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DELIRIUM, DEMENTIA, AND AMNESTIC and OTHER COGNITIVE DISORDERS
Dementia Definition
Multiple Cognitive Deficits:
Memory dysfunction
especially new learning, a prominent early symptom
At least one additional cognitive deficit
aphasia, apraxia, agnosia, or executive dysfunction
Cognitive Disturbances:
Sufficiently severe to cause impairment of occupational or social functioning and
Must represent a decline from a previous level of functioning
Differential Diagnosis: Top Ten
(commonly used mnemonic device: AVDEMENTIA)
1. Alzheimer Disease (pure ~40%, + mixed~70%)
2. Vascular Disease, MID (5-20%)
3. Drugs, Depression, Delirium
4. Ethanol (5-15%)
5. Medical / Metabolic Systems
6. Endocrine (thyroid, diabetes), Ears, Eyes, Environ.
7. Neurologic (other primary degenerations, etc.)
8. Tumor, Toxin, Trauma
9. Infection, Idiopathic, Immunologic
10. Amnesia, Autoimmune, Apnea, AAMI
Diagnostic Criteria For Dementia Of The Alzheimer Type (DSM-IV, APA, 1994)
A. Multiple Cognitive Deficits
1. Memory Impairment
2. Other Cognitive Impairment
B. Deficits Impair Social/Occupational
C. Course Shows Gradual Onset And Decline
D. Deficits Are Not Due to:
1. Other CNS Conditions
2. Substance Induced Conditions
E. Do Not Occur Exclusively during Delirium
F. Not Due to Another Psychiatric Disorder
Alzheimer’s Disease versus Dementia
50 - 70% of dementias are AD
Probable AD - 30% of cases, 90% correct
20% have other contributing diagnoses
Possible AD - 40% of cases, 70% correct
40% have other contributing diagnoses
Unlikely AD - 30% of cases, 30% are AD
80% have other contributing diagnoses
Vascular Dementia
(DSM-IV - APA, 1994)
A. Multiple Cogntive Impairments
1. Memory Impairment
2. Other Cognitive Disturbances
B. Deficits Impair Social/Occupational
C. Focal Neurological Signs and Symptoms or Laboratory Evidence Indicating Cerebrovascular Disease Etiologically Related to the Deficits
D. Not Due to Delirium
Factors Associated with Multi-infarct Dementia
History of stroke (especially in Nursing Home)
Followed by onset of dementia within 3 months
Abrupt onset, Step-wise deterioration
Cardiovascular disease - HTD, ASCVD, & Atrial Fib
Depression (left anterior strokes), personality change
More gait problems than in AD
MRI evidence of T2 changes (? Binswanger’s disease)
Basal ganglia, putamen
Periventricular white matter
SPECT / PET show focal areas of dysfunction
Neuropsychological dysfunctions are patchy
Post-Cardiac Surgery
53% post-surgical confusion at discharge (delirium)
42% impaired 5 years later (dementia)
May be related to anoxic brain injury, apnea
May be related to narcotic/other medication
May occur in those patients who would have developed dementia anyway (? genetic risk)
Cardio-vascular disease and stress may start Alzheimer pathology
Any surgery may have a similar effect related to peri-op or post-op anoxia or vascular stress
Drug Interactions
Anticholinergics: amitriptyline, atropine, benztropine, scopolamine, hyoscyamine, oxybutynin, diphenhydramine, chlorpheniramine, many anti-histaminics
May aggravate Alzheimer pathology
GABA agonists: benzodiazepines, barbiturates, ethanol, anti-convulsants
Beta-blockers: propranolol
Dopaminergics: l-dopa, alpha-methyl-dopa
Narcotics: may contribute to dementia
Drug Toxicity
Anti-cholinergic
Peripheral: blurred vision, dry mouth, constipation, urinary obstruction
Central: confusion, memory encoding block
Gaba-agonist:
Muscle relaxant, anti-convulsant, sedative, anti-anxiety, amnesic, confusion
Medication induced electrolyte imbalance
Confusion (watch for in nursing home)
Depression
Onset: rapid
Precipitants: psycho-social (not organic)
Duration: less than 3 months to presentation
Mood: depressed, anxious
Behavior: decreased activity or agitation
Cognition: unimpaired or poor responses
Somatic symptoms: fatigue, lethargy, sleep, appetite disruption
Course: rapid resolution with treatment, but may precede Alzheimer’s disease
Delirium Definition
(more often a problem in medical in-patients)
Disturbance of consciousness
i.e., reduced clarity of awareness of the environment with reduced ability to focus, sustain, or shift attention
Change in cognition (memory, orientation, language, perception)
Development over a short period (hours to days), tends to fluctuate
Evidence of medical etiology
Delirium
Susceptibility may be symptom of early dementia, or delirium may predispose to later dementia
Predisposing factors - Age, infections, dementia
Medical conditions
Infections:
G.U. - urinary
Respiratory (URI, pneumonia)
G.I.
Constipation
Drug toxicity
Fracture (especially related to hip fracture)
Ethanol
Possibly Neuroprotective
May not kill neurons directly (?Dietary recommendation?)
Accidents, Head Injury
Dietary Deficiency
Thiamine – Wernicke-Korsakoff syndrome
Hepatic Encephalopathy
Withdrawal Damage (seizures) Delayed Alcohol Withdrawal
Watch for in hospitalized patients
Chronic Neurodegeneration
Cerebellum, gray matter nuclei
Medical / Endocrine
Thyroid dysfunction
Hypothyoidism – elevated TSH
Compensated hypothyroidism may have normal T4, FTI
Hyperthyroidism
Apathetic, with anorexia, fatigue, weight loss, increased T4
Diabetes
Hypoglycemia (loss of recent memory since episode)
Hyperglycemia
Hypercalcemia
Nephropathy, Uremia
Hepatic dysfunction (Wilson’s disease)
Vitamin Deficiency (B12, thiamine, niacin)
Pernicious anemia – B12 deficiency, ?homocysteine
Eyes, Ears, Environment
Must consider sensory deficits might contribute to the appearance of the patient being demented
Central Auditory Processing Deficits (CAPD)
Hearing problems are socially isolating
Visual problems are difficult to accommodate by a demented patient, ?To do cataract op?
Environmental stress factors can predispose to a variety of conditions
Nutritional deficiencies (tea & toast syndrome)
Neurological Conditions
Primary Neurodegenerative Disease
Diffuse Lewy Body Dementia (? 7 - 50%)
Note relation to Parkinson’s disease, symptoms
Hallucinations, fluctuating course, neuroleptic hypersensitivity)
Fronto-temporal dementia (tau gene)
Impaired attention, behavioral dyscontrol
Decrease blood flow, hypometaboism on SPECT / PET
(Pick’s disease, Argyrophylic grain disease)
Focal cortical atrophy
Primary progressive aphasia (many causes)
Unilateral atrophy, hypofunction on EEG, SPECT, PET
Normal pressure hydrocephalus
Dementia with gait impairment, incontinence
Suggested on CT, MRI; need tap, ventriculography
Other Neurologic Conditions
Subdural hematoma
Huntington’s disease
Creutzfeldt-Jakob disease
Rapid progression
Characteristic EEG changes
Multiple sclerosis
Corticobasal degeneraton
Cerebellar degeneration
Progressive supranuclear palsey
Tumor
Primary brain tumor
Meningioma (treatable)
Glioma (usually not responsive to therapy)
Metastatic brain tumor
Remote effects of carcinoma
Toxins
Heavy metal screen if considered
Trauma
Concussion, Contusion
Occult head trauma if recent fall
Subdural hematoma
Hydrocephalus:
Normal pressure (late effect of bleed)
Dementia pugilistica
Possible contributor to Alzheimer’s disease initiation and progression (? 4% of cases)
Concern re: physical abuse by caretakers
Infectious Conditions Affecting the Brain
HIV
Neurosyphilis
Viral encephalitis (herpes)
Bacterial meningitis
Fungal (cryptococcus)
Prion (Creutzfeldt-Jakob disease); (mad cow disease)