Geriatrics Flashcards
A 72-year-old man who has recently been diagnosed with vascular dementia seeks advice on how to treat his new diagnosis.
He has a past medical history of high cholesterol, atrial fibrillation and currently smokes 10 cigarettes per day.
What is the best intervention?
Smoking cessation
Tight control of vascular risk factors, rather than antidementia medication, is recommended by NICE in vascular dementia
Smoking is a risk factor for vascular dementia and so stopping smoking will be most beneficial for him. NICE recommend tight control of vascular risk factors, rather than anti-dementia medication.
Which of the following would represent a relative contraindication to donepezil prescription?
Donepezil is generally avoided (relative contraindication) in patients with bradycardia and is used with caution in other cardiac abnormalities
Which other medication if present on the patients repeat prescription may represent the strongest potential contraindication to donepezil?
One of the important possible side effects of the acetylcholinesterase inhibitors (donepezil, rivastigmine and galantamine) is bradycardia (or SA block or AV block). Hence these medications might be contraindicated or should be started with caution in patients with conduction abnormalities or those already taking negatively chronotropic medications such as beta blockers, rate-limiting calcium channel blockers or digoxin. Other possible side effects include gastrointestinal effects (nausea, vomiting, anorexia, diarrhoea), agitation, hallucinations, syncope; and less commonly gastrointestinal ulcers, seizures, conduction disorders, urinary retention and extrapyramidal symptoms. Neuroleptic malignant syndrome is also listed in the BNF as a very rare adverse reaction.
Observations all lie in the normal range.
What is the most likely cause of this woman’s confusion?
Constipation can cause delirium in the elderly
Vascular dementia
Stepwise deterioration in cognitive function? - think vascular dementia
The stepwise deterioration in cognitive function along with risk factors for cerebrovascular disease (hypertension and smoking) point towards a diagnosis of vascular dementia. In this case, cognitive impairment is caused by ischaemia or haemorrhage secondary to cerebrovascular disease.
Lewy body dementia
typically presents with fluctuating cognition in contrast to other forms of dementia
Unlike other forms of dementia, it presents with a fluctuating pattern of confusion, especially in regard to attention and executive functioning. Sleep disturbance, visual hallucinations and parkinsonism may also be present. This patient will of course need formal cognitive testing, relevant blood tests and a CT head scan to exclude other diagnoses. SPECT imaging may also be considered if there is still uncertainty as it is both highly sensitive and specific for Lewy body dementia.
Difference 1. Dementia with Lewy bodies (DLB).
2. Parkinson’s disease dementia.
in Parkinson’s disease dementia the tremor, bradykinesia, and rigidity will develop before dementia. In DLB, the opposite is true and this is the key to this question. Other clues that point towards DLB include the ‘periods of confusion and sleepiness that seemed to come and go at random’ referring to fluctuating cognition and ‘his wife tells you that she has slept in a separate bed for the last 30 years because her husband suffers from bad nightmares’, which is alluding to the REM-sleep disorder that is a distinctive feature of DLB. Patients and their partners may report violently acting out their dreams as many as 40 years before the onset of the dementia symptoms.
Alzheimer’s disease dementia
classically presents as slowly worsening memory loss and forgetfulness that progresses to affect speech, orientation, and concentration. It is not associated with tremor, fluctuating cognition, or REM-sleep disturbances.
Frontal lobe dementia
Frontal lobe dementia classically presents primarily with behavioural changes and reckless behaviour. It is not associated with tremor, fluctuating cognition, or REM-sleep disturbances.
Vascular dementia
classically presents as a step-wise decline in cognitive function associated with a series of cerebrovascular events. Vascular dementia does not fluctuate. It is not associated with tremor, fluctuating cognition, or REM-sleep disturbances.
ACE-3
ACE-3 is a validated tool that is both sensitive and specific for the detection of dementia. A score of 82 or less strongly suggests dementia.
The domains tested are Memory, Attention, Fluency, Language and Visuospatial.
People with Alzheimer’s dementia show a global deficit in all of the domains. Later, particular deficits might be seen in memory and attention, in keeping with damage to the medial temporal lobe.
Those with frontotemporal dementia will show deficits in fluency and language, reflecting primarily damage to the frontal lobe.
Vascular dementia deficits will depend on if there was a previous stroke and the location of this damage. Because of this variability, and the fact that vascular dementia often co-exists with other types, there is no consistent pattern seen in ACE-3 examinations.
Mild cognitive impairment (MCI) is a prodromal phase to many forms of dementia that includes a cognitive deficit but normal functioning. An ACE-3 score of 82-88 suggests MCI. As the patient in this scenario had a score of 68, the diagnosis is not MCI.
People with Parkinson’s dementia often show deficits in the visuospatial domain as well as memory and attention.
In view of his dementia, which one of the following medications should you consider stopping?
Amitriptyline
There are multiple causes of dementia as outlined below, the majority of which are progressive and irreversible. There are medications that can be used to slow progression, but as clinicians we also have a responsibility to ensure that our patients aren’t taking medications which may make things worse.
The STOPP-START Criteria (Gallagher et al., 2008) outlines medications that we should consider withdrawing in the elderly. One example of this is the use of tricyclic antidepressants in patients with dementia, due to the risk of worsening cognitive impairment.
Which of the following best describes the mechanism of action of memantine?
NMDA receptor antagonist
Delirium
involves an impairment of conscious level and often involves psychotic symptoms
A 76-year-old woman is diagnosed with Alzheimer’s disease. Which one of the following could be a contraindication to the prescription of donepezil?
Donepezil is generally avoided (relative contraindication) in patients with bradycardia and is used with caution in other cardiac abnormalities
Sick sinus syndrome. Donepezil, a cholinesterase inhibitor, is commonly used in the management of Alzheimer’s disease. However, it can increase vagal tone and cause bradycardia. In patients with sick sinus syndrome - a group of heart rhythm disorders where the sinus node doesn’t work properly - this could lead to severe symptomatic bradycardia or even sinus arrest. Therefore, donepezil should be used with caution in these patients.
