Dementia — Written Clinical Reasoning

SAQ 1 — Mixed Dementia with BPSD, Polypharmacy, and Carer Strain (20 marks, 30 minutes)

Prompt: Outline your integrated assessment and management plan for this patient, including the diagnostic reasoning, the medication review, the approach to his behavioural symptoms, the discussion of driving and capacity, and the plan to support his wife. Justify each decision with reference to evidence and guideline recommendations. [1]

Model Answer

Diagnostic reasoning and problem framing (3 marks): [1]

This man has a progressive cognitive decline over 3 years, now with functional impairment and behavioural symptoms — the clinical picture is of a major neurocognitive disorder (dementia), most likely mixed Alzheimer and vascular dementia. The insidious progressive memory and executive decline over years supports Alzheimer pathology; the white matter changes on CT, the hypertension, the ischaemic heart disease, the brisk reflexes and shuffling gait, and the stepwise contribution of his recent hospitalisation all add a vascular component. Pure subtypes are uncommon in a 79-year-old — mixed dementia is the most likely real-world diagnosis. The recent urinary tract infection and the evening confusion raise the question of delirium superimposed on the dementia, but the trajectory of decline over 3 years is the underlying dementia. [1]

The problems are: [1]

1. Mixed Alzheimer and vascular dementia, moderate stage (MoCA 14, functional impairment in finances and medications).
2. Behavioural and psychological symptoms (BPSD) — evening agitation ("sundowning"), accusatory delusions (theft of the wallet), nocturnal wandering — driving carer strain and safety risk.
3. High anticholinergic and sedative drug burden — oxybutynin (a potent antimuscarinic directly opposing any cholinergic strategy), codeine (an opioid contributing to sedation, constipation, and cognitive impairment).
4. Fall risk — unsteady gait, evening agitation, nocturnal wandering, and the vasodilatory effect of amlodipine all increase fall and fracture risk.
5. Vascular risk factor management — hypertension (on amlodipine), ischaemic heart disease (on aspirin and atorvastatin), and the prevention of further cerebrovascular events.
6. Driving safety and capacity assessment — he was driving until recently and is now clearly unsafe.
7. Carer strain — his wife is exhausted and is the pillar of his community care; her health and wellbeing are central to his.
8. Advanced care planning — power of attorney, guardianship, future care preferences — to be initiated while he retains some capacity. [1]

Medication review (4 marks): [1]

This is one of the most effective interventions I can make. I will review every drug against its cognitive and functional impact: [1]

• Oxybutynin — stop it. It is a potent antimuscarinic anticholinergic with high blood-brain barrier penetration, directly worsening cognition and opposing the mechanism of any cholinesterase inhibitor I might start. For his overactive bladder, I would switch to a non-anticholinergic option (mirabegron, a beta-3 agonist) or manage with timed voiding and bladder training.
• Codeine — stop or minimise. It is an opioid causing sedation, cognitive blunting, and constipation. I would switch to regular paracetamol for his osteoarthritis, consider topical NSAIDs, and reserve a short-acting opioid only for severe pain.
• Amlodipine — review the dose. His evening agitation, his unsteadiness, and his falls raise the possibility of orthostatic hypotension (exacerbated by the vasodilatation). I would check lying and standing blood pressure, and reduce or adjust his antihypertensive to avoid hypotension — the target in dementia with falls is a balance between vascular protection and fall prevention.
• Aspirin and atorvastatin — continue. These address his ischaemic heart disease and secondary vascular prevention; statins have not been shown to worsen cognition and should not be stopped for that reason.
• Start a cholinesterase inhibitor. Donepezil 5 mg at night, increasing to 10 mg after 4 weeks, is first-line for mild to moderate Alzheimer (and has modest benefit in mixed and vascular dementia; Birks 2006, PMID 16437532). I will check a baseline ECG first (donepezil can cause bradycardia and AV block). As the disease progresses to moderate-severe, I would add memantine. [1]

Management of the behavioural symptoms (BPSD) (4 marks): [1]

I will follow the BPSD escalation ladder: [1]

Step 1 — Search for and treat precipitants. The evening agitation ("sundowning") and the recent change in behaviour may be driven by unmet needs: pain (his osteoarthritis), a recurrence of urinary symptoms (retention or infection, especially after stopping oxybutynin), constipation (from codeine), dehydration, sensory deprivation (does he have his glasses and hearing aids?), or intercurrent delirium. I will check a urinalysis, a bladder scan, a rectal examination, and a blood panel. [1]

Step 2 — Non-pharmacological measures. A structured evening routine, adequate lighting as dusk falls (to reduce sundowning), familiar objects, a clock and calendar, reassurance and redirection (not argument) around the delusional beliefs, a safe environment for nocturnal wandering (alarms on the door, a clear walkway), and increased daytime activity and light exposure to consolidate the sleep-wake cycle. [1]

Step 3 — Pharmacological treatment, targeted and time-limited. For the accusatory delusions and the evening agitation, if non-pharmacological measures and the precipitant search are insufficient and the behaviour is causing distress or risk, I would consider a time-limited trial of risperidone 0.25 mg in the evening, titrated cautiously, reviewed every 2 to 4 weeks, and stopped if ineffective — recognising the increased mortality (Schneider 2005, PMID 16234500) and stroke risk. I would first exclude Lewy body dementia (the fluctuation, hallucinations, and parkinsonism are not the dominant features here, and the shuffling gait and brisk reflexes fit the vascular picture), because an antipsychotic would be absolutely contraindicated if DLB were the diagnosis. An SSRI (citalopram) is an alternative for the agitation, with a lower side-effect burden than antipsychotics. [1]

Driving and capacity (3 marks): [1]

Driving: He is no longer safe to drive. The MoCA of 14, the impaired orientation, the visuospatial and executive impairment, the recent falls, and the nocturnal wandering all indicate that he lacks the judgement, reaction time, and attention required. In Australia, there is a legal obligation to report his condition to the licensing authority (the requirements differ by state); I would counsel him and his wife honestly, document the advice, and provide a medical certificate. I would frame the conversation compassionately and pair it with a plan for alternative transport (community transport, family) to preserve his autonomy and social engagement. [1]

Capacity: Capacity is decision-specific and time-specific. He may retain capacity to express care preferences and to appoint his wife as enduring guardian, but he clearly lacks capacity to manage his finances or to make complex medical decisions. I would assess his capacity using the functional test (understand, retain, weigh, communicate) at the best time of day (usually morning). I would facilitate the appointment of an enduring power of attorney (for financial decisions) and an enduring guardian (for health and lifestyle decisions) while he retains the capacity to participate, and I would initiate an advance care directive documenting his values and preferences. [1]

Supporting his wife (3 marks): [1]

His wife is exhausted, and carer strain is the commonest reason for institutionalisation. I would offer: [1]

• Education about the diagnosis, the trajectory, and the management — demystifying the behaviour and giving her practical strategies (the Validation technique, structured routines, managing the delusional beliefs without arguing).
• Formal carer support — a carer assessment, referral to a dementia support organisation (Dementia Australia in ANZ, Alzheimer's Society in the UK), and a carer support group.
• Respite — in-home respite, day programmes, and eventually residential respite — to give her regular breaks.
• Practical help — a community aged care package (home care package in Australia) for assistance with shopping, cleaning, medications, and personal care.
• Monitoring of her own health — carers have high rates of depression, anxiety, and physical illness; I would screen her with the Zarit Burden Interview or a depression screen and treat actively.
• A safety plan — what to do if he becomes aggressive, if he wanders and is lost (an identification bracelet or GPS tracker), or if she is unable to cope (the number for crisis respite). [1]

Prognosis and follow-up (3 marks): [1]

I would set realistic expectations: the dementia will progress, the cholinesterase inhibitor will provide a modest stabilisation rather than a reversal, and the goal is to maintain his function, safety, and quality of life and to support his wife for as long as possible. I would arrange regular review (3 to 6 monthly), a cognitive reassessment to track the trajectory, medication review at each visit, and escalation of community support as needs increase. I would discuss the eventual transition to residential care as a future possibility (not an immediate plan), so the family is prepared. The principles of the Lancet Commission (Livingston 2020, PMID 32738937) — addressing vascular risk, sensory correction, social engagement, and carer support — are the framework for the longitudinal management. [1]

SAQ 2 — Dementia with Lewy Bodies Admitted with Behavioural Disturbance (10 marks, 15 minutes)

Prompt: A 76-year-old man with an 18-month history of cognitive impairment is admitted to hospital after a fall at home. His wife reports that his thinking fluctuates markedly from day to day, that he sees people in the house who are not there, and that for the past 2 years he has shouted and thrashed in his sleep. On examination he has a mask-like face, rigidity in all four limbs, and a shuffling, festinating gait. His MoCA is 19 out of 30. On the ward, the nursing staff report that he is agitated at night and accuse them of being imposters. The registrar has written up haloperidol 2.5 mg intramuscularly for severe agitation. Outline your diagnostic reasoning, your immediate management of this situation, and your longer-term pharmacological plan. [1]

Model Answer

Diagnostic reasoning (2 marks): [1]

This man has dementia with Lewy bodies (DLB). He meets all four core clinical features of the McKeith 2017 consensus criteria (PMID 28592671): fluctuating cognition (day-to-day variation), recurrent well-formed visual hallucinations (people in the house), spontaneous parkinsonism (mask-like face, rigidity, shuffling gait), and REM sleep behaviour disorder (shouting and thrashing in sleep, preceding the cognitive symptoms by 2 years — a highly specific prodromal feature). The Capgras delusion (the belief that the nurses are imposters) is a recognised supportive feature of DLB. The one-year rule is satisfied because the parkinsonism and the cognitive impairment emerged together. [1]

Immediate management — the dangerous prescription (4 marks): [1]

The most urgent action is to cancel the haloperidol prescription. Haloperidol — and any typical or atypical antipsychotic — is absolutely contraindicated in dementia with Lewy bodies because of the risk of catastrophic neuroleptic sensitivity: severe rigidity, hyperthermia, autonomic instability, immobility, and irreversible cognitive and physical decline, sometimes after a single dose. This is the single most dangerous prescribing error in dementia medicine and a high-yield exam point. [1]

Instead, I will: [1]

1. Assess for and treat precipitants of delirium — his agitation may reflect delirium superimposed on DLB. I will check for a urinary tract infection (he fell — was there a precipitant?), pain from the fall, constipation, urinary retention, dehydration, and any newly added sedating or anticholinergic drug.
2. Use non-pharmacological de-escalation — a quiet, low-stimulation environment, reassurance and validation (acknowledging his fear without arguing with the delusion), familiar objects and family presence, and one-to-one nursing if he is at risk of falling.
3. Optimise his cholinesterase inhibitor — DLB has a profound cholinergic deficit, and cholinesterase inhibitors are particularly effective. Rivastigmine is the agent with the strongest trial evidence in DLB (1.5 mg twice daily, titrated, or the transdermal patch). If he is not already on one, I would start rivastigmine; if he is on donepezil, I would continue and optimise the dose.
4. If pharmacological treatment for the psychosis is absolutely essential (severe distress or danger unresponsive to the above), the agent with the lowest reported risk in DLB is quetiapine at a very low dose (12.5 to 25 mg), used with extreme caution, with the family informed of the risk — but the default is to avoid antipsychotics entirely. [1]

Longer-term pharmacological plan (4 marks): [1]

• Cholinesterase inhibitor — rivastigmine (first-line in DLB, with patch formulation to reduce gastrointestinal side effects) or donepezil. These improve cognition, the hallucinations, and the fluctuation in DLB more than in any other dementia subtype.
• Memantine — may be added for additional cognitive and behavioural benefit in moderate-stage DLB, with a modest evidence base.
• Levodopa for the parkinsonism — if the parkinsonism is disabling, a low-dose, cautious trial of levodopa may help, but the response is often partial and the risk of worsening the hallucinations and psychosis is significant; start low and monitor.
• Avoid all antipsychotics (especially haloperidol, risperidone, and olanzapine), anticholinergics (which worsen cognition, hallucinations, and urinary retention — oxybutynin is a particular trap), and benzodiazepines (which worsen cognition and increase falls).
• Treat constipation, autonomic dysfunction (orthostatic hypotension — midodrine or fludrocortisone), and depression — these are common supportive features that reduce quality of life.
• Advanced care planning, falls prevention, and carer support — as in SAQ 1, structured around the trajectory of DLB (slightly shorter survival than Alzheimer, high risk of falls and recurrent admissions). [1]

I would explain the diagnosis to the patient and his wife, emphasising that the hallucinations and the fluctuation are part of the illness (not separate psychiatric problems), that the antipsychotic must be avoided, and that the cholinesterase inhibitor is the cornerstone of his treatment. I would arrange review by a geriatrician or neurologist with an interest in cognitive disorders, and ensure the GP and the residential or community team are aware of the antipsychotic contraindication for every future admission. [1]