What Are the Most Common Types of Irreversible Dementia?

Dementia is a broad term for decline in memory. It affects three areas of the brain: language, memory and decision making. These changes make it difficult for people who have dementia to perform basic daily activities. Dementia is classified into two groups, reversible (pseudo-dementia) and irreversible (non pseudo-dementia). Irreversible dementia causes changes in behavior and personality.

The most common irreversible types of dementia are as follows:

Alzheimer’s disease
Vascular dementia
Lewy body dementia
Parkinson’s disease
Frontotemporal dementia
Huntington’s disease
Creutzfeldt-Jakob disease
Chronic traumatic encephalopathy
Pick’s disease

1 in 3 seniors dies with a form of dementia (Source: Alz.org), which is why it’s imperative that the search for a cure is supported through research, education and monetarily.

Alzheimer’s Disease

Alzheimer’s is the most common type of dementia and is the 6th leading cause of death in the United States. (Source: Alz.org) This brain disorder is an irreversible, progresses slowly and continually gets worse by destroying memory and thinking skills. It will become severe enough to interrupt the activities of daily living and those who have it will not be able to carry out the simplest of tasks. Estimates vary, but experts suggest that as many as 5.5 million Americans age 65 or older may have Alzheimer’s. (Source: National Institute for Aging).

Vascular Dementia

Vascular dementia is the second most common form of dementia. This disease can co-exist with other types of dementia, including Alzheimer’s disease and Lewy body dementia. Similar symptoms occur between them, which can make diagnosing the exact type difficult. Causes of Vascular dementia include stroke, hypertension, smoking, diabetes mellitus, cardias arrest, cardiovascular diseases, and lupus.

Lewy Body Dementia

Lewy body dementia, or LBD, is the third most common form of dementia, accounting for 5 to 10 percent of cases. LBD is caused by brain abnormalities and symptoms include depression, confusions, hallucinations, stooped posture, rigidity, and shuffling gait. Lewy bodies are found in other brain disorders, including Alzheimer’s disease and Parkinson’s disease. The overlap in symptoms between Parkinson’s disease and Lewy body dementia suggest that the dementia may be linked to the same underlying abnormalities in how the brain processes alpha-synuclein, the chief component of Lewy bodies.

Parkinson’s Disease

Parkinson’s disease is a neurodegenerative disorder that affects the nerve cells in the brain that produce dopamine. The progression of this disease is slow, and symptoms include slowness, tremors, muscle rigidity, stooped posture, speech and gait, depression and dementia in the later stages. Parkinson’s disease appears similar to dementia with Lewy bodies. This disease is extremely diverse, and no two people experience it in the same way. Parkinson’s affects about one million people in the United States and ten million worldwide.

Frontotemporal Dementia

Frontotemporal dementia is caused by cell damage that shrinks the brain’s frontal and temporal lobes. It is generally diagnosed in people between the ages of 45-65 and the disease generally starts with personality and behavior changes and may eventually lead to severe memory loss. It is linked to a variety of gene mutations; the exact cause remains unknown.

Huntington’s Disease

Huntington’s disease is inherited, caused by a single defective gene and is dominant, so anyone who inherits it from a parent with Huntington’s will eventually develop it. Huntington’s is caused by the protein ‘huntingtin’ whose function is not known. Defective huntingtin leads to a breakdown of the central nervous system. Symptoms include confusion, memory loss, hallucinations, difficulties with coordination, fidgeting/jerking movements and behavioral changes.

Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob disease affects about one person in every one million per year worldwide; in the United States there are about 350 cases per year. (Source: National Institute of Neurological Disorders and Stroke) It can resemble other brain-like disorders but progresses much more rapidly. Symptoms of CJD include personality changes, anxiety, memory loss, impaired thinking, blurred vision, insomnia, difficulty speaking, muscle jerks (myoclonus), possible blindness.

There are three major categories of CJD:

Sporadic: This is the most common type of CJD appears even though the person has no known risk factors for the disease. It’s sporadic and unclear how it comes about.
Hereditary: This type of CJD appears when a person may have a family history of the disease and test positive for genetic mutation associated with the disease.
Acquired: This type of CJD is transmitted by exposure to brain or nervous system tissue, usually through medical procedures. This can also be acquired by eating meat affected by a disease similar to CJD called ‘Bovine Spongiform Encephalopathy’ or commonly known as ‘Mad Cow Disease’.

Chronic Traumatic Encephalopathy

Chronic traumatic encephalopathy, or CTE, is a degenerative brain disease caused by repeated hits to the head sustained over a period of years (ConcussionFoundation.org). CTE has been found in military veterans, victims of domestic abuse, and athletes in boxing, football, soccer, and ice hockey among others. CTE can only be diagnosed after death through brain tissue analysis. Symptoms include difficulty thinking, impulsive behavior, depression, short-term memory loss, difficulty planning, emotional instability, substance misuse and suicidal thoughts/behavior.

Pick’s Disease

Pick’s disease is not as common. It affects the frontal lobes of the brain and is a progressive form of dementia. Frontal lobe dementia is not usually associated with memory loss in its early stages. Pick’s disease is distinguished for the aphasia. Aphasia removes your ability to community and can affect the ability to speak, write and understand language, both verbal and written.

This blog post is an introduction to the types of irreversible (non-pseudo dementia) dementia and is not a complete or comprehensive overview. If you believe that you or your loved one may have Alzheimer’s or dementia, please reach out as soon as possible to your licensed health care provider. To learn more about Alzheimer’s disease and dementia and find supportive resources, visit: https://www.alz.org/help-support.