Dementia
Dementia is a neurodegenerative disease or condition, such as 'chest pain'. We understand that chest pain usually means something is wrong with the heart and there can be different causes. A dementia is a brain condition with different causes where irreversible impairments in language, memory, judgement, visuospatial sense, behavior or other skills are impaired enough that individuals cannot maintain their normal independent level of function. A dementia is not normal brain aging. Changes (or pathologies) in the brain are varied and spread slowly over 5-15 years or longer. It is important to realize that individuals with a dementia can still have a good quality of life with adding structure and support to their routines and following a healthy lifestyle with adjustment in medications as appropriate. Diagnosis of a dementia still depends on reviewing the history of events, neurological and cognitive testing as well as laboratory studies and brain imaging. With this information we can determine the specific type of a dementia. Frequently the underlying brain changes are mixed, but Alzheimer's is the most common type of dementia affecting 60-80% of cases.
Alzheimer's Dementia
Memory loss, or the ability to learn and recall new information is frequently seen early in an Alzheimer's. There are other common symptoms such as difficulty following and contributing to conversations, anxiety and social withdrawal. A reduced sense of relationships in time and space can make Degenerative changes occur outside the cells (amyloid protein plaques) as well as inside (tangles of tau protein). Research is ongoing yo identify factors that can contribute to inflammation and cell loss. Continued investment in research and involvement in clinical trial is essential to find better treatments.
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For now, there are medications available that can lessen or stabilize symptoms for some time by modifying the levels of neurochemicals in the brain that have changed. These neurochemicals affect memory and mood, so adjustments can generate tangible benefits in behavior and relationships.
Vascular Dementia
This type of dementia can develop after a stroke blocks arteries to the brain, but strokes don't always cause vascular dementia. It depends on where the stroke occurs. Avascular Dementia can also result from small vessel disease reducing oxygen and nutrients (also described as white matter disease on MRI scans. A Vascular Dementia may impair planning, judgment and other thought processes more than memory, but this is variable; every person is different.
Lewy Body Dementia (LBD)
In this Dementia, abnormal protein collections called Lewy bodies appear in nerve cells leading to damage and cell loss. This same protein is seen in Parkinson’s Disease leading to some similarities. LBD affects areas of the brain related to thinking, memory and movement. The signs we see relate to the region most heavily damaged.
The dementia in DLB typically relates to attention and thought processes linked to visuospatial skills. Other symptoms include fluctuating alertness, stiff or slowed movements and visual hallucinations.
This is a group of uncommon dementia syndromes affecting predominantly behavior and language. It is broken down into different groups relative to the brain region most affected and pattern of behavior or language change.
The damage in this type of dementia relates to another type of abnormal tau protein as well as the protein TDP-43. Onset is also typically in the 50’s to 60’s- much younger than an Alzheimer’s Dementia. A few genes that increase risk have also been identified.
Frontotemporal Dementias
Mixed Dementia
This means that there is more than one kind of process contributing to cell damage and disruption of networks in the brain. Some estimate that in half of the people with an Alzheimer’s that a Vascular Dementia is contributing to the challenges.
Risks for vascular disease are modifiable. So controlling blood pressure, cholesterol, diabetes with regular exercise and not smoking takes on a new meaning!
Other Dementias
There are many other conditions that can evolve into a dementia. Parkinson's Disease Dementia (PDD) and Traumatic Brain Injury (TBI) are important ones to consider. Signs and symptoms in PDD and DLB may look similar, but slowed movement or tremor always come at least a year before any cognitive changes in PDD.
Treatable Dementia Syndromes
There are other potentially reversible conditions that can mimic a dementia. This includes: Infections and immune disorders, metabolic and endocrine abnormalities such as thyroid disorder, imbalance of electrolytes (salts in the blood) nutritional deficiencies (such as deficiency of vitamin B 12 or excess of alcohol), side effects of both prescription and over-the-counter medications for sleep, colds or loose stool, cerebral hemorrhage or subdural hematoma (bleeding in or around the brain) normal pressure hydrocephalus (an excess of the cerebral spinal fluid in the brain, and lack of oxygen in sleep as can be seen with sleep disorders.
All the more reason to get a thorough evaluation!