Clinical assessment of dementiahe diagnosis of Alzheimer’s
disease (AD) isessentially
a two-stage process. First, a diagnosis of demen-tia is made, the main conditions
from which it should bedifferentiated
being delirium, depression, concomitantphysical
illness, drug treatment, learning disability, theeffects of a severely impoverished environment, and
thenormal memory
loss that accompanies aging. Dementiais
a clinical syndrome, and determining the cause of thesyndrome is the second stage. The
commonest cause isAD, followed
by vascular dementia, Lewy-body dementia,and
frontal lobe dementia. There are many so-called sec-ondary causes of dementia, some
of which are treatable.The
clinical syndrome of dementia has three primaryexpressions. First, a neuropsychological
element consistingof
amnesia (loss of memory); aphasia (either
a receptiveaphasia
or expressive aphasia, the latter being more appar-ent in conversation, and nominal
aphasia tested by directquestioning
of naming of objects); apraxia (the inability
tocarry out tasks
despite intact sensory and motor nervoussystems, manifest
in dementia most usually by an inabilityto
dress often described as putting on a shirt or coat backC l i n i c a l
r e s e a r c hDiagnosis and management
of Alzheimer’s
diseaseAlistair
Burns, MD, FRCP, FRCPsych Address
for correspondence: University of Manchester, Dept of Psychiatry,
Withington Hospital, West Didsbury, Manchester M20 8LR,
UK
(e-mail: A_Burns@fs1.wph.man.ac.uk)1 2 9Keywords:
Alzheimer's disease; vascular dementia; Lewy-body
dementia; diagnostic instrument; geneticsAuthor affiliations: Professor
of Old Age Psychiatry, University of Manchester, Dept
of Psychiatry, Withington Hospital, West Didsbury, Manchester,
UKThe
diagnosis of Alzheimer’s disease (AD) is a 2-stage process.
In stage 1, the dementia syndrome, compris-ing neuropsychologic
and neuropsychiatric components together with deficits in activities
of daily living, isdifferentiated
on clinical grounds from a number of other conditions (delirium,
concomitant physical illness,drug
treatment, normal memory loss, etc). In stage 2, the cause is
determined, AD being the most common,followed
by vascular dementia, Lewy-body dementia, frontal lobe dementia,
and a host of so-called sec-ondary
causes. Although a mixed Alzheimer/vascular picture is common,
gradual onset of multiple cognitivedeficits
is typical of AD, while abrupt onset, a fluctuating course, hypertension,
and focal neurologic signssuggest
vascular dementia. In Lewy-body dementia, memory loss may not
be an early feature, and fluctua-tion
can be marked by distressing psychotic symptoms and behavioral
disturbance. Investigations should beminimally
invasive and relatively cheap, confined to routine blood tests,
chest x-ray and/or electrocardiogramif
clinically indicated, cardiologic or neurologic referral in the
presence of cerebrovascular signs, and com-puted tomography if
an intracranial lesion is suspected. Accurate diagnosis enables
the clinician to outlinethe
disease course to the family and inform them of genetic implications.
Numerous instruments for assess-ing
cognitive function, global status, psychiatric well-being, and
activities of daily living are briefly reviewed.T
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