Cognitive Disorders Flashcards
Benign Senescent Forgetfulness
- A mild decline in short-term memory
- Age-relaed
- Does not progress to other mental impairments
- NOT dementia
- **Difficult to partition from memory impairments secondary to polypharmacology [pt is on too many drugs]
Dementia
A decline in intellectual function (memory and other mental abilities) severe enough to interfere with a person’s relationships and ability to carry out daily activities
- cognitive impairments affecting memory and orientation plus one or more of the following problems:
- -Abstract thinking
- -Judgment/problem solving
- -Language – reduction in frequency
- -Personality
Alzheimer’s dementia
The most common dementia among older adults (50-70% of cases)
Vascular dementia
- multi-infarct or “mini” strokes
- An insidiously, subtly-progressive worsening of memory and cognition
- Due to chronic, reduced blood flow in the brain as a result of age-related vascular changes
Dementia with Lewy bodies (DLB)
- third most common cause of dementia after Alzheimer’s disease and vascular dementia
- accounting for 10-25% of cases
- Lewy bodies are also found in other brain disorders, including Alzheimer’s disease dementia and Parkinson’s disease dementia
- DLB & Parkinson’s disease dementia may be linked to the same underlying abnormalities in how the brain processes the protein alpha-synuclein
Causes of Irreversible Dementia
Alzheimer’s Disease Vascular dementia Dementia with Lewy bodies Parkinson’s Disease Huntington’s Disease HIV
Treatable, Reversible conditions that can cause dementia-like symptoms
Depression Medication side effects Drug interactions Hypothyroidism Chronic alcoholism Vitamin B12 deficiency Benign brain tumor Brain infection
Alzheimer’s Disease def
- most common form of dementia among older adults.
- involves parts of the brain that control thought, memory, and language & can seriously affect a person’s ability to carry out daily activities
- definitive diagnosis is not possible till autopsy
AD Epidemiology
- Prevalence: ~ 5 million Americans
- 7th leading cause of death in US
- ~5% older adults age 65-74 have AD
- Nearly ½ of those age 85 & older may have the disease
- Time from onset to death is typically 7-11 years
AD Lesion Site
Cerebral cortex
-Accumulation of fibrous material called amyloid
Amyloid forms “senile plaques”
AD: Histology
Amyloid Plaques
Neurofibrillary tangles
Amyloid Plaques
Abnormal clumps of protein fragments, build up between nerve cells
Found throughout the cortex
Neurofibrillary tangles
- Twisted strands of protein inside dead and dying nerve cells
- Most common in the temporal lobe structures, such as the hippocampus and amygdala
In the Alzheimer’s brain…
- The cortex “shrinks”, damaging areas involved in thinking, planning and remembering (executive functions)
- Shrinkage is especially severe in the hippocampus, an area of the cortex that plays a key role in formation of new memories
- Damage to hippocampus explains memory loss and inability to learn new things
- Ventricles become larger
Executive Functions
- used to explain certain higher-level cognitive abilities that enable an individual to successfully engage in independent goal-directed behavior
- Frontal or pre-frontal cortex: complex behavior
- Executive Functions include: Organization & Regulation
AD Progression through the brain
- Plaques and tangles tend to spread through the cortex in a predictable pattern
- The rate of progression varies-People w/ AD live an average of 7-8 years after Dx, but some may survive up to 20 years.
- The course of the disease depends in part on age at diagnosis and whether a person has other health conditions.
Early AD
-May not be detected in this stage
-Slight changes in thinking and planning & learning and memory
-before symptoms
can be detected with current tests,
plaques and tangles begin to form in
brain areas involved in higher cortical functions
Mild to Moderate AD
- generally lasts for 2-10 years
- Often definitive diagnosis in this stage
- Develop problems with memory or thinking serious enough to interfere with work or social life
- May also get confused and have trouble handling money, expressing themselves and organizing their thoughts
- Experience changes in personality and behavior & have trouble recognizing friends and family members
Mild to Moderate AD- Speech and Sensory
-Speech impairments: Speaking and comprehension
-Sensory integration: association cortex
Somatosensation deficits -> perception issues
-Visual-spatial deficits
Severe (Advanced) AD
- may last from 1-5 years
- Most of the cortex is seriously damaged
- Brain shrinks dramatically due to widespread cell death
- Individuals lose their ability to communicate, to recognize self, family and loved ones and to care for themselves
Total # of AD Stages
7
Death is often secondary to dehydration or infection
AD: Medical Diagnosis
- Physical exam
- MRI
- -Rule out other reversible causes of dementia
- -Difficult to see tangles and plaques (rather see atrophy)
- Rate of cognitive change: Progressive decline without improvement or fluctuation
- Cognitive screening test
- -Mini-Mental State Examination (MMSE)
- -Clock drawing test
- Neuropsychological testing: extremely detailed, but lengthy
Mini-Mental State Exam (MMSE)
Score: < 20/30 indicates cognitive impairment
Clock Drawing Test
Normal: If all numbers are present in the correct sequence and position, and the hands readably display the requested time
Temporal Lobe structures
Hippocampus and amygdala: STM, LTM, and working memory
AD Intervention
- No cure
- Anti-cholinesterase (may improve memory)
- Antioxidants, vitamin E to control free radical damage
- Anti-inflammatory drugs (NSAIDs)
- Experimental: Hormone replacement
- Experimental: Immunotherapy
- -Drugs may slow down the progression, but do not stop or reverse progression
PT Considerations
- Over-simplification of interventions for now
- Fall prevention
- General exercises - decreases restlessness and wandering
- Periodic intervention as decline
- pts lose motor skills ~ increased rigidity and muscle weakness
