Understanding Dementia
Dementia is an umbrella term for a collection of symptoms that are caused by neurological disorders affecting the brain. These disorders impact memory, thinking, behavior and emotion, and result in gradual, persistent and progressive cognitive decline. This loss of ability to think, remember and reason affects daily life and activities, causes changes in personality and interferes with the ability to function independently.
Individuals affected by these disorders typically suffer from memory loss, impaired language and communication skills. They may lose the ability to recognize objects and perform previously learned tasks. Loss of reasoning, judgment and planning skills is also common. They will require special care and supervision.
Causes of Dementia
Our brains are made up of around 86 billion nerve cells or neurons. These neurons connect and communicate with each other. Such connections are called synapses. Each neuron has anywhere between a few to hundreds of thousands of synaptic connections with neighboring neurons, neurons in other regions of the brain, and even with itself, forming an intricate web of connected nerve cells. The outer layer of the brain’s surface, called the cerebral cortex, is located on top of the cerebrum. It carries out the essential functions of the brain, like memory, thinking, learning, reasoning, problem-solving, emotions, consciousness, and sensory functions.
The degeneration, or progressive loss of these neurons is the pivotal physiological change leading to most brain-related disorders. Neurons and synapses stop working properly, disrupting normal brain function. Cognitive impairment stems from injury to the cerebral cortex caused by synaptic failure, inflammation, and change in cerebral metabolism resulting from neurological diseases.
Neurological diseases
The National Institute of Aging describes several different neurological diseases that lead to this neurodegeneration. Alzheimer’s disease is the most common dementia diagnosis among older adults. It is caused by changes in the brain, including abnormal buildups of proteins known as amyloid plaques and tau tangles, and accounts for 60-80% of all dementia cases. Vascular dementia is the second most common form. It is caused by conditions that damage blood vessels in the brain or interrupt the flow of blood and oxygen to the brain. Lewy body dementia is caused by abnormal deposits of the protein alpha-synuclein, called Lewy bodies.
A rare form of dementia that tends to occur in people younger than 60 is Frontotemporal dementia. It is associated with abnormal amounts or forms of the proteins tau and TDP-43. Research shows that many people have a combination of brain changes associated with more than one form of these diseases, leading to a diagnosis of Mixed dementia.
Prevalence & Impact
The Alzheimer’s Association has a detailed report on these diseases in the United States. It estimates that 55 million people are living with Alzheimer’s and other dementias worldwide, including around 7 million in the US. One in nine adults in the US over the age of 65 has Alzheimer’s.
In 2022, over 11 million Americans provided more than 18 billion hours of unpaid care for people living with Alzheimer’s or another dementia, valued at nearly $340 billion. Deaths from Alzheimer’s increased 145% between 2000 and 2019 while those from heart disease – the leading cause of death – decreased in the same period. Alzheimer’s now kills more people than breast cancer and prostate cancer combined.
Know the signs and symptoms
Early detection of Alzheimer’s and other forms of dementia matters, and it is important we all learn to recognize the signs and symptoms. The most common early sign is forgetting recently learned information. Memory loss that disrupts daily life – a decline in aspects of thinking: finding the right words, impaired reasoning or judgment, and vision or spatial issues are often signals of the very early stages.
The Alzheimer’s Association has compiled a list of the 10 early warning signs of Alzheimer’s and dementia. In addition to disruptive memory loss, there are: challenges in planning or solving problems, difficulty in completing familiar tasks, confusion with time or place, trouble understanding visual images or spatial relationships, new problems with speaking or writing, misplacing things and losing the ability to retrace steps, decreased or poor judgment, withdrawing from work or social activities, and changes in mood and personality. Mild cognitive impairment (MCI) is a condition that can be an early sign of Alzheimer’s, but not everyone with MCI will develop the disease.
Diagnosing and treating dementia
The first step you should take when cognitive difficulties are suspected is to visit your primary-care physician. Doctors will first assess whether there is an underlying and potentially treatable condition that is causing the cognitive difficulties. A diagnosis of dementia is generally made after cognitive and neurological tests, psychiatric evaluation, genetic tests, cerebrospinal fluid tests, blood tests and other evaluations.
At present there is no cure for dementia, although there are treatments that could manage neurodegenerative disorders, slow their progression, and help with associated symptoms including memory, behavioral changes and sleep. Several promising new treatments are in the early stages of evaluation; however, very little data exist right now on their efficacy.
Avoiding cognitive decline
Can we act to avoid cognitive decline or mitigate its effects as we age? Scientific research provides evidence for steps we can take to reduce our risk of cognitive decline and help maintain cognitive health. I’ll discuss details, describe the risk factors, and provide experts’ recommendations to maintain good cognitive health in a follow-on article.
