CHAPTER 14
CHAPTER OUTLINE
I.
The assessment of brain damage. Cognitive disorders are behavioral disturbances that
result from transient or permanent damage to the brain and affect thinking, memory,
consciousness, and perception and are affected by social and psychological factors, such
as coping ability and stress. DSM-IV-TR differentiates delirium, dementia, amnestic
disorders, and other cognitive disorders. Brain damage can be assessed through
neuropsychological testing and neurological tests. The first uses behavioral responses
from the patient on memory or manual dexterity tasks. The second directly monitors the
brain through electroencephalography (EEG), computerized axial tomography (CT)
scans, positron emission tomography (PET), magnetic resonance imaging (MRI), and
cerebral blood flow measurements. Each has its strengths and weaknesses.
II. Types of cognitive disorders. Within the types of cognitive disorders, clinicians
categorize according to cause, such as psychoactive substance-induced or general
medical condition. The most prominent features of dementia are memory impairment
and cognitive disturbance, including language disturbance (aphasia, impairments in
motor activities (apraxia), misidentification of faces or objects (agnosia), and problems
with planning and abstractions. Delirium involves impairments in consciousness and
changes in cognition (disorientation, incoherent speech, perceptual distortions), and it
usually develops rapidly. Amnestic disorders entail an inability to retain new
information or recall old information, or both, and may be caused by head trauma,
stroke. While the three conditions have overlapping symptoms, dementias are usually
accompanied by language problems such as aphasia and come on gradually (as opposed
to delirium). Memory loss is the primary symptom of amnestic disorders.
III. Etiology of cognitive disorders. Traumatic brain injury(TBI)—a physical wound to the
brain-is one cause of cognitive disorders. Head injuries include concussions, when
blood vessels are damaged by a blow to the head; contusions, when blood vessels
rupture because of the brain’s impact against the skull; and lacerations, when tissue is
torn or pierced by an object penetrating the skull. Personality changes as well as
cognitive and motor impairments are common. Only one-third of closed-head injury
patients return to gainful employment after traditional rehabilitation. The aging
population of the United States is growing, due both to longer life expectancy and the
large numbers. Stroke, the third major cause of death in the United States, is a common
cognitive disorder in the elderly. Strokes (cerebrovascular accidents) occur when blood
flow to an area of the brain is cut off, causing a loss of brain function. Causes of stroke
include bursting of blood vessels and narrowing or blockage of blood vessels owing to
the buildup of fatty material on interior walls (atherosclerosis), which results in cerebral
infarction (death of the brain cells results). A series of small strokes is known as
vascular dementia; it is characterized by uneven deterioration of physical and
intellectual abilities. Risk factors include hypertension, heart disease, cigarette smoking,
diabetes, and excessive alcohol consumption. Memory loss in the elderly may be due to
brain cell deterioration, vascular dementia, and the normal aging process. A common
cause is intoxication from prescribed medications. To assess age-related cognitive
deficits, the individual’s performance can be compared with general population norms,
age-group norms, norms based on similarity in status or education, and the person’s
previous functioning. Alzheimer’s disease, involving atrophy of cortical tissue, leads to
intellectual and emotional deterioration, including memory loss, irritability, and social
withdrawal. Autopsies show neurofibrillary tangles and senile plaques in the brains of
people with the disease. The etiology of Alzheimer’s are unknown, but heredity may
play a role in some subtypes; infection, head injury, exposure to aluminum, and reduced
neurotransmitter levels may be related to others. Protective factors include genetic
endowment with the ApoE-e2 allele, higher education, use of non-steroidal antiinflammatories or estrogen replacement, and vitamin E. Parkinson’s disease has the
following symptoms: muscle tremors, a stiff, shuffling gait, and an expressionless face.
The disorder is associated with lesions in the motor area of the brain stem and
insufficient dopamine levels. Treatment is generally L-dopa or a similar drug. The
majority of AIDS patients also suffer from some form of dementia. It is not clear
whether the AIIDS virus affects the brain; AIDS-related infections cause
neuropsychological problems, or depression and anxiety about having AIDS cause
cognitive symptoms. Neurosyphilis (general paresis) is brain damage caused by the
delayed effect of a syphilis infection. It occurs in about 10 percent of syphilis cases.
Symptoms include memory impairment, delusions, paralysis, and death within five
years. Encephalitis (sleeping sickness) is a viral infection of the brain that produces
long periods of sleep followed by agitation and seizures. Meningitis, an inflammation of
the membrane around the brain, can be caused by bacteria, viruses, or fungi, and has a
wide range of effects and potential residual disturbances. Huntington’s disease is a
genetically transmitted disorder that first shows in early middle age. Symptoms begin
with twitches and progress to uncontrollable jerking movements, irritability, and
confusion. Death comes within thirteen to sixteen years after onset. A gene has been
identified that causes the disorder. It is frequently misdiagnosed as schizophrenia. A
cerebral tumor is a mass of abnormal tissue growing in the brain. Fast-growing tumors
in the brain produce severe mental symptoms, such as diminished attention, drowsiness,
dementia, and mood changes, or may be severe enough to result in coma. Removal of
tumors can result in dramatic improvement of functioning. Epilepsy is a set of
symptoms, not a disorder. It involves brief periods of altered consciousness, often
accompanied by seizures. About 2.7 million children and adults in the United States
have epilepsy or some other seizure disorder. Causes are genetic a well as
environmental. Although epilepsy cannot be cured, it can be controlled with medication.
IV. Treatment/prevention considerations. Treatment approaches include medical
strategies such as surgery and medication (for the disorder itself or to control emotional
problems accompanying the disorder), and psychological efforts such as skills
acquisition, cognitive preparation, application training, and psychotherapy, such as
behavior modification and biofeedback. How family and friends can assist those with
cognitive disorders is an important issue. In preventing or reducing the effects of
cognitive disorders, research suggests that lifestyle changes are important. For vascular
dementia, health habits related to preventing stroke—e.g., avoiding smoking, obesity,
and hypertension—are relevant to prevention. Some suggestions are preserving a sense
of independence and control, maintaining interpersonal contacts that do not overwhelm,
engaging in pleasant diversions, providing tasks that increase self-worth, and ensuring
that caregivers obtain social support for themselves.
V. Implications. We have not directly focused on the multi-path model simply because
cognitive disorders are usually classified by etiology. Because most cognitive disorders,
including mental retardation, have underlying damage, deterioration, or abnormalities to
the brain or its processes, biological factors are apparent. However, we have also noted
the importance of psychological, social, and sociocultural factors in the disorders.