Learn About Dementia

Dementia is a syndrome that refers to a condition where a decline in memory and thinking skills results in an inability to perform everyday tasks and activities. There are many causes of dementia, but the most common cause of dementia is Alzheimer’s disease. Some causes of dementia actually other health conditions and may be reversible. However, other causes of dementia lead to a slow progression of cognitive impairment that will continue over time and are not curable, but there are medications and other treatments to slow the progression and improve symptoms.

What causes dementia?

In the majority of cases, the cause of dementia is not known. One of the goals of current research studies is to find the cause of the different types of dementia. Many neurodegenerative diseases, which include Alzheimer’s disease, are progressive disorders and involve a build of abnormal levels of proteins in the brain. Another possible cause is changes in blood vessels with aging that lead to damage to the brain.

Some of the common causes of dementia are:

Alzheimer’s disease 

The most common cause of dementia, Alzheimer’s disease is a progressive disorder of the brain, meaning it gets worse over time. The cause of Alzheimer’s disease is unknown. We do know that in patients with Alzheimer’s disease, there is an abnormal build of two different proteins in the brain, Amyloid and Tau. The Amyloid protein builds up outside the brain cells into what are called Amyloid plaques and the Tau protein builds up inside the brain cell into what are call neurofibrillary tangles leading to the term “plaques and tangles” as a description of the way the brain of someone with Alzheimer’s disease looks under the microscope. It is not clear if these proteins are the cause of the disease, but as these proteins build up in the brain, the brain cells malfunction and eventually die. When brain cells die, this leads to shrinkage of the brain which is called atrophy.

Alzheimer’s disease most commonly affects people over 65 and the risk of developing Alzheimer’s disease increases with age. For most patients with Alzheimer’s disease the initial symptom is worsening memory loss which leads to things like misplacing items and repeating questions. Over time additional symptoms can develop such as trouble with language, difficulty with navigation and difficulty making decisions.

There are now tests to diagnose Alzheimer’s disease accurately and include blood tests, Amyloid PET scans and lumbar puncture. There are also ongoing advances in the treatment of Alzheimer’s disease that include medications that have been shown to slow progression as well as those that can improve thinking to a small degree. Medications are also sometimes used to improve mood, anxiety and other behavioral symptoms. In addition to the medication treatments, we know that lifestyle modifications, including increasing physical, mental and social activity as well as a heart healthy diet may also help a patient maintain their function.

Resources for patients with Alzheimer’s disease and dementia:
Alzheimer's Association | Alzheimer's Disease & Dementia Help

Vascular dementia

Vascular dementia may be the second most common form of dementia. The cause of this type of dementia are conditions that damage blood vessels either by causing reduced blood flow to the brain or bleeding in the brain. These conditions include strokes and hemorrhages. Both types of conditions lead to permanent injury to the brain and when this injury affects parts of the brain that controls thinking, this leads to changes in thinking. Because the part of the brain can be different in different people, the types of thinking problems can vary from person to person and depends on what part of the brain is injured. Some patients with vascular dementia have problems with memory and others can have problems with language, problem solving and navigation ability. Vascular dementia also can occur in patients with other causes of dementia, but most often in patients with Alzheimer’s disease. Vascular dementia can be diagnosed using brain imaging that shows the damage to the brain and tests of thinking to show how that injury has affected thinking. 

Vascular dementia happens more often in patients with uncontrolled risk factors for vascular disease, such as smoking, untreated high blood pressure, untreated high cholesterol and untreated diabetes. Vascular dementia may or may not be progressive, meaning it may or may not get worse depending on how well the risk factors for vascular disease are controlled. There are no medications that are FDA approved for vascular dementia, but there are medications that can manage some of the symptoms. In particular, some patients with vascular dementia have mood symptoms and these can be treated with medications and other treatments. Physical activity and other health lifestyle measures also can help control the risk factors for vascular dementia. 

Lewy body Dementia 

The category of Lewy body disorders includes dementia with Lewy bodies, Parkinson’s disease with dementia and multiple system atrophy, Parkinsonism type. It is not clear if these are all related disorders, but these are all progressive disorders, meaning they get worse over time. The cause of these disorders is unknown.  In patients with dementia with Lewy bodies dementia, abnormal buildup of the alpha synuclein protein build up in brain cells as well as cells in other parts of the nervous system. In brain cells the alpha synuclein collections are called Lewy bodies. This leads to changes in thinking and behavior as well as changes in movement that affect overall function. The changes in movement that develop in patients with dementia with Lewy bodies are similar to the changes that develop in patients with Parkinson’s disease.

In addition to a decline in thinking and movement, patients with dementia with Lewy bodies also can have other changes including pronounced fluctuations in alertness and attention, recurrent visual hallucinations, dream enactment behavior that causes them to act out their dreams violently in their sleep, poor sense of smell and constipation. 

Tests are being developed to allow more accurate diagnoses of dementia with Lewy bodies. There are no FDA approved medications for patients with Lewy bodies, but there are medications that can be used to manage many of the symptoms. It is important for patients with dementia with Lewy bodies to avoid the use of “typical” antipsychotic medications such as haloperidol, as these medications can cause dramatic worsening. Non medication treatments such as physical exercise has also been shown to help maintain overall function.

Resources for patients with dementia with Lewy bodies and their caregivers:
Lewy Body Dementia Symptoms, Diagnosis, and Treatment (lbda.org)

Frontotemporal dementia

Frontotemporal dementia is now felt to be one of many types of frontotemporal lobar degenerations. These are a group of different disorders that lead to changes in behavior, language ability, movement changes and weakness. Frontotemporal dementia is sometimes referred to as behavioral variant frontotemporal dementia as this condition affects the brain’s frontal and temporal lobes and leads to changes in personality more so than thinking. This leads to symptoms that can include dramatic changes in how a person behaves. Frontotemporal dementia is a progressive disorder, meaning it gets worse over time.

The cause of frontotemporal dementia is unknown, but is associated with a buildup of several different types of proteins that go by names such as Tau and TDP-43. These proteins build up in the brain cells, but is not clear if the proteins cause the disease. Frontotemporal dementia is more likely to affect someone under the age of 65 than Alzheimer’ disease. There are no known medications for frontotemporal dementia, but there are medications that can be tried if behavioral issues cannot be managed by lifestyle changes. We also know that providing support for the caregiver is important to reduce the stress of caregiving. 

Resources for patients with frontotemporal dementia and their caregivers:
AFTD - The Association for Frontotemporal Degeneration (theaftd.org)

Primary progressive aphasia

Primary progressive aphasia is a clinical syndrome of progressive difficulty with understanding language, producing language or both. There are several different types of primary progressive aphasia and each of these types can have several different underlying causes. 

Variants of primary progressive aphasia:

• Semantic (sometimes called semantic variant of primary progressive aphasia or semantic dementia): The main difficulty in this type is trouble coming up with names of things as well as understanding what words mean. 
• Agrammatic (sometimes called progressive non fluent aphasia): The main difficulty in this type is trouble “getting the words out” so that the persons speaking and writing becomes very difficult.
• Logopenic: The main difficulty in this type is coming up with words, but there is less difficulty with understanding words

The most common causes of primary progressive aphasia are the frontotemporal lobar degenerations due to either Tau or TDP-43 protein deposition and Alzheimer’s disease.  

In terms of treatment, the most important first step is to determine the underlying cause of the primary progressive aphasia and use this information to determine the appropriate treatment options. 

Resources for patients with primary progressive aphasia and their caregivers:
AFTD - The Association for Frontotemporal Degeneration (theaftd.org)

Alzheimer's Association | Alzheimer's Disease & Dementia Help

Mild cognitive impairment (MCI)

Mild cognitive impairment is not officially a dementia diagnosis, but for some patients diagnosed with mild cognitive impairment, they are in the prodromal phase of a neurodegenerative disorder, most commonly Alzheimer’s disease.  Mild cognitive impairment is diagnosed when the person or those around him her notice changes in memory or other areas of thinking and when the person has memory testing, the memory testing shows that the person has had a decline in thinking that is more than normal changes with aging. However, the person is still able to function normally. Because we have come to realize that a number of people diagnosed with mild cognitive impairment actually have the beginning of things like Alzheimer’s disease, there are now tests such as Amyloid PET scans, lumbar puncture and even blood tests that can determine if the person diagnosed with mild cognitive impairment has the brain changes of Alzheimer’s disease. This is important as there are now medications that have been shown to slow the progressive of decline in patients with mild cognitive impairment due to Alzheimer’s disease.