w4: Vascular dementia & Frontotemporal dementia Flashcards
vascular dementia definition
Vascular Dementia (VaD) is a type of dementia caused by reduced blood flow to the brain, leading to damage in brain regions responsible for cognitive functions.
vascular cognitive impairments definition
Vascular Cognitive Impairment (VCI) is a broader term encompassing all forms of cognitive decline due to vascular brain damage, ranging from mild impairment to severe dementia.
Vascular Dementia - DSM-5
A. the criteria are met for major or mild neurocognitive disorder
B.clinical features are consistent w vascular etiology suggested by:
- cognitive deficit onset related to one or more cerebrovascular event
- decline is complex in attention- including processing speed- and frontal-executive functions
C. evidence of presence of cerebrovascular disease from history, physical examination, neuroimaging
D. symptoms not better explained by other disease or systemic disorder
Cerebrovascular Events
There is a huge number of blood vessels in your brain, and if something goes wrong it can lead to vascular dementia.
vascular dementia is the result of cerebral vascular pathology
Neuropathology Vascular Dementia
no definitive pathological criteria - diff from alzh
underlying cerebrovascular pathology is expansive- result of diffuse injury
difficult to define gold standard.
features- presence of:
- small or large vessle disease
- white matter lesions
- infrarcts
- lacunes
absence of:
confounding pathologies
- neurofibilary tangles, amyloid pl, lewy bodies
Causes Vascular Dementia
Large Vessel Disease:
Stroke (ischemic or haemorrhagic).
Blockage in major arteries, causing infarcts.
Small Vessel Disease:
Chronic narrowing of small blood vessels.
Leads to lacunar infarcts and white matter lesions.
Mixed Pathology:
Combination of vascular pathology and Alzheimer’s disease processes.
White Matter Lesions
= damage in the brain’s white matter
Key Features:
Varied and diffuse: not confined to specific regions.
White matter hyperintensities (leukoaraiosis):
Common in older adults, especially those with vascular risk factors (e.g., hypertension, diabetes).
Visible as hyperintensities on MRI scans.
Diffuse demyelination: Damage to the myelin sheath that insulates nerve fibres, impairing communication between brain regions.
Causes:
Chronic ischemia (lack of blood flow).
Stroke or lacunes (small, localised areas of tissue death due to blockages in tiny blood vessels).
Stroke (Ischaemic)
occlusion of major cerebral blood vessle or a series of small cerebral blood vessles
due to:
- acute blockage due to embolism
- thickening of the vascular wall
Haemorrhagic Stroke
rupture of large or small cerebral blood vessle
**Large vessel stroke or large vessel disease **
- One or more arteries supplying blood to the brain rupture or experience blockage.
- Effects are relatively focal.
**Small vessel stroke/ disease or lacunar stroke **
- Blockage of the cerebral microvessles – strongly associated with hypertension
- Effects are relative diffuse- because of the build up of dsamage in small vessels.
- = more often associated with vascular dementia.
Vascular Dementia - the result of
- extensive white matter lesions and lacunar infarcts due to small vessle disease = VaD has slow gradual onset, gradual decline
OR
- one or more strokes to the main cebrebral arteries (large vessel disease)
= VaD has an abrupt onset and stepwise decline
OR.
combination of 1 and 2
Clinical Manifestation VaD
heterogeneity is the rule = all different
- contrast to alzh
neuropsychological manifestation is driven by extent of focal and diffuse vascular lesions- what is affected depends on what area and how much of it is affected.
CLinical Manifestation
Middle cerebral artery
- hemiplegia -Paralysis of one side of the body
- aphasia - Impairment of language abilit
- hemianesthesia -Loss of sensation on one side of the body
Clinical Manifestation
Anterior Cerebral Artery
- paraplegia -Paralysis of the lower half of the body
- abulia -lack of willpower or motivation
- executive dysfunctions -higher-order cognitive processes like planning
- personality changes - Alterations in behaviour, emotional responses
clinical manifestations
posterior cerebral artery
- alexia with or without agraphia
with:Inability to read and write
without:Inability to read while retaining the ability to write - visual agnosia - Inability to recognise or interpret visual information
- balint syndrome - inability to percieve multiple objects, inability to reach for objects
- prosopagnosia - recognise familiar faces
People with vascular dementia can have impairments in:
- Learning or memory
- Executive functions.
- Attention
- Language
- Visuoperceptual function
- Psychomotor skills
Impairments in attention and executive functions are most salient.
- Impaired performance on test of:
- Planning
- Set-shifting
- Inhibition
- Selective attention
- Information processing
other typical features VaD
Language
- Naming difficulties- worsen as vascular dementia progresses
Visuoperceptual skills:
- Impaired performance on visual organisation tasks
Psychomotor function:
- Impaired performance on test of psychomotor speed
Neuropsychiatric disturbances:
not everyone will develop this but some might.
- depression
- anxiety
- apathy
Alzh vs Vad
alzh:
onset: gradual
memory: early episodic loss
executive function: impaired later
attention: preserved early
imaging: atrophy in hippocampus
progression: stedy decline
Vad:
onset:absrupt/ stepwise
memory: mild impairment initiallt
executive function: early impairment
attention: early impairment
imaging: ischemic lesions, white matter changes
progression: stepwise decline
VaD AND Alzh
Post-mortem findings: pathology of alzh disease is relatively common in people with vascular dementia.
mixed dementia.
plaques and tangles
when one or more strokes occurm less pathology is needed to cause dementia
Risk Factor VaD
- age
- diabities
- hypertension
- cerebrovascular fragility
- genetics (vacular dementia = CADASIL gene)
- cardiovascular disease
- cardiac arrhythmis
= all because reduced blood flow and therefore oxygen to brain.
Frontotemporal Dementia (FTD)
Frontotemporal Dementia (FTD), also called Frontotemporal Lobar Degeneration, is a progressive neurodegenerative disorder primarily affecting the frontal and/or temporal lobes.
Previously known as Pick’s Disease, first described by Arnold Pick in 1892.
Key Features FTD
Common in younger individuals, often affecting those under 65 years.
Mean age of onset: 52–56 years.
More prevalent than Alzheimer’s in people under 60.
Caused by the inclusion of Pick bodies (tau-positive protein aggregates).
Pathological Causes FTD
- Prick Bodies- intracellular inclusions composed of hyperphosphorylated tau protein.
Impact:
Disrupt normal neuronal functioning.
Commonly found in the frontal and temporal lobes, aligning with the areas of atrophy in FTD.
Distinct from tau pathology in Alzheimer’s, as Pick bodies are more localised.
Frontal Lobe Atrophy: Loss of executive functions: planning, decision-making, and judgement
Temporal Lobe Atrophy: Loss of semantic memory, Language production and fluency issues in non-fluent primary progressive aphasia.
Frontotemporal Dementia- subtypes
Frontotemporal dementia:
- behavioural or dysexecutive variant
- primary progressive aphasia
primary progressive aphasia (further subtypes)
- semantic
- logopenic
- non-fluent / agrammatic
Frontotemporal dementia- DSM-5
A. the critria are met for major or mild neurocognitive disorder
B. the disturbance has insidious onset and gradual progression.
C. either 1 or 2:
1. behavioural variant:
three or more of the following behavioural symptoms
- behavioural disihibition
- apathy or inertia
- loss of sympathy or empathy
- perseverative, stereotyped or compulsive/ ritualistic behavois
- hyperorality and dietary changes
prominent decline in social cognition and/ or executive abilities
- language variant:
- prominent decline in language ability, in the form of speech production, word finding, object naming, grammar, or word comprehension
D. Relation sparing of learning and memory and perceptual-motor function
E. The disturbance is not better explained by cerebovascular disease, another neurodegenerative disorder.