Nervous system: Dementia and delirium
Definitions & Key takeaways
Dementia and delirium are both conditions that can affect cognitive function, which is the ability to think, remember, and reason. However, they are distinct conditions with different causes and characteristics.
Dementia refers to a decline in a mental function, like memory, language, or behavior that is caused by structural changes in the brain. It is gradual, progressive, and lasts for a long period of time. Dementia can be caused by a variety of conditions, including Alzheimer's disease, vascular dementia, and Lewy body dementia.
On the one hand, delirium has an acute onset and usually results from an underlying disorder or the use of certain medications. Symptoms last only for a while and fluctuate over time. People with delirium can present with disorientation, confusion, agitation, and hallucinations, which often reverse once the underlying cause is treated.
Intro0:00–0:26
The brain is responsible for various mental functions, including memory, thinking, language, behavior, mood, and personality.
Dementia vs delirium0:26–0:56
Dementia is generally caused by structural changes in the brain, has a gradual onset, lasts months to years, and the symptoms usually progress over time.
On the other hand, delirium classically occurs as a consequence of another underlying condition, like an infection or medication toxicity; is acute in onset; lasts only a couple of hours to days; and symptoms fluctuate, meaning they come and go.
Stages of dementia0:56–1:17
Dementia goes through three main stages. In the early stage, the client's memory starts to become impaired, which may lead to repeating conversations or misplacing belongings.
At this point, the client typically recognizes their memory lapses, and this can generate feelings of shame, embarrassment, or frustration.
In the middle stage, the client has trouble identifying common objects or faces and carrying out tasks that involve multiple steps, like grooming or cooking.
Stages of dementia 1:17–2:25
Language can also become affected, and they can have trouble processing verbal or written communication. Sometimes, family members notice a change in the client’s behavior or personality.
Many clients may also experience loss of bladder control, which can lead to urinary incontinence. In the late stage, clients become dependent for all everyday activities.
Mobility decreases, so they are unable to walk or sit up without assistance. Ultimately, this can progress to them becoming bed bound.
Their ability to swallow food or fluids as well as communicate through language or facial expressions becomes limited or completely lost.
Total urinary and fecal incontinence can also be expected at this point. These clients are also susceptible to respiratory and urinary tract infections, which may lead to serious illness or death.
Okay, now, dementia can result from reversible and irreversible causes. Reversible causes can be controlled and possibly cured with the right treatment.
Causes of dementia2:25–4:43
Some common examples of this include infectious conditions, like syphilis and HIV; dietary deficiencies, especially vitamin B12 deficiency; and hormone imbalances, such as thyroid problems.
Irreversible causes cannot be cured and include Alzheimer disease, which is by far the most common cause of dementia; vascular dementia, which is the second most common cause; frontotemporal dementia; and Lewy body dementia.
Starting with Alzheimer disease. Its exact cause isn't completely understood, but there are abnormal protein deposits between both the neurons, called plaques, as well as inside the cells, called tangles, that get in the way of neuron-to-neuron signaling.
And these neurons that don’t function properly may end up undergoing programmed cell death where they self-destruct. Next up is vascular dementia, where there’s a progressive loss of brain function caused by poor blood flow to the brain over a long period of time, typically due to a series of strokes, also known as cerebrovascular accidents or brain attacks.
Τhe main risk factor for vascular dementia is atherosclerosis. That’s when there’s a buildup of plaque that thickens and hardens the artery wall.
When this process affects the arteries supplying the brain, it leads to a gradual decrease in blood flow to the brain. Now, factors that can increase the client's risk for having vascular dementia include anything associated with atherosclerosis, like a past heart attack, also called myocardial infarction; smoking; obesity; hypertension, or high blood pressure; diabetes; and a diet high in saturated fat.
Frontotemporal dementia refers to the degeneration of the frontal lobe, which is a part of the brain involved in shaping personality and behavior, as well as the temporal lobe, which plays a key role in language and communication.Finally, Lewy body dementia is caused by the aggregation of abnormal proteins known as Lewy bodies inside of neurons, which causes them to die.Okay, over time, as neurons die, the brain atrophies, or shrinks, and its functions get seriously impaired.
Common behaviors of dementia 4:43–6:31
This may cause the client to alter the way they behave and act. Now, there are some behaviors commonly exhibited by clients with dementia, some of which can be frustrating for the caregivers or risky for the clients themselves.
These include wandering and getting lost, which can increase the risk for a fall or injury; restlessness, or the constant need to move around or pace back and forth, sometimes to the point of exhaustion; repetitive speech or actions; rummaging or hiding things; agitation; and becoming angry, worried, or distressed, which may cause them to yell, swear, or even try to hit someone.
Other common behaviors include catastrophic reactions, meaning that they react excessively to something seemingly trivial; sundowning, meaning that symptoms of confusion or loss of orientation may intensify late in the afternoon or evening; as well as inappropriate sexual behavior.
Communication and language problems can make it hard to think of common words. Now, some behavior patterns are seen more often in certain forms of dementia than others.
For example, delusions, which are false beliefs that the client might feel very strongly about so much so that they won’t change their mind even if they are given the evidence against it; as well as hallucinations, which can be any kind of sensation that’s not actually there, like hearing voices or commands or seeing people or lights; are classically associated with Lewy body dementia.
Abnormal motor behavior, like resting tremors, stiff and slow movements, and limited facial expressions similar to what’s seen in Parkinson's disease, is also common in clients with Lewy body dementia.
All right, as a quick recap… Dementia refers to a decline in a mental function, like memory, language, or behavior that is caused by structural changes in the brain, is gradual, progressive, and lasts for a long period of time.
Recap6:31–7:44
This shouldn’t be confused with delirium, which is a result of an underlying disorder, has an acute onset, lasts only for a while, and symptoms fluctuate over time.
Dementia has three main stages and can result from reversible causes, like infections, vitamin B12 deficiency, and thyroid problems.
But it usually results from irreversible causes, such as Alzheimer disease, which is by far the most common cause of dementia; vascular dementia; frontotemporal dementia; and Lewy body dementia.
Now, some behavior patterns are seen more often in certain forms of dementia than others. Delusions, hallucinations, and abnormal movements are more common in Lewy body dementia.
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