain cells, like AD and Lewy body dementia.
• Lewy body dementia is associated with the build-up of a protein called alpha-synuclein in the brain. Motor symptoms similar to those of Parkinsonism are present along with visual hallucinations.
• Mixed dementia is a term used when the individual shows signs of both AD and vascular dementia. Symptoms are therefore mixed, and it is not clear how one condition affects the other.
• Dementia-like symptoms may occur in some conditions like Creutzfeldt-Jakob disease, Huntington’s disease, or HIV. Many medical conditions, including alcoholism, depression, brain infections or tumors, and thyroid or liver disease, which are linked to dementia-like memory impairments.

Sometimes the person just has forgetfulness due to old age, but this is not the same as dementia or AD.

Alzheimer's dementia

AD is a condition in which the cognitive skills are slowly but irreversibly eaten away. The affected person finally becomes unable to do even simple things and requires total care. It is the sixth leading cause of death in the US, and death usually occurs about eight years, on average, after it becomes symptomatic.

To diagnose AD, two or three areas of cognition must be obviously abnormal, such as memory, language, disorganization, and disorientation.

The brain in such individuals shows characteristic plaques of a protein called beta-amyloid, and tangles of a neurofibrillary protein called tau. A new method of imaging the living brain by PET scanning with an amyloid-binding tracer helps detect these abnormalities in the brain and diagnose AD more accurately. However, it is only a little more accurate than the traditional clinical method of diagnosis and is reserved for patients who have atypical AD.

Why is the difference between AD and other dementias important?

Different remedies are required for different conditions. Patients with some types of dementia other than AD might need antidepressants and various types of support and medication. People with AD might get medications to improve cognitive performance, on the other hand.

More importantly, AD can be partially prevented. By being careful about the seven main risk factors for AD, other than genetics and age, at least a third of AD can potentially be prevented.

The seven preventable risk factors include:

• Diabetes – High blood sugar
• Hypertension – High blood pressure
• Obesity – Excessive body weight
• Physical inactivity
• Depression – Low mood
• Smoking
• Poor education

Exercising stimulates better blood flow and also helps increase connections between the brain cells. Mental exercise, such as learning a new game or language, playing chess, or reading new books, also helps the brain improve its performance and may slow the onset of age-related dementia. And a healthy diet is key to overall good health.

The latest advice would, therefore, be to pursue a healthy eating pattern, take regular adequate exercise, and exercise the brain as well in an enjoyable way. Doing as much as possible to enrich life is essential to remaining well, rather than focusing on one area alone.

Further Reading

• All Alzheimer's Disease Content
• Alzheimer’s Disease | Definition, Causes, Diagnosis & Treatment
• Alzheimer’s Disease Causes
• Alzheimer’s Disease Symptoms
• Alzheimer’s Disease Diagnosis

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.