What are Neurocognitive Disorders? - Chapter 15

What are the cognitive impairments in neurocognitive disorders?

Amnesia is common in neurocognitive disorders. Anterograde amnesia or anterograde memory dysfunction is amnesia for information acquired after the onset of the amnesia. The first indications of neurocognitive problems are when the individual shows signs of a lack of attention, being easily distracted, and being slower in performing well-learned activities. In addition, it may be difficult to follow a conversation and more time may be needed to make a decision.

Language impairments are collectively known as aphasia: speech impairments that result in difficulty producing or understanding speech. This can take several forms:

• An inability to understand speech or repeat speech accurately and correctly
• Fluent aphasia: the production of incoherent, messy speech
• Non-fluent aphasia: An inability to initiate or respond to speech other than a few simple words

A distinction can be made between Broca's aphasia and Wernicke's aphasia. Broca's aphasia is a disturbance in the ability to speak, with difficulty organizing and finding words and articulation. Wernicke's aphasia is a disturbance in speech comprehension in which there is difficulty recognizing spoken words and converting thoughts into words.

Agnosia is the inability to recognize objects, people, sounds, shapes, or smells without significant memory loss. This can occur with a wide variety of functions.

Apraxia is the inability to perform learned movements despite having the will and physical ability to perform the movements.

Executive functions are normally associated with the prefrontal cortex, an area of ​​the brain important for maintaining representations of goals and the means of achieving them. The Wisconsin card sorting task is a test used to test executive functioning in which individuals must sort cards for a number of trials with one rule (e.g., colour) and then another rule (e.g., shape). This requires the ability to shift and inhibit attention.

Another indication of neurocognitive impairment is impairment in more abstract mental tasks. For example, individuals cannot perform simple mathematical calculations.

How does assessment in clinical neuropsychology take place?

Assessment is important for a number of reasons:

• To determine the nature of impairments and the location of related tissue damage in the brain
• To obtain information about the onset, type, severity and progression of symptoms
• To distinguish between neurological impairments that have an organic basis and psychiatric symptoms that do not
• To identify the focus for rehabilitation programs and to test progress in these programs

A diagnosis is usually based on neuropsychological testing, nowadays often supplemented with brain tests such as EEG scans and fMRI. The WAIS-IV is one of the most widely used tests, this is the fourth edition of the Wechsler adult intelligence test. This test provides insight into skills such as verbal comprehension, perceptual organization, working memory and the speed of information processing.

A very short test to perform is the Mini Mental State Examination, which provides reliable information about the client's level of cognitive and mental functioning in ten minutes.

How are Neurocognitive Disorders diagnosed?

Diagnosis can be tricky because the impairments found in neurocognitive disorders are often symptoms of other psychological disorders as well. In addition, experiencing cognitive limitations in the early stages often leads to the development of psychological problems, such as depression.

The symptoms of neurological disorders overlap. For example, damage to specific areas due to closed head injury can cause cognitive impairments that are also found in more general degenerative disorders. Closed head injury is a concussion or head trauma, the symptoms include loss of consciousness after the trauma, confusion, headache, nausea or vomiting, blurred vision, loss of short-term memory and perseveration.

What diagnostic categories are there in the DSM-5?

There are two broader categories of neurocognitive disorders. These are delirium, (a disturbance of consciousness that develops over a short period of time) and major or mild neurocognitive impairment, more commonly known in the DSM-IV as dementia (the development of multiple cognitive impairments, including memory impairment and at least one other specific impairment). The DSM-5 criteria for delirium are:

• A decreased ability to focus and to direct and maintain attention and awareness, this develops over a short period of time (hours to a few days) and fluctuates in severity over that period of time;
• Additional disturbances in cognitive functioning are also seen
• Disturbances are not the result of a previous neurological condition and do not happen during a coma or other impaired levels of consciousness
• There is no evidence that the disturbance is a direct physiological result of another medical condition, substance abuse or withdrawal

The DSM-5 defines neurocognitive disorders as conditions in which there is significant impairment in one or more cognitive domains, such as complex attention, executive functioning, learning and memory, language, perceptual-motor, or social cognition. This can be diagnosed as major neurocognitive impairment (substantial impairment) or mild neurocognitive impairment (moderate impairment). DSM-5 criteria for a major neurocognitive disorder are:

• Significant cognitive impairment in at least one cognitive domain, based on (1) patient, informant, or physician concerns that there is a substantial impairment in cognitive function (2) a substantial impairment in cognitive performance, desirable as documented by standard testing;
• The cognitive impairment interferes with self-reliance in everyday activities;
• The impairment does not occur in the context of delirium; and
• The disability is not better explained by other mental disorders, such as depression or schizophrenia

DSM-5 criteria for a mild neurocognitive disorder are:

• Moderate cognitive impairment in at least one cognitive domain, based on patient, informant, or physician concerns that there is moderate impairment in cognitive function moderate impairment in cognitive performance, desirable as documented by standard testing
• The cognitive impairment does not interfere with self-reliance in everyday activities
• The impairment does not occur in the context of delirium
• The disability is not better explained by other mental disorders, such as depression or schizophrenia.

What types of major neurocognitive disorder are there?

There can be several causes for neurocognitive disorders, such as cerebral infection, traumatic brain injury, cerebrovascular events (CVAs) and degenerative disorders. One of the viruses that can infect the brain is the human immunodeficiency virus type 1 (HIV-1). The DSM-5 criteria for a neurocognitive disorder due to HIV infection are:

• Criteria for major or mild neurocognitive impairment are met
• The patient is infected with HIV
• The disorder is not better explained by non-HIV conditions including secondary brain diseases
• The disturbance is not due to another medical condition and is not better explained by another medical condition

Spongiform encephalopathy is a fatal infectious disease that attacks the brain and central nervous system. This is also known as 'mad cow disease' or variant Creutzfeldt-Jakob disease. The infectious agent in this disease is said to be a prion: an abnormal, transmissible agent that can trigger the abnormal folding of normal cellular proteins in the brain, leading to brain damage. The rapid dementia that develops appears to be due to prions, or proteins that destroy or replace neurons in the brain or central nervous system, which is why it is also referred to as prion disease. The DSM-5 criteria for neurocognitive impairment due to prion disease are:

• Criteria for major or mild neurocognitive impairment are met
• The onset is slow, with rapid progression
• Motor features of the prion disease are evident, such as involuntary twitching or ataxia
• The disturbance is not due to another medical condition and is not better explained by another medical condition.

One of the most common neurological disabilities is traumatic brain injury. This can be due to blunt or penetrating trauma to the head. Indirect damage can also result from movement of the brain within the skull from the impact of the trauma, causing damage to the opposite side of the brain. The DSM-5 criteria for a neurocognitive disorder due to traumatic brain injury are:

• Criteria for major or mild neurocognitive impairment are met;
• Traumatic brain injury is sustained with at least one of the following features:

1. Unconsciousness,
2. Post-traumatic amnesia,
3. Disorientation and confusion,
4. Neurological signs, such as neuroimaging showing damage
5. The disorder is present immediately after sustaining the traumatic brain injury.

Brain damage can also result from cardiovascular events (CVA) or stroke: sudden loss of consciousness due to rupture or occlusion of a blood vessel in the brain leading to oxygen deprivation. If the blood flow to the brain is obstructed, it is referred to as an infarction. If a blood vessel ruptures, it is called a haemorrhage. The most common causes of infarction are embolism and thrombosis. A cerebral embolism is a blood clot that forms somewhere in the body, then travels to the brain and damages brain cells, causing a lack of oxygen. Cerebral thrombosis is when a blood clot forms in a blood vessel that supplies blood to the brain. The clot interrupts the blood supply and brain cells die from lack of oxygen. A haemorrhage is often the result of hypertension or high blood pressure and is often caused by an aneurysm: the localized bulging of a blood vessel due to disease or the weakening of the blood vessel wall. Depression is an important feature in disability caused by strokes. The DSM-5 criteria for a vascular neurocognitive disorder are:

• Criteria for major or mild neurocognitive impairment are met;
• The clinical features suggest vascular aetiology, which is marked by one of the following: (1) the onset of cognitive impairment is temporally related to at least one cardiovascular event, (2) impairment is noticeable in complex attention and frontal-executive
• There is evidence of cerebrovascular disease accounting for the neurological impairments
• The symptoms are not better explained by another brain disease or disorder.

Degenerative disorders represent the neurocognitive disorders characterized by a slow, generalized deterioration in cognitive, physical, and emotional functioning due to changes in the brain. The diagnosis is complex, firstly because the disorder must be distinguished from the normal process of aging. Second, it is often difficult to distinguish between different degenerative disorders that affect cognitive and physical functioning. Third, these disorders are mostly found in the elderly and this population often has multiple deficits that make diagnosis more complex. Finally, the manifestation of these disorders depends on factors such as educational level and the degree of family and social support.

Alzheimer's is the most common form of dementia. It is a slowly progressive disorder in which there is impairment in short-term memory, with symptoms of aphasia, apraxia and agnosia, along with limited judgment, decision making and limited orientation. Risk factors for Alzheimer's include age, gender (more females than males), genetics (having a first-degree relative with Alzheimer's), family history of Alzheimer's, past head injury, and low educational attainment. The aetiology of Alzheimer's lies in the development of beta amyloid plaques and neurofibrillary tangles. Beta amyloid plaques are abnormal cell development, caused by abnormal protein synthesis in the brain, they clump together killing healthy neurons. Neurofibrillary tangles are abnormal collections of twisted nerve cell threads that cause errors in impulses between nerve cells and can lead to cell death. In addition, improper production of the brain neurotransmitter acetylcholine (involved in memory and learning) is thought to be important in Alzheimer's disease. DSM-5 criteria for a neurocognitive disorder due to Alzheimer's are:

• Criteria for major or mild neurocognitive impairment are met;
• Onset is slow with gradual progression of disability;
• The disturbance is not better explained by a cerebrovascular disorder or other neurodegenerative diseases or disorders

For major neurocognitive disorder:

Possible Alzheimer's is diagnosed if any of the following are present:

• Evidence of Alzheimer's genetic mutation in the patient's family history or through genetic testing; and
• The following three are present:

1. Decline in memory and learning and at least one other cognitive ability
2. Steady, gradual decline in cognition
3. No other neurodegenerative or cerebrovascular disease;

For mild neurocognitive impairment:

Probable Alzheimer's is diagnosed if there is evidence of Alzheimer's genetic mutation in the patient's family history or through genetic testing. Otherwise, possible Alzheimer's should be diagnosed if the following three things are present:

1. Impairment of memory and learning and at least one other cognitive ability,
2. Steady, gradual decline in cognition
3. No other neurodegenerative or cerebrovascular diseases.

Fronto-temporal neurocognitive disorder is associated with a loss of neurons in the frontal and temporal regions of the brain leading to the progressive development of behavioral and personality changes and language impairments. DSM-5 criteria for a fronto-temporal neurocognitive disorder are:

• Criteria for major or mild neurocognitive impairment are met
• Onset is slow with gradual progression of disability
• A behavioral or language variant is present. The behavioral variant involves marked decline in social cognition and at least three of the following:

1. Lack of inhibition,
2. Sluggishness or lethargy,
3. Compulsive/ritual behavior,
4. Inappropriate things in the stopping mouth or dietary changes. In the language variant there is a clear decline in language skills;

• Limited learning and memory functions and limited perceptual motor functions
• The disturbance is not better explained by a cerebrovascular disorder or other neurodegenerative diseases or disorders, or by the effects of a substance.

Parkinson's is a progressive neurological condition that affects movements such as walking, talking and writing. This disease causes psychological problems in 40% to 60% of patients. This disease arises as a result of damage to the basal ganglia, specifically the substantia nigra. Cells in this area are responsible for producing dopamine, and dopamine carries messages to areas that coordinate movement. Depression is common in Parkinson's. The fact that depression is a risk factor for a variety of neurodegenerative diseases has led to the view that depression is associated with an allostatic state (biological state of stress) that can accelerate the disease process and cause nerve cell atrophy. DSM-5 criteria for Parkinson's neurocognitive disorder are:

• Criteria for major or mild neurocognitive impairment are met
• The disturbance occurs during the existence of Parkinson's disease
• Onset is slow with gradual progression of disability
• The disturbance is not better explained by other medical conditions or mental disorders

Major or mild neurocognitive impairment probably due to Parkinson's is diagnosed if both of the following are present and major or mild neurocognitive impairment possibly due to Parkinson's if any of the following are present:

• No evidence of other neurodegenerative or cerebrovascular diseases,
• The Parkinson's diagnosis precedes the neurological disorder.

Lewy bodies are abnormal protein deposits that interfere with the normal functioning of the brain. These are found in the brainstem where they deplete the neurotransmitter dopamine and lead to Parkinson's symptoms. The Lewy bodies are also found in other parts of the brain. The DSM-5 criteria for a neurocognitive disorder with Lewy bodies are:

• Criteria for major or mild neurocognitive impairment are met;
• Onset is slow with gradual progression of disability;

Probable major or mild neurocognitive disorder with Lewy bodies is diagnosed when two core features are present or at least one suggestive feature with other features. Possible major or mild neurocognitive impairment with Lewy bodies is diagnosed if one core feature or at least one suggestive feature is present.

Core features are:

• Varying cognition with marked variability in attention and alertness,
• Recurrent, detailed hallucinations,

Suggestive features are:

• REM sleep behaviour disorder
• Adverse reactions to neuroleptics
• The disturbance is not better explained by cerebrovascular disease, other neurodegenerative diseases or disorders, or by the effects of a substance

Huntington's disease is an inherited, degenerative central nervous system disorder caused by a dominant gene. The genetic abnormality is found on the fourth chromosome, resulting in the production of a protein, mutant Huntingtin, which causes cell death in the basal ganglia. In this disease are affective symptoms, cognitive impairments, personality disorganization, stubbornness, loss of sanity, hallucinations, delusions, strange behavior and obsessions. The DSM-5 criteria for Huntington's neurocognitive disorder are:

• Criteria for major or mild neurocognitive impairment are met
• Onset is slow with gradual progression of disability
• The disruption occurs during the existence of Huntington's disease or when there is a known risk of Huntington's disease based on family history or genetic testing
• The disturbance is not better explained by other medical conditions or mental disorders.

There are drawbacks and benefits to genetic testing for a neurodegenerative disorder. The benefits are that researchers can better understand the disease and thus develop better treatments, that people are encouraged to adopt a healthier lifestyle, that people who are at high risk can use new treatments in the future and finally that they can help people plan for the future. Disadvantages are that if a defect comes out of the test it can cause fear, there is a risk of reading too much into a test, a positive test does not necessarily mean that the disease will develop and finally that people who test positive can be discriminated against, for example, with regard to insurance.

What about treatment and rehabilitation for Neurocognitive Disorders?

Often the neurological damage is such that it is permanent, and the patient has to learn to live with it. Rehabilitation focuses on helping the patient with exercises that help improve limited cognitive functions, training in the use of cognitive and behavioral aids, assistive technology, and basic drug treatment and psychotherapy.

What kind of biological treatments can be used?

The most common form of biological treatments are drug treatments, which help stabilise or slow degenerative disorders. Other forms are drug treatments to combat cerebral infections, and electrical brain stimulation for some forms of dementia. Cholinesterase inhibitors are drugs that prevent acetylcholine from being broken down by acetylcholinesterase in the synaptic cleft and increase the reuptake of acetylcholine at the postsynaptic receptors. The most common of these drugs are donepezil, rivastigmine and galantamine. Only for a fronto-temporal neurocognitive disorder, the effectiveness of these drugs has not been shown.

The drug mainly used in Parkinson's disease that counteracts the decay of dopamine is levodopa, an amino acid that is converted into dopamine by the brain. This drug works mainly for the motor symptoms. Thrombolytic therapy uses drugs that dissolve or break up blood clots. This is used to reduce disability in CVAs. Medication is also used in the treatment of disability due to cerebral infections. Bacterial meningitis is the inflammation of the meninges, the membranes that cover the brain and spine. These types of infections can be treated with antibiotics. Antiretroviral drugs have been shown to be effective in HIV-1 associated dementia. These are drugs that inhibit the replication of retroviruses. In addition, depression is an important feature in neurological disorders. Addressing depression can be viewed as directly treating the disorder itself rather than viewed as a side effect. Drugs such as SSRIs and tricyclic antidepressants have been shown to be effective.

What is deep brain stimulation?

Deep brain stimulation is a form of treatment for Parkinson's that uses a surgically inserted battery-operated device (a neurostimulator). This device delivers electrical stimulation to the ventral intermediate nucleus of the thalamus or the subthalamic nucleus area in the basal ganglia. This ensures the improvement of physical skills.

What is cognitive rehabilitation?

Many of these programs are basic training procedures that provide the client with structured, extensive training in the area of ​​their disability. Holistic rehabilitation approaches are treatment approaches for neurological disorders that attempt to target multiple aspects of the dysfunction.

What is attention process training (ATP)?

Attention process training (ATP) uses different strategies to promote and stimulate attention skills. Time pressure management (TPM) is not aimed at improving attention itself, but at providing clients with compensatory skills that help them cope with their delayed information processing.

How can visual-spatial deficits be treated?

Several programs have been developed for visual impairments. An example is the computer-assisted program visual scanning, which consists of several tasks to reduce symptoms of unilateral neglect.

What about apraxia and deficits in coordinated self-help behaviours?

Gestural training is a form of rehabilitation training that has been shown to be effective for limb apraxia, teaching the client to recognize gestures and postures that are appropriate and contextual. For example, a client must demonstrate how to use a guitar.

Virtual reality environments have been developed to teach patients how to improve basic skills of daily living. Exercises in this safe and controlled environment lead to improvements in real-world performance.

How can language and communication deficits be treated?

Many patients undergo standard forms of speech therapy to stimulate speech production and comprehension. A specific technique used in aphasia is constraint-induced movement therapy, which involves practicing verbal responses, requiring the patient to communicate without gestures or pointing to describe various objects of varying complexity.

Another specific form that has been shown to be effective for language production and understanding is known as group communication treatment, which focuses on increasing conversation initiation and information exchange through any form of communication.

How can memory deficits be treated?

Memory deficits are mainly treated with compensatory strategies. In addition, computer-based procedures can help, for example by means of an electronic agenda. nTeaching memory strategies is also helpful. There is a technique where the patient is trained to use visual imagery mnemonics to help store and retrieve items and events. Errorless learning in which individuals with amnesia are prevented from making mistakes when learning a new skill or information.

How can executive functioning deficits be treated?

Goal management training (GMT) is a procedure in which problem-solving training is provided to help evaluate a problem, followed by a specification of the major goals and the division of the problem-solving process into sub-goals or steps. Self-instructional training (SIT) is a procedure in which individuals learn a set of instructions to talk themselves through certain problems.

What do holistic rehabilitation methods look like?

It is helpful to take a holistic approach that takes all cognitive, emotional, and functional limitations into account. These rehabilitation methods show significant improvement in the overall functioning of patients, and awareness of the limitations is also developed. This approach is superior to standard neurorehabilitation programs in improving social integration and patient satisfaction with cognitive functioning.

What are caregiver support programs?

Many people with neurological disorders live with their families or caregivers, such as their partners. So, these people need support and training. It is important that caregivers provide physical and emotional support to patients. In addition, there is quite a lot on their plate because they often have substantial economic costs due to the care for a patient. Several recommendations have been made for caregivers that include tips on taking care of themselves. There are also support groups with carers who are in the same boat that you can join. In addition, tips have also been drawn up for caregivers that help to deal better with the patient.