Cognitive Disorders Flashcards
What are the 4 things cognitive disorders affect?
What do they result from?
- Cognitive disorders affect
- Memory
- Orientation
- Attention
- Judgment
- Result from primary or secondary abnormalities of the CNS
What are the main categories of cognitive disorders?
- Dementia
- Delirium
- Amnestic disorders
What is the Mini Mental State Exam (MMSE)?
- Used to assess a patient’s current state of cognitive functioning
- Can be used as a daily barometer to evaluate interval changes but should NOT be used to make a formal diagnosis
What does the MMSE test? How is it scored?
- Tests
- Orientation
- Registration
- Attention & calculation
- Recall
- Language
- Perfect score: 30
- Dysfunction: <25
Dementia vs. Delirium
- Dementia: memory impairment
- Delirium: sensorium impairment
What is Dementia?
What does it affect?
- Impairment of memory & other cognitive functions w/o alteration in the level of consciousness
- Most forms progressive & irreversible
- Major cause of disability in the elderly
- Affects memory, cognition, language skills, behavior & personality
Dementia
What is the incidence?
What is associated with it?
- Incidence increases w/ age
- 20% of people >80 yo have a severe form of dementia
- Delusions & hallucinations in 30% of pts
- Affective symptoms (depression/anxiety) in 40-50% of pts
- Personality changes common
What are the 3 most common causes of dementia?
- Alzheimer’s disease (50-60%)
- Vascular dementia (10-20%)
- Major depression (“pseudodementia”)
What are the 3 categories of differential diagnoses for dementia?
- Psychiatric
- Organic
- Drugs
What is the psychiatric differential for dementia?
- Depression (pseudodementia)
- Delirium
- Schizophrenia
- Malingering
What is the organic differential for dementia?
-
Structural
- Benign forgetfulness of normal aging, Parkinson’s disease, Huntington’s disease, Down’s syndrome, head trauam, brain tumor, normal pressure hydrocephalus, multiple sclerosis, subdural hematoma
-
Metabolic
- Hypothyroidism, hypoxia, malnutrition (B12, folate, thiamine deficiency), Wilson’s disease, lead toxicity
-
Infectious
- Lyme disease, HIV dementia, Creutzfeldt-Jakob disease, neurosyphilis, meningitis, encephalitis
What is the minimum workup to exclude reversible causes of dementia?
- CBC
- Electrolytes
- TFTs
- VDRL/RPR
- B12 & folate levels
- Brain CT or MRI
What is the drug differential for dementia?
- Alcohol (chronic & acute)
- Phenothiazines
- Anticholinergics
- Sedatives
Differential & diagnostic test for scenario
Dementia with stepwise increase in severity + focal neurologic signs
Multi-infarct dementia
CT/MRI
Differential & diagnostic test for scenario
Dementia + cogwheel rigidity + resting tremor
Lewy body dementia, Parkinson’s disease
Clinical
Differential & diagnostic test for scenario
Dementia + ataxia + urinary incontinence + dilated cerebral ventricles
Normal pressure hydrocephalus
CT/MRI
Differential & diagnostic test for scenario
Dementia + obesity + coarse hair + constipation + cold intolerance
Hypothyroidism
T4, TSH
Differential & diagnostic test for scenario
Dementia + diminished position and vibration sensation + megaloblasts on CBC
Vitamin B12 deficiency
Serum B12
Differential & diagnostic test for scenario
Dementia + tremor + abnormal LFTs + Kayser-Fleischer rings
Wilson’s disease
Ceruloplasmin
Differential & diagnostic test for scenario
Dementia + diminished position & vibration sensation + Argyll-Robertson Pupils (Accommodation Response Present, response to light absent)
Neurosyphilis
CSF fluorescent treponemal antibody absorption test (CSF FTA-ABS) or CSF VDRL
What is the hallmark of delirium?
What can it be caused by?
What is the prognosis?
- Hallmark of delirium
- Waxing/waning of consciousness
- Can be caused by virtually any medical disorder
- High mortality rate if untreated
- Can last days to weeks, can be chornic
What is the DSM-IV criteria for delirium?
2 types of delirium
-
Quiet
- Pt may seem depressed or exhibit symptoms similar to failure to thrive
- MMSE must be done to distinguish from depression and other diagnostic criteria
-
Agitated
- Obvious pulling out lines; may hallucinate
How is delirium treated?
- Rule out life-threatening causes
- Treat reversible causes
- Example: hypothyroidism, electrolyte imbalance, UTIs
-
Antipsychotics first line
- Quetiapine (Seroquel)
- Haloperidol PO/IM - don’t use IV unless on cardiac monitor b/c can cause TdP
- Positive/negative use of benzos
- Paradoxical disinhibition
- Respiratory depression
- Increased risk for falls
- 1:1 nursing for safety
- Frequently reorient patient
- Avoid napping
- Keep lights on, shades open during the day
- In your orders, write “hold for sedation” after medication order so medications are not given when already sedated & calm
What is the pneumonic for the delirium differential?
AEIOU TIPS
- Alcohol
- Electrolytes
-
Iatrogenic
- Anticholinergics, benzos, anti-epileptics, BP meds, insulin, hypoglycemics, narcotics, steroids, H2 receptor blockers, NSAIDs, antibiotics, antiparkinsonians
-
Oxygen hypoxia
- Bleeding, central venous, pulmonary
- Uremia/hepatic encephalopathy
- Trauma
- Infection
- Poisons
- Seizures (post-ictal)
Delirium vs. Dementia
- Definition
- Onset
- Duration
- Orientation
- Memory
- Hallucinations
- Symptoms
- Reversibility
- Awareness
- EEG
-
Delirium
- Clouding of consciousness
- Acute onset
- 3 days - 2 wks
- Orientation impaired
- Immediate/recent memory impaired
- Visual hallucinations common
- Symptoms fluctuate, worse at night
- Usually reversible
- Awareness reduced
- EEG changes (fast waves or generalized slowing)
-
Dementia
- Loss of memory/intellectual ability
- Insidious onset
- Lasts months to yrs
- Orientation often impaired
- Recent & remote memory impaired
- Hallucinations less common
- Symptoms stable throughout the day
- 15% reversible
- Awareness clear
- No EEG changes
_______ is the most common dementia (80%)
Alzheimer’s disease
Alzheimer’s Disease
- Incidence
- Women vs. Men
- Average life expectancy
- ___% of pts have a family hx
- 5% of all people >65 yo
- 15-25% of all people >85 yo
- Women >> men
- Average life expectancy: 8 yrs after diagnosis
- 40% of pts have a family hx
What are the clinical manifestations of Alzheimer’s disease?
- Gradual progressive decline of cognitive functions (memory & language)
- Personality changes
- Mood swings
What is the DSM-IV criteria for Alzheimer’s Disease?
Memory impairment plus at least 1 of the following:
-
Aphasia
- Disorder of language affecting speech & understanding
-
Apraxia
- Inability to perform purposeful movements
-
Agnosia
- Inability to interpret sensations correctly (visual agnosia: can’t recognize previously known object)
-
Diminished executive functioning
- Problems w/ planning, organizing, abstracting
*personality/mood changes: depression, anxiety, anger, suspiciousness are common; psychotic symptoms such as paranoia are common
Alzheimer’s patients have decreased levels of _____ and _____.
-
Acetylcholine
- Loss of noradrenergic neurons in the locus ceruleus of the brainstem
-
Norepinephrine
- Preferential loss of cholinergic neurons in the basal nucleus of Meynert of the midbrain
What is the gross pathology of the brain of an Alzheimer’s patient?
diffuse atrophy
enlarged ventricles
flattened sulci
What is the microscopic pathology of the brain of an Alzheimer’s patient?
- Senile plaques composed of amyloid protein
- Neurofibrillary tangles derived from Tau proteins
- Neuronal & synaptic loss
What is the only way to definitively diagnose Alzheimer’s disease?
pathological examination of the brain at autopsy
How is Alzheimer’s disease treated?
- No cure or truly effective treatment
- Physical & emotional support, proper nutrition, exercise & supervision
- NMDA receptor antagonists: memantine
- Cholinesterase inhibitors to help slow progression
- Tacrine (Cognex)
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Treatment of symptoms as necessary
- Low-dose, short-acting benzodiazepines for anxiety
- Low-dose antipsychotics for agitation/psychosis (quetiapine)
- Antidepressants for depression (if pt fulfills criteria for major depression)
What is vascular dementia?
What is the process of function loss?
- Caused by microvascular disease in the brain that produces multiple small infarcts
- Substantial infarct burden must accumulate before dementia develops
- Classically, patients have a stepwise loss of function
What are the clinical manifestations of Vascular Dementia?
- Memory impairment and at least 1 of the following must be present:
- Aphasia
- Apraxia
- Agnosia
- Diminished executive functioning
- Personality changes: depression, anger, suspiciousness are common; psychotic symptoms such as paranoia are common
What is mild cognitive impairment characterized by?
normal daily function but abnormal memory for age
most progress to Alzheimer’s
Vascular dementia vs. Alzheimer’s
- Since vascular dementia is caused by small brain infarcts, pts have focal neurological symptoms
- Hyperreflexia, paresthesias
- VD onset more abrupt than Alzheimer’s
- Greater preservation of personality in VD
- Can reduce risk by modifying risk factors
- Smoking, HTN, DM
How is vascular dementia diagnosed?
How is it treated?
- MRI
- No cure or truly effective treatment
- Physical & emotional support, proper nutrition, exercise, supervision
- Treatment of symptoms as necessary
What are the clinical manifestations of Pick’s Disease/Frontotemporal Dementia (FTD)?
- Rare cause of slowly progressing dementia
- Hallmarks: aphasia, apraxia, agnosia
- Difficult to distinguish from Alzheimer’s clinically, but personality & behavioral changes are more prominent early in the disease
What is the pathology of FTD?
- Atrophy of frontotemporal lobes
-
Pick bodies
- Intraneuronal inclusion bodies
- Not necessary for diagnosis
How is FTD treated?
- No effective treatment
- Physical, emotional & nutritional support
- Treat emotional/behavioral symptoms as needed
What is Huntington’s Disease?
- Autosomal dominant disorder
- Results in progressively disabling cognitive, physical & psychological functioning
- Ultimately results in death after approx 15 yrs
What are the clinical manifestations of Huntington’s Disease?
- Onset: 35-50 yrs of age
- Hallmarks
- Progressive dementia
- Bizarre choreiform movements (dancelike flailing of arms & legs)
- Muscular hypertonicity
- Depression & psychosis very common
What is the pathology of Huntington’s disease?
How is it diagnosed?
What is the treatment?
- Trinucleotide repeat on short arm of chr 4
- Primarily affects basal ganglia
- MRI shows caudate atrophy (sometimes cortical atrophy)
- Genetic testing & MRI are diagnostic
- No effective treatment, supportive only
Cortical vs. Subcortical dementias
-
Cortical dementias: decline in intellectual functioning
- Alzheimer’s disease
- Pick’s disease
- CJD
-
Subcortical dementias: more prominent affective & movement symptoms
- Huntington’s disease
- Parkinson’s disease
- NPH
- Multi-infarct dementia
What is Parkinson’s disease?
- Progressive disease w/ prominent neuromal loss in substantia nigra, which provides dopamine to the basal ganglia, causing physical & cognitive impairment
- 30% of pts develop dementia
What are the clinical manifestations of Parkinson’s disease?
- Bradykinesia
- Cogwheel rigidity
- Resting tremor - “pill-rolling” tremor most common
- Masklike facial expression
- Shuffling gait
- Dysarthria (abnormal speech)
- 50% of pts suffer from depression
- Dementia symptoms resemble Alzheimer’s
What is the etiology of Parkinson’s disease?
- Idiopathic (most common)
- Traumatic
- Drug or toxin-induced
- Encephalitic
- Familial (rare)
What is the pathology & pathophysiology of Parkinson’s disease?
- Loss of cells in the substantia nigra of the basal ganglia leads to decrease in dopamine & loss of the dopaminergic tracts
How is Parkinson’s disease treated pharmacologically?
-
Levodopa
- Degraded to dopamine by dopadecarboxylase
-
Carbidopa
- Peripheral dopadecarboxylase inhibitor prevents levodopa from being converted to dopamine before it reaches the brain
-
Amantadine
- Mechanism unknown
-
Anticholinergics
- Help relieve tremor
-
Dopamine agonists
- Bromocriptine, etc.
-
Monoamine oxidase B inhibitors (selegiline)
- Inhibit breakdown of dopamine
How do levodopa & carbidopa interact with the BBB?
-
Levodopa
- Crosses the BBB
- Free to convert to dopamine once it corsses the BBB
-
Carbidopa
- Does NOT cross the BBB
- Prevents conversion of levodopa to dopamine in the periphery
How is Parkinson’s disease treated surgically?
Thalamotomy or pallidotomy may be performed if no longer responsive to pharmacotherapy
What is Creutzfeldt-Jakob Disease (CJD)?
- A rapidly progressive, degenerative disease of the CNS caused by a prion
- Inherited, sporadic or acquired
- Small percentage of patients have become infected through corneal transplants
What are the clinical manifestations of CJD?
How quickly do these symptoms occur?
- Rapidly progressive dementia 6-12 mo after onset of symptoms
- >90% of patients have myoclonus (sudden spasms of muscles)
- Extrapyramidal signs, ataxia, LMN signs
- Long latency period btwn exposure & disease onset
What are prions?
- Proteinaceous infectious particles that are normally expressed by healthy neurons of the brain
- Accumulations of abnormal forms of prions are responsible for disease
What are other examples of prion diseases?
- Kuru
- Gerstmann-Straussler syndrome
- Fatal familial insomnia
- Bovine spongiform encephalopathy
- “Mad cow disease”
What is the gross pathology of CJD?
- Spongiform changes of cerebral cortex
- Neuronal loss
- Hypertrophy of glial cells
How is CJD diagnosed? (definitive vs. probable)
- Definitive - pathological demonstration of spongiform changes of brain tissue
-
Probable - presence of both rapidly progressive dementia & periodic generalized sharp waves on EEG plus at least 2 of the following:
- Myoclonus
- Cortical blindness
- Ataxia, pyramidal signs, extrapyramidal signs
- Muscle atrophy
- Mutism
What is the treatment & course of CJD?
- No treatment
- Relentless course
- Progressing to death usually w/i a year
What is Normal Pressure Hydrocephalus?
What is the etiology?
- Reversible cause of dementia
- Enlarged ventricles w/ increased CSF pressure
- Etiology
- Idiopathic
- Secondary to obstruction of CSF reabsorption sites due to trauma, infection, hemorrhage
What is the clinical triad of NPH?
- Gait disturbance (often appears first)
- Urinary incontinence
- Dementia (mild, insidious onset)
How is NPH treated?
relieve increased pressure w/ shunt
of the clinical triad, dementia least likely to improve
What is delirium?
acute disorder of cognition related to impairment of cerebral metabolism
Unlike demented patients, delirious patients have…..
- Rapid onset of symptoms
- Periods of altered levels of consciousness
- Potential reversal of symptoms w/ treatment of the underlying cause
How do delirious patients appear clinically?
- Appear confused
- Have a fluctuating course w/ lucid intervals
- May be either stuporous or agitated
- Perceptual disturbances (hallucinations) common
- Pts often anxious, incoherent, unable to sleep normally
What are the common causes of delirium?
- CNS injury or disease
- Systemic illness
- Drug abuse/withdrawal
- Hypoxia
What are some additional causes of delirium?
- Fever
- Sensory deprivation
- Medications
- Anticholinergics
- Steroids
- Antipsychotics
- Antihypertensives
- Insulin
- Post-op
- Electrolyte imbalances
What is the differential diagnosis for delirium?
- Dementia
- Fluent aphasia (Wernicke’s)
- Acute amnestic syndrome
- Psychosis
- Depression
- Malingering
What is the acronym for causes of delirium?
I’M DELIRIOUS
- Impaired delivery (of brain substrates, such as vascular insufficiency due to stroke)
- Metabolic
- Drugs
- Endocrinopathy
- Liver disease
- Infrastructure (structural disease of cortical neurons)
- Renal failure
- Infection
- Oxygen
- Urinary tract infection
- Sensory deprivation
How is delirium treated?
- First & foremost: treat the underlying cause!
- Provide physical & sensory support
- Treat drug withdrawal
- Treat symptoms of psychosis (low-dose antipsychotic) and insomnia (sedative-hypnotic)
What is the diagnosis & testing for this scenario?
Delirium + hemiparesis or other focal neurological signs & symptoms
Cerebrovascular accident (CVA) or mass lesion
Brain CT/MRI
What is the diagnosis & testing for this scenario?
Delirium + elevated BP + papilledema
Hypertensive encephalopathy
Brain CT/MRI
What is the diagnosis & testing for this scenario?
Delirium + dilated pupils + tachycardia
Drug intoxication
Urine toxicology screen
What is the diagnosis & testing for this scenario?
Delirium + fever + nuchal rigidity + photophobia
Meningitis
Lumbar puncture
What is the diagnosis & testing for this scenario?
Delirium + tachycardia + tremor + thyromegaly
Thyrotoxicosis
T4, TSH
What is the acronym for treatment of delirium?
FEUD
- Fluids/Nutrition
- Environment
- Underlying cause
- Drug withdrawal
Avoid using ___________ in delirious patients, as they will often exacerbate delirium.
benzodiazepines
What are amnestic disorders?
- Impairment of memory w/o other cognitive problems or altered consciousness
- Always occur secondary to an underlying medical condition
What are causes of psychiatric disorders?
- Hypoglycemia
- Systemic illness (like thiamine deficiency)
- Hypoxia
- Head trauma
- Brain tumor
- CVS
- Seizures
- Multiple sclerosis
- Herpes simplex encephalitis
- Substance use (alcohol, benzodiazepines, medications)
What is the course & prognosis of amnestic disorders?
- Variable depending on underlying medical cuase
-
Usually transient w/ full recovery
- Seizures, medication-induced
-
Possibly permanent
- Hypoxia, head trauma, herpes simplex encephalitis, CVA
How are amnestic disorders treated?
- Treatment of underlying cause
- Supportive psychotherapy if needed (to help patients accept their limits & understand their course of recovery)
