CH14 Neurocognitive Disorders
Overview
Unit 14 explores brain impairment in adults, delirium, dementia, amnestic
disorder, and disorders involving head injury.
Learning Objectives
1. Explain why the DSM dropped the terms “functional mental disorders”
and “organic mental disorders.”
- DSM's Terminology Change: Shifted from "functional mental
disorders" and "organic mental disorders" to "Neurocognitive
Disorders".
- This change reflects a more accurate understanding of the disorders'
nature, emphasizing their basis in brain function and structure. The
term "neurocognitive disorders" is more straightforward and
conceptually coherent, focusing on disorders involving loss of
previously attained cognitive ability, presumably caused by brain
damage or disease.
- Alignment with Neuroscience: Recognizes the complex relationship
between brain and behavior.
- Avoids Misleading Distinctions: Eliminates the unclear separation
based on presumed etiology (origin or cause).
2. Discuss diagnostic issues and clinical signs of brain damage.
**Nature of Brain Damage:
- Brain cell bodies and neural pathways lack regenerative power;
damage is usually permanent.
- Loss of established functioning occurs after brain injury in older
children and adults.
**Awareness and Psychological Impact:
- Some patients are painfully aware of their functional loss, adding
psychological burden.
- Others may have anosognosia 认知障碍, a lack of awareness of their
impairments, affecting rehabilitation motivation.
**Variability in Mental Impairment:
- The degree of mental impairment relates to the extent of brain
damage.
- The impact varies based on damage nature and location, as well as
individual's premorbid competence and personality
**Impairments Associated with Brain Disorders:
- Memory Impairment: Difficulty remembering recent events,
sometimes leading to confabulation.
- Orientation Impairment: Inability to recognize location, time, or
familiar people.
- Learning, Comprehension, Judgment Impairment: Clouded, sluggish,
or inaccurate thinking; loss of planning and abstract understanding.
- Emotional Control/Modulation Impairment: Overreactivity in
emotions (e.g., sudden crying, laughing).
- Apathy or Emotional Blunting: Emotional underreactivity, seeming
indifference.
- Initiation of Behavior Impairment: Difficulty self-starting actions,
needing frequent reminders.
- Propriety and Ethical Conduct Impairment: Lowered personal
standards in various areas.
- Receptive and Expressive Communication Impairment: Difficulty
understanding and expressing language.
- Visuospatial Ability Impairment: Problems in coordinating motor
activity with visual environment
3. Explain diffuse versus focal damage as they relate to brain
impairment.
**Diffuse Brain Damage:
- Often results in widespread neurocognitive problems.
- May be caused by moderate oxygen deprivation or exposure to toxic
substances like mercury.
- Symptoms include memory issues due to an inability to maintain
focused retrieval efforts.
- The capacity to store new information may not be affected.
- Example: Nail salon technicians exposed to organic solvents show
more cognitive and neurological impairments and perform worse on
attention and information processing tests.
**Focal Brain Damage:
- Involves specific, circumscribed areas of abnormal change in brain
structure.
- Typically results from acute, clearly defined events such as traumatic
injuries or strokes.
- Damage is localized, affecting a specific part of the brain.
- The nature of impairment depends on the brain area affected by the
stroke or injury.
4. Describe how neuropsychology and psychopathology interact with
each other.
- Cognitive Deficits in Psychopathology: Individuals with
psychopathological disorders may experience cognitive deficits. For
instance, patients with bipolar disorder can have persistent cognitive
impairments, even when their illness is in remission, illustrating a
close link between neuropsychological function and psychopathology.
- Brain Impairment and Psychological Symptoms: While most people
with neurocognitive disorders do not develop classic
psychopathological symptoms, many exhibit mild deficits in cognitive
processing and self-regulation, indicating an overlap between
neurocognitive and psychological domains.
- Individual Variability: The psychopathological symptoms that
accompany brain impairment are not always predictable and can
reflect individual nuances, such as a person's age, previous
personality, and their psychological situation.
- Attribution of Psychological Disorders: Psychological disorders that
follow brain injury, such as depression, may not always be directly
attributable to brain damage itself. They could also be a reaction to
the individual’s awareness of their reduced abilities and skills loss.
- Suicide Risk and Brain Injury: The risk of suicide attempts increases
after brain injury. This suggests that the psychological impact of brain
injury can be profound, affecting behavior and mental health
significantly.
- Life Circumstances and Recovery: People with more favorable life
situations generally have better outcomes after brain injury, which
indicates that psychosocial factors play a role in the recovery and
adaptation to brain injury.
- Resistance to Deterioration: Intelligent, well-educated, and mentally
active people tend to have a better resistance to mental and
behavioral deterioration following significant brain injury, suggesting
that cognitive reserve can impact the interaction between
neuropsychological impairment and psychopathology.
- Limits to Compensation: There are limits to how much brain damage
an individual can compensate for without exhibiting abnormal
behavior, indicating that there is a threshold where
neuropsychological damage will inevitably result in
psychopathological symptoms.
5. Define delirium 譫妄症 in terms of clinical presentation, and discuss
clinical treatments and outcomes.
**Clinical Presentation of Delirium 譫妄症:
- Acute state between normal wakefulness and stupor or coma.
- Characterized by confusion, disturbed concentration, and cognitive
dysfunction.
- Involves a sudden onset and a fluctuating state of reduced awareness.
- Accompanied by impairments of memory and attention, disorganized
thinking.
- Hallucinations and delusions are common.
- Symptoms fluctuate in severity throughout the day.
**DSM-5 Criteria for Delirium:
- Disturbance in attention and awareness.
- Development over a short period, change from baseline, fluctuates
during the day.
- Additional disturbance in cognition, such as memory, disorientation,
or perception.
- Not explained by another neurocognitive disorder and not in the
context of a coma.
- Evidence that the disturbance is due to a medical condition,
substance intoxication or withdrawal, toxin exposure, or multiple
etiologies.
**Risk Factors and Prevalence:
- Can occur at any age but is especially common in the elderly and
children.
- Associated with surgery, especially in patients over age 80.
- Risk factors include dementia, depression, and tobacco use.
- Prevalence varies but is high in surgical patients, particularly those
with cardiac surgery.
**Treatments for Delirium:
- Treated as a medical emergency; underlying cause must be identified
and managed.
- Reversible in most cases, except when caused by terminal illness or
severe brain trauma.
- Treatment includes medication, environmental manipulations, and
family support.
- Neuroleptics are commonly used, benzodiazepines for withdrawal
cases.
**Outcomes of Delirium:
- Delirium is associated with cognitive decline, longer hospital stays,
more health problems, and increased mortality.
- Environmental support to aid in orientation can be effective.
- Some patients, especially the elderly, may continue to experience
problems even after recovery from an acute episode.
6. Define dementia, and describe Alzheimer’s, dementia from HIV-1
infection and vascular dementia in terms of clinical picture,
prevalence, genetic or environmental aspects, treatment outcomes,
and effects on caregivers.
**Dementia
- Cognitive Deficits: Major neurocognitive disorders involve significant
deficits in cognitive abilities which may include:
o Attention
o Executive functions
o Learning and memory
o Language
o Perceptual-motor abilities
o Social cognition
- Decline from Previous Functioning: There must be evidence of a
decline from a previously attained level of cognitive functioning.
- Impact on Daily Life: The cognitive deficits are severe enough to -
interfere with independence and day-to-day activities
**Alzheimer
Clinical Picture:
- Alzheimer’s disease presents as a progressive neurodegenerative
disorder with a characteristic dementia syndrome.
- Initial symptoms are often mild cognitive impairments, such as
difficulty recalling recent events and performing routine tasks.
- As the disease progresses, deficits become severe, covering multiple
domains, leading to disorientation, poor judgment, and neglect of
personal hygiene.
Prevalence:
- The most common cause of dementia, with increasing rates after the
age of 40.
- Prevalence is higher in older age groups, with up to 40 percent of
those aged 85 and older affected.
- Over 5 million people in the United States and over 35 million
worldwide live with Alzheimer’s disease.
Genetic or Environmental Aspects:
- Early-onset Alzheimer’s disease is often linked to genetic mutations
on chromosomes 21, 14, and 1.
- Late-onset Alzheimer’s disease is associated with the APOE gene on
chromosome 19, particularly the APOE-E4 allele.
- Lifestyle factors such as diet, obesity, type 2 diabetes, and insulin
levels may influence the risk and progression of Alzheimer’s disease.
Treatment Outcomes:
- Currently, no treatment can restore lost functions.
- Treatments focus on managing symptoms, such as agitation and
aggression, and aim to support patients and caregivers.
- Behavioral treatments can mitigate some problematic behaviors, with
moderate success in easing the burden on caregivers.
Effects on Caregiver:
- Caregivers face significant emotional and physical stress due to the
demanding nature of caring for a person with Alzheimer’s.
- Behavioral management strategies can reduce frustration and
difficulty for caregivers, although the overall burden remains high.
Neuropathology:
- Characterized by amyloid plaques, neurofibrillary tangles, and brain
atrophy, especially in the temporal lobes.
- Accumulation of beta-amyloid is thought to interfere with synaptic
functioning and lead to neuronal death
**Dementia form HIV-1 infection
**Vascular dementia 血管性痴呆
Clinical Picture:
- Vascular dementia is often confused with Alzheimer's disease due to
similar symptoms of progressive dementia.
- It is caused by a series of small strokes leading to cerebral infarcts,
which destroy neurons over expanding brain regions.
- The early clinical picture may be more varied than Alzheimer’s
disease, with symptoms like abnormalities of gait being early
predictors.
- The condition leads to brain atrophy and behavioral impairments that
eventually resemble those of Alzheimer’s disease.
Prevalence:
- Vascular dementia tends to occur after the age of 50 and is more
common in men.
- It accounts for about 19 percent of dementia cases in individuals aged
65 years or older.
- Patients with vascular dementia are at risk of sudden death from
stroke or cardiovascular disease, leading to a shorter course of illness.
Genetic or Environmental Aspects:
- Mood disorders are more common in vascular dementia than in
Alzheimer’s disease, which may be related to the subcortical areas of
the brain being more affected.
- The document provided does not elaborate extensively on the genetic
or environmental aspects specific to vascular dementia.
Treatment Outcomes:
- The treatment of vascular dementia offers slightly more hope than
that for Alzheimer’s disease.
- Cerebral arteriosclerosis can be medically managed to some extent,
potentially decreasing the likelihood of further strokes.
- However, the problems faced by caregivers are similar to those
dealing with Alzheimer’s disease, emphasizing the need for support
groups and stress reduction techniques.
Effects on Caregiver:
- Caregivers of individuals with vascular dementia face daunting
challenges, often similar to those caring for people with Alzheimer's
disease.
- The document does not provide detailed information on the specific
effects on caregivers of those with vascular dementia, but it can be
inferred that the caregiving burden is significant due to the
progressive and debilitating nature of the disease
7. Explain amnetic 失忆 syndrome.
**Memory Impairment: The most striking feature of amnestic
syndrome is severely disturbed memory. While immediate recall and
memory for remote past events are usually relatively preserved, short-
term memory is typically so impaired that individuals are unable to
recall events that occurred only minutes earlier. To compensate,
patients may confabulate, inventing events to fill in memory gaps.
**Overall Cognitive Functioning: Aside from memory impairment,
overall cognitive functioning in patients with amnestic disorder is
often quite good. Affected individuals might be capable of executing
complex tasks, especially if these tasks provide distinctive cues for
each stage of the sequence.
**Causes: Amnestic syndrome can result from various types of brain
damage, including strokes, injury, tumors, or infections. Not all causes
of brain damage leading to amnestic syndrome are permanent. For
instance, Korsakoff’s syndrome, a type of amnestic disorder caused by
a vitamin B1 (thiamine) deficiency, can sometimes be reversed if
detected early and treated appropriately.
**Treatment and Prognosis: The prognosis and treatment of amnestic
syndrome largely depend on the underlying cause. In cases where the
cause is reversible, such as with thiamine deficiency in Korsakoff’s
syndrome, early detection and treatment can lead to improvement in
memory problems. However, in cases where the brain damage is more
extensive or permanent, treatment focuses on managing symptoms
and helping the individual adapt to their memory limitations.
8. Explain traumatic brain injury (TBI), describe the clinical picture, and
discuss treatment outcomes.
**Definition and Incidence:
- TBI affects nearly 2 million people annually in the United States.
- Common causes include falls, motor vehicle accidents, assaults, and
sports injuries.
- Higher incidence in children aged 0-4, adolescents aged 15-19, and
adults over 65.
- Rates are higher in males across all age groups.
- Recently, an increase in TBI cases among military personnel due to
explosive blasts has been noted.
**Clinical Picture:
- TBIs result from either closed-head injuries (where the skull remains
intact) or penetrating head injuries (where an object enters the
brain).
- Closed-head injuries often cause indirect brain damage due to inertial
forces, leading to violent contact of the brain with the skull or
rotational forces that twist the brain mass.
- These injuries can cause diffuse neuron damage due to the shearing
effect on nerve fibers and their synaptic interconnections.
- Severe head injuries typically result in unconsciousness, retrograde
amnesia (inability to recall events immediately preceding the injury),
and anterograde amnesia (inability to store new memories after the
trauma).
- Recovery of consciousness can vary significantly in duration, and in
severe cases, individuals may experience coma, delirium, and
disorientation.
**Treatments and Outcomes:
- Immediate medical treatment is crucial for saving lives and
mitigating brain damage.
- Long-term effects vary widely. Some individuals experience few
residual effects, especially with brief unconsciousness.
- Common symptoms of minor TBI include headaches, memory
problems, sensitivity to light and sound, dizziness, anxiety,
irritability, fatigue, and impaired concentration.
- Extensive brain damage can lead to significant reductions in
intellectual level, delays in returning to work, social role dysfunction,
posttraumatic epilepsy, and increased risks of depression and other
psychological disorders.
**Personality Changes:
- TBI can lead to changes in personality, including emotional
dysregulation, irritability, disinhibition, apathy, and paranoia.
- These changes are reported in a significant proportion of children and
adults who have experienced severe TBI.
- The nature of personality changes often depends on the site and
extent of the brain injury.
9. Discuss the research on the benefits of dietary supplements on brain
functioning.
**Cognitive Enhancers Use Among Healthy Individuals:
- Many people, both young and old, are turning to drugs that may offer
cognitive benefits.
- Commonly used substances include caffeine, which improves
vigilance, working memory, and incidental learning, and nicotine,
which may temporarily enhance episodic memory, working memory,
and attention.
**Prescription Stimulants Trend:
- The use of prescription stimulants, such as methylphenidate (Ritalin)
and modafinil (Provigil), is increasing.
- These drugs are intended for attention-deficit disorder and excessive
daytime sleepiness, respectively.
- However, they are now being used by students for better academic
performance and by military personnel for staying awake during
missions.
- Around 16% of college students report using methylphenidate
recreationally.
**Physicians' Reluctance to Prescribe:
- Physicians are generally reluctant to prescribe these medications to
young, cognitively healthy individuals.
- This hesitance is due to concerns about the safety of these drugs and
the belief that the benefits for healthy individuals are minimal.
**Evidence on Benefits and Ethical Issues:
- The benefits of cognitive enhancers in healthy individuals are
considered very modest.
- There are ethical concerns about the use of these drugs for
enhancement rather than treatment.
- Questions arise about access to these enhancers, potential for a
"cognitive arms race," and fairness in contexts like academic testing,
drawing parallels to steroid use in sports.
**Impact on Dietary Supplements:
- The discussion about cognitive enhancers extends to the use of
dietary supplements for brain functioning, like omega-3 fatty acids,
antioxidants, vitamins, and minerals.
- The trend reflects a broader interest in enhancing cognitive
performance beyond traditional treatments.
