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 – 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:– Metabolic– Toxic (Medication)– Infectious– Structural

Delirium – Metabolic Causes

• 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

• 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

• 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

• 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:– 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

• AgitationAgitation 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

• MedicationMedication 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

• 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. Dementia predisposes oneself to delirium. A diagnosis of Dementia cannot be made A diagnosis of Dementia cannot be made while a patient is delirious.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)Primary dementia (cortical dementia)

• Alzheimer’s disease

• Pick’s disease

• Frontal lobe dementia syndromes

• Mixed dementia with Alzheimer’s component

Dementia - Classification

Vascular DementiaVascular Dementia

• Multi-infarct dementia

• Strategic infarct dementia

• Lacunar state

• Binswanger’s disease

• Mixed vascular dementia

Dementia – Lewy Body

Dementia associated with Lewy Body Dementia associated with Lewy Body DiseaseDisease

• Parkinson’s-associated dementia

• Progressive supranuclear palsy

• Diffuse Lewy body disease

Dementia - Toxicity

Dementia due to toxic ingestionDementia due to toxic ingestion

• Alcohol-associated dementia

• Dementia due to heavy metal or other toxin exposures

Dementia - Infection

Dementia due to infectionDementia due to infection

• Viral: HIV_associated dementia, postencephalitis syndromes

• Spirochetal: neurosyphilis, Lyme disease

• Prion: Creutzfeldt-Jakob disease

Dementia - Structural

Dementia due to structural brain Dementia due to structural brain abnormalitiesabnormalities

• Norma-pressure hydrocephalus

• Chronic subdural hematomas

• Brain tumors

Dementia - Reversible

Some potentially reversible conditions Some potentially reversible conditions mimicking dementiamimicking 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?