Neurology Flashcards
Define Alzheimer’s disease?
Alzheimer’s disease (AD) is a progressive degenerative disease of the brain accounting for the majority of dementia seen in the UK
What are the risk factors for Alzheimer’s disease?
Increasing age
Family history
Inherited autosomal trait
Apoprotein E allele E4
Caucasian ethnicity
Down syndrome
What autosomal dominant traits are associated with an increased risk of Alzheimer’s disease?
Mutations in:
- The amyloid precursor protein (chromosome 21)
- Presenilin 1 (chromosome 14)
- Presenilin 2 (chromosome 1) genes
What genetic condition is associated with an increased risk of Alzheimer’s disease?
Down syndrome
What macroscopic pathological changes are seen in Alzheimer’s disease?
Widespread cerebral atrophy, particularly involving the cortex and hippocampus
What microscopic pathological changes are seen in Alzheimer’s disease?
Cortical plaques due to deposition of type A-Beta-amyloid protein and intraneuronal neurofibrillary tangles caused by abnormal aggregation of the tau protein
Hyperphosphorylation of the tau protein has been linked to AD
What biochemical pathological changes are seen in Alzheimer’s disease?
There is a deficit of acetylcholine from damage to an ascending forebrain projection
What are some non-pharmacological managements of Alzheimer’s disease?
A range of activities to promote wellbeing that are tailored to the person’s preference
Group cognitive stimulation therapy for patients with mild and moderate dementia
Group reminiscence therapy and cognitive rehabilitation
What pharmacological management can be given for mild to moderate Alzheimer’s disease?
Donepezil, Galantamine and Rivastigmine
What types of drugs are donepezil, galantamine and rivastigmine?
Acetylcholinesterase inhibitors
What second line pharmacological management can be given for Alzheimer’s disease?
Memantine
What type of drug is memantine?
NMDA receptor antagonist
Under what conditions can the second line pharmacological management be used for Alzheimer’s disease?
For moderate Alzheimer’s who are intolerant of, or have a contraindication to, acetylcholinesterase inhibitors.
As an add-on drug to acetylcholinesterase inhibitors for patients with moderate or severe Alzheimer’s.
Monotherapy in severe Alzheimer’s
What feature would contraindicate use of donepezil?
Bradycardia
What is an adverse effect of donepezil?
Insomnia
List some causes of Parkinsonism?
Parkinson’s disease
Drug-induced e.g. antipsychotics, metoclopramide*
Progressive supranuclear palsy
Multiple system atrophy
Wilson’s disease
Post-encephalitis
Dementia pugilistica (secondary to chronic head trauma e.g. boxing)
Toxins: carbon monoxide, MPTP
What is the cause of parkinsonism?
Parkinson’s disease is a progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the substantia nigra.
What is the classic triad of parkinson’s disease?
The reduction in dopaminergic output results in a classical triad of features: bradykinesia, tremor and rigidity.
The symptoms of Parkinson’s disease are characteristically asymmetrical.
Describe the bradykinesia seen in Parkinson’s disease?
Poverty of movement also seen, sometimes referred to as hypokinesia
Short, shuffling steps with reduced arm swinging
Difficulty in initiating movement
Describe the tremor seen in Parkinson’s disease?
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
What are some other ‘axillary’ characteristics seen in Parkinson’s disease?
Mast-like facies
Flexed posture
Micro-graphia
Drooling of saliva
Impaired olfaction
REM sleep disturbance
Fatigue
Postural hypertension
What is the first line management for Parkinson’s disease if motor symptoms are affecting the quality of life?
Levodopa nearly always combined with a decarboxylase inhibitor (e.g. carbidopa or benserazide)
Why is levodopa combined with a decarboxylase inhibitor for Parkinson’s therapy?
This prevents the peripheral metabolism of levodopa to dopamine outside of the brain and hence can reduce side effects
List some common side effects of levodopa?
Dry mouth
Anorexia
Palpitations
Postural hypotension
Psychosis
What pharmacological agent can be given for excessive salivation in Parkinson’s disease?
Glycopyrronium bromide
What pharmacological agent should be considered if a patient with Parkinson’s disease develops orthostatic hypotension? What is the mechanism of this drug?
Midodrine - acts on peripheral alpha-adrenergic receptors to increase arterial resistance
What pharmacological agent should be considered if excessive daytime sleepiness occurs in a patient with Parkinson’s disease?
Modafinil
What is the first line management for Parkinson’s disease if motor symptoms are NOT affecting the quality of life?
Dopamine agonist (non-ergot derived)
Levodopa
Monoamine oxidase B (MAO-B) inhibitor
List some dopamine receptor agonists that are used in the treatment of Parkinson’s disease?
Bromocriptine
Ropinirole
Cabergoline
Apomorphine
What investigations should be organised before prescribing ergot-derived dopamine receptor agonists?
Echocardiogram
ESR
Creatinine
Chest x-ray
Due to being associated with pulmonary, retroperitoneal and cardiac fibrosis
What class of Parkinson’s drugs have potential for impulse control disorders?
Dopamine receptor agonists
What is the mechanism of action of MAO-B inhibitors? Give an example of this class of drug?
Monoamine Oxidase-B inhibitors work by inhibiting the breakdown of dopamine secreted by the dopaminergic neurones.
Selegiline
Give some examples of COMT inhibitors for Parkinson’s disease?
Entacapone
Tolcapone
What is the mechanism of action of COMT inhibitors?
Catechol-O-Methyl Transferase inhibitors - an enzyme involved in the breakdown of dopamine, and hence may be used as an adjunct to levodopa therapy
What anti-muscarinics can be used in drug-induced Parkinson’s disease?
Procyclidine
Benzotropine
Trihexyphenidyl (benzhexol)
What is ‘end-of-dose’ wearing off phenomenon in Parkinson’s disease management?
Symptoms often worsen towards the end of dosage interval. This results in a decline of motor activity
What is ‘on-off phenomenon’ in Parkinson’s disease management?
Large variations in motor performance, with normal function during the ‘on’ period, and weakness and restricted mobility during the ‘off’ period
What side-effects may be seen at peak dose of levadopa?
Dystonia, chorea and athetosis (involuntary writhing movements)
What is Huntington’s disease?
Huntington’s disease is an inherited neurodegenerative condition.
It is a progressive and incurable condition that typically results in death 20 years after the initial symptoms develop.
In what pattern is the gene for Huntington’s disease inherited?
Autosomal dominant fashion
What type of genetic disease is Huntington’s disease?
Trinucleotide repeat disorder: repeat expansion of CAG
As Huntington’s disease is a trinucleotide repeat disorder, the phenomenon of anticipation may be seen, where the disease is presented at an earlier age in successive generations
What is the genetic mechanism of Huntington’s disease?
Due to defect in huntingtin gene on chromosome 4
Results in degeneration of cholinergic and GABAergic neurons in the striatum of the basal ganglia
What are the classical features of Huntington’s disease?
Typically develop after 35 years old:
Chorea
Personality changes (e.g. irritability, apathy, depression and intellectual impairment)
Dystonia
Saccadic eye movements
What is motor neurone disease?
Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs.
What are the main types of motor neurone disease?
Amyotrophic lateral sclerosis
Primary lateral sclerosis
Progressive muscular atrophy
Progressive bulbar palsy
In what motor neurone disease is there a potential genetic component and what chromosome does the gene in question reside on?
Amyotrophic lateral sclerosis - in familial cases the gene responsible lies on chromosome 21 and codes for superoxide dismutase
What does UMN sign mean?
Upper motor neurone (UMN) signs are a set of symptoms that can indicate a lesion in the brainstem, cerebral cortex, or spinal cord.
What does LMN sign mean?
Lower motor neurone (LMN) signs are a set of symptoms that can indicate a lesion in the lower (anterior horn cell, motor nerve roots or peripheral motor nerve) motor neurones.
List some classical UMN signs?
Disuse atrophy (minimal) or contractures
Increased tone (spasticity/rigidity) +/- ankle clonus
Pyramidal pattern of weakness (extensors weaker than flexors in arms, and vice versa in legs)
Hyperreflexia
Upgoing plantars (Babinski sign)
List some classical LMN signs?
Marked atrophy
Fasciculations
Reduced tone
Variable patterns of weakness
Reduced or absent reflexes
Downgoing plantars or absent response
What would the pattern of signs be in ALS?
LMN signs in arms and UMN signs in legs
What would the pattern of signs be in PLS?
UMN signs only
What would the pattern of signs be in PMA?
LMN signs only
Affects distal muscles before proximal
What would the pattern of signs be in PBP?
Palsy of the tongue
Muscles of chewing/swallowing and facial muscles due to loss of function of brainstem motor nuclei
Which subclass of motor neurone disease carries the worst and best prognosis?
Progressive muscular atrophy - best prognosis
Progressive bulbar palsy - worst prognosis
A motor neurone disease with mixed UMN and LMN signs would be which subtype?
Amyotrophic lateral sclerosis
A motor neurone disease with UMN signs only would be which subtype?
Primary lateral sclerosis
A motor neurone disease with LMN signs only and affects distal muscles before proximal ones would be which subtype?
Progressive muscular atrophy
Palsy of the tongue, muscles of chewing/swallowing and facial muscles due to loss of function of brainstem motor nuclei would be which motor neurone disease?
Progressive bulbar palsy
What symptoms are ‘spared’ in motor neurone disease?
Doesn’t affect external ocular muscles
No cerebellar signs
Abdominal reflexes are usually preserved
Sphincter dysfunction if present is a late feature
What is the pharmacological management for motor neurone disease?
Riluzole
Prolongs life for about 3 months
What is the mechanism of action of riluzole?
Prevents stimulation of glutamate receptors
What is the non-pharmacological management for motor neurone disease?
Non-invasive ventilation (usually BIPAP) is used at night (survival benefit - 7 months)
PEG tube for nutritional support
What is multiple sclerosis?
Multiple sclerosis is chronic cell-mediated autoimmune disorder characterised by demyelination in the central nervous system
What is relapsing-remitting multiple sclerosis?
Acute attacks (e.g. last 1-2 months) followed by periods of remission
Most common form (85%)
What is secondary progressive multiple sclerosis?
Describes relapsing-remitting patients who have deteriorated and have developed neurological signs and symptoms between relapses.
65% of patients with relapsing remitting will develop secondary progressive within 15 years of diagnosis
What is primary progressive multiple sclerosis?
Symptoms get progressively worse from diseaseonsetwithno periods of remission
10% of patients. More common in older people
What is progressive relapsing multiple sclerosis?
One constant attack but there are bouts superimposed during which the disability increases even faster
What are the visual features of multiple sclerosis?
Optic neuritis
Optic atrophy
Uhthoff’s phenomenon: worsening of vision following rise in body temperature
Internuclear ophthalmoplegia
What are the sensory features of multiple sclerosis?
Pins and needles
Numbness
Trigeminal neuralgia
Lhermitte’s syndrome: paraesthesiae in limbs on neck flexion
What are the motor features of multiple sclerosis?
Spastic weakness: most commonly seen in the legs
What are the cerebellar features of multiple sclerosis?
Ataxia: more often seen during an acute relapse than as a presenting symptom
Tremor
What are some other signs of multiple sclerosis?
Urinary incontinence
Sexual dysfunction
Intellectual deterioration
What would multiple sclerosis show on an MRI?
High signal T2 lesions
Periventricular plaques
Dawson fingers: often seen on FLAIR images - hyperintense lesions penpendicular to the corpus callosum
High signal T2 lesions, periventricular plaques and Dawson’s fingers on an MRI would indicate what?
Multiple sclerosis
What would analysis of CSF in multiple sclerosis show?
Oligoclonal bands (and not in serum)
Increased intrathecal synthesis of IgG
Oligoclonal bands (and not in serum) and increased intrathecal synthesis of IgG in CSF would indicate what pathology?
Multiple sclerosis
What is the management for multiple sclerosis during an acute relapse?
High-dose steroids (e.g. oral or IV methylprednisolone) may be given for 5 days to shorten the length of an acute relapse.
Shorten length of relapse but do not alter degree of recovery.
What disease modifying drugs should be used first-line in patients with multiple sclerosis?
Natalizumab
Ocrelizumab
Fingolimod
What is the mechanism of action of natalizumab?
A recombinant monoclonal antibody that antagonises alpha-4 beta-1-integrin found on the surface of leucocytes inhibit migration of leucocytes across the endothelium across the blood-brain barrier
What is the mechanism of action of fingolimod?
Sphingosine 1-phosphate (S1P) receptor modulator prevents lymphocytes from leaving lymph nodes
What is the management for fatigue in multiple sclerosis?
Rule out other causes e.g. anaemia, thyroid, depression
Trial of amantadine
What is the management for spasticity in multiple sclerosis?
Baclofen and gabapentin are first-line.
Other options include diazepam, dantrolene and tizanidine
What is the management for oscillopsia in multiple sclerosis?
Gabapentin
What are the indications for disease modifying drugs in relapsing remitting multiple sclerosis?
2 relapses in past 2 years + able to walk 100m unaided
What are the indications for disease modifying drugs in secondary progressive multiple sclerosis?
2 relapses in past 2 years + able to walk 10m (aided or unaided)
What is the pattern of inheritance of Duchenne muscular dystrophy?
X-linked recessive inherited disorder in the dystrophin genes required for normal muscular function.
What are the classical features of Duchenne muscular dystrophy?
Progressive proximal muscle weakness from 5 years
Calf pseudohypertrophy
Gower’s sign: child uses arms to stand up from a squatted position
30% of patients have intellectual impairment
What are the investigations for Duchenne muscular dystrophy?
Raised creatinine kinase
Genetic testing is GOLD STANDARD
What is bulbar palsy?
A unilateral lower motor neurone lesion of cranial nerves IX, X, XI and XII, and it’s caused by a lesion in the medulla that affects the nucleus ambiguus and the hypoglossal nucleus.
What are the classical features of bulbar palsy?
Characterised by weakness or paralysis of muscles innervated by the cranial nerves located in the brainstem.
These cranial nerves control functions such as swallowing, speech, facial movements and respiratory functions
Symptoms specifically depends on the affects cranial nerves
What is chronic fatigue syndrome (myalgic encephalomyelitis)?
Diagnosed after at least 3 months of disabling fatigue affecting mental and physical function more than 50% of the time in the absence of other disease which may explain symptoms
What is narcolepsy?
Narcolepsy is a chronic sleep boundary disorder that affects the control of sleep and wakefulness with rapid eye movement sleep (REM) intrusion into the wake state
What gene and protein is narcolepsy associated with?
HLA-DR2 is the gene
Low levels of orexin (hypocretin), a protein which is responsible for controlling appetite and sleep patterns
What is the management for narcolepsy?
Daytime stimulants - modafinil
Nightime sodium oxybate
What is normal pressure hydrocephalus? What is it thought to be caused by?
Normal pressure hydrocephalus is a reversible cause of dementia seen in elderly patients. It is thought to be secondary to reduced CSF absorption at the arachnoid villi.
What is the classic triad of features seen in normal pressure hydrocephalus?
Urinary incontinence
Dementia and bradyphrenia
Gait abnormality (may be similar to Parkinson’s disease)
What would the triad of urinary incontinence, dementia and bradyphrenia, gait abnormality (may be similar to Parkinson’s disease) suggest?
Normal pressure hydrocephalus
What would normal pressure hydrocephalus present with on imaging?
Hydrocephalus with ventriculomegaly in the absence of, or out of proportion to, sulcal enlargement
Ventriculomegaly without sulcal enlargement on imaging of the brain would indicate what?
Normal pressure hydrocephalus
What is the management of normal pressure hydrocephalus?
Ventriculoperitoneal shunting
What are the complications of ventriculoperitoneal shunting?
Around 10% of patients who have shunts experience significant complications such as seizures, infection and intracerebral haemorrhages
What is Meniere’s disease?
Meniere’s disease is a disorder of the inner ear of unknown cause.
It is characterised by excessive pressure and progressive dilation of the endolymphatic system.
What are the classical features of Meniere’s disease?
Recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural).
Aural fullness or pressure
Nystagmus and positive Romberg’s test
Symptoms are typically unilateral
What is the management for acute attacks of Meniere’s disease?
Buccal or intramuscular prochlorperazine
What is the prevention management for Meniere’s disease?
Betahistine and vestibular rehabilitation exercises may be of benefit
What is the classic triad of Wernicke’s encephalopathy?
Confusion
Ataxia
Nystagmus/ophthalmoplegia
What is Wernicke’s encephalopathy?
Wernicke’s encephalopathy is a neuropsychiatric disorder caused by thiamine deficiency which is most commonly seen in alcoholics
What is the classic pentad of Korsakoff syndrome?
Confusion
Ataxia
Nystagmus/ophthalmoplegia
Amnesia (retrograde and anterograde)
Confabulation
What is the management for Wernicke’s encephalopathy?
Pabrinex (IV B/C vitamins)
Replacement of thiamine
What mnemonic can be used for features of Wernicke’s encephalopathy?
A useful mnemonic to remember the features of Wernicke’s encephalopathy is CAN OPEN
Confusion
Ataxia
Nystagmus
Ophthamoplegia
PEripheral
Neuropathy
What is temporal arteritis?
A vasculitis of unknown cause that affects medium and large-sized vessels arteries.
It occurs in those over 50 years old, with a peak incidence in patients who are in their 70s.
What are the classic features of temporal arteritis?
Headache
Jaw claudication
Ocular complications
What is the normal age of a patient with temporal arteritis?
Over 50 years old with peak incidence at 70s
What is the main ocular complication seen in temporal arteritis?
Anterior ischemic optic neuropathy accounts for the majority of ocular complications.
It results from occlusion of the posterior ciliary artery (a branch of the ophthalmic artery) → ischaemia of the optic nerve head.
What would fundoscopy show in a patient with temporal arteritis?
Swollen pale disc and blurred margins
Swollen pale disc and blurred margins on fundoscopy would indicate what?
Anterior ischemic optic neuropathy - temporal arteritis
What would the management of temporal arteritis be if there is no visual loss?
High-dose prednisolone
What would the management of temporal arteritis be if there is evolving visual loss?
IV methylprednisolone is usually given prior to starting high-dose prednisolone
Aside from high-dose glucocorticoids, what else should be prescribed in temporal arteritis?
Alendronate (bisphosphonates)
Define stroke?
A stroke (also known as cerebrovascular accident, CVA) represents a sudden interruption in the vascular supply of the brain.
What about the metabolism of neural tissue means that strokes are devastating?
Neural tissue is completely dependent on aerobic metabolism so any problem with oxygen supply can quickly lead to irreversible damage.
What are the two types of stroke?
Ischeamic - 85% - ‘Blockage’ in the blood vessel stops blood flow
Haemorrhagic - 15% - Blood vessel ‘bursts’ leading to reduction in blood flow
What is the difference between a stroke and TIA?
TIA describes the sudden onset of a focal neurologic symptom and/or sign lasting typically less than an hour, brought on by a transient decrease in blood flow. A stroke on the other had will cause permanent damage.
What are the subtypes of ischaemic stroke?
Thrombotic stroke - thrombosis from large vessel
Embolic stroke - blood clot, fat, air, bacteria
What are the subtypes of haemorrhagic stroke?
Intracerebral haemorrhage - bleeding within the brain
Subarachnoid haemorrhage - bleeding on the surface of the brain
What would the symptoms of a cerebral hemisphere infarct be?
Contralateral hemiplegia: Initially flaccid then spastic
Contralateral sensory loss
Homonymous hemianopia
Dysphasia
What would the symptoms of a brainstem infarct be?
May result in more severe symptoms including quadriplegia and lock-in-syndrome
What would the symptoms of a lacunar infarct be?
May result in pure motor, pure sensory, mixed motor and sensory signs or ataxia
What classification system is used to classify strokes based on the initial symptoms?
Oxford stroke classification (also known as the Bamford classification)
What is the Oxford stroke classification (Bamford classification) used for?
Used to classify strokes based on the initial symptoms
What criteria are assessed in the Oxford stroke classification (Bamford classification)?
- Unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- Homonymous hemianopia
- Higher cognitive dysfunction e.g. dysphasia