Dementia is a term used to describe when the loss of certain behavioral abilities, remembering, thinking, and reasoning causes interference in an individual’s daily activities and life.
Several cognitive functions are affected when an individual develops dementia, including language skills, problem-solving, ability to focus, memory, visual perception, nonverbal communication skills, and self-management.
Dementia patients may experience changes in their personality and may experience difficulty in controlling their emotions.
The severity of a patient’s dementia can range from mild cognitive impairment and occasional forgetfulness to severe stages where they are entirely dependent on others in their basic activities of daily life.
Dementia develops when neurons in the brain become non-functional, lose the ability to communicate with other cells in the brain, and die. Some neuron loss due to aging is normal and natural, but dementia defines an excessive and much greater neuron loss.
5 Major Types of Dementia
Of course, there are different types of dementia depending on factors such as the cause as well as the symptoms and overall progression of the condition. Learn about these types now.
1. Alzheimer’s Disease
The most common form of dementia in the general population is referred to as Alzheimer’s disease. Alzheimer’s disease develops when clumps of certain proteins referred to as tangles and plaques build up in the junctions in between the nerve cells.
Alzheimer’s disease patients also experience a decrease in certain chemicals called neurotransmitters, which are responsible for the passing of signals between the cells.
Symptoms that Alzheimer’s disease is interfering with a patient’s daily life include losing items around the house, forgetting names of family members and friends, unable to remember recent events and conversations, get lost on a familiar route or in a familiar place, forget significant dates, and do not remember to attend appointments.
Alzheimer’s disease patients may also struggle to follow a conversation, repeat themselves often, have reduced visuospatial skills, are unable to make decisions, cannot carry out a sequence of tasks, unable to solve problems, lose track of the day, experience mood changes, and lose interest in hobbies and activities that they once enjoyed.
Every case is different, but most patients have a life expectancy of between eight and ten years following the onset of their first symptoms.
2. Vascular Dementia
One of the most common types of dementia in the general population is referred to as vascular dementia. For the brain cells to function and be healthy, they require a consistent supply of oxygen and nutrients from the blood.
The vascular system is a network of blood vessels that supplies the brain tissues with blood. When the blood vessels in the vascular system become obstructed or damaged, blood is unable to get to the cells in the brain.
Without a consistent blood supply, the cells in the brain begin to die. When an individual experiences an ischemic or hemorrhagic stroke, they can develop a form of vascular dementia known as post-stroke dementia.
If an individual is affected by a series of smaller strokes rather than a single severe stroke, they can develop forms of vascular dementia called single-infarct and multi-infarct dementia.
When the smallest blood vessels in the brain become twisted and stiff to the degree that they restrict blood flow, it is referred to as small vessel disease.
Individuals affected by small vessel disease in their brain may develop the most common type of vascular dementia: subcortical dementia.
3. Lewy Body Dementia
Between ten and fifteen percent of all cases of dementia are referred to as Lewy body dementia. Tiny deposits of a protein referred to as alpha-synuclein that develops in the nerve cells in the brain are known as Lewy bodies.
While the exact mechanism linking the development of Lewy bodies to dementia is not clear, it is thought to be associated with low dopamine and acetylcholine, as well as connection loss between nerve cells.
When Lewy bodies develop in the base of the brain, it causes Parkinson’s disease. When Lewy bodies develop in the outer layers of the brain, it causes the cognitive symptoms of Lewy body dementia. Lewy body dementia patients may experience alterations in their attention and alertness that may or may not be accompanied by visual hallucinations.
Individuals who have Lewy body dementia may experience poor regulation of the autonomic nervous system that controls pulse, blood pressure, sweating, and digestive processes. Visuospatial problems, sleep difficulties, disorganized speech, confusion, and dizziness are also common symptoms seen in Lewy body dementia patients.
4. Mixed Dementia
Mixed dementia is a form of dementia only used in cases where a patient exhibits clear clinical features of more than one cognitive disease that contribute to their symptoms of dementia. One in every ten individuals diagnosed with dementia will have more than one form of the disease.
Mixed dementia is more prevalent among individuals who are a part of older age groups, like those who are over seventy-five years old. In most cases of mixed dementia, the patient will experience more symptoms associated with one type of dementia than the other type or types.
The form of dementia that produces more symptoms is referred to as the predominant form of dementia. The two most common variations of mixed dementia are Alzheimer’s disease with vascular dementia and Alzheimer’s disease with Lewy body disease.
Only a few medications, called cholinesterase inhibitors, have shown efficacy in the treatment of mixed dementia. Medications that prevent vascular problems and strokes may also be used to treat mixed dementia.
5. Frontotemporal Dementia
When the lobes of an individual’s brain behind the forehead, the frontal lobes and temporal lobes, become affected by the damage that causes dementia, it is referred to as frontotemporal dementia.
The left temporal lobe is responsible for conveying the names of objects and the meanings of words, while the right temporal lobe is responsible for the recognition of familiar objects and faces.
When the cells in the frontal or temporal lobes die off, the connecting pathways between these lobes of the brain become altered. As the damage accumulates, the frontal and temporal lobes begin to shrink in size, causing these lobes to lose function.
This mechanism is what results in the symptoms of frontotemporal dementia, including changes in personality, changes in behavior, and difficulties with language.
Frontotemporal dementia is the most prevalent types of dementia that develops in individuals between forty-five and sixty-five years old. This type of dementia in younger individuals tends to be the mildest form of the disease and does not present with a short life expectancy like others.