6. Major and minor neurocognitive disorders (Dementia): etiology, diagnostic criteria, and clinical management Flashcards
Neurocognitive disorder def
a group of conditions defined by a decline from a previous level of cognitive functioning.
six cognitive domains that may be affected in neurocognitive disorders
1) Complex attention
*
2) Executive function
*
3) Learning and memory
4) Language
*
5) Perceptual-motor skills
*
6) Social cognition (interaction
The DSM-5 divides the NCDs into
three main categories:
* delirium,
* minor NCDs, and
* major NCDs (dementia).
Minor NCDs
individuals with mild cognitive impairment.
These individuals have trouble with some of the more complex activities of living but are able to maintain their independence
Major NCDs
: these individuals require assistance with independent activities of daily living (e.g., paying bills, managing medications, or shopping for groceries).
Over time, the basic activities of daily living (e.g., feeding, toileting, and bathing) are affected, eventually leading to total dependence.
The dementias are —- and —–
progressive and irreversible major NCDs that primarily affect the elderly.
what is dementia
Dementia is not a disease,
but rather a set of symptoms comprising poor memory, and difficulties with learning and language.
dementia dsm5
name other major NCDs present similarly to the dementias, but their progression may be arrested or even reversed with treatment
- vitamin B12 deficiency,
- thyroid dysfunction)
Pseudodementia def
- symptoms of major depression in the elderly often include problems with memory, concentration, and cognitive functioning.
- Because this clinical picture may be mistaken for a major NCD (dementia), it is termed pseudodementia; the presence of apparent cognitive deficits in patients with major depression.
Diagnosis dementia
- Mini Mental State Exam (MMSE):
*Assess orientation, attention/concentration, language, constructional ability, immediate and delayed recall - Mini-Cog: item recall (3 items) and clock-drawing tasks
Mini Mental State Exam (MMSE is sensitive for which NCDs
Sensitive for major NCDs (dementias), particularly moderate-to-severe forms
Maximal score: 30,
dysfunctional score: < 25
etiology of dementia
- Alzheimer’s disease (most common)
- Vascular dementia
- Lewy body dementia
- Frontotemporal dementia
- Prion disease
- Normal pressure hydrocephalus
- HIV infection
Alzheimer’s disease characteristics
Gradual progressive decline in cognitive functions; primary domains affected are memory, learning, and language
etiology of alzheimers
Accumulation of
* extra-neuronal beta-amyloid plaques and
* intra-neuronal tau protein tangles
→ result in brain atrophy
Alzheimer’s disease types
o Sporadic type: 95%
▪Late onset
▪Genetic and environmental factors
o Familial type:
▪Early onset
▪Dominant gene
Alzheimer’s disease treatment
o Cholinesterase inhibitors (rivastigmine, galantamine)
o NMDA receptor antagonist (memantine)
o Supportive care via behavioral, social, and environmental interventions
Lecanemab
Vascular dementia how does it happen
Cognitive decline 2° to: large vessel strokes, small vessel strokes, or microvascular disease affecting the periventricular white matter
oLong-term poor blood flow to the brain → ischemic stroke → permanent tissue damage
▪The brain tissue liquefies → liquefactive necrosis
▪As a result, there is a loss of mental function
which cognitive domains are lost in vascular dementia
Complex attention and executive function are the cognitive domains typically affected in small vessel disease
in vascular dementia Symptoms vary depending on
the region of damage
Vascular dementia treatment
o
Prevent further strokes
o
Supportive and symptomatic care
eg. prevent Hypertension
Lewy body dementia
Lewy bodies (accumulation of alpha-synuclein) in the brain, primarily in the basal ganglia
which cognitive domain affective in lewy body dementia
Waxing and waning of cognition esp
attention and alertness
symptoms in lewy body dementia
- Visual hallucinations (usually vivid, colorful, well-formed images)
- REM sleep behavior disorders
- Called Lewy body dementia if there is development of extrapyramidal signs (Parkinsonism) and cognitive decline start less than 1 year apart
Lewy body dementia treatment
o Cholinesterase inhibitors → for cognitive and behavioral symptoms
o Quetiapine or clozapine → for psychotic symptoms
o Levodopa-carbidopa → for Parkinsonism
o Melatonin or clonazepam → for sleep disorder
Frontotemporal dementia
- Marked atrophy of the frontal and temporal lobes (visible on brain imaging)
- Early changes in personality and behavior
Frontotemporal dementia subtypes
o Behavioral variant: disinhibited verbal, physical, or sexual behavior
o Language variant: difficulties with speech and comprehension
Frontotemporal dementia treatment
o Symptom-focused approach
o Serotonergic medications (SSRIs) → may help reduce disinhibition, anxiety, impulsivity, and repetitive behavior
Prion disease what is it
Subacute spongiform encephalopathy caused by proteinaceous infectious particles
The most common type is Creutzfeldt-Jakob disease
Prion disease onset
Insidious onset with rapidly progressive cognitive decline
prion disease symptoms
- Difficulties with concentration, memory, and judgment occur early
- More than 90% of patients experience myoclonus
- nystagmus, and hypokinesia (due to Basal ganglia and cerebellar dysfunction)
Prion disease: definitive diagnosis done by
brain tissue analysis (biopsy or autopsy)
Prion disease treatment
no effective treatment is available; most patients die within 1 year of diagnosis
Normal pressure hydrocephalus
*
Enlarged ventricles with an episodic elevation of CSF pressure
Normal pressure hydrocephalus etiology
*
Idiopathic
or
secondary to obstruction of CSF reabsorption sites
Normal pressure hydrocephalus Characteristic triad of:
1) gait disturbance
2) urinary incontinence
3) cognitive impairment → executive dysfunction, psychomotor retardation
Normal pressure hydrocephalus treatment
o
Lumbar puncture
o
Ventriculoperitoneal shunt
HIV infection
The most common infectious agent to cause cognitive impairmen
HIV infection: neurocognitive impaiment presentation
Variable presentation depending on the part of the brain affected
in HIV infection congntive impairement
Decline may be observed in
executive functioning,
attention,
working memory and
motor activity
HIV infection treatment
antiretroviral therapy
