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Cognitive Disorder and dementia - Coggle Diagram
Cognitive Disorder and dementia
Definition
Dementia
Not a single disorder
Numerous potential causes, majority of which are neurodegenerative proteinopathies
General term for loss of memory, language, problem-solving and other thinking abilities that are severe enough to interfere with daily life
Mild Cognitive Impairment
MCI
A syndrome refers to a cognitive impairement that does not meet the criteria for dementia but is more than normal ageging
Characterised by measurable deficit in cognition in at least one domain in the absence of dementia or impairment in everyday functioning
Epidemiology
Leading cause of death
Early Detection
Timely diagnosis
When pt or family seeks help
To protect from harm
Appropriate invetigation and treatment
Research and trials
Support benefit and advice
Allows involvement in decisions when most able to do so
Reduces anxiety and depression
For tirals and Disease modifying treatment we need
To go earlier
Accurately diagnose underlying disease
Causes
Alzheimers 50-60%
Vascular dementia 15%
Dementia 15%
Frontotempora dementia 2-5%
Others 2%:
HIV
Head injury
Prion disease / CJD
Corticobasal degeneration
PSP
Huntington's
Alcohol related
Tumours
Infectoins
Vitamine / hormone deficiencies
History
Patient
Cognitive / Neuropsychiatric / Neuroogical Symptoms
FIRST symptoms
TEMPO of symptoms
Memory
Language
Other cognitive areas
BEhaviour
Any neurological symptoms
Medical symptoms
PMHx
Meds
Fhx - needs to be detail esp <65y/o
Sx - driving
More Detailed
Walk around the brain
Subcortical / Primary sensory
Alert / orientated
Can they hear
Left "dominant" hemisphere
Peri-Sylvian language areas
Medial temporal - verbal memory
Right temporal
Visual memory / facial recognition
Right parietal
Visuospatial / perceptual skills
Left parietal
Literacy, calculation, limb praxis, forwards digit span
Frontal
Executive function
Attention
Memory
Episodic
Elaborate examples vs the head turn sign
Insight
Rapid forgetting - repetitive questioning, failure to follow sports / current affairs / TV plots
Functional Impact - Occupational / saftey / medication / financial / forensic
Beware compensatory factors - ceiling effects / surrogate agents
Visual
Topographical disorientataion - landmark agnosia
Prosopagnosia
Language
Listen for paraphasias, agrammatism, apraxia of speech
Progressive non-fluent aphasia (PNFA): Telegramatic speech, poor multisyllabic repetition
Logopaenic aphasia (LpA): relative fluency but lng word finding pauses, elaborate circumlocation, supra-ordinal replacements, poor sentence repetition
Semantic demntia (SemD) extends byond language alone, failure of semantic memory
Visuoperceptual Function
Subtle (pinpads / mobile phones) or overt
Accompanying dominant parietal features - left right disorientation, dyscalculia
Dressing apraxia
Visual hallucinations - always ask as rarely volunteered
Forme fruste: Pareidolia, sense of passage / extracampine experiences
Praxis
Apraxia: difficulty in execution of skilled purposful movements in the absence of weakness or sensory comprehension deficits
Often referred to by the patient / informant as incoordination or disorientation
Ask re use of tools / white goods / electronic devices / mobile phones
Rare: alien limb phenomenon
Executive Function
Umbrella term: working memory, attentional flexibility, judgement, inhibitory control
Pallning / multi-tasking / distractibility
Speed of processing information
Loss of cognitive flexibility - narrowing of repertoir
Poor judgement - uncharacteristic vacillation - DLPFC
Disinhibition, hyperorality - orbitofrontal features
Lack of empathy: theory of mind - anterior cingulate
Tempo
Static
Stepwise
Fluctuant - spontanously / amplitude
Progressive - insidious or rapid
Other Symptoms
Motor Symptoms
14% MND satisfy FTD criteria at diagnosis
Further 34% have largely frontal dyssexecutive cognitive deficits
Early bulbar symptoms imply a more diffuse process than a pure cortical dementia
Extrapyramidal symptoms in DLB (but can be subtle or absent)
Myoclonus / chorea
Hyposmia or dysosmia
Hyposmia or dysosmia
Autonomic symptoms
Sleep - quality, quantitiy, parasomnias
Mood - depression, anxiety, apathy, psychotic symptoms
Family hx
25% of individuals >55y/o have a 1st degree relative with dementia
One first degree relative diagnosed <80 doubles risk
Vast majority polygenic
Mendelian AD is extremely rare but consider in multigenerational kindres with onset <60 y/o
FTD has a greater genetic basis but a monogenic basis is established in only 10-30%
Social Hx
Important to contextualised symptoms
Educational, occupational and cultural factors
Alcohol, smoking, recreational drugs, diet
Driving
Collateral
Exam
Observing Behaviour
Impulsive
Disinhibited / inappropriate
Irritable
Utilization behaviour
Apathetic or impassive (looking to partner to respond)
Eye conact
General Neurological Examination
Amyotrophy
Parkinsonism
Myclonus
Chorea
Frontal release signs
Parietal function and praxis
Gait
Frontal release signs & Executive function
Grasp
Pout
Rooting
Signe d'applause (perseveration)
Luria
Parietal Signs
Left / right orientation
Ideational praxis (mimickry)
Ideomotor praxis (pantomime
Astereognosis
Dysgraphaestheia
Cognitive Screening
MMS Mini Mental State Exam
Blunt
Biased towards attention and mnestic function
Prone to ceiling effects in early stage cognitive syndromes, and those with higher educational exposure
Montreal Cognitive Assessment (MoCA)
Somewhat robust
Includes executive funtion tests
Addenbrooke's Cognitive Examination ACE
Semi quantitive
Investigations
Initial Investigations
Bloods / Labs
FBC
Renal (Na+)
Liver (NH3)
Bone (Ca2+)
B12
Folate
TFTs
VDRL
HIV
HbA1c
Lipids
+/- auto ab screen
Specific
Imaging
Structural neuroimaging MRI Brain >> CT Brain
MRI
Potential Findings
CSF neurogenerative markers : AD signiture ↑ pTau
↑ tTau
↓ β amyloid
Functional Neuroimaging
FDG-PET brain
DaTScan
Amyloid-PET
Alzheimer's disease
Clinical presentation
Insidious onset with memory impairement
Subsequent global cognitive deficits
Nrological exam normal in early disease
Amyloid plaques & tau pos neurofibrillary tangles
Deficiency of acetylcholine biochemically
Initially hippocampal atrophy - later global cerebral artophy
Some esp younger pts present with prominent visual perceptual / visuospatial deficits - posterior cortical atrophy
Management
Risk factor modification
Lifestyle
Cognitive stimulation
Medication
Cholinesterase inhibitors - donepezil
Modest symptomatic benefit
Memantine
MX of non-cognitive symptoms (eg psychiatric) that evolve over time
Lewy Body Disease
Clinical Presentation
Insidious onset
Executive fx and posterior cortical functions also affected
Memory less affected than AD
Fluctuating cognition
Visual hallucinations
Motor features of parkinsonism (alpha-synucleinopathy)
Sensitivity to neuroleptic drugs
Management
Medication
Disease modification
Low dose levodopa - parkinsonism
Caution - visual hallucinations
Symptom control
AChE
Cognitive symptoms, fluctuations and VH
Melatonin> clonazepam for RBD
Frontotemporal dementia
Pick's Disease
Clinical Presentation
Behavioural syndrome
Personality change
Inappropriate social behaviour / disinhibition
Apathy, reduced speech
Loss of empathy
Loss of insight
Abormal eating behaviour
Executive fx decline but memory relatively preserved
Frontal and temporal lobe atrophy
Semantic dementia
Loss of knowledge of concepts
Leadsto difficulty with naming and understanding speech
Speech is empty with circumlocution
Progressive non-fluent aphasia
Difficulty with speech production
Comprehension intacts
Management
Medication
Symptom Control
Mood
SSRI
Trazadone
Mood stabilising AEDS used for impulsivity
no evidence base for bvFTD
Lifestyle / OT
Behavioural modification techniques
Vascular Dementia
Presentation
Step-wise progression OR insidious onset
Focal neurological signs / symptoms
May be a contributing pathology
~
Other Causes of Dementia
Metabolic
Vit B / folate deficiency
Hypothyroidism
Wilson's disease
Inflammation / Infection
HIV
MS
Vasculitis
Autoimmune
Degenerative
Huntington's disease
Parkinson's plus disease
Prion disease
Structural
Chronic subdural haematoma
Brain tumour
Other
SEizure
Chronic alcohol abuse - Korsakoff syndrome
Genetics
Consider in cases with mutigenerational pedigree esp young age of onset
C1% AD Mendelian inheritance : APP, PSEN1, PSEN2
FTD more heritable than other dementias (10-30%) mutations MAPT, GRN, C9orf72
Young Onset
Prevalence
AD
FTD
AD most common byt up to 40% will ahve variant presentation - behaviour-dysexecutive AD / logopaenic aphasia / posterior cortical atrophy
Genetic aetiology more common but still rel rare 10%
Greater carer burder and psychosocial implications
Rapidly Progressive Dementia
Subacute onset weeks-months
Autoimmune encephalitis
Prion disease
Infx eg neurosyphilis
Vasculitis
Toxic / nutritional eg Korsakoff's
Disease Modifying Tx for AD
Lecanemab
Clears up amyloid protein build-up