21 COGNITIVEDISORDERS 523
such as paranoia, delusions, hallucinations,
inattention to hygiene, and belligerence. It
is evidenced by atrophy of cerebral neurons,
senile plaque deposits, and enlargement
of the third and fourth ventricles of the
brain. Risk of Alzheimer’s disease increases
with age, and average duration from onset of
symptoms to death is 8 to 10 years. Demen-
tia of the Alzheimer’s type especially with
late onset (after 65 years of age) may have
a genetic component. Research has shown
linkages to chromosomes 21, 14, and 19
(APA, 2000).- Vascular dementiahas symptoms similar
to those of Alzheimer’s, but onset is typically
abrupt followed by rapid changes in function-
ing, a plateau or leveling-off period, more
abrupt changes, another leveling-off period,
and so on. Computed tomography (CT) scan
or magnetic resonance imaging (MRI)
usually shows multiple vascular lesions of
the cerebral cortex and subcortical struc-
tures resulting from the decreased blood
supply to the brain. - Pick’s diseaseis a degenerative brain
disease that particularly affects the frontal
and temporal lobes and results in a clinical
picture similar to that of Alzheimer’s. Early
signs include personality changes, loss of
social skills and inhibitions, emotional blunt-
ing, and language abnormalities. Onset is
most commonly 50 to 60 years of age; death
occurs in 2 to 5 years.- Creutzfeldt-Jakob diseaseis a central
nervous system disorder that typically
develops in adults 40 to 60 years of age.
It involves altered vision, loss of coordina-
tion or abnormal movements, and dementia
that usually progresses rapidly (a few
months). The cause of the encephalopathy
is an infectious particle resistant to
boiling, some disinfectants (e.g., formalin,
alcohol), and ultraviolet radiation. Pres-
sured autoclaving or bleach can inactivate
the particle. - HIV disease can lead to dementia and other
neurologic problems; these may result directly
from invasion of nervous tissue by HIV or
from other AIDS-related illnesses such as
toxoplasmosis and cytomegalovirus. This
type of dementia can result in a wide variety
of symptoms ranging from mild sensory
impairment to gross memory and cognitive
deficits to severe muscle dysfunction.
Figure 21-1.Metabolic activity in a subject with Alzheimer’s disease (left) and in a
control subject (right). (Courtesy of Monte S. Buchsbaum, MD, The Mount Sinai
Medical Center and School of Medicine, New York, New York.)