Dementia is a descriptive term that covers impaired memory and the loss of other cognitive abilities which interfere with a person’s functioning in daily life.
There are multiple types of dementia, the most common is Alzheimer’s disease.
Early diagnosis helps with the treatment of symptoms, and with some types of dementia, early treatment may reverse the diagnosis. Some forms of dementia, however, are manageable, but not reversible, and worsen over time.
Treatable Causes of Dementia
Medical treatment, as well as lifestyle and diet change, may reverse these causes of dementia:
- Alcohol or drug abuse
- Blood clots of the brain
- Normal-pressure hydrocephalus (buildup of fluid in the brain)
- Metabolic disorders (including vitamin deficiencies)
- Hypothyroidism (low levels of thyroid hormones)
- Hypoglycemia (low blood sugar)
- HIV/AIDS-associated neurocognitive disorders
Types of Dementia
Let’s look at the various types of dementia that are currently not reversible, starting with the most common, Alzheimer’s disease.
Alzheimer’s affects between 60 and 80 percent of all people with dementia, and approximately 5.5 million people in the United States.
In the early stages of Alzheimer’s disease, people typically have difficulty remembering recent events such as conversations and names of people. Depression is also a common early-on symptom of Alzheimer’s. Typically, cognitive impairment progresses within 2-4 years of Alzheimer’s onset.
Alzheimer’s is not reversible, but some of the early memory symptoms and cognitive changes can be slowed or moderately improved through medication.
Vascular dementia, one of the most common types of dementia after Alzheimer’s disease, accounts for 5 to 10 percent of all cases of dementia.
The cause of vascular dementia is cerebrovascular disease, a condition consisting of damaged blood vessels and brain tissue injury, which deprives brain cells of oxygen and nutrients. This is often related to an event such as a stroke, or a small blood vessel disease, or changes in the brain such as white matter lesions and narrowing of the arteries.
Symptoms of vascular dementia include confusion, disorientation, difficulty speaking or understanding speech, and vision loss. Depression commonly co-exists with vascular dementia and can contribute to cognitive symptoms.
There are no drugs that specifically treat symptoms of vascular dementia, but some people are modestly helped by drugs that treat Alzheimer’s.
The control of risk factors is important in improving the outcome of vascular dementia and may assist with postponing or preventing further decline. Risk factors include smoking, alcohol and drug abuse, high blood pressure, high cholesterol, uncontrolled blood sugar, as well as poor diet and lack of exercise.
Parkinson’s Disease Dementia (PD)
Age appears to be a common factor in the development of dementia in people with Parkinson’s disease (PD). Dementia is rare in people with the onset of Parkinson’s before the age of 50 years but is more common with an onset at 70 years and older.
Cognitive changes develop about one year following the onset of motor and mobility symptoms (mainly shaking or trembling of the hands, arms, jaw, and face, as well as stiffness of the trunk and limbs), but impairment that is severe enough to diagnose dementia occurs in only 20% of people with Parkinson’s disease, and typically these symptoms progress slowly over a period of 10 to 15 years.
There is no cure for Parkinson’s disease dementia, but therapy and supportive medications ease the symptoms.
Huntington Disease Dementia (HD)
Huntington disease (HD) is genetic in origin, passed on from generation to generation.
Huntington disease is a devastating disorder which destroys nerve cells and lowers levels of neurotransmitters, chemicals that carry signals in the brain. HD typically affects people in their 30s and 40s, but symptoms can appear at other ages.
Symptoms of HD dementia normally include abnormal movement and emotional behavior, with cognitive symptoms that appear gradually and worsen over time.
There is no cure or treatment to slow down the progression of Huntington disease. Treatment focuses on relieving symptoms.
Lewy Body Dementia (LBD)
This type of dementia isn’t a common household name, but Lewy body dementia (LBD) affects an estimated 1.4 million individuals and their families in the United States.
LBD is a disease which gets its name from deposits of a protein called alpha-synuclein in the brain. These deposits are called Lewy bodies. Lewy bodies affect chemicals in the brain which lead to impaired thinking, problems with movement (tremors, stiffness, slowness, difficulty walking), visual hallucinations, sleep disorders, behavioral and mood symptoms, and changes in body functions, such as blood pressure control, temperature regulation, and bladder and bowel function.
Currently, there is no cure for Lewy body dementia, however, the symptoms are treatable. Medications that treat other diseases such as Alzheimer’s and Parkinson’s with dementia are typically beneficial for cognitive, movement, and behavioral problems.
Creutzfeldt-Jakob Disease (CJD)
An extremely rare type of dementia, Creutzfelt-Jakob disease (CJD) is a degenerative, fatal brain disorder, which affects approximately one person in every one million per year worldwide.
There are three major categories of Creutzfelt-Jakob disease:
- Sporadic CJD appears in a person that has no known risk factors for the disease. This accounts for at least 85 percent of cases.
- Hereditary CJD appears in a person that has a family history of the disease and tests positive for genetic mutations associated with the disease. This accounts for 10 to 15 percent of all cases of CJD in the United States.
- Acquired CJD is transmitted by exposure to brain or nervous system tissue. Evidence suggests that CJD is not transferred by common contact, but may be acquired through certain medical procedures, or through eating meat from cattle affected by a similar disease called bovine spongiform encephalopathy, commonly called “mad cow” disease.
Symptoms of CJD typically include loss of muscle coordination, personality change, and impaired vision. Symptoms progress rapidly and eventually; patients lose the ability to move and speak and enter a coma. Pneumonia and other infections are common in individuals with the disease and can lead to death.
There is no cure or specific treatment for Creutzfelt-Jakob disease. Symptoms, such as pain, are typically treated to improve the comfort level of the patient.
Frontotemporal Dementia (FTD)
Frontotemporal dementia (FTD) is a term that umbrellas a span of uncommon disorders that affect the frontal and temporal lobes of the brain. FTD tends to occur at a younger age than other diseases related to dementia, such as Alzheimer’s, generally between the ages of 40 and 45.
The frontal and temporal lobes of the brain shrink with frontotemporal dementia. These areas of the brain are associated with personality, behavior, language, and in rarer cases, movement difficulties like those with Parkinson’s disease.
The cause of FTD is unknown. The risk may increase if you have a family history of dementia, otherwise, there are no known risk factors.
Treatment for frontotemporal dementia focuses on managing some of the symptoms, but currently, there is no treatment that slows down the progression of the disease.
Posterior Cortical Atrophy (PCA)
Posterior cortical atrophy (PCA), also called Benson’s syndrome, is a disease resulting in gradual and progressive degeneration of the outer layer of the brain located in the back of the head.
It is not fully known if PCA is a variant form of Alzheimer’s disease, but the brain shows similar plaques and changes that occur in Alzheimer’s disease. Some brain changes also resemble Lewy body dementia or a form of Creutzfeldt-Jakob disease. Most cases of PCA occur between the ages of 50 and 65, as opposed to Alzheimer’s disease which generally occurs in people 65 or older.
Symptoms of Posterior cortical atrophy varies from person to person, but the most common symptoms are consistent with damage to the posterior section of the brain, and typically leads to difficulties with visual tasks. Hallucinations are not uncommon. People living with PCA may also have trouble completing mathematical calculations or spelling and may experience anxiety. In the early stages of PCA, most patients do not have reduced memory, but memory can be affected in later stages.
The cause of posterior cortical atrophy is unknown, and there are no known cures or treatments specific to the disease. Some people benefit from drugs used to temporarily relieve patients from brain dysfunction in Alzheimer’s disease.
The diagnosis of mixed dementia is made when brain changes and abnormalities associated with more than one type of dementia occur simultaneously.
Symptoms of mixed dementia are related to the type of brain changes that have occurred and which brain regions are affected, so symptoms vary with mixed dementia.
There is no cure or specific treatment for mixed dementia. Frequently, people with mixed dementia are diagnosed with a single type of dementia, and physicians base their treatment on that diagnosis.
Traumatic Brain Injury
Brain injuries often result in symptoms that are commonly seen in dementia, such as confusion, memory loss, changes in speech, vision, and personality. These symptoms may go away, either quickly or slowly, but some may never go away. The difference between brain injury symptoms and those of a disease such as Alzheimer’s is that the symptoms don’t generally worsen over time.
Some types of head injuries can raise the risk of Alzheimer’s or other types of dementia later in life. Risk factors increase based on the severity of the brain injury, as well as the age (55 and older) that the injury occurred.
Tips for Reducing Dementia Risk Factors
You may not be able to totally prevent the onset of all types of dementia, but you can take preventive measures to reduce the risk.
Here’s the short list for reducing the risk of dementia, and in many cases, these measures also help to relieve symptoms of some types of dementia:
- Avoid tobacco use
- Avoid alcohol and drug abuse
- Strive for a healthy well-balanced diet
- Exercise your body and mind
- Maintain blood pressure and cholesterol at healthy levels
Talk with your physician to ensure you and your family members are not at an increased risk for any type of dementia. Prevention starting at an early age is key!