Lesser Known and Rare Types of Dementia

Last Updated: August 22, 2018

There are many diseases or conditions that are associated with dementia. Sometimes dementia is an early symptom of these diseases, and other times dementia occurs as the disease progresses and gets worse. Alzheimer’s disease, Lewy body dementia, frontotemporal dementia, and vascular dementia are common diseases that are associated with dementia, but there are also several lesser-known diseases associated with dementia. These are listed below as follows:


Parkinson’s Disease Related Dementia

Parkinson’s disease is associated with dementia or may lead to dementia. It is a progressive disease that affects many middle-aged and older adults. This disease includes motor symptoms such as tremors, stiffness, slowed movement, and impaired balance. According to the Alzheimer’s Association, approximately 50 – 80% of people with Parkinson’s may develop Parkinson’s disease related dementia as the disease progresses. Symptoms may include memory loss, trouble finding words, diminished attention span, and more.

Per the National Parkinson Foundation, if dementia symptoms begin at least a year after motor issues started, a diagnosis of Parkinson’s dementia is warranted. Sometimes these dementia symptoms are just considered part of the disease, but sometimes a separate diagnosis — for instance, of Alzheimer’s disease — may be made. Please note, there is also a great deal of overlap in the symptoms of Parkinson’s disease and Lewy Body dementia. Physicians use a variety of techniques and tests to make a correct diagnosis.


Huntington’s Disease Related Dementia

Huntington’s disease (HD) is a genetic disease that is connected with, or may contribute to dementia. If an individual’s parent has the defective gene and he or she inherits it, HD is inevitable in the future. Huntington’s disease generally begins earlier in life, between ages 30 and 50, and is characterized by mood swings, lack of coordination, impaired judgment, and involuntary movement of the head, trunk and limbs (Huntington’s Disease Society of America, 2018). Also, people with Huntington’s may develop dementia symptoms as the disease progresses. Compared to Alzheimer’s disease, people with dementia from Huntington’s disease have fewer memory problems, but more problems with language/communication and decision-making.


Creutzfeldt-Jakob Disease Related Dementia

Creutzfeldt-Jakob disease (CJD) is the most common of a group of rare dementia types called spongiform encephalopathy or prion diseases. CJD and other related diseases are the result of abnormal proteins in the brain called prions. Once present in the brain, prions “infect” healthy proteins, creating new prions. These prions affect the brain’s normal functions and lead to personality changes and problems with memory, movement, and vision. This process occurs very quickly, and most individuals who develop Creutzfeldt-Jakob disease die within a year.

Creutzfeldt-Jakob disease is very rare, and only affects approximately 350 Americans each year (National Institute of Neurological Disorders and Stroke, 2018). CJD is a transmissible disease. However, a person who has daily contact with someone with the disease is at very low risk of contracting it. The highest risk for infection comes from exposure to tissue and fluids from the brain and spine. Less than one percent of CJD cases are caused by person-to-person transmission. In most cases, the cause of CJD is unknown.


Dementia in Persons with HIV/AIDS

Dementia in HIV infection occurs when the HIV virus attacks one’s nervous system and causes damage to the brain cells. Symptoms may include memory loss, poor judgment, confusion, mood swings, difficulty with coordination, and trouble learning new things. Dementia in HIV varies with the stage of the illness, whether or not it is being treated, and even the age of the person who is infected. Some symptoms that may occur with early infection may reverse with treatment, but any destruction of brain tissue (encephalopathy) is irreversible. When the symptoms mentioned above are severe enough that they interfere with one’s daily living activities, a diagnosis of HIV-associated dementia may be given.


Dementia Resulting from Traumatic Brain Injury

Trauma (physical injury) to the head can lead to cognitive and memory problems similar to dementia. Symptoms depend upon the severity of the trauma and what part of the brain was affected. Potential symptoms of a head injury include dizziness and loss of balance (vertigo), headache, blurred vision, memory and cognitive (thinking) problems, sleeping problems, restlessness, irritability, apathy, depression, emotional outbursts, impulsiveness, and anxiety. Milder injuries may include symptoms like difficulty concentrating, paying attention, and attending to so-called “executive functions” (planning, organizing, abstract reasoning, problem solving, and making judgments). If the injury is severe, the person may lose many higher-level mental skills. Common examples are the loss of the ability to retain past memories and/or the ability to form new ones. In its extreme forms, memory loss is called amnesia. Treatment for traumatic brain injuries commonly includes medications, counseling, and/or occupational therapy.


Wernicke-Korsakoff Syndrome Related Dementia (Includes Dementia from Alcohol Abuse)

Wernicke-Korsakoff Syndrome (WKS) is caused by a deficiency in vitamin B1, which is also called thiamine. Deficiency in this vitamin is sometimes seen in alcoholism and is also seen in a number of other conditions, such as malnutrition and eating disorders, which deplete this vitamin. The symptoms of Wernicke-Korsakoff Syndrome include memory loss and cognitive decline as well as confabulation (making up stories), vision changes, and loss of muscle coordination. In cases where this disease is caught in the early stages, a person can make a significant recovery.


Leukodystrophy Related Dementia

Leukodystrophy is a group of genetic diseases that affect children, although there are also cases of adult onset leukodystrophy. These diseases result from a problem with myelin, the covering for nerves that makes up the white matter in the brain. Signs and symptoms vary with the particular type of leukodystrophy, but most types are characterized by gradual decline of various abilities, such as limited speech and movement in a child who previously seemed well. The treatment and outcome for the disease depend on the type of leukodystrophy.


Mild Cognitive Impairment

While Mild Cognitive Impairment (MCI) is not actually a form of dementia, it has been called “early Alzheimer’s disease ”. In MCI, a slight decline in speech, memory, and thinking is generally present, but persons are still able to function independently. Some people with MCI do go on to develop dementia, while others do not. Learn more about MCI.