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Delirium and Dementia
A Brief Overview and Differentiation
Of These Clinical Entities
Differences
Delirium
• Develops rapidly
• Fluctuating course
• Potentially reversible
• Profoundly affects
attention
• Requires emergent
investigation of
underlying cause and
treatment
Dementia
• Develops slowly
• Slow progressive course
• Not reversible
• Profoundly affects
memory
• Nonemergent evaluation
and treatment
Differences
• Both delirium and dementia represent states
of cognitive impairment and dysfunction.
Differences
• Hypothyroidism can progress to a
progressive state resembling dementia
clinically, however is generally reversible
with treatment. All patients seen in the
office who begin to appear to be showing
some signs of dementia should be screened
for thyroid illness for this reason.
Delirium
• An acute confusional state
• Fluctuating disturbances in
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cognition
mood
attention
arousal
self awareness
Delirium
• Disorientation can be rapidly fluctuating
and accompanied by diminished level of
consciousness
• Many authors propose slightly varied
definitions/descriptions but there is a
general consensus that ability to pay
attention to surrounds (attentiveness) is
poor.
Delirium
• Changes in personality and affect are
common
• Full medical workup is ncessary to
distinguish the two (delirium vs dementia)
• Treatment of delirium is directly aimed at
underlying cause and psychoactive
medications have a limited role.
Delirium
• Etiology can be divided into four general
categories:
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Metabolic
Toxic (Medication)
Infectious
Structural
Delirium – Metabolic Causes
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Hypoxia
Thyroid disorder
Metabolic or Respiratory acidosis (hypercapnea)
Hypoglycemia or severe hyperglycemia
Hypercalcemia
Potassium imbalance, sodium imbalance (common
in elderly)
• Post-ictal state or transient ischemic state
Delirium - Drugs
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Anticholinergices
TCA’s
Antiemetics
Older generation antihistamines
Muscle relaxants
CNS depressants (benzo’s narcotics, and
psychotics)
Delirium – Drugs continued
• Cimetidine
• Withdrawal of substances and medications
is also an important consideration (alcohol,
benzodiazepines)
Delirium – Infectious Causes
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Acute CNS infections
Systemic infections
Remote infections
Fever itself will cause a delirium
Pneumonia (frequent culprit in elderly)
UTI’s (frequent culprit in elderly)
Delirium - Structural
• Any structural abnormality in the brain can
cause delirium
– Acute CVA
– Tumor
– Abscess
Delirium – Structural
• Many physicians will argue that CT and
MRI are imperative, however such defects
will produce lateralizing signs on clinical
exam, and if imaging is not correlated with
findings at bedside, utility of this testing is
limited.
Delirium - Workup
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CBC
BMP or CMP
Ammonia Level
Urinalysis with culture and sensitivity
Blood cultures
Chest x-ray
Toxicology screen if indicated
Delirium – Workup
• Vitamin B12 if CBC suggests longstanding
deficiency
• CT of the head
• EEG
• MRI if clinical exam and history warrants
Delirium - Workup
• VDRL if history of syphyllis
• Lumbar puncture if indicated:
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Culture
Gram stain
Cell count
Total protein
Glucose
Delirium – Workup
• Thyroid studies are controversial in acutely
ill patients, usually reserved for suspicion of
myxedema coma or acute thyroid storm.
• Remember cognition deficits secondary to
thyroid illness will typically progress slowly
and mimic dementia.
Delirium - Treatment
• Focused toward underlying cause.
• ETOH withdrawal treated with
benzodiazepine's and thiamine.
• Medications need to be thoroughly
reviewed.
• Electrolyte/metabolic abnormalities
corrected and infections treated
appropriately.
Delirium - Treatment
• Agitation in the hospital needs to be
assessed in person by the physician. All
efforts need to be made to orient the person
to place and time.
Delirium - Treatment
• Medication is considered a chemical
restraint, needs to be administered
judiciously, and must be thoroughly
documented on the chart.
Delirium - Treatment
• The American Geriatric Society estimates up to
18% of hospitalized elderly patients with delirium
die
• Length of hospital stay is twice as long for those
who develop confusion during hospitalization
• Try to avoid writing for routine PRN sedatives on
the elderly for “agitation”. Acute mental status
changes need to be assessed.
Dementia
• Chronic deterioration of memory, especially
short term
• Intellectually function eventually severe
enough to interfere with ability to perform
Activities of Daily Living
• Mostly a disease of the elderly
• Affects young people primarily as a result
of injury or prolonged hypoxia.
Dementia - Prevalence
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1 to 2% in people < 65
5 to 15% in people > 65
30 to 50% in people > 80
Prevalence increases rapidly with age.
It accounts for more than 50% of nursing
home admissions. It’s prevalence in Nursing
home population is estimated to be 60 to
80%.
Dementia
• In general, it is a condition most feared by
the aging adults.
• Dementia predisposes oneself to delirium. A
diagnosis of Dementia cannot be made
while a patient is delirious.
Dementia
• Early dementia presents as short term memory
loss and must be differentiated from benign
senescent forgetfulness (age related memory loss).
Given extra time for recall, these individuals do
not show much change in intellectual
performance. These individuals are often more
concerned about their mental status than family
members, typically the reverse of that observed in
dementia.
Dementia - Early
• Early dementia, with its short term memory
loss often results in forgetting where they
placed certain belongings. This can lead to
some paranoia (often patients in nursing
homes will insist that people are stealing
from them).
Dementia - Intermediate
• Intermediate dementia shows the ability to
perform ADL’s actually declines. Significant
paranoia is seen in 25% of patients.
• Wandering is a significant problem.
• A poignant delusion/paranoia that has been
described is the inability of the individual to
recognize themselves in a mirror, leading to
suspicion that a stranger has entered their home.
Dementia - Severe
• Severe dementia results in complete
dependence on others for essential ADL’s.
Long term memory also becomes lost.
Family members are not recognized.
• The natural course of death in individuals
who progress to severe dementia is often
due to bacterial infection.
Dementia - Classification
Primary dementia (cortical dementia)
• Alzheimer’s disease
• Pick’s disease
• Frontal lobe dementia syndromes
• Mixed dementia with Alzheimer’s
component
Dementia - Classification
Vascular Dementia
• Multi-infarct dementia
• Strategic infarct dementia
• Lacunar state
• Binswanger’s disease
• Mixed vascular dementia
Dementia – Lewy Body
Dementia associated with Lewy Body
Disease
• Parkinson’s-associated dementia
• Progressive supranuclear palsy
• Diffuse Lewy body disease
Dementia - Toxicity
Dementia due to toxic ingestion
• Alcohol-associated dementia
• Dementia due to heavy metal or other toxin
exposures
Dementia - Infection
Dementia due to infection
• Viral: HIV_associated dementia,
postencephalitis syndromes
• Spirochetal: neurosyphilis, Lyme disease
• Prion: Creutzfeldt-Jakob disease
Dementia - Structural
Dementia due to structural brain
abnormalities
• Norma-pressure hydrocephalus
• Chronic subdural hematomas
• Brain tumors
Dementia - Reversible
Some potentially reversible conditions
mimicking dementia
• Hypothyroidism
• Depression
• Vitamin B12 deficiency
Dementia
• Alzheimer’s disease is by far the most
common type of dementia with accounting
for approximately 65 to 70% of all
diagnosed cases of dementia in the elderly.
• Vascular etiology dementia are second most
common accounting for approximately 20%
of cases in the elderly.
Dementia - Treatment
• Screening with mental status exams
• If possible, family members should be
interviewed
• Rule out correctable factors (thyroid, B12
deficiency)
• Inquire about medication (including OTC’s)
and alcohol use
Dementia - Treatment
• If possible eleminate all poten psychoactive
drugs and repeat MMSE 4-6 weeks
• Physical exam should screen for signs in
self-care deficits
• Brain imaging is controversial. Reversible
abnormalities (mass lesions) should
manifest with thorough physical exam.
Dementia - Treatment
• Most common use of imaging has been to
differentiate Alzheimer’s dementia from vascular
dementia. CT is adequate in this case.
• In several studies, the use of diagnostic imaging
did not justify the cost in patients presenting with
classic Alzheimer’s Dementia, as patient with
vascular dementia already often have readily
identifiable risk factors of HTN, hyperlipidemia,
known carotid vessel disease, or known vascular
disease.
Dementia - Treatments
• Medications exist that are aimed at
improving cognition in early stages of
common forms of dementia
• These function by inhibiting
acetylcholinesterase in the CNS and for a
short period of time slow progression of
disease and in some patients can cause short
term improvement in function.
Dementia - Treatments
Medications include:
• Aricept
• Reminyl
• Exelon
• Cognex
Because they are potent cholinergic medications, one
must limit anticholinergic medication use for full
benefit, otherwise little benefit may be observed
secondary to pharmacologic antagonism
Dementia - Treatments
• Namenda (mamentadine) is a NMDA receptor
agonist that shows promise in treatment of more
progressive cases and can be utilized in
conjunction with cholinesterase inhibitors.
• SSRI’s are recommended for treatment of
depressive symptoms.
• Depression occurs in up to 40% of patients with
early dementia.
Dementia - Treatments
• Support must be provided for family
members and caregivers.
• These individuals suffer a much higher rate
of depression, especially as they reach their
threshold for burnout.
Dementia - Treatments
• End of life issues should be addressed early
• There is no prognostic model for dementia,
unlike other terminal conditions such as
cancer
• Rate of progression is unpredictable
Delirium – Dementia
• Questions?