dementia Flashcards
what is dementia
- Not specific disease, umbrella term
- Affects ≥2 domains of cognition
- Memory, language, attention, problem solving
- Many causes
- Endocrine, AD, hypothyroidism
- Static or progressive
- Occur at any age
- Need occur ≥ 6mnths
- Otherwise is just delirium
AD
- Specific disease
- Progressive disease
- Sx:
- Dementia + neuropsychiatric sx
- Old age (predominantly)
DSM5 dementia definition
major & minor
- Evidence of sig/ modest cognitive decline from prior level of performance in one or more cognitive domains
* Complex attention, executive function, learning & memory, language, perceptual-motor, social cognition
* Concern of the indiv, a knowledgeable informant or clinician there has been a significant/ mild decline in cognitive function
* A substantial/ modest impairment in cognitive performance preferably documented by standardised neuropsychological testing or in its absence other quantified clinical assessment - Cognitive deficits interfere with independence in everyday activities
- Cognitive deficits do not occur exclusively in the context of delirium
- Cognitive deficits are not better explained by another mental disorder
types of dementia
- Alzheimer’s disease (Slow gradual onset)
○ Brain atrophy (mesial temporal lobe)
○ Neuritic plaques (b-amyloid)
○ Neurofibrillary tangles (phospho TAU) - Vascular dementia
○ Cognitive impairment after vascular impairment (stroke)
○ Small, chronic infarcts/ large infarct (hemorrhage) - Lewy body dementia
○ Brain atrophy. Generalised (PD: substantia nigra) - Frontotemporal dementia
○ Focal brain atrophy affecting frontal/ anterior temporal lobes - Mixed type
manifestation of dementia
cognitive
(memory, attention, language, problem solving)
EARLY
* ST memory loss
* Word-finding difficulty
LATER
* Memory loss, unable to process and store info
* Loss of language, comprehension (aphasia)
manifestation of dementia
psychological
EARLY
* Apathy
* Depressive sx
LATER
* Delusions
* Anosognosia
manifestation of dementia
behavioural
EARLY
* Withdrawal from social engagement
* disinhibition
LATER
* agression
* hallucination
* wandering
manifestation of dementia
sleep
EARLY
* REM behavioural disorder
LATER
* altered sleep-wake cycle
manifestation of dementia
physical
EARLY
* gait impairment
* falls
LATER
* repititve, purposeless movements
* parkinson
* seizure
risk factors of AD
- Age >85yo
- Female
- Ethnicity: black, Hispanic
- Genetics: apoliprotein E (APOE4) gene
non-modifiable
* Hypertension
* DM
* Binge drinking
* Smoking
* Limited physical activities
* Obesity
* Hearing loss
* Depression
AD pathological characteristics
1) senile plaques
2) neurofibrillary tangles
senile plaque
- Aggregates AB-amyloid peptide
- APP (amyloid precursor protein) cleaved by:
- B- secretases (longer amino peptide length, more sticky)
◊ Forms plaque
◊ Very inflammatory, fibrosis - Y-secretases (soluble fragments)
neurofibrillary tangles
- TAU: tubulin associated protein (needed for microtubule stabilisation and intracellular transport)
□ Hyper-phosphorylated TAU protein aggregates
□ form paired helical filaments (PHF)
□ Less intracell transport = NEURON DEATH
loss of microtubules
AD brain atrophy
- Areas critical to cognition (neocortex, hippocampus)
- neurodegeneration
* involve neurons of multiple neurotransmitters (cholinergic, 5HT, glutamatergic, DA)
* neurochemical deficits and alterations
neurochemical deficit
- Eg: tryptophan hydroxylase immunoreactive (serotonergic) neurons
* Reduced in dorsal raphe nucleus (DRN) of AD - Mainly cholinergic systems in AD
* Central cholinergic neurons project to widespread areas of cortex
◊ Role: learning, attentional processes
* Degeneration in central cholinergic system in AD (nucleus basalis –> neocortex)
presentation of AD from neurochemical deficits & alterations
- psychiatric: behavioural abnormality
- neuropsychiatric: psychiatric behaviour that occur due to struc abnormality
* AD primary cause
impact of AD
- Caregiver distress – neuropsychiatric sx of AD
- Progressive loss of cognitive functions
* Memory, learning, thinking, personality, self
Brief cognitive screening tools
- Mini mental state examination (MMSE)
- Orientation
- Registration
- Attention and calculation
- Recall
- Language
- Copying
- montreal cognitive assessment (MoCA)
AD stage score
- MMSE (out of 30)
- Mild: 20-24
- Mod: 10-19
- Severe: <10
- MoCA (montreal cognitive assessment)
- Mild: 18-25
- Mod: 10-17
- Severe: <10
what tests to dx of AD
- PMH (pt, fam)
- Cognitive deficits
* Mini mental state examination (MMSE), neuropsychological test
* Functional deficits (ADL) - physical exam
* neurologic sign (cognitive impair, focal signs, parkinsonism)
* pertinent systemic signs (vascular, metabolic) - Lab:
* CSF
* Blood biomarkers of AB and pTAU (not routine)
* TFT, vit B12
* metabolic, infectious, autoimmune, other tests - struc imaging:
* CT, MRI – exclude other brain pathologies
* Hippocampus, neocortex shrink
struc imaging differentials
- AD: generalised, focal cortical atrophy. Often asymmetrical (hippocampal atrophy)
- Shrinkage of cerebral cortex
- Shrinkage of hippocampus
- Enlarged ventricles
- Vascular: brain infarcts, white matter lesions
- Frontotemporal: frontal lobe or anterior temporal lobe atrophy
- Abnormalities: brain mass (tumor), hydrocephalus
AD management goals
- Slow progression (reduce cognitive decline and preserve function)
- Delay need to institutionalise
- Manage behavioural sx of AD
- Support & educate caregiver
- Unable to modify disease