Ch 13. Neurocognitive Disorders
Neurocognitive Disorder Due to Traumatic Brain Injury
(TBI) requires evidence of impact to the head along with loss of consciousness, amnesia following the trauma, disorientation and confusion, and neurological abnormalities such as seizures symptoms must occur immediately after the trauma or after recovery of consciousness, and past the acute postinjury period Post Concussion Syndrome (PCS); from mild TBI in which they continue to have symptoms such as fatigue, dizziness, poor concentration, memory problems, headache, insomnia, and irritability. repeated injuries over time may lead to chronic traumatic encephalography (CTE) which causes a form of neurocognitive disorder, and can lead to premature death.
Neurocognitive Disorders Due to Another General Medical Condition
Amnesia; inability to recall information that was previously learned or to register new memories Substance-Induced persisting amnestic disorder; when drugs or medications cause serious memory impairment most common cause of this is chronic alcohol abuse memory loss must persist over time for the clinician to assign the diagnosis of neurocognitive disorder for some people the condition lasts for life, causing severe impairment that the individual may require custodial care for others, such as those whose condition results from medications, full recovery is possible
Neurocognitive Disorders Due to Neurological Disorders Other than Alzheimer's Disease
Frontotemporal Neurocognitive Disorder; neurocognitive disorder involving the frontotemporal area of the brain. Reflected in personality changes, such as apathy, lack of inhibition, obsessiveness, and loss of judgment. Eventually individual becomes neglectful of personal habits and loses the ability to communicate. The onset is slow and insidious. Neurocognitive Disorder with Lewy Bodies; progressive loss of memory, language, calculation, and reasoning, as well as other higher mental functions. Disorder gets name from presence in the brain of Lewy bodies (abnormal deposits of a protein called alpha-synuclein) these deposits affect dopamine and norepinephrine, which in turn affect motor functioning and memory. Vascular Neurocognitive Disorder; researchers link to a variety of cardiovascular risk factors. Most common form is Multi-Infarct Dementia (MID), caused by transient attacks in which blood flow to the brain is interrupted by a clogged or burst artery. The damage to the artery deprives the surrounding neurons of blood and oxygen, which causes the neurons to die. Pick's Disease; progressive degenerative disease that affects the frontal and temporal lobes of the cerebral cortex. Caused by the accumulation in neurons of unusual protein deposits called Pick bodies. People with this disorder become socially disinhibited, either acting inappropriately and impulsively or appearing apathetic and unmotivated. Those with Pick's disease undergo personality alterations before they begin to have memory problems.
Neurocognitive Disorder Due to Parkinson's Disease
brings about neuronal degeneration of the basal ganglia, the subcortical structures that control motor movements deterioration of diffuse areas of the cerebral cortex may occur disease is usually progressive, with various motor disturbances being the most striking feature Akinesia; when muscles become rigid and it is difficult for the person to initiate movement Bradykinesia; general slowing of motor activity and fine motor coordination Difficulty starting to walk, and once they start, they have difficulty stopping. Signs of cognitive deterioration - slowed scanning on visual recognition tasks, diminished conceptual flexibility, and slowed motor responses. Individual's face also appears expressionless and speech becomes stilted, losing its normal rhythmic quality Difficulty producing words on tests that demand verbal fluency Many cognitive functions, such as attention, concentration, and immediate memory, remain intact
Neurocognitive Disorders
decline acquired in one or more domains of cognition associated with alterations in the brain Neuropsychological testing and neuroimaging techniques and individual's medical history helps to decide whether individual's symptoms fall into diagnosis. Domains: Complex Attention Executive Function Learning and Memory Language Perceptual-Motor Social Cognition after diagnosing level of cognitive impairment, clinician next must take on the process of specifying which disease appears to be responsible for the cognitive symptoms. When one specific disease cannot be diagnosed, the clinician can indicate this or multiple diseases that contribute to the symptoms
Neurocognitive Disorder Due to Huntington's Disease
degenerative neurological disorder that can also affect personality and cognitive functioning abnormality on chromosome 4 that causes a protein, now known has huntingtin, to accumulate and reach toxic levels symptoms first appear during adulthood, between ages 30 and 50 disease results in the death of neurons in subcortical structures that control motor behavior altered cognitive functioning, social and personality changes mood disturbances, changes in personality, irritability and explosiveness, suicidality, changes in sexuality, and a range of specific cognitive deficits. because of these symptoms, clinicians may incorrectly diagnose the disorder as schizophrenia or a mood disorder - even if the individual has no history suggestive of these disorders can appear apathetic because of their decreased ability to plan, initiate, or carry out complex activities uncontrolled motor movement interferes with sustained performance of any behavior, even maintaining a upright posture, and eventually most people with Huntington's disease become bedridden
Theories and Treatment of Alzheimers
development of two characteristic abnormalities in the brain: neurofibrillary tangles amyloid plaques Neurofibrillary tangles; made up of tau (a protein which seems to play a role in maintaining the stability of microtubules supporting the axon's internal structure.) Microtubules are like train tracks that guide nutrients from the cell body down to the axon's ends. The tau proteins are like the railroad ties or crosspieces of the microtubule train tracks. In Alzheimer's disease the tau changes chemically and loses its ability to separate and support the microtubules. With their support gone, the tubules begin to wind around each other and can no longer perform. The collapse of the system within the neuron may first result in malfunctions in communication between neurons and may eventually lead to neuron death.' development of neurofibrillary tangles appears to occur early in the disease process and may progress quite substantially before the individual shows any behavioral symptoms Amyloid Plaques; collections of clusters outside the neuron made up of abnormal protein fragments called beta amyloid. Formed when a substance found in the brain (APP) embeds itself in the neuron's membrane. In healthy aging, enzymes called Secretases harmlessly trim away the extra length of APP. In Alzheimer's something goes wrong with this process so that the APP does not snip neatly ad the cell membrane. The cut-off fragments of the beta amyloid eventually clump together into plaques that the body cannot dispose of or recycle The most probable is that an underlying defect in the genetic programming of neural activity triggers the formation of tangles and plaques. Treatment: Medications to treat mild to moderate Alzheimer's; Galantamine (Razadyne) Rivastigmine (Exelon) Donepezil (Aricept) Tacrine (Cognex) (only rarely prescribed due to concerns about safety) Medications inhibit the action of acetylcholinesterase, the enzyme that normally destroys the acetylcholine after its release into the synaptic cleft; which is implicated as a contributor to memory loss. Behavioral strategies aim at increasing patient's independence include giving prompts, cues, and guidance for self-maintenance.
Major Neurocognitive Disorder
diagnosed when individuals show significant cognitive decline from a previous level of performance in the six domains based on a standardized quantified neruopsych clinical assessment cognitive deficits must interfere with the individual's ability to perform necessary tasks in everyday living, not occur exclusively with delirium
Neurocognitive Disorder Due to Alzheimer's Disease
disorder associated with progressive, gradual declines in memory, learning, and at least one other cognitive domain first symptoms of memory loss precede a cascade of changes that eventually ends in death due to the development of medical illness resulting from infection or failure of vital bodily organs in individuals who develop Alzheimer's disease, the loss of independent function continues in a progressive manner until death factors related to more rapid decline in early stages of disease include being younger at the age of onset, having higher education, and having poorer cognitive status when symptoms of the disease are first recognized clinicians devote significant energy and attention to the develop of behavioral tests for diagnosing in initial stages only an autopsy can produce a definitive diagnosis of Alzheimer's by allowing pathologists to observe the characteristic changes in brain tissue Mini Mental State Examination (MMSE) Pseudodementia; false neurocognitive disorder, severe form of depression that has primarily cognitive symptoms
Neurocognitive Disorder Due to Prion Disease/ Creutzfeldt-Jakob Disease
researchers believe is caused by an infectious agent and that results in abnormal protein accumulations in the brain initial symptoms include fatigue, appetite disturbance, sleep problems, and concentration difficulties as the disease progresses, the individual shows increasing signs of neurocognitive loss and eventually dies underlying symptoms is widespread damage known as spongiform encephalopathy; meaning large holes develop in the brain tissue disease appears to be transmitted to humans from cattle that have eaten the body parts of dead farm animals infected with the disease
Delirium
temporary in nature involving disturbances in attention and awareness acute state of confusion or impairment in cognitive processing that affects memory, orientation, executive functioning, ability to use language, visual perception, and learning. To diagnose; individual must show these changes in consciousness or awareness over a very short period of time. Diagnosis also requires that a general medical condition must cause the disturbance. Specify whether the delirium results from substance intoxication, substance withdrawal, a medication, or other medical condition (s). Rate either acute (few hours or days) or persistent (weeks or months) Can develop for a variety of reasons, including substance intoxication or withdrawal, head injury, high fever, and vitamin deficiency. People of any age can experience, but it is more common among older adults who have been hospitalized for medical or psychiatric reasons. Infection is another precipitating factor in at-risk individuals. Apart from cognitive symptoms of inattention and memory loss, individuals experiencing delirium may also have hallucinations, delusions, abnormalities in sleep/wake cycles/ changes in mood, and movement abnormalities. Once they experience this condition, people who have delirium are more likely to experience medical complication that can cause rehospitalization and a higher risk of mortality. Alzheimer's disease is another potential outcome due to the effects on the brain of inflammation of the immune system following a surgical procedure or injury. Delirium Rating Scale-Revised (DRS-R-98) Treatment includes a pharmacological approach that relies on antipsychotics including haloperidol and risperidone. Although haloperidol is considered potentially useful in reducing delirium in high-risk patients, research does not support its efficacy as a preventive. Instead of medications, clinicians can provide high-risk patients with cognitively stimulating activities such as discussions of current events or word games.
Mild Neurocognitive Disorder
when individual shows modest levels of cognitive decline declines are not severe enough to interfere with individual's capacity for living independently
Neurocognitive Disorders Due to Substances/Medications and HIV Infection
wide range of infectious diseases can cause the changes that occur with neurocognitive disorder cognitive functioning can also be negatively affected by anoxia (oxygen deprivation to the brain) exposure to certain drugs and environmental toxins can cause brain damage and result in substance/medication-induced neurocognitive disorder nutritional deficiencies can also cause cognitive decline cognitive losses that occur with physical disorders and toxic reactions may be reversible if the person receives prompt and appropriate medical treatment; however if intervention for a treatable neurocognitive disorder is not introduced in the early stages, the brain damage becomes irreversible. the more widespread the structural damage to the brain, the lower the chance the person will ever regain lost functions