Cognitive Disorders

Question 1

What is the frontal lobe responsible for?

Answer 1

judgement, reasoning, behaviour, voluntary movements, expressive language (Broca’s area)

Question 2

What is the temporal lobe responsible for?

Answer 2

emotions, learning and memory, audition, olfaction, language comprehension (Wernicke’s area)

Question 3

What is the parietal lobe responsible for?

Answer 3

spatial orientation, perception, initial cortical processing of tactile and proprioceptive information, language comprehension (Wernicke’s area)

Question 4

What is the occipitial lobe responsible for?

Answer 4

Vision

Question 5

Common causes of dementia?

Answer 5

• Alzheimer’s (AZ) (MC-55%)
• Vascular dementia (20%)
• Dementia with Lewy bodies
• Fronto-temporal dementia
• General medical condition + substance (e.g. alcohol) induced persisting disorders (10%)

Question 6

Reversible causes of dementia? (15%)

Answer 6

Subdural haematoma, Normal pressure hydrocephalus (NPH), Vitamin B12 deficiency, Hypothyroidism, Metabolic causes

Question 7

What are the cognitive domains?

Answer 7

Executive function, sensorimotor, attention, memory, language, intellect, emotion, visuo-spatial.

Question 8

AMTS?

Answer 8

1. Age
2. Current time (to the nearest hour)
   - Recall: Ask the patient to remember 42 West Street. Ensure they are able to say it back to you immediately, then check recall at the end of the test
3. Current year
4. Current location (e.g. name of hospital or town)
5. Recognise two people (e.g. relatives, carers, or if none around, the likely profession of easily identified people such as doctor/nurse)
6. Date of birth
7. Years of the first (or second) world war
8. Name of the current monarch (or prime minister)
9. Count sequentially backwards from 20 to 1
10. Recall 42 West Street
    A score of less than 8 in the AMTS implies the presence of cognitive impairment

Question 9

Epidemiology of Alzheimer’s Disease?

Answer 9

50% of all dementia – 500,000 people in UK. Prevalence doubles for every 5 years of age from 65 to 90. More common in females (longer life expectancy).

Question 10

Aetiology of AD?

Answer 10

Selective neuronal and synaptic loss  neurochemical abnormalities (↓Ach) and symmetrical cortical atrophy (↑in temporal and parietal lobes). Senile β-amyloid plaques and neurofibrillary tangles (tau protein). Glial proliferation, granulovascular degeneration and Hirano inclusion bodies.

Risk Factors = Age, female sex, family history, Down’s syndrome, head injury, dialysis (aluminium-containing dialysis fluids).

Protective factors = High educational attainment, healthy/engaged lifestyle (not lonely), NSAIDs, HRT, non-smoking and vitamins C and E.

Question 11

Principal features of AD? (In order of progression?

Answer 11

1. Memory Loss – short-term  impaired learning and disorientation (in time, then place and person).
2. Impaired thinking – Poor judgement, decreased fluency, dyscalculia, concrete thinking and impaired abstraction, lack of ability to plan or sequence behaviour, delusions.
3. Language impairments – Expressive/receptive dysphasia/aphasia.
4. Deterioration in personal functioning – occupational & social functioning and self-care.
5. Disturbed personality and behaviour – euphoria and emotional lability or apathy and irritability, disinhibition —> aggressive and socially inappropriate behaviour, inattention and distractibility, obsession and stereotyped behaviours.
6. Perceptual abnormalities – visual/auditory agnosia, visuospatial difficulties, body hemineglect, prosopagnosia, illusions, hallucinations, cortical blindness.
7. Motor impairments – apraxia, spastic paresis, urinary incontinence.

Question 12

5 As of AD?

Answer 12

amnesia (memory), aphasia (speech), agnosia (recognition), apraxia (doing) and associated behaviours (BPSD)

Question 13

Assessment of AD?

Answer 13

History – from patient and someone who knows them well.

Physical examination – may identify physical cause of cognitive impairment. FBC, U&Es, calcium, serum cholesterol, LFTs, TFTs, serum B12/folate, serum glucose and CXR. Neuroimaging – CT/MRI. Other tests on case-by-case basis – HIV, syphilis, vasculitic, autoimmune, neoplastic and toxicological screens, copper studies, CSF examination, genetic testing.

Neurocognitive testing – dementia screen such as MMSE/AMTS/TYM plus short tests of verbal recall (HVLT).

Question 14

Prognosis of AD?

Answer 14

Insidious and irreversible decline in cognitive function until death.

Question 15

Biological management of AD?

Answer 15

Cholinesterase inhibitors - donepezil, rivastigmine and galantamine - (↑cholinergic transmission, modestly reduce cognitive/behavioural problems in minority of patients).

NMDA receptor antagonists – memantine - blocks the effects of excess glutamate.

Benzodiazepine – anxiety and agitation.
SSRIs – depressive symptoms.

Antipsychotic – for psychosis. Should not be used to manage behavioural problems.

Question 16

Social management of AD?

Answer 16

Assess patient’s functional abilities and risk exposure. Ensure personal hygiene and adequate nutrition. Regular daily routine, environmental modifications, graded assistance, encourage physical/mental activity, memory aids. Accommodation, social isolation, financial and legal matters – power of attorney, wills etc. Carer education and support.

Question 17

Epidemiology of vascular dementia?

Answer 17

Third commonest cause – 20% of all dementias. More common in males.

Question 18

Aetiology of VD?

Answer 18

Biological – focal disease can result from single, or multiple thrombotic or embolic infarcts. Small vessel disease leads to diffuse disease (Binswanger’s disease and lacunar state).

Risk factors – old age, male sex, cardiovascular/cerebrovascular disease, valvular disease, hypercoagulation disorders, hypertension, hypercholesterolemia, diabetes, smoking, alcohol.

Question 19

Presentation of VD?

Answer 19

Classically has abrupt onset and step-wise progression. Clinical features variable and depend on location of infarcts – mood and behavioural changes common. Insight usually retained until late.

Question 20

Management of VD?

Answer 20

Same as AD – antipsychotics should be used with care so as to avoid severe extrapyramidal side-effects. Manage vascular risk factors.

Question 21

Prognosis of VD?

Answer 21

Significant comorbidity leads to shorter mean life expectancy than in AD.

Question 22

Epidemiology of Lewy Body Dementia?

Answer 22

Overlaps with AD and parkinsonian dementia. 2nd commonest cause of dementia – 20% of all cases. Onset = 50-85 years (F>M)

Question 23

Aetiology of LBD?

Answer 23

Neuropathology – Lewy bodies = intracellular eosinophilic inclusions consisting of abnormally phosphorylated neurofilament proteins aggregated with ubiquitin and alpha-synuclein. Associated neuronal loss –> ↓Ach, but minimal cortical atrophy.

Aetiology – unclear. May form part of spectrum of LB disorders that includes PD.

Question 24

Presentation of LBD?

Answer 24

Presenting Features
CENTRAL = marked fluctuations in cognitive impairment and alertness, vivid visual hallucinations and other psychotic symptoms, early parkinsonism and neuroleptic sensitivity, frequent faints and falls.

CORE = Progressive cognitive decline and prominent or persistent memory impairment are central features. Memory loss may not be a marked feature in early stages of LBD. Deficits on tests of attention, executive function and visuospatial ability.

SUGGESTIVE = REM sleep behaviour disorder, severe neuroleptic sensitivity, low dopamine transporter uptake in basal ganglia (SPECT or PET imaging – DAT scan).

SUPPORTIVE = Repeated falls/syncope, severe autonomic dysfunction, systematized delusions.

LOOKS LIKE ALZHEIMER’S BUT WITH PARKINSONIAN FEATURES AND VISUAL HALLUCINATIONS.

Question 25

Assessment of LBD?

Answer 25

Same as AD.

CT: Generalised atrophy – but 40% have preserved medial temporal lobe structures.

Question 26

Management of LBD?

Answer 26

Acetylcholinesterase inhibitors and psychosocial interventions/carer support.

Question 27

Prognosis of LBD?

Answer 27

Life expectancy from time of diagnosis = 6 years.

Question 28

Epidemiology of fronto-temporal dementia?

Answer 28

5% of all cases of dementia. More common in females, peak age of onset = 45-60.

Question 29

Aetiology of FTD?

Answer 29

selective, often asymmetrical, ‘knife-blade’ atrophy of the gyri, neuronal loss, and gliosis affecting the frontal and temporal lobes. Characteristic ‘ballooned’ neurons (Pick cells) and tau-positive neuronal inclusions called (Pick bodie)s. No senile plaques or neurofibrillary tangles.

Risk factors = unclear. Familial forms exist and are more common in people of Scandinavian descent.

Question 30

Presentation of FTD?

Answer 30

Insidious and progressive dementia characterised by early and prominent personality changes and behavioural disturbances, eating disturbances, mood changes, cognitive impairment, language abnormalities and motor signs.

Question 31

Core clinical features of FTD?

Answer 31

Core Features = Insidious onset and gradual progression, early decline in social interpersonal conduct, early impairment in regulation of personal conduct, early emotional blunting, early loss of insight

Question 32

Supportive features of FTD?

Answer 32

Behavioural - Decline in personal hygiene and grooming, mental rigidity and inflexibility, distractibility and impersistence, hyperorality and dietary changes,
perseverative and stereotyped behaviour, utilisation behaviour

Speech/Language - Altered speech output (aspontaneity and poverty of speech/pressured speech), Stereotypy of speech, Echolalia, Perseveration, Mutism

Question 33

Management of FTD?

Answer 33

No specific treatments. AChEIs unlikely to be beneficial. SSRIs of limited benefit for behavioural symptoms (disinhibition, overeating and compulsions).