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Flashcards in Cognitive Disorders- Dementia Types/Forms Deck (49):

Alzheimer's Disease or Dementia of the Alzheirmer's Type (DAT)

- most common etiology of dementia

- typically impacts those 65+ years

- can be difficult to diagnose


DAT diagnostic criteria

- build upon the basic criteria for diagnosing dementia

- gradual onset and progressive cognitive deterioration

- cognitive deficits are not due to: other CNS issues, systemic conditions, substance-induced conditions

- cognitive deficits are not due to an axis I disorder (schizophrenia or major depressive disorder)

- diagnosis of AD is presumptive until autopsy or brain biopsy can be completed; focus is on criteria leading to “degree of confidence”


Possible Alzheimer's Disease

- dementia in the absence of other dementia-producing causes but w/atypical onset, presentation or course

- dementia presenting with another systemic or brain disorder sufficient enough to produce dementia but which is not considered to be the cause of the dementia

- severe progressive decline of a single cognitive function in the absence of another specific cause


Probable Alzheimer's Disease

- dementia is established by clinical exam documented by mental status examinations and confirmed by neuropsychological tests

- deficits exist in 2+ areas of cognition

- progressive worsening of memory and other cognitive functions has occurred

- no disturbance of consciousness

- onset was b/w 40-90; most often after age 65

- absence of systemic disorders or other brain disease that in of themselves could account for the progressive deficits in memory and cognition


Neuropathology of DAT

- typically begins in areas most related to episodic memory

--- (perirhinal cortex, hippocampal complex in temporal lobes and basal forebrain)

- as disease worsens, changes in frontal lobe are noted and working memory is affected

- once disease gets to the temporal and parietal areas, sensory memory becomes impacted

- motor and occipital functions are typically spared

- since motor is not usually affected, speech remains intact


Motor impairments associated with DAT

- motor symptoms can develop as the disease progresses

- typical EPS s/s

--- change in muscle tone, cogwheel rigidity, postural instability and difficulty with gait

- the presence of EPS s/s are associated with greater dementia severity


Microscopic Changes with DAT

- microscopic examination of brain tissue, often postmortem reveals the presence of:

--- neuritic plaques

--- neurofibrillary tangles

--- atrophy

--- areas of granulovacular degeneration

--- amyloid deposits may also be seen in the blood vessels


Neuritic Plaques with DAT

- bits and pieces of degenerating neurons that clump together and have a beta-amyloid core

- beta-amyloid is a protein fragment that has been separated from a larger protein

- disjoined beta-amyloid fragments aggregate and mix with other molecules, neurons and non-nerve cells

- most prevalent in the outer half of the cortex where the number of neuronal connections is largest


Neurofibrillary Tangles and DAT

- disintegrating microtubules

--- microtubules are part of the internal structure of healthy neurons

- they break down due to changes in the protein tau (these stabilize the microtubules)

- as they break down they become entangled

- they are a signature morphological sign of AD


DAT and Atrophy

- shrinking of brain tissue

- may not show up on CT if Pt is in the early stages of AD

- better visualization using PET and MRI scans


Granulovacuolar degeneration and DAT

- refers to fluid-filled spaces within cells that contain granular debris

- along with all of the other microscopic changes in the brain facilitate interruption of intercellular communication and thus information processing


DAT Risk Factors

- age

- family history

- less education

- head trauma

- gender

- maternal age

- having two copies of the type 4 allele of apolipoprotein E

- having MCI


Preclinical DAT

- AD occurs many years before a clinical diagnosis is made

- cognitive decline may occur 6y before clinical diagnosis of AD

- preclinical deficits are apparent for both verbal and nonverbal information

- lower scores on measures of memory and abstract reasoning are particularly strong predictors of probable AD


Predictors of disease progression in DAT

- average duration of AD is 8y+

- more rapid decline is associated with:

--- early age at onset

--- presence of delusions or hallucinations

--- presence of EPS s/s


Cognitive/communication effects of DAT

- consistent features of AD include:

--- impairment of episodic and working memory

--- other executive function declines

- longitudinal studies using the MMSE indicate that the average amount of decline per year is 2-4 points


DAT early stage 1

- lasts from 2-4y

- caregivers report changes with:

--- difficulty handling finances

--- memory problems

--- concentration problems

--- difficulty w/complex tasks

--- forgetting the location of objects

--- decreased awareness of recent events

- mental status: disoriented for time

- motor function: good, ambulatory

- memory: problems w/episodic memory and working memory


DAT early stage 2

- basic ADLs: can complete basic ADLs

- MMSE: 16-24 points (Mini mental status exam)

- linguistic skills:

--- fluent speech

--- spelling/grammar errors are common in written language

--- increased number of empty words (thing, it)

--- anomia

--- vocabulary shrinks

--- difficulty with sarcasm and understanding jokes


DAT Middle Stage 1

- 4-10y post diagnosis

- MMSE: 8-15 points

- mental status: becomes disoriented for place and time

- motor: good, restlessness is common

- memory: episodic memory worsens, pt is easily distractible

- incontinence: mostly bladder

- basic ADLs: can complete w/supervision; managing finances and driving becomes difficult


DAT Middle Stage 2

- linguistic skills:

--- fluent speech, but is slower and halting

--- use fewer nouns than verbs

--- vocabulary continues to decrease

--- diminished comprehension of written and spoken language

--- anomia

--- difficulty repeating phrases

--- problems defining words


DAT Late Stage

- MMSE: 0-9 points

- mental status: place, time, person disorientation

- motor: impaired; some pts are non-ambulatory

- incontinence: both bowel and bladder

- basic ADLs: unable to complete

- linguistic skills:

--- fluent speech but is slow/halting w/meaningful expression reduced

--- some pts are mute; some have palilalia; some have jargon

--- reading comprehension is severely impaired

--- considerable variability exits among late-stage AD


Vascular Dementia

- VaD

- cerebrovascular disease is the second most common cause of dementia

- more common in men

- caused by disease to the smaller blood vessels of the brain

- median survival time after onset of vascular dementia is 3.3y

- has also been referenced as multi-infarct dementia

- greater risk of morbidity and mortality than AD


Neuropathology of VaD

- defined as the loss of cognitive functions to a degree that interferes w/ADLs resulting from ischemic or hemorrhagic CVD

- type of vascular disease, its location, and the amount of brain damage dictate the clinical presentation of the dementia


Major etiologic subtypes of VaD

- large vessel disease associated w/multiple infarcts in cortex, white matter, and basal ganglia

- small blood vessel disease associated w/multiple infarcts

- multilacunar state

- hypoperfusion in border zones and granular cortical activity

- post-ischemic encephalopathy


Risk Factors for VaD

- more common in males

- incidence/prevalence increases with age

- history of stroke or a first-degree relative w/a history of stroke

- poor life-style choices: dietary habits, lack of exercise, alcohol abuse and smoking

- HTN: single most important risk factor for VaD

- diabetes; 3x more likely to develop stroke-related dementia


Diagnostic criteria for possible VaD

possible VaD:

- dementia


- onset of dementia w/in 3 months of stroke

- abrupt deterioration in cognitive functions


Diagnostic criteria for probable VaD

probable VaD:

- dementia


- onset of dementia w/in 3 months of stroke

- abrupt deterioration in cognitive functions

- gait disturbance

- falls (unsteadiness)

- urinary symptoms

- personality/mood changes

- absence of other disorders capable of producing dementia


VaD impact on cognition

- no one pattern of cognitive decline

- executive dysfunction is the most common cognitive consequence of CVD whereas memory impairment is typically associated with AD


VaD impact on communication

- communicative function is impacted most in pts with VaD

- will vary depending upon the type of vascular disease

- significant aphasia

- comprehension deficits

- difficulty w/language formulation

- dysarthria

- motor weakness

- changes in pitch, melody, and rate of articulation


Mixed Dementia

- presence of both AD pathology and vascular disease

- produces earlier and more severe cognitive impairment

- shorter length of survival


Lewy Body Dementia

- possibly the second most common type of dementia

- first described in 1961

- between 15% and 25% of pts with dementia have diffuse cortical lewy bodies

- lewy body: abnormal aggregation of protein in the cell processes of neurons

- age of onset for LBD is 50-83y

- according to the LBD association, LBD is now considered a spectrum disorder; it now includes:

[1] dementia w/lewy bodies

[2] parkinson’s disease dementia


Diagnostic criteria for lewy body dementia 1

- central feature:

- essential for a diagnosis of possible or probable lewy body dementia

--- dementia defined as progressive cognitive decline that interferes w/normal social/occupational functions

--- persistent memory impairment is evident w/progression noted

--- deficits in attention, executive function, and visuospatial ability


Diagnostic criteria for lewy body dementia 2

- core feature:

- two core features are sufficient for a diagnosis of probable lewy body dementia, one for possible lewy body dementia

- fluctuating cognition w/pronounced variations in attention and alertness

- recurrent visual hallucinations that are typically well formed/detailed

- spontaneous features of parkinsonism


Diagnostic criteria for lewy body dementia 3

- suggestive features:

- reference p. 107 for criteria

--- REM sleep behavior disorder [pt acts out dreams; not paralyzed]

--- severe neuroleptic sensitivity [medication that blocks dopamine receptors]

--- low dopamine uptake in the basal ganglia


Diagnostic criteria for lewy body dementia 4

- supportive features:

- commonly present but not proven to have diagnostic specificity

--- repeated falls

--- transient LOC

--- severe autonomic dysfunction

--- hallucinations in other modalities

--- systematized delusions

--- depression


Diagnostic criteria for lewy body dementia 5

- a diagnosis of lewy body dementia is less likely if:

--- pt has CVD

--- any other illness or disorder can account for the clinical picture

--- parkinsonism only appears for the first time at the stage of severe dementia

- lewy body dementia should be:

--- diagnosed when dementia occurs before or concurrently w/parkinsonism

- parkinson disease dementia should be:

--- used to describe dementia that occurs in the context of well established parkinson’s disease


LBD vs. PD

- fluctuation of cognitive symptoms is a defining feature of lewy body dementia

- 50%+ of pts with lewy body dementia do not respond to treatment w/Ldopa

- in lewy body dementia, dementia signs precede parkinsonism

- in PD, parkinsonism signs usually precede dementia


Cognition and communication LBD

- cognitive impairment is present, severity fluctuates

- hallucinations are present

- sleep disorders, daytime drowsiness, and apathy develop

- aphasia and apraxia may appear in the later stages

- issues arise regarding fluency

- abnormal gait

- slow movements may be present


Frontotemporal Dementia

- describes a clinical syndrome associated with various degenerative conditions

- SLPs are likely to work with pts who have:

--- pick’s disease

--- primary progressive aphasia

--- semantic dementia


Pick's Disease

- behavioral component

- affects more women than men; usually in their 50s

- disease duration can last from 3-17y

- presence of pick bodies

- secondary to frontal lobe issues, changes in personality are present

- pts demonstrate: poor judgment, are emotionally blunted, compulsively explore their environment, hyperorality, altered dietary preferences, changes in sexual behavior, visual/auditory agnosia

- 78% exhibit repetitive behaviors


Cognitive changes in Pick's Disease 1

- attention deficits

- executive function issues

- some memory issues as well, however, most pts can track day-to-day events until late in the disease

- there is preservation of visuospatial abilities


Cognitive changes in Pick's Disease 2

- majority of pts w/pick’s disease do not have aphasia early in the disease

- many do develop communication disorders that take the form of nonfluent aphasia with phonological and articulatory impairments

- agrammatism is also present

- slow speech


Primary progressive aphasia (PPA)

- diagnosis is made for those that demonstrate progressive aphasia in the absence of other cognitive/behavioral problems

- although aphasia may interfere with performance on memory and reasoning tests, the pt w/PPA will have no difficulty recalling day-to-day events or in problem solving


Language characteristics of PPA

- high level of variability

- researchers usually break PPA down into the taxonomies of fluent vs. nonfluent

- kertesa, et al., (2003) examined 67 pts with PPA and found that most were fluent initially but became agrammatic and nonfluent later in the course of the disease

- some prefer to use the term “PPA” only for those individuals who are nonfluent and the term “semantic dementia” for those w/fluent aphasia

- our class will use fluent PPA and nonfluent PPA


Nonfluent PPA

- anomia

- effortful, agrammatic speech that lacks function words

- good comprehension w/the exception of more grammatically complicated sentences

- occasional oral apraxia, neurogenic stuttering, impaired repetition, dyslexia, dysgraphica, and sometimes mutism


Fluent PPA

- anomia

- poor comprehension

- normal articulation

- reading/spelling skills deteriorate

- paraphasias

- some suggest that fluent PPA is synonymous with semantic dementia


Neuropathology of PPA

- left perisylvian atrophy (most common pathology)

- nonfluent PPA: pathology is inferior frontal lobes and anterior temporal lobe

- fluent PPA: pathology is in the parietal lobe and temporal lobe

- pathology is greatest in the left hemisphere


Semantic Dementia

- pts progressively lose their semantic “conceptual” knowledge

- have difficulty understanding the meaning of words, objects, faces, nonverbal sounds, tastes, smells, etc

- nonsemantic aspects of cognition remain intact

- difficulty arises when attempting to attach meaning to perception preserved:

--- visuoperceptual and spatial abilities

--- nonverbal reasoning

--- executive functions

--- episodic memory


Language deficits in semantic dementia

- typically complaint is “loss of words”

- verbally fluent w/intact grammar and syntax

- testing reveals anomia (greater for nouns than verbs)

- comprehension deficit for single words and difficulty providing definitions

- occasionally anomia is masked in conversation by circumlocutions


Neuropathology of semantic dementia

- MRI scans reveal bilateral but asymmetric pathology of the temporal lobes w/left hemisphere more affected