Dementia, 290.8
I. Definition
A. Broad (global) acquired impairment of intellectual function (cognition) that usually is progressive and that interferes with normal social and occupational activities
B. Key features of dementia consist of intact arousal state and impairment of memory, intellect, and personality.
C. Disorder characterized by one or more of the following: general decrease in level of cognition, behavioral disturbance, and interference with daily function and independence
D. Loss of mental functions such as thinking, memory, and reasoning
E. Not a disease, but rather a group of symptoms caused by various diseases
F. Refer to Chapter 74 for ways to differentiate dementia from delirium.
II. Etiology
A. As many as 50 known causes of dementia
B. Develops when parts of the brain that are involved with learning, memory, and decision making are affected by various infections or diseases
C. Alzheimer-type dementia (AD)
1. Most common form of dementia in the elderly
2. Accounts for 60% to 80% of dementia cases
3. Neuronal damage in AD is irreversible; therefore, the disease cannot be cured.
4. Histopathology of AD is characterized by neuritic plaques, neurofibrillary tangles, and degeneration of cholinergic neurons in the hippocampus and cerebral cortex.
6. Results in cerebral atrophy
D. Diseases that cause degeneration or loss of nerve cells in the brain
1. Alzheimer’s
2. Parkinson’s
3. Huntington’s
E. Vascular
1. Multi-infarct dementia
2. Stroke
3. Arteritis (15%-20%)
F. Infectious
1. HIV
2. Syphilis
3. Meningitis
4. Encephalitis
5. Abscess
6. Creutzfeldt-Jakob disease
G. Postencephalitic syndrome, CNS anoxia (drug overdose, cardiac arrest)
H. Nutritional deficiencies
1. Vitamin B12 deficiency
2. Folate deficiency
3. Other vitamin deficiencies
I. Toxic reactions
1. Chronic alcoholism
2. Drug toxicity
J. Subdural hematoma
K. Hydrocephalus
L. Chronic seizures
M. Illness other than in the brain
1. Kidney
2. Liver
3. CHF
4. Hypercapnia
5. Hypoxemia
6. Rhythm disturbance
7. Acute MI
8. Hypothyroidism/hyperthyroidism
N. Hearing loss
O. Blindness
P. Rule out depression
Q. Electrolyte imbalance
III. Clinical manifestations
A. Onset may be slow, continuing over a period of months or years.
C. Misplacing things: putting an iron in the refrigerator
D. Problems with language: forgetting simple words or using wrong words
E. Impaired abstract reasoning: unable to balance a checkbook because of forgetfulness about what the numbers are and what to do with them
F. Higher cognitive functions may be impaired
1. Aphasia
2. Apraxia: inability to perform previously learned purposeful movements (i.e., previously learned tasks) or to use objects properly
3. Agnosia: loss of comprehension of auditory, visual, or other sensations, although the sensory sphere is intact; inability to recognize objects, shapes, persons, sounds, smells, and so forth
G. Disorientation: Patients may become easily lost, even in familiar surroundings, or may wander.
H. Patients may have difficulty with learned tasks, such as dressing or cooking.
I. Poor judgment: Patients may forget that they are watching a child and may leave the child at home.
J. Loss of initiative: becoming passive; not wanting to go places or see other people
K. Clouding of consciousness and orientation does not occur until the terminal stages.
L. Emotional problems such as depression, lability, or flattened affect
M. Changes in mood: fast mood swings—calm to tears to anger in minutes
N. Agitation, anxiousness, sleeplessness
O. Drastic personality changes: irritable, suspicious (paranoid ideation), fearful
P. Patients often lose insight into their deficits.
Q. Difficulty recognizing family and friends
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