Dementia & Cognitive Neurology Flashcards
What are the different brain functions which together make up cognition?
Attention Social Function - i.e. how to act in situations Language Executive function - i.e. planning Memory
What criteria do patients usually meet before a diagnosis of dementia?
Cognitive decline in 1 domain (attention, executive, memory, language, praxis, social)
+ deficits interfere everyday activities/ independence
Most patients with dementia are >65 years. TRUE/FALSE?
TRUE
BUT dementia is NOT a consequence of ageing
What types of brain insult can cause acute cognitive disorders?
Viral encephalitis
Head injury
Stroke
What symptoms are characteristics of transient global amnesia?
- abrupt onset antegrade amnesia => struggle to lay down new memories
- no retrograde amnesia => preserved self knowledge
- Transient 4-6 hours (always <24 hours)
What factors are thought to trigger transient global amnesia
emotion
changes in temperature
What features characterise transient epileptic amnesia?
- Forgetful / repetitive questioning
- Carry out complex activities with no recollection
- Short lived (20 – 30 minutes)
What type of seizure is associated with transient epileptic amnesia?
Associated with temporal lobe seizures
What are the potential causes of sub-acute cognitive disorders?
Toxins Neurodegeneration e.g. CJD Metabolic: B12 Inflammatory Mood disorders Functional Infection
What is functional cognitive impairment also referred to as?
Subjective cognitive impairment
What is functional cognitive impairment?
- patient has everyday forgetfulness that is impacting on functioning
- However, they can usually hold down a higher functioning job without issue
=> symptom and function mismatch
CJD is a neurodegenerative subacute cognition problem. What is the other name for this condition and why?
Prion disease (due to defect in prion protein)
What are the 4 main types of Prion disease/CJD?
Sporadic
Variant (due to mad cow disease exposure)
Iatrogenic (growth hormone inj. from infected cadavers)
Genetic
What histological change is seen in all types of CJD?
Spongiosis
What proteinopathy is responsible for alzheimers dementia?
Amyloid protein deposition
Explain what is seen extra- and intra-cellularly in alzheimers dementia?
Extra-cellular = amyloid plaques (disrupt cholinergic pathways) Intra-cellular = neurofibrillary tangles (tau protein)
Where in the brain does alzheimers degeneration start and progress to? And what symptoms does each cause?
Degeneration of:
- medial hippocampus (forgetfulness)
- later parietal lobes (apraxia)
What would usually cause an alzheimers presentation before the age of 65?
- Genetic influences (familial)
- atypical presentation
Alzheimers cortical atrophy in this region of the brain causes difficulties in facial recognition and depth perception on stairs etc.
Posterior cortical atrophy
What are the different types of primary progressive aphasia in alzheimers?
Semantic (difficulty naming objects)
Logopenic aphasia (repeating things)
Non-fluent aphasia (staccato speech, difficult for patient)
What investigations can be carried out on suspicion of alzheimers and what do these show?
MRI: Atrophy of temporal / parietal lobes
SPECT: temporoparietal ↓metabolism
CSF : ↓amyloid as it is in plaques
How is Alzheimers disease treated?
- Address vascular risk factors
- ACh boosting medication
=> Cholinesterase inhibitors (eg Rivastigmine)
=> NMDA receptor blocker (eg Memantine)
What age group normally gets Fronto-temporal dementia?
Early onset dementia (majority <65 years old)
What features do patients with fronto-temporal dementia present with?
- disinhibition
- loss of empathy
- compulsive behaviours
- hyperorality (want to put anything in their mouth, will often continuously eat biscuits/sweet food
- Early loss of insight
What other neurological disease can be linked to fronto-temporal dementia?
MND
What investigation findings would you expect in fronto-temporal dementia?
MRI: Atrophy of frontotemporal lobes
SPECT: Frontotemporal ↓metabolism
CSF: ↑ tau / normal amyloid
How are patients with fronto-temporal dementia treated?
- Trial of Trazadone / antipsychotics to help behavioural features
- Safety management
=> Controlled access to food / money - Power of attorney
- MND nurse specialist if co-existent MND
Is vascular dementia early or late onset?
Late onset >65 yrs
How is vascular dementia diagnosed?
1) Presence of cerebrovascular disease
2) Clear temporal relationship between onset of dementia and cerebrovascular disease
What are the two main subtypes/causes of vascular dementia?
Small vessel disease
Post-stroke
How is vascular dementia treated?
Manage vascular risk factors
support through community psychiatric nurses
Dementia with lewy bodies is caused by what proteinopathy interrupting what pathways?
Alpha-synuclein
cholinergic and dopaminergic pathways
What age do patient usually develop dementia with lewy bodies?
> 65
What criteria need to be met for a diagnosis of Dementia with Lewy Bodies?
1) Fluctuating cognition AND 2) Visual hallucinations \+/- 3) Extrapyramidal features
What investigations are used in Dementia with Lewy Bodies?
Investigations: DaT scan (dopamine => used in PD)
New techniques: α-synuclein ligand imaging / α-synuclein in CSF
What treatments can be used for dementia with Lewy bodies?
- Small dose Levodopa /↓ acetylcholine
- trial cholinesterase inhibitors
- Support: PD nurse specialist / Community psychiatric nurses
How are parkinsons dementia and dementia with lewy bodies differentiated?
Patients who have had motor parkinsons symptoms for over a year before the start of their dementia are considered to have Parkinson’s dementia
Parkinsons dementia and dementia with lewy bodies are managed similarly. TRUE/FALSE?
TRUE
What are the normal symptoms of huntingtons dementia?
- Dysexecutive syndrome
- slowed speed of processing
- memory loss
- changes in mood / personality
- later psychosis
What feature of Huntingtons disease can be seen on MRI?
Loss of Caudate heads
How is Huntington’s disease treated?
- Mood stabilisers
- drugs to reduce chorea
- nurse specialist
Where should dementia patients be referred on to?
if >65 and no additional neuro features
=> Old age psychiatry
if <65 and unusual features/additional neurology
=> Neurology referral
What blood tests can be considered a “dementia screen” in a neurology clinic?
B12 TFTs syphilis/HIV Ca2+ genetics
What investigations are normally used in a neurology clinic?
- MRI (patterns of atrophy)
- SPECT imaging (metabolism)
- CSF (amyloid / tau analysis)
What is used to assess cognition in a neurology clinic?
Addenbrooke’s Cognitive Assessment
