Neurology - Memory Impairment Flashcards
Most common cause of dementia in the UK.
- Alzheimer’s disease
- Vascular dementia
- Lewy body dementia
Assessment tools recommended by NICE for dementia screening.
- 10 point cognitive screener (10-CS)
- 6-item cognitive impairment test (6-CIT)
- Mini-Cog
6-CIT test for dementia screening.
An MMSE score of __ out of 30 suggests dementia.
<24
Reversible causes of memory decline.
- hypothyroidism (TFTs)
- anaemia & infection (FBC)
- U&Es (uraemia, AKI)
- hypercalcaemia (calcium)
- hypoglycaemia (glucose)
- hyperbillirubinaemia (LFTs)
- B12 / folate deficiency
Risk factors for Alzheimer’s disease.
- increasing age
- family history of Alzheimer’s disease
- Down’s syndrome
Macroscopic changes seen in Alzheimer’s disease.
Widespread cerebral atrophy, particularly involving the cortex and hippocampus.
Microscopic changes seen in Alzheimer’s disease.
Hyperphosphorylation of tau protein results in deposition of beta-amyloid plaques and neurofibrillary tangles.
Biochemical changes seen in Alzheimer’s disease.
Deficit of acetylcholine.
Non-pharmacological management of Alzheimer’s disease.
Say you will write to patient’s GP and get social prescriber involved.
- NICE recommend offering ‘a range of activities to promote wellbeing that are tailored to the person’s preference’
- NICE recommend offering group cognitive stimulation therapy for patients with mild and moderate dementia
- other options to consider include group reminiscence therapy and cognitive rehabilitation
First line treatment for Alzheimer’s disease.
Acetylcholinesterase inhibitors.
Donepezil; Galantamine; Rivastigmine
Second line treatment for Alzheimer’s disease.
Memantine (NMDA receptor antagonist) used instead of or in adjunct to acetylcholinesterase inhibitors.
Should you prescribe antidepressants for moderate depression in patients with dementia?
No - NICE do not recommend.
Should you prescribe antipsychotics in Alzheimer’s dementia?
Only use when patients are at high risk of harming themselves or others.
Or where distress is severe.
Contraindications of donepezil.
Bradycardia
Adverse effects of donepizil.
Insomnia
Subtypes of vascular dementia.
- stroke related BD (multi-infarct)
- subcortical VD (small vessel disease)
- mixed dementia (VD + alzheimers)
Risk factors for vascular dementia.
- history of stroke / TIA
- atrial fibrillation
- hypertension
- diabetes mellitus
- hyperlipidaemia
- smoking
- obesity
- coronary heart disease
- family history of stroke / cardiovascular disease
Presentation of VD.
Several months of years of a history of sudden or stepwise deterioration of cognitive function:
- visual disturbance, sensory or motor symptoms
- difficulty with attention / concentration
- seizures
- memory disturbance
- gait disturbance
- speech disturbance
- emotional disturbance
Non-pharmacological management of VD.
Tailored to the individual
Include: cognitive stimulation programmes, multisensory stimulation, music and art therapy, animal-assisted therapy
Managing challenging behaviours e.g. address pain, avoid overcrowding, clear communication
Pharmacological management of VD.
No specific pharmacological management of VD - no evidence aspirin is effective.
Only consider AChE inhibitors or memantine for people with VD + comorbid dementia.
Pathophysiology of Lewy-Body dementia.
Lewy body deposition in:
- substantia nigra
- paralimbic areas
- neocortical areas
Features of Lewy body dementia (LBD).
- progressive cognitive impairment
- fluctuating cognition
- parkinsonism
- visual hallucinations
How is Lewy body dementia and Parkinson’s disease dementia differentiated?
Parkinson’s disease dementia: motor symptoms present for at least one year before cognitive symptoms.
LBD: cognitive impairment typically occurs before Parkinsonism
Diagnosis of Lewy body dementia.
- usually clinical
Management of LBD.
- Acetycholinesterase inhibitors (rivastigmine, donepizil)
- NMDA antagonist (memantine)
What drugs are contraindicated in Lewy body dementia?
Neuroleptics (e.g. haloperidol) - as patients are extremely sensitive and may develop irreversible Parkinsonism.
What is frontotemporal lobar degeneration?
Third most common type of cortical dementia.
Types of FTLD.
- frontotemporal dementia (Pick’s disease)
- chronic progressive aphasia (CPA)
- semantic dementia
Common features of FTLD.
- onset before 65
- insidious onset
- relatively preserved memory and visuospatial skills
- personality change
- social conduct problems
Macroscopic changes seen in Pick’s disease.
- atrophy of frontal and temporal lobes
Microscopic changes seen in Pick’s disease.
- Pick bodies
- gliosis
- neurofibrillary tangles
- senile plaques
Features of Pick’s disease.
- personality change
- impaired social conduct
- hyperorality
- disinhibition
- increased appetite
- perseveration behaviour
Management of Pick’s disease.
Do NOT recommend AChE inhibitors or memantine.
Pathophysiology of Parkinson’s disease.
Progressive degeneration of dopaminergic neurons in the substantia nigra, resulting in reduced dopamine output.
Triad of features of Parkinson’s disease.
- bradykinesia
- tremor
- rigidity
Features of Parkinson’s disease - bradykinesia.
- poverty of movement also seen, sometimes referred to as hypokinesia
- short, shuffling steps with reduced arm swinging
- difficulty in initiating movement
Features of Parkinson’s disease - tremor.
- most marked at rest, 3-5 Hz
- worse when stressed or tired, improves with voluntary movement
- typically ‘pill-rolling’, i.e. in the thumb and index finger
Features of Parkinson’s disease - rigidity.
Lead pipe rigidity: constant resistance to motion throughout entire range of movement.
Cogwheel rigidity: resistance that stops and starts as the limb is moved through its range of motion.
Psychiatric features associated with Parkinson’s disease.
- depression
- dementia
- psychosis
- sleep disturbance
Autonomic dysfunction associated with Parkinson’s disease.
- postural hypotension
Drug-induced parkinsonism has slightly different features to Parkinson’s disease.
- motor symptoms are generally rapid onset and bilateral
- rigidity and rest tremor are uncommon
If there is difficulty differentiating between essential tremor and Parkinson’s disease, NICE recommend which imaging/
Single photon emission computed tomography (SPECT)
First line treatment of Parkinson’s disease
a) troublesome motor symptoms
b) no motor symptoms that are troublesome
a) levodopa
b) dopamine agonist, MAO-B inhibitors
Adverse effects of medications used to treat Parkinson’s disease.
- excessive sleepiness
- hallucinations
- impulse control disorders
Levodopa and MOA-B inhibitors usually better tolerated than dopamine antagonists.
If a patient with Parkinson’s disease continues to have symptoms despite optimal levodopa treatment, what do NICE recommend?
Addition of:
- MAO-B inhibitor
- COMT inhibitor
- dopamine agonist
What is co-prescribed with levodopa?
Decarboxylase inhibitor (e.g. carbidopa).
Prevents the peripheral metabolism of levodopa to dopamine outside of the brain, therefore reduced the side effects.
Common side effects of levodopa.
- dry mouth
- anorexia
- palpitations
- postural hypotension
- psychosis
Risk of acutely stopping levodopa.
Acute dystonia.
If the patient cannot take medication orally, they can be given a dopamine agonist patch as rescue medication.
What is an acute dystonia?
Acute withdrawal of dopamine results in painful and involuntary muscular contractions.
Causes of acute dystonias.
- acutely stopping levodopa
- antidopaminergic agents
- dopamine receptor antagonsits (e.g. metoclopramide, haloperiodol)
Treatment of acute dystonia.
- urgent senior input
- IV medication (benzodiazepines and anticholinergics)
- terminate or reduce triggering medication
What is the role of anti-muscarinics in Parkinson’s disease?
Block cholinergic receptors to help tremor and rigidity.
Usually used to treat drug-induced Parkinsonism rather than idiopathic Parkinson’s disease.
What medication can be prescribed to manage salivation in Parkinson’s?
Glycopyrronium bromide.
Causes of thiamine deficiency.
Alcoholism most common.
Rarer causes include:
- persistant vomiting
- stomach cancer
- dietary deficiency
What is Wernicke’s encephalopathy?
Neuropsychiatric disorder caused by thiamine deficiency.
Classic triad of Wernicke’s encephalopathy.
- nystagmus
- gait ataxia
- encephalopathy (ie. confusion, disorientation, inattentiveness)
Treatment of Wernicke’s encephalopathy.
Urgent replacement of thiamine.
Relationship between Wernicke’s encephalopathy and Korsakoff syndrome.
Korsakoff syndrome - untreated Wernicke’s can result in permanent antero- and retrograde amnesia, plus confabulation.
