Comprehensive Overview of Dementia

Dementia is a disorder characterized by a progressive loss of memory and other cognitive abilities. Like the word cancer, dementia does not refer to a single disease but rather to many diseases that all share commonalities. In the DSM-5, these diseases are formally called major neurocognitive disorders. Because dementia is not one disease but several, diagnosing dementia is a two-step process. First, you need to determine whether dementia is present or not. If it is, then you need to determine what type of dementia it is. You can answer the first question by using the diagnostic criteria in the DSM. The criteria for a major neurocognitive disorder are quite simple and can be captured in the mnemonic Dyer. First, there needs to be a clear decline in cognition. Most often this takes the form of memory loss, although other cognitive domains such as language, attention, and the ability to plan are often impacted as well. In clinical settings, a variety of bedside tests including the Mini Mental State Exam or MMSE and the Montreal Cognitive Assessment or MOCA can be used to provide a standardized assessment of various cognitive domains. This can be helpful not only for establishing the initial diagnosis but also for tracking progression over time. Next, these cognitive deficits must be severe enough that they lead to functional impairment. In early stages of dementia, this is first noticeable when it comes to instrumental activities of daily living. or IADLs, which are more complex tasks such as shopping, housekeeping, accounting, food preparation, and transportation. You can remember these using the acronym SHAFT. As dementia progresses, impairment is seen in even more fundamental areas known as activities of daily living, or ADLs, which are basic self-care tasks that a person must do in order to survive. These can be remembered using the acronym DEATH, which stands for dressing, eating, ambulating, toileting, and hygiene. Use the death shaft mnemonic to memorize the ADLs and IADLs as these will give you a structured way of assessing functional impairment in clinical settings. After establishing both a cognitive decline and functional impairment, you need to rule out delirium as a possible cause. Delirium is an acute state of confusion that can present similarly with memory loss and other cognitive deficits. However, it's not permanent in the same way that dementia is and will generally resolve once you've treated the underlying condition. Because of these major differences in both prognosis and treatment, ruling out delirium is essential. Finally, you need to make sure to exclude other psychiatric conditions like depression and schizophrenia as possible causes. These disorders can sometimes mimic dementia as well, especially in the elderly where symptoms like impaired concentration or lack of motivation can easily be mistaken for dementia. Provided you have done all these things however, a diagnosis of dementia is appropriate. Asking the second question, what type of dementia is it, relies upon a good understanding of the different forms that dementia can take. The main forms to be aware of here are Alzheimer's disease, vascular dementia, dementia with Lewy bodies, and frontotemporal dementia. It's also possible for someone to have multiple forms of dementia at the same time, which is known as mixed dementia. Alzheimer's disease is the most common form of dementia and is the prototypical neurocognitive disorder, with other types of dementia often being compared and contrasted with it. For that reason, we'll focus exclusively on Alzheimer's disease in this lecture and save a discussion of other forms of dementia for the next video. Okay, let's talk about Alzheimer's disease. When learning about dementia, people sometimes assume that Alzheimer's disease is a default or catch-all term for any cases of dementia that don't fit another pattern. However, this is the wrong way of thinking about it. Instead, you should conceptualize Alzheimer's disease as a unique condition with its own specific signs, symptoms, and patterns. Let's use the phrase, Grandpa, you okay? to memorize the main clues to be looking for when diagnosing Alzheimer's disease. First, G is for gradual. A hallmark of Alzheimer's disease is that it has a gradual and insidious onset, with subtle deficits accumulating over months or even years before a diagnosis. This contrasts with other causes of memory loss, such as delirium, which are more often sudden or dramatic in onset. Next, R is for relentless. Alzheimer's disease has an unremitting and steady progression in which additional deficits continue to accumulate without letting up. This contrasts not only with conditions like delirium, which can be reversible, but also with disorders like depression, which tend to occur in discrete episodes with symptom-free periods in between. Next, A, N, and D stand for amnesia and other neurocognitive deficits. These neurocognitive deficits are the defining feature of Alzheimer's disease, so pay close attention here. They are sometimes referred to as the four A's, not to be confused with the five A's of negative symptoms and schizophrenia. The first A is for amnesia. Loss of memory is the defining cognitive feature of Alzheimer's disease, as it is not only the most likely area to be impacted, but it's also typically the first sign of the disorder as well. There are a few nuances to be aware of here. Both retrograde and anterograde amnesia are seen, with patients having difficulty with both retrieving old memories and encoding new ones. In addition, short-term memory, involving things that happened within the past several hours or days, like what you ate for dinner last night, is affected earlier and more severely than long-term memory, such as where you grew up or went to school. Finally, explicit or declarative memory, which involves consciously recalling specific facts or events, like which friend you ran into at the store yesterday, is affected more often than implicit or non-declarative memory, which instead involves things outside your conscious awareness like being able to sing the melody of the happy birthday song. However, these distinctions tend to break down as the disease progresses with all forms of memory generally being impacted in later stages. The next A is for aphasia which is a loss of language abilities including not only speaking but reading and writing as well. This is often first noticeable as an expressive aphasia. with patients having word-finding difficulties or otherwise finding it hard to express exactly what they want to say. As the disease progresses, receptive aphasia often develops as well, with patients having trouble understanding what's being said to them. In severe forms of Alzheimer's disease, the ability to communicate can be lost entirely. The next A is for apraxia, or an inability to execute voluntary motor skills. In early stages of the disease, it is typically more complex tasks like typing on a computer or driving a car that are affected. However, as the disease progresses even more simple tasks like walking and eating can be impaired. Apraxia puts patients at high risk of falls and other injuries, especially in advanced stages of the disease which is a major cause of disability and even death in this population. The final A is for agnosia which is an inability to translate what we perceive with our senses into a cohesive signal that we can act upon. For example, when we see a stop sign, we need to be able to not only recognize its basic attributes, like the fact that it's red, but also to translate the intended meaning of the object, which in this case means that we need to bring our car to a halt. Patients with Alzheimer's disease tend to first have difficulty recognizing the meaning of an object, but as the disease progresses they may even struggle to recognize the object itself, such as mixing up a toothbrush with a hairbrush. In the final stages of the disease, even basic signals like feeling the heat from a fire or the need to urinate can go unrecognized, leading to injury, infection, and death. Outside of the four A's, neurocognitive deficits can occur in a few other areas as well. Loss of visuospatial skills is common and, like other domains, tends to occur in a gradual manner. For example, one of the tasks on the MOCA, a cognitive test mentioned earlier in this lecture, involves asking the patient to draw a clock from memory. The ability to successfully complete this task declines as dementia progresses, as seen in this image. Finally, executive functioning, or the ability to plan and execute an idea, is another domain that is often impacted in Alzheimer's disease. This is because executive functioning relies upon many other cognitive domains as well. If there is impairment in any of these domains, then the ability to carry out the idea will be lost. For example, someone who's going fishing needs to have the ability to make a list of everything that they'll need to bring which tests executive functioning, fill out the permit, which tests language, use a map to find the lake, which tests visuospatial skills, have the fine motor skills to pit a piece of bait on the line, which tests apraxia, and interpret what a sudden pull on the line means, which tests agnosia, among many other things. As Alzheimer's disease progresses, the ability to engage in higher-level activities like this is lost as well, with the patient engaging in progressively simpler tasks and finally ceasing most forms of goal-directed behavior. and late stages of the disease. Next, P is for psychiatric symptoms. While all the symptoms we talked about so far involve the loss of previous function, Alzheimer's disease can also cause the onset of new dysfunction as well. Psychiatric symptoms are common, with patients often showing mood changes such as depression, anxiety, irritability, and apathy. Sleep disruptions, including insomnia and daytime somnolence, are common as well. As the disease progresses, around one-third of patients will develop psychosis-like symptoms, including paranoia and delusions, with delusional misidentification, such as believing that a friend or family member is an imposter who has come to harm them, being a common pattern. These psychiatric symptoms can be a major source of disability for the patient, as well as frustration for the family and other caregivers. In addition, they can drive changes in activity, which is the next core pattern seen in this disorder. These can involve both decreases in purposeful behaviors such as reading, writing, and socializing, as well as increases in purposeless behaviors such as wandering, babbling, and agitation. A particular pattern of behavior known as sundowning, or a state of confused restlessness that is more prominent in the evening, is observed in about a third of patients. In some cases, wandering and agitation can become so problematic that patients need to be hospitalized or placed into long-term care facilities to prevent them from injury. In final stages of the disease, many patients are bed-bound and entirely dependent upon others for survival. Next, the U is for unable to function. This is just to remind you that, as with all forms of dementia, the neurocognitive deficits seen in Alzheimer's disease directly lead to distress, disability, and dysfunction. Next, O is for objective biomarkers. Unlike many of the disorders in psychiatry, which are diagnosed solely on the basis of clinical signs and symptoms, Alzheimer's disease has specific biomarkers that can be objectively demonstrated as well. Nowhere is this more apparent than when looking at the brains of patients with Alzheimer's disease on autopsy, which often reveal widespread cortical atrophy as seen in this image, with a normal brain on the left and an affected brain on the right. In particular, parts of the brain that produce the neurotransmitter acetylcholine are most affected, leading to a loss of cholinergic neurons. You can remember this by thinking that Alzheimer's disease is caused when acetylcholine goes down. Cholinergic neurons are particularly concentrated in the hippocampus, which can be visualized as hippocampal atrophy on structural brain imaging in mid to late stages of the disease. Functional neuroimaging can also show widespread decreases in metabolic activity as seen in this image. with a normal scan on the left and a scan from a patient with Alzheimer's disease on the right. On a microscopic level, a few additional biomarkers can be seen. Senile plaques consist of extracellular proteins known as amyloid beta that have clumped together, while neurofibrillary tangles are made up of a protein called tau. Levels of both amyloid and tau protein can be measured in cerebrospinal fluid by doing a lumbar puncture, while senile plaques and neurofibrillary tangles can be seen on brain biopsy. However, Due to the invasive nature of these procedures, they are not routinely done as part of the diagnostic workup for Alzheimer's disease. Finally, genetic testing for the APOE4 gene is another biomarker for Alzheimer's disease. APOE4 codes for a poorly functioning version of apolipoprotein E, which is the protein that clears away amyloid beta, which sets the stage for high levels of senile plaque formation. Because of this link, the APOE4 gene is the largest risk factor for developing Alzheimer's disease aside from age. with people having one copy being at three times the risk of developing it and people having two copies being at 15 times the risk compared to people with no copies of this gene. All in all, these structural, functional, pathologic, and genetic biomarkers can help to provide additional diagnostic clarity when assessing cases of Alzheimer's disease. The final letter in our GRANDPA UOK mnemonic is K, which stands for knowledge of illness. One of the features that differentiates Alzheimer's disease from the unremarkable forgetfulness of normal aging is that patients are generally unaware that they are losing cognitive function. So when a patient comes in saying that they are having problems with their memory, this is often a sign that they don't have Alzheimer's disease and vice versa. While this can be diagnostically useful for clinicians, for patients and their families, the lack of insight seen in Alzheimer's disease can lead to major problems. For example, if the patient has cognitively declined to the point where they are unable to safely operate a vehicle, they may become upset or even agitated when told that they can't drive because they don't believe that there is anything wrong. Both diagnostically and for treatment purposes, it's important to pay attention to the patient's knowledge of their illness when evaluating any sort of concern related to memory. Now that we know how to diagnose Alzheimer's disease in clinical settings, let's turn our attention to the data behind this disorder, including who gets it, what happens once they have it. and what forms of treatment are effective. Alzheimer's disease affects less than 1% of the total population at any given time. While that would seem to make it a rare disorder, in clinical practice, you're going to be considering a diagnosis of dementia almost exclusively in patients who are elderly, and in this population, it is much more prevalent. While the chance of having Alzheimer's disease is around 3% at the age of 65, this risk doubles every 5 years after that, meaning that over 20% of people above the age of 80 and a whopping 50% of people above the age of 90 will develop this disease. However, younger age does not rule out this disorder entirely, as early onset forms of Alzheimer's disease beginning in one's 50s or early 60s do exist. While early onset Alzheimer's disease is uncommon, accounting for less than 10% of all cases, it should remain on your differential, especially when there is a family history, as about a third of these cases are inherited in an autosomal dominant fashion. Looking at the gender ratio, studies show that women are affected more often than men, although this may have more to do with their longer lifespan. than it does with any risk factors that are inherent to their gender. As noted by the R in the Grandpa UOK mnemonic, once Alzheimer's disease has set in, it does not stop. For most patients with this disorder, additional deficits accumulate for the rest of their life, leading to ongoing decreases in functional ability. People in early stages of Alzheimer's disease often require assistance with IADLs like shopping or finances, while those in later stages of the disease can require assistance with even basic IADLs like eating and bathing. Alzheimer's disease is a highly lethal condition, as the risk of death is increased significantly compared to people the same age without the disorder. The average life expectancy from the time of diagnosis is around 5 years, with death almost always occurring within 10 years. Alzheimer's disease is rarely the direct cause of death. Instead, the progressive functional decline leads to a lack of mobility which increases the risk of infection as well as cardiovascular complications like clotting. Incontinence of urine and stool is also seen in advanced stages of the disease and generally portends a poor prognosis with a high risk of death within the next year. Treatments for Alzheimer's disease are available, however, they are often quite limited in their impact with no medication or therapy having the ability to halt or reverse the progression of Alzheimer's disease. Instead, the goal of treatment is restricted to symptom reduction and preservation of remaining function rather than restoration of previous function. Most of the medications used to treat Alzheimer's disease are cholinesterase inhibitors, which increase the amount of acetylcholine in the brain. As we learned earlier, destruction of acetylcholine-releasing neurons is a pathologic hallmark of Alzheimer's disease, and cholinesterase inhibitors help to make up for this imbalance, resulting in improvements in memory. The only other common anti-dementia drug is memantine, which works as an NMDA receptor antagonist and can improve not only cognition but mood and behavior as well. However, the effect of both of these drug types is not only limited but also transient, with small improvements that last only a few months before the normal course of the illness resumes. In real-world settings, it's not uncommon for antidepressants and antipsychotics to be used for treating Alzheimer's disease, especially in cases where there are pronounced mood or behavioral features. However, the effect of these medications tends to be minimal and, in the case of antipsychotics, may even be associated with an increased risk of mortality in this patient population. Because of this, they should only be used after carefully weighing the possible benefits against the known risks and considering the overall goals of the patient's care. Psychotherapy, at least in the traditional sense, is not effective for people with Alzheimer's disease, as their cognitive deficits prevent them from meaningfully engaging in this type of treatment. In contrast, behavioral interventions may be more effective and can improve quality of life in specific areas such as toileting abilities. Because both therapy and medications are limited in their ability to treat this disease, treatment instead should be focused on social and environmental interventions to protect the safety of the patient and those around them, such as removing the patient's driver's license to prevent accidents. Working with families and other caregivers during this process is also crucial. The specific goals of care should be made clear from the time of diagnosis, with support given to goals that are reasonable, such as someone wanting their father to be able to continue living at home as long as possible. and education provided when they are not, such as someone wanting their mother to return to working as an engineer again. As the disease progresses, helping with social interventions, such as arranging for residential care or financial conservatorship, can be invaluable. Finally, make sure to assess for caregiver burnout. Having a family member with Alzheimer's disease can be physically, emotionally, and financially draining, so encouraging family members to engage in self-care and seek help when they need it can make a world of difference. If you are working to maximize function for the patient and minimize burden for their caregivers, then you are doing what you can to help people manage this difficult and complicated disease. Congrats on making it through this lecture! Alzheimer's disease is complex and it's only one of the various forms of dementia that you'll need to know. We'll cover the other types of dementia in our next video, so consider subscribing to the channel to be notified when that is available. You can also check out my book Memorable Psychiatry on Amazon as well. Until next time, bye for now.

Because dementia is not one disease but several, diagnosing dementia is a two-step process. First, you need to determine whether dementia is present or not. If it is, then you need to determine what type of dementia it is. You can answer the first question by using the diagnostic criteria in the DSM.

The criteria for a major neurocognitive disorder are quite simple and can be captured in the mnemonic Dyer. First, there needs to be a clear decline in cognition. Most often this takes the form of memory loss, although other cognitive domains such as language, attention, and the ability to plan are often impacted as well. In clinical settings, a variety of bedside tests including the Mini Mental State Exam or MMSE and the Montreal Cognitive Assessment or MOCA can be used to provide a standardized assessment of various cognitive domains. This can be helpful not only for establishing the initial diagnosis but also for tracking progression over time.

Next, these cognitive deficits must be severe enough that they lead to functional impairment. In early stages of dementia, this is first noticeable when it comes to instrumental activities of daily living. or IADLs, which are more complex tasks such as shopping, housekeeping, accounting, food preparation, and transportation. You can remember these using the acronym SHAFT.

As dementia progresses, impairment is seen in even more fundamental areas known as activities of daily living, or ADLs, which are basic self-care tasks that a person must do in order to survive. These can be remembered using the acronym DEATH, which stands for dressing, eating, ambulating, toileting, and hygiene. Use the death shaft mnemonic to memorize the ADLs and IADLs as these will give you a structured way of assessing functional impairment in clinical settings. After establishing both a cognitive decline and functional impairment, you need to rule out delirium as a possible cause.

Delirium is an acute state of confusion that can present similarly with memory loss and other cognitive deficits. However, it's not permanent in the same way that dementia is and will generally resolve once you've treated the underlying condition. Because of these major differences in both prognosis and treatment, ruling out delirium is essential.

Finally, you need to make sure to exclude other psychiatric conditions like depression and schizophrenia as possible causes. These disorders can sometimes mimic dementia as well, especially in the elderly where symptoms like impaired concentration or lack of motivation can easily be mistaken for dementia. Provided you have done all these things however, a diagnosis of dementia is appropriate. Asking the second question, what type of dementia is it, relies upon a good understanding of the different forms that dementia can take. The main forms to be aware of here are Alzheimer's disease, vascular dementia, dementia with Lewy bodies, and frontotemporal dementia.

It's also possible for someone to have multiple forms of dementia at the same time, which is known as mixed dementia. Alzheimer's disease is the most common form of dementia and is the prototypical neurocognitive disorder, with other types of dementia often being compared and contrasted with it. For that reason, we'll focus exclusively on Alzheimer's disease in this lecture and save a discussion of other forms of dementia for the next video. Okay, let's talk about Alzheimer's disease.

When learning about dementia, people sometimes assume that Alzheimer's disease is a default or catch-all term for any cases of dementia that don't fit another pattern. However, this is the wrong way of thinking about it. Instead, you should conceptualize Alzheimer's disease as a unique condition with its own specific signs, symptoms, and patterns. Let's use the phrase, Grandpa, you okay?

to memorize the main clues to be looking for when diagnosing Alzheimer's disease. First, G is for gradual. A hallmark of Alzheimer's disease is that it has a gradual and insidious onset, with subtle deficits accumulating over months or even years before a diagnosis. This contrasts with other causes of memory loss, such as delirium, which are more often sudden or dramatic in onset.

Next, R is for relentless. Alzheimer's disease has an unremitting and steady progression in which additional deficits continue to accumulate without letting up. This contrasts not only with conditions like delirium, which can be reversible, but also with disorders like depression, which tend to occur in discrete episodes with symptom-free periods in between.

Next, A, N, and D stand for amnesia and other neurocognitive deficits. These neurocognitive deficits are the defining feature of Alzheimer's disease, so pay close attention here. They are sometimes referred to as the four A's, not to be confused with the five A's of negative symptoms and schizophrenia. The first A is for amnesia.

Loss of memory is the defining cognitive feature of Alzheimer's disease, as it is not only the most likely area to be impacted, but it's also typically the first sign of the disorder as well. There are a few nuances to be aware of here. Both retrograde and anterograde amnesia are seen, with patients having difficulty with both retrieving old memories and encoding new ones.

In addition, short-term memory, involving things that happened within the past several hours or days, like what you ate for dinner last night, is affected earlier and more severely than long-term memory, such as where you grew up or went to school. Finally, explicit or declarative memory, which involves consciously recalling specific facts or events, like which friend you ran into at the store yesterday, is affected more often than implicit or non-declarative memory, which instead involves things outside your conscious awareness like being able to sing the melody of the happy birthday song. However, these distinctions tend to break down as the disease progresses with all forms of memory generally being impacted in later stages. The next A is for aphasia which is a loss of language abilities including not only speaking but reading and writing as well.

This is often first noticeable as an expressive aphasia. with patients having word-finding difficulties or otherwise finding it hard to express exactly what they want to say. As the disease progresses, receptive aphasia often develops as well, with patients having trouble understanding what's being said to them. In severe forms of Alzheimer's disease, the ability to communicate can be lost entirely.

The next A is for apraxia, or an inability to execute voluntary motor skills. In early stages of the disease, it is typically more complex tasks like typing on a computer or driving a car that are affected. However, as the disease progresses even more simple tasks like walking and eating can be impaired. Apraxia puts patients at high risk of falls and other injuries, especially in advanced stages of the disease which is a major cause of disability and even death in this population.

The final A is for agnosia which is an inability to translate what we perceive with our senses into a cohesive signal that we can act upon. For example, when we see a stop sign, we need to be able to not only recognize its basic attributes, like the fact that it's red, but also to translate the intended meaning of the object, which in this case means that we need to bring our car to a halt. Patients with Alzheimer's disease tend to first have difficulty recognizing the meaning of an object, but as the disease progresses they may even struggle to recognize the object itself, such as mixing up a toothbrush with a hairbrush. In the final stages of the disease, even basic signals like feeling the heat from a fire or the need to urinate can go unrecognized, leading to injury, infection, and death.

Outside of the four A's, neurocognitive deficits can occur in a few other areas as well. Loss of visuospatial skills is common and, like other domains, tends to occur in a gradual manner. For example, one of the tasks on the MOCA, a cognitive test mentioned earlier in this lecture, involves asking the patient to draw a clock from memory.

The ability to successfully complete this task declines as dementia progresses, as seen in this image. Finally, executive functioning, or the ability to plan and execute an idea, is another domain that is often impacted in Alzheimer's disease. This is because executive functioning relies upon many other cognitive domains as well. If there is impairment in any of these domains, then the ability to carry out the idea will be lost.

For example, someone who's going fishing needs to have the ability to make a list of everything that they'll need to bring which tests executive functioning, fill out the permit, which tests language, use a map to find the lake, which tests visuospatial skills, have the fine motor skills to pit a piece of bait on the line, which tests apraxia, and interpret what a sudden pull on the line means, which tests agnosia, among many other things. As Alzheimer's disease progresses, the ability to engage in higher-level activities like this is lost as well, with the patient engaging in progressively simpler tasks and finally ceasing most forms of goal-directed behavior. and late stages of the disease.

Next, P is for psychiatric symptoms. While all the symptoms we talked about so far involve the loss of previous function, Alzheimer's disease can also cause the onset of new dysfunction as well. Psychiatric symptoms are common, with patients often showing mood changes such as depression, anxiety, irritability, and apathy.

Sleep disruptions, including insomnia and daytime somnolence, are common as well. As the disease progresses, around one-third of patients will develop psychosis-like symptoms, including paranoia and delusions, with delusional misidentification, such as believing that a friend or family member is an imposter who has come to harm them, being a common pattern. These psychiatric symptoms can be a major source of disability for the patient, as well as frustration for the family and other caregivers.

In addition, they can drive changes in activity, which is the next core pattern seen in this disorder. These can involve both decreases in purposeful behaviors such as reading, writing, and socializing, as well as increases in purposeless behaviors such as wandering, babbling, and agitation. A particular pattern of behavior known as sundowning, or a state of confused restlessness that is more prominent in the evening, is observed in about a third of patients. In some cases, wandering and agitation can become so problematic that patients need to be hospitalized or placed into long-term care facilities to prevent them from injury. In final stages of the disease, many patients are bed-bound and entirely dependent upon others for survival.

Next, the U is for unable to function. This is just to remind you that, as with all forms of dementia, the neurocognitive deficits seen in Alzheimer's disease directly lead to distress, disability, and dysfunction. Next, O is for objective biomarkers. Unlike many of the disorders in psychiatry, which are diagnosed solely on the basis of clinical signs and symptoms, Alzheimer's disease has specific biomarkers that can be objectively demonstrated as well.

Nowhere is this more apparent than when looking at the brains of patients with Alzheimer's disease on autopsy, which often reveal widespread cortical atrophy as seen in this image, with a normal brain on the left and an affected brain on the right. In particular, parts of the brain that produce the neurotransmitter acetylcholine are most affected, leading to a loss of cholinergic neurons. You can remember this by thinking that Alzheimer's disease is caused when acetylcholine goes down.

Cholinergic neurons are particularly concentrated in the hippocampus, which can be visualized as hippocampal atrophy on structural brain imaging in mid to late stages of the disease. Functional neuroimaging can also show widespread decreases in metabolic activity as seen in this image. with a normal scan on the left and a scan from a patient with Alzheimer's disease on the right. On a microscopic level, a few additional biomarkers can be seen.

Senile plaques consist of extracellular proteins known as amyloid beta that have clumped together, while neurofibrillary tangles are made up of a protein called tau. Levels of both amyloid and tau protein can be measured in cerebrospinal fluid by doing a lumbar puncture, while senile plaques and neurofibrillary tangles can be seen on brain biopsy. However, Due to the invasive nature of these procedures, they are not routinely done as part of the diagnostic workup for Alzheimer's disease.

Finally, genetic testing for the APOE4 gene is another biomarker for Alzheimer's disease. APOE4 codes for a poorly functioning version of apolipoprotein E, which is the protein that clears away amyloid beta, which sets the stage for high levels of senile plaque formation. Because of this link, the APOE4 gene is the largest risk factor for developing Alzheimer's disease aside from age. with people having one copy being at three times the risk of developing it and people having two copies being at 15 times the risk compared to people with no copies of this gene. All in all, these structural, functional, pathologic, and genetic biomarkers can help to provide additional diagnostic clarity when assessing cases of Alzheimer's disease.

The final letter in our GRANDPA UOK mnemonic is K, which stands for knowledge of illness. One of the features that differentiates Alzheimer's disease from the unremarkable forgetfulness of normal aging is that patients are generally unaware that they are losing cognitive function. So when a patient comes in saying that they are having problems with their memory, this is often a sign that they don't have Alzheimer's disease and vice versa.

While this can be diagnostically useful for clinicians, for patients and their families, the lack of insight seen in Alzheimer's disease can lead to major problems. For example, if the patient has cognitively declined to the point where they are unable to safely operate a vehicle, they may become upset or even agitated when told that they can't drive because they don't believe that there is anything wrong. Both diagnostically and for treatment purposes, it's important to pay attention to the patient's knowledge of their illness when evaluating any sort of concern related to memory.

Now that we know how to diagnose Alzheimer's disease in clinical settings, let's turn our attention to the data behind this disorder, including who gets it, what happens once they have it. and what forms of treatment are effective. Alzheimer's disease affects less than 1% of the total population at any given time.

While that would seem to make it a rare disorder, in clinical practice, you're going to be considering a diagnosis of dementia almost exclusively in patients who are elderly, and in this population, it is much more prevalent. While the chance of having Alzheimer's disease is around 3% at the age of 65, this risk doubles every 5 years after that, meaning that over 20% of people above the age of 80 and a whopping 50% of people above the age of 90 will develop this disease. However, younger age does not rule out this disorder entirely, as early onset forms of Alzheimer's disease beginning in one's 50s or early 60s do exist.

While early onset Alzheimer's disease is uncommon, accounting for less than 10% of all cases, it should remain on your differential, especially when there is a family history, as about a third of these cases are inherited in an autosomal dominant fashion. Looking at the gender ratio, studies show that women are affected more often than men, although this may have more to do with their longer lifespan. than it does with any risk factors that are inherent to their gender.

As noted by the R in the Grandpa UOK mnemonic, once Alzheimer's disease has set in, it does not stop. For most patients with this disorder, additional deficits accumulate for the rest of their life, leading to ongoing decreases in functional ability. People in early stages of Alzheimer's disease often require assistance with IADLs like shopping or finances, while those in later stages of the disease can require assistance with even basic IADLs like eating and bathing.

Alzheimer's disease is a highly lethal condition, as the risk of death is increased significantly compared to people the same age without the disorder. The average life expectancy from the time of diagnosis is around 5 years, with death almost always occurring within 10 years. Alzheimer's disease is rarely the direct cause of death. Instead, the progressive functional decline leads to a lack of mobility which increases the risk of infection as well as cardiovascular complications like clotting. Incontinence of urine and stool is also seen in advanced stages of the disease and generally portends a poor prognosis with a high risk of death within the next year.

Treatments for Alzheimer's disease are available, however, they are often quite limited in their impact with no medication or therapy having the ability to halt or reverse the progression of Alzheimer's disease. Instead, the goal of treatment is restricted to symptom reduction and preservation of remaining function rather than restoration of previous function. Most of the medications used to treat Alzheimer's disease are cholinesterase inhibitors, which increase the amount of acetylcholine in the brain. As we learned earlier, destruction of acetylcholine-releasing neurons is a pathologic hallmark of Alzheimer's disease, and cholinesterase inhibitors help to make up for this imbalance, resulting in improvements in memory. The only other common anti-dementia drug is memantine, which works as an NMDA receptor antagonist and can improve not only cognition but mood and behavior as well.

However, the effect of both of these drug types is not only limited but also transient, with small improvements that last only a few months before the normal course of the illness resumes. In real-world settings, it's not uncommon for antidepressants and antipsychotics to be used for treating Alzheimer's disease, especially in cases where there are pronounced mood or behavioral features. However, the effect of these medications tends to be minimal and, in the case of antipsychotics, may even be associated with an increased risk of mortality in this patient population.

Because of this, they should only be used after carefully weighing the possible benefits against the known risks and considering the overall goals of the patient's care. Psychotherapy, at least in the traditional sense, is not effective for people with Alzheimer's disease, as their cognitive deficits prevent them from meaningfully engaging in this type of treatment. In contrast, behavioral interventions may be more effective and can improve quality of life in specific areas such as toileting abilities.

Because both therapy and medications are limited in their ability to treat this disease, treatment instead should be focused on social and environmental interventions to protect the safety of the patient and those around them, such as removing the patient's driver's license to prevent accidents. Working with families and other caregivers during this process is also crucial. The specific goals of care should be made clear from the time of diagnosis, with support given to goals that are reasonable, such as someone wanting their father to be able to continue living at home as long as possible. and education provided when they are not, such as someone wanting their mother to return to working as an engineer again. As the disease progresses, helping with social interventions, such as arranging for residential care or financial conservatorship, can be invaluable.

Finally, make sure to assess for caregiver burnout. Having a family member with Alzheimer's disease can be physically, emotionally, and financially draining, so encouraging family members to engage in self-care and seek help when they need it can make a world of difference. If you are working to maximize function for the patient and minimize burden for their caregivers, then you are doing what you can to help people manage this difficult and complicated disease. Congrats on making it through this lecture!

Alzheimer's disease is complex and it's only one of the various forms of dementia that you'll need to know. We'll cover the other types of dementia in our next video, so consider subscribing to the channel to be notified when that is available. You can also check out my book Memorable Psychiatry on Amazon as well.

Until next time, bye for now.

Transcript for:Comprehensive Overview of Dementia

Transcript for:
Comprehensive Overview of Dementia