Chapter 15 – Cognitive Disorders
In this chapter we examine the brain disorders that affect cognitive processes such as learning, memory,
attention, perception, thinking andconsciousness. Cognitive disorders develop much later in life.
- Delirium – an often temporary condition displayed as confusion and disorientation
- Dementia – a progressive condition marked by gradual deterioration of a range of cognitive abilities
- Amnestic disorders – dysfunctions of memory due to a medical condition or a drug or toxin
The consequences of a cognitive disorder often include profound changes in a person’s behaviour and
personality. Intense anxiety or depression is common, especially among people with dementia. In addition,
paranoia is frequently reported, as are extreme agitation and aggression. The deterioration of cognitive
ability, behaviour & personality and the effects on others are a major concern for mental health professionals.
Delirium is characterized by impaired consciousness and cognition during the course of several hours or
days. Delirium is one of the earliest recognized mental disorders.
- People with delirium appear confused, disoriented and out of touch with their surroundings. They
cannot focus and sustain their attention on even the simplest tasks. They have marked impairments in
memory and language.
Mr. J has trouble speaking; he was not only confused but also couldn’t remember basic facts such as
his own name.
- The symptoms of delirium do NOT come on gradually; they develop over hours or a few days, and they
can vary over the course of a day. Delirium subsides rather quickly, with full recovery expected in
most cases within several weeks.
- Many medical conditions that impair brain function have been linked to delirium, including
intoxication by drugs and poisons; withdrawal from drugs such as alcohol and sedative, hypnotic and
anxiolytic drugs; infections; head injury, and other types of brain trauma.
The criteria for delirium due to a general medical condition include a disturbance in consciousness
(reduced awareness of the environment) and a change in cognitive abilities such as memory and language
skills, occurring over a short period and brought about by a general medical condition.
Other subtypes for diagnosis include: substance-induced delirium, delirium due to multiple etiologies
and delirium not otherwise specified. Since delirium can be brought on by the improper use of medication
can be a particular problem for older adults, because they use more and multiple prescription medications.
- Delirium may be experienced by children who have high fevers or who are taking certain medications.
It is often mistaken for noncompliance. 44% of people with dementia have 1+ episodes of delirium.
- Sleep deprivation, immobility, and excessive stress can cause delirium.
- Environmental factors can play a role in risk for severe delirium in hospitalized elderly people.
Hospital room changes, for example, can disrupt older patients’ ability to correctly perceive
environmental cues, resulting in their misinterpretation of stimuli around them. Chapter 15 – Cognitive Disorders
- Acute delirium and delirium brought on by withdrawal from alcohol or other drugs is usually treated
with haloperidol or other antipsychotic medications, which help calm the individual.
- Psychosocial interventions may also be beneficial. Nonmedical treatment would to reassure the
person in order to help him or her deal with the agitation, anxiety, and hallucinations of delirium.
- A patient who is included in all treatment decisions retains a sense of control. This psychsocial
treatment can help the person manage during this disruptive period until the medical causes are
identified and addressed.
- Proper medical care for illnesses and therapeutic drug monitoring can play a significant role in preventing
delirium. A broad spectrum of interventions (education, support, reorientation, anxiety-reduction,
preoperative medical assessment) may be moderately effective in preventing delirium in surgical patients.
Dementia is the cognitive disorder that include a gradual deterioration of brain functioning that affects
judgment, memory, language, and other advanced cognitive processes. Dementia is caused by several medical
conditions and by the abuse of drugs and alcohol that cause negative changes in cognitive functioning. Some
of these conditions (such as infection or depression) can cause dementia, although it is often reversible
through treatment of the primary condition.
Although delirium and dementia can occur together, dementia has a gradual progression as opposed to
deliriums acute onset; people with dementia are not disoriented or confused in early stages. Like delirium,
however, dementia has many causes, including a variety of insults to the brain such as stroke (which
destroys blood vessels), the infectious diseases of syphilis and HIV, severe head injury, the introduction of
certain toxic or poisonous substances, and diseases such as Parkinson’s, Huntington’s, and the most common
cause of dementia, Alzheimer’s disease.
- In the initial stages, memory impairment is seen as an inability to register ongoing events.
- Diana couldn’t find her way home b/c Visuospatial skills are impaired among people with dementia.
Agnosia - the inability to recognize and name objects, is one of the most familiar symptoms.
Facial agnosia - the inability to recognize familiar faces
- Perhaps because victims of dementia are aware that they are deteriorating mentally, emotional
changes often occur as well. Common side effects are delusions (irrational beliefs), depression,
agitation, aggression, and apathy.
- Cognitive functioning continues to deteriorate until the person requires almost total support to carry
out day-to-day activities. Ultimately, death occurs as the result of inactivity combined with the onset
of other illnesses such as pneumonia.
- Results suggest that dementia is a relatively common disorder among older adults, and the chances of
developing it increase rapidly after the age of 75. Chapter 15 – Cognitive Disorders
- Five classes of dementia based on etiology have been identified:
o Dementia of the Alzheimer’s type
o Vascular dementia
o Dementia due to other general medical conditions
o Substance-induced persisting dementia
o Dementia due to multiple etiologies
o Dementia not otherwise specified
DEMENTIA OF THE ALZHEIMER’S TYPE
- The DSM diagnostic criteria for dementia of the alzheimer’s type include multiple cognitive deficits that
develop gradually and steadily. This includes impairment of memory, orientation, judgment & reasoning. The
inability to integrate new information results in failure to learn new associations. They forget important
events and lose objects. Their interest in nonrountine activities narrows. They tend to lose interest in others
and thus, become socially isolated. As the disorder progresses, they can become agitated, confused,
depressed, anxious, or even combative. Many of these difficulties become more pronounced late in the day –
referred to as “sundowner syndrome” – maybe resulting from fatigue or a disturbance in the brains bio clock.
- People with dementia of the Alzheimer’s type also display one or more other cognitive disturbances,
including aphasia (difficulty with language), apraxia (impaired motor functioning), agnosia (failure to
recognize objects), or difficulty with activities such as planning, organizing, sequencing, or abstracting info.
One example of the language difficulties experienced by people with Alzhiemer’s disease is anomia
(problems with naming objects).
- A simplified version of a mental status exam, called the Mini Mental State Examination, is used to assess
language and memory problems. This simple exam has been shown to be quite accurate in identifying people
with dementia. When detecting dementia and Alzheimer’s disease, the clock-drawing subtest of the Clock
Test is used to supplement the mental status exam.
- Approximately 50% of cases of dementia are found to be the result of Alzheimer’s disease.
Those with the least amount of formal education are more likely to develop dementia than those with more
education. The cerebral reserve hypothesis suggests that the more synapses a person develops throughout
life, the more neuronal death must take place before obvious signs of dementia. Mental activity that occurs
with education builds up this reserve of synapses and serves as a protective factor in the development of the
disorder. Both skill development & the changes in the brain with education may contribute to how quickly
the disorder progresses.
- Alzheimer’s disease may be more prevalent among women. Women tend to live longer and likely to
experience Alzheimer’s and other diseases. Women lose the hormone estrogen, as they grow older, so
perhaps it is protective against the disease.
- The word vascular refers to blood vessels. When the blood vessels in the brain are blocked or
damaged and no longer carry oxygen and other nutr