Cognitive assessment, brain networks and the dementias Professor Adam Zeman University of Exeter Medical School
Cognition, networks, dementias What is dementia? Dementia vs delirium Cortical vs subcortical dementia Cognitive Domains Networks Assessment Dementias The ACE-R/ACE-III
What is dementia? A disorder of two or more domains of cognition: memory language visuoperceptual ability Praxis abstract thinking and judgement personality social conduct Not primarily due to disordered attention Substantially impacting everyday life
Delirium vs dementia FEATURE DELIRIUM DEMENTIA Onset abrupt/sub-acute insidious Course fluctuating slow progression Duration hours-weeks months-years Alertness abnorm high or low typically normal Sleep-wake disrupted typically normal Attention impaired relatively normal Orientation impaired intact in early dement. Working mem impaired intact in early dement. Episodic mem impaired impaired Thought disorganised, delus. impoverished Speech slow/rapid, incoh. word-finding difficulty Perception illusn/halln common us. intact in early dem. Behaviour withdrawn/agitated varies: oft. intact early
Cortical vs subcortical dementia FUNCTION CORTICAL SUBCORTICAL eg AD eg MS Alertness normal slowed up Attention normal early impaired Executive ftn normal early impaired Episodic mem amnesia forgetfulness language aphasic reduced output Praxis apraxia relatively normal Perception + vis/sp impaired impaired Personality preserved (unless apathetic, inert frontal type)
Causes of dementia Inherited HD, Wilson s, leucodystrophies Primary degen Alzheimer s, Cortical Lewy Body disease, Fronto-temporal dementia Vascular multi-infarct, subcortical, strategic infarction Infective HIV, TSE, HSE, Whipple s, SSPE Inflammatory MS, vasculitis, Hashimoto s Neoplastic 1 o /2 o CNS tumours, limbic encephalitis Traumatic Post head injury Structural hydrocephalus, chronic subdurals Metabol/endoc hypothyroidism Deficiency B12/folate Sleep-related OSA Substances/drugs alcohol, anticholinergics, hypnotics etc Psychiatric depression (pseudo-dementia)
Domains and disorders Domain Network Assessment Disorder
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Daytime sleepiness: Epworth Sleepiness Scale Sitting and reading Watching TV Sitting inactive in a public place eg theatre, meeting Passenger in a car for an hour Lying down to rest in the afternoon Sitting and talking to someone Sitting quietly after lunch In a car while stopped in traffic 0 = would never dose 1 = slight chance of dosing 2 = moderate chance 3 = high chance
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Assessing attention Sustained attention: Serial 7s WORLD backwards Months backwards
Disorders of attention Sustained attention Delirium/confusional states
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Domains Consciousness Attention Memory episodic Executive function Language Perception Praxis
Memory Assessment Working (short term) memory Registration of 3 items or name and address Long term (episodic) memory Recall of 3 items or name and address after filled delay Long term (semantic memory) Naming, general knowledge
Alzheimer s disease Episodic memory impairment -> widespread cognitive decline apathy, disinhibition, agitation; psychosis; mood disturbance slowly progressive: circa 3 point MMSE decline/year pyramidal, extrapyramidal signs; primitive reflexes; epilepsy neuritic plaques: Abeta amyloid derived from APP neurofibrillary tangles: hyperphosphorylated tau Cholinergic deficit <5% autosomal dominant: presenilin 1(14), 2(1), APP (21) Apolipoprotein E alleles 2, 3 and 4; Down s syndrome; vascular risk factors CT, MRI, SPECT, PET, amyloid imaging central Achase inhibitors; memantine
Domains Consciousness Attention Memory semantic Executive function Language Perception Praxis
Memory Assessment Working (short term) memory Registration of 3 items or name and address Long term (episodic) memory Recall of 3 items or name and address after filled delay Long term (semantic memory) Naming, general knowledge
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Executive function Planning problem-solving initiation of action sequencing of action self-monitoring set-shifting social judgement empathy
Executive function: tests Verbal fluency: letter, category Luria three hand position test go - no go cognitive estimates
Frontotemporal dementia 10-15% dementia < 65 years, 25-50% familial Frontal lobe (behavioural) variant personality and behavioural change with loss of insight Temporal lobe variant L: semantic dementia R: recognition + knowledge of people Progressive non-fluent aphasia NB relative preservation of episodic memory Pathologies: tau +ve, tau -ve Imaging: focal atrophy
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Classification of dysphasia Type fluency Comprhn Reptn Naming Global + + + + Broca s + - + + Wernicke - + + + Condn - - + + Transc mot Transc sens + - - + - + - +
Frontotemporal dementia 10-15% dementia < 65 years, 25-50% familial Frontal lobe (behavioural) variant personality and behavioural change with loss of insight Temporal lobe variant L: semantic dementia R: recognition + knowledge of people Progressive non-fluent aphasia NB relative preservation of episodic memory Pathologies: tau +ve, tau -ve Imaging: focal atrophy
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Testing visual perception Overlapping pentagons cube clock face Dot counting Fragmented letters Object recognition
Posterior cortical atrophy - PCA Circa 5% AD cases have visual presentation Early onset, typically mid 50s-early 60s Mild female predominance Most common features are Alexia and agraphia Simultanagnosia Optic ataxia dorsal stream symptoms and signs predominate but both ventral and dorsal streams affected Relative preservation of memory, insight, language, executive function
Atypical presentations of AD <10% AD Posterior cortical atrophy (PCA) Almost always due to AD Slowly progressive aphasia More varied pathology Usually non-fluent, occasionally fluent in AD Slowly progressive apraxia Dysexecutive or behavioural presentation
EXECUTIVE FUNCTION Frontal lobe syndrome PRAXIS Apraxia PERCEPTUO- SPATIAL FUNCTION Agnosia Spatial disorientation MEMORY Amnesia AROUSAL LANGUAGE Aphasia Alexia Agraphia Acalculia
Domains Consciousness Attention Memory Executive function Language Perception Praxis
Testing praxis Mimes Unfamiliar hand positions Look out for: utilisation behaviour imitation behaviour alien limb
PSP + CBD PSP supranuclear gaze palsy truncal rigidity, instability, akinesia, falls bulbar features subcortical dementia mood, personality, behaviour neurofibrillary tangles (tau) in basal ganglia and brain stem MRI: midbrain atrophy CBD asymmetric limb apraxia alien limb phenomena limb myoclonus Parkinsonism cognitive impairment neurofibrillary tangles (tau) in frontal and parietal cortex and basal ganglia MRI: frontoparietal atrophy
PSP
PSP
Cognition, networks, dementias What is dementia? Dementia vs delirium Cortical vs subcortical dementia Cognitive Domains Networks Assessment Dementias The ACE-R