Neurology Flashcards
what medication is contraindicated in absence seizures?
Carbamazepine
when should anti-epileptics be started following a first seizure?
he patient has a neurological deficit
brain imaging shows a structural abnormality
the EEG shows unequivocal epileptic activity
the patient or their family or carers consider the risk of having a further seizure unacceptable
what is the treatment for generalised tonic-clonic seizures?
males: sodium valproate
females: lamotrigine or levetiracetam
girls aged under 10 years and who are unlikely to need treatment when they are old enough to have children or women who are unable to have children may be offered sodium valproate first-line
what is the treatment of focal seizures?
first line: lamotrigine or levetiracetam
second line: carbamazepine, oxcarbazepine or zonisamide
what is the treatment of absence seizures?
first line: ethosuximide
second line:
male: sodium valproate
female: lamotrigine or levetiracetam
** carbamazepine may exacerbate absence seizures
what is the treatment for myoclonic seizures?
males: sodium valproate
females: levetiracetam
what is the treatment for tonic or atonic seizures?
males: sodium valproate
females: lamotrigine
what are the symptoms of MS?
Visual
optic neuritis: common presenting feature
optic atrophy
Uhthoff’s phenomenon: worsening of vision following rise in body temperature
internuclear ophthalmoplegia
Sensory
pins/needles
numbness
trigeminal neuralgia
Lhermitte’s syndrome: paraesthesiae in limbs on neck flexion
Motor
spastic weakness: most commonly seen in the legs
Cerebellar
ataxia: more often seen during an acute relapse than as a presenting symptom
tremor
Others
urinary incontinence
sexual dysfunction
intellectual deterioration
What is vestibular neuronitis?
Vestibular neuronitis is a cause of vertigo that often develops following a viral infection
what are the features of vestibular neuronitis?
recurrent vertigo attacks lasting hours or days
nausea and vomiting may be present
horizontal nystagmus is usually present
no hearing loss or tinnitus
what are the differentials for vestibular neuronitis?
viral labyrinthitis
posterior circulation stroke: the HiNTs exam can be used to distinguish vestibular neuronitis from posterior circulation stroke
How can you manage vestibular neuronitits?
buccal or intramuscular prochlorperazine is often used to provide rapid relief for severe cases
a short oral course of prochlorperazine, or an antihistamine (cinnarizine, cyclizine, or promethazine) may be used to alleviate less severe cases
vestibular rehabilitation exercises are the preferred treatment for patients who experience chronic symptoms
What are the laws around seizure and driving?
first unprovoked/isolated seizure: 6 months off if there are no relevant structural abnormalities on brain imaging and no definite epileptiform activity on EEG. If these conditions are not met then this is increased to 12 months
for patients with established epilepsy or those with multiple unprovoked seizures:
may qualify for a driving licence if they have been free from any seizure for 12 months
if there have been no seizures for 5 years (with medication if necessary) a ‘til 70 licence is usually restored
withdrawawl of epilepsy medication: should not drive whilst anti-epilepsy medication is being withdrawn and for 6 months after the last dose
what are the rules around syncope and driving?
simple faint: no restriction
single episode, explained and treated: 4 weeks off
single episode, unexplained: 6 months off
two or more episodes: 12 months off
how long do you need off driving with stroke or TIA?
stroke or TIA: 1 month off driving, may not need to inform DVLA if no residual neurological deficit
multiple TIAs over short period of times: 3 months off driving and inform DVLA
how is motor neurone disease managed?
MND - both upper and lower motor neurone disease
Riluzole - prevents stimulation of glutamate receptors, used mainly in ALS, prolongs life by 3 months
Respiratory care - NIV, usually BIPAP is used at night - survival benefit of around 7 months
Nutrition - PEG
what characterised Meziere’s disease?
Meniere’s disease is characterized by unilateral sensorineural hearing loss, in which case sound lateralizes towards the contralateral normal ear during the Weber test.
Tinnitus
Aural Fullness
vertigo attacks
What is otosclerosis?
Otosclerosis describes the replacement of normal bone by vascular spongy bone. It causes a progressive conductive deafness due to fixation of the stapes at the oval window. Otosclerosis is autosomal dominant and typically affects young adults
what are the characteristics of otosclerosis?
what is the management?
Onset is usually at 20-40 years - features include:
conductive deafness
tinnitus
tympanic membrane
the majority of patients will have a normal tympanic membrane
10% of patients may have a ‘flamingo tinge’, caused by hyperaemia
positive family history
Management
hearing aid
stapedectomy
when is Rinnes test positive?
Rinnes test is positive when air conduction is better than bone conduction. This is seen in normal examinations or when patients have sensorineural hearing loss. A negative test signifies conductive hearing loss.
What is Guillain Barre syndrome?
Guillain-Barre syndrome describes an immune-mediated demyelination of the peripheral nervous system often triggered by an infection (classically Campylobacter jejuni)
what is the pathogenesis of Guillain Barre Syndrome?
cross-reaction of antibodies with gangliosides in the peripheral nervous system
correlation between anti-ganglioside antibody (e.g. anti-GM1) and clinical features has been demonstrated
anti-GM1 antibodies in 25% of patients
What is Miller Fisher Syndrome?
variant of Guillain-Barre syndrome
associated with ophthalmoplegia, areflexia and ataxia. The eye muscles are typically affected first
usually presents as a descending paralysis rather than ascending as seen in other forms of Guillain-Barre syndrome
anti-GQ1b antibodies are present in 90% of case
What are the features of Guillan-Barre Syndrome?
progressive, symmetrical weakness of all the limbs.
the weakness is classically ascending i.e. the legs are affected first
reflexes are reduced or absent
sensory symptoms tend to be mild (e.g. distal paraesthesia) with very few sensory signs
Other features
there may be a history of gastroenteritis
respiratory muscle weakness
cranial nerve involvement
diplopia
bilateral facial nerve palsy
oropharyngeal weakness is common
autonomic involvement
urinary retention
diarrhoea
what are the investigations of Guillain Barre syndrome?
lumbar puncture
rise in protein with a normal white blood cell count (albuminocytologic dissociation) - found in 66%
nerve conduction studies may be performed
decreased motor nerve conduction velocity (due to demyelination)
prolonged distal motor latency
increased F wave latency
How is Guillain Barre syndrome managed?
IVIG or plasma exchange (IVIG is first line)
FVC regular to monitor respiratory function
at what time should a lumbar puncture be done when suspecting a subarachnoid haemorrhage?
To detect a subarachnoid haemorrhage the LP should be done at least 12 hours after the start of the headache
what are the causes of SAH?
intracranial aneurysm (saccular ‘berry’ aneurysms)
accounts for around 85% of cases
conditions associated with berry aneurysms include hypertension,adult polycystic kidney disease, Ehlers-Danlos syndrome and coarctation of the aorta
arteriovenous malformation
pituitary apoplexy
mycotic (infective) aneurysms
what is the clinical presentation of SAH?
headache - usually of sudden-onset (‘thunderclap’ or ‘hit with a baseball bat’), severe (‘worst of my life’), occipital
typically peaking in intensity within 1 to 5 minutes, there may be a history of a less-severe ‘sentinel’ headache in the weeks prior to presentation
nausea and vomiting
meningism (photophobia, neck stiffness)
coma
seizures
ECG changes including ST elevation may be seen
this may be secondary to either autonomic neural stimulation from the hypothalamus or elevated levels of circulating catecholamines
what are the investigations for SAH?
non-contrast CT - acute blood (hyperdense/bright on CT) is typically distributed in the basal cisterns, sulci and in severe cases the ventricular system.
If CT head is done within 6 hours of onset and is normal new guidelines suggest not doing a LP, consider alternative diagnosis
If CT head is done > 6 hours after onset and is normal then LP should be done, at least 12 hours following onset
LP - xanthochromia,
If SAH confirmed - CT intracranial angiogram +/- digital subtraction angiogram
How is SAH managed?
supportive
bed rest
analgesia
venous thromboembolism prophylaxis
discontinuation of antithrombotics (reversal of anticoagulation if present)
vasospasm is prevented using a course of oral nimodipine
intracranial aneurysms are at risk of rebleeding and therefore require prompt intervention, preferably within 24 hours
most intracranial aneurysms are now treated with a coil by interventional neuroradiologists, but a minority require a craniotomy and clipping by a neurosurgeon
what are the complications of aneurysmal SAH ?
re-bleeding - happens in around 10% of cases and most common in the first 12 hours, if rebleeding is suspected (e.g. sudden worsening of neurological symptoms) then a repeat CT should be arranged, associated with a high mortality (up to 70%)
hydrocephalus - hydrocephalus is temporarily treated with an external ventricular drain (CSF diverted into a bag at the bedside) or, if required, a long-term ventriculoperitoneal shunt
vasospasm (also termed delayed cerebral ischaemia), typically 7-14 days after onset
ensure euvolaemia (normal blood volume)
consider treatment with a vasopressor if symptoms persist
hyponatraemia (most typically due to syndrome inappropriate anti-diuretic hormone (SIADH))
seizures
what are common side effects of MAO-B inhibitors?
fatigue, constipation and a dry mouth.
what is the treatment for Parkinson’s ?
if the motor symptoms are affecting the patient’s quality of life: levodopa
if the motor symptoms are not affecting the patient’s quality of life: dopamine agonist (non-ergot derived), levodopa or monoamine oxidase B (MAO-B) inhibitor
If a patient continues to have symptoms despite optimal levodopa treatment or has developed dyskinesia then NICE recommend the addition of a dopamine agonist, MAO-B inhibitor or catechol-O-methyl transferase (COMT) inhibitor as an adjunct.
what can happen if Parkinson’s medication is not taken/absorbed?
risk of acute akinesia or neuroleptic malignant syndrome
when is impulse control disorder more common in Parkinson’s medication?
dopamine agonist therapy
a history of previous impulsive behaviours
a history of alcohol consumption and/or smoking
what medication can be used in orthostatic hypotension in parkinsons?
midodrine
what medication can be used to manage drooling of saliva in patients with parkinsons
glycopyronium bromide
why is levodopa prescribed with a decarboxylase inhibitor?
e.g. carbidopa or benserazide
this prevents the peripheral metabolism of levodopa to dopamine outside of the brain and hence can reduce side effects
what are the common adverse effects of levodopa?
dry mouth
anorexia
palpitations
postural hypotension
psychosis
some adverse effects are due to the difficulty in achieving a steady dose of levodopa
end-of-dose wearing off: symptoms often worsen towards the end of dosage interval. This results in a decline of motor activity
‘on-off’ phenomenon: large variations in motor performance, with normal function during the ‘on’ period, and weakness and restricted mobility during the ‘off’ period
dyskinesias at peak dose: dystonia, chorea and athetosis (involuntary writhing movements)
these effects may worsen over time with - clinicians therefore may limit doses until necessary
what are examples of dopamine receptor agonists?
bromocriptine, ropinirole, cabergoline, apomorphine
What are the adverse effects of dopamine receptor agonists?
ergot-derived dopamine receptor agonists (bromocriptine, cabergoline) have been associated with pulmonary, retroperitoneal and cardiac fibrosis. The Committee on Safety of Medicines advice that an echocardiogram, ESR, creatinine and chest x-ray should be obtained prior to treatment and patients should be closely monitored
more likely than levodopa to cause hallucinations in older patients. Nasal congestion and postural hypotension are also seen in some patients
What are MAO-B inhibitors?
MAO-B (Monoamine Oxidase-B) inhibitors
e.g. selegiline
inhibits the breakdown of dopamine secreted by the dopaminergic neurons
what is the mechanism of action of amantadine and what are the side effects?
mechanism is not fully understood, probably increases dopamine release and inhibits its uptake at dopaminergic synapses
side-effects include ataxia, slurred speech, confusion, dizziness and livedo reticularis
what are COMT inhibitors ?
Catechol-O-Methyl Transferase inhibitors
e.g. entacapone, tolcapone
COMT is an enzyme involved in the breakdown of dopamine, and hence may be used as an adjunct to levodopa therapy
used in conjunction with levodopa in patients with established PD
when are antimuscarinics and when are they used?
block cholinergic receptors
now used more to treat drug-induced parkinsonism rather than idiopathic Parkinson’s disease
help tremor and rigidity
e.g. procyclidine, benzotropine, trihexyphenidyl (benzhexol)
what is syringomyelia?
Syringomyelia (‘syrinx’ for short) describes a collection of cerebrospinal fluid within the spinal cord.
Syringobulbia is a similar phenomenon in which there is a fluid-filled cavity within the medulla of the brainstem. This is often an extension of the syringomyelia but in rare cases can be an isolated finding.
what are the causes of Syringomyelia?
a Chiari malformation: strong association
trauma
tumours
idiopathic
what are the features of Syringomyelia?
a ‘cape-like’ (neck, shoulders and arms) loss of sensation to temperature but the preservation of light touch, proprioception and vibration
classic examples are of patients who accidentally burn their hands without realising, this is due to the crossing spinothalamic tracts in the anterior commissure of the spinal cord being the first tracts to be affected
spastic weakness (predominantly of the lower limbs)
neuropathic pain
upgoing plantars
autonomic features:
Horner’s syndrome due to compression of the sympathetic chain, but this is rare
bowel and bladder dysfunction
scoliosis will occur over a matter of years if the syrinx is not treated
What are the investigations and treatment for Syringomyelia?
Investigations
full spine MRI with contrast to exclude a tumour or tethered cord
a brain MRI is also needed to exclude a Chiari malformation
Treatment will be directed at treating the cause of the syrinx. In patients with a persistent or symptomatic syrinx, a shunt into the syrinx can be placed.
what is internuclear ophthalmoplegia?
a cause of horizontal disconjugate eye movement
due to a lesion in the medial longitudinal fasciculus (MLF) - controls horizontal eye movements by interconnecting the IIIrd, IVth and VIth cranial nuclei, located in the paramedian area of the midbrain and pons
what are the features of internuclear ophthalmoplegia?
impaired adduction of the eye on the same side as the lesion
horizontal nystagmus of the abducting eye on the contralateral side
what are the causes of internuclear ophthalmoplegia?
multiple sclerosis
vascular disease
where would the lesion be leading to the left homonymous hemianopia?
lesion of the right optic tract
where would the lesion be for homonymous quadrantopias?
homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior)
when would you see incongruous visual field defects vs congruous visual field defects?
incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex
A congruous defect simply means complete or symmetrical visual field loss and conversely an incongruous defect is incomplete or asymmetric.
what would cause homonymous hemianopia?
incongruous defects: lesion of optic tract
congruous defects: lesion of optic radiation or occipital cortex
macula sparing: lesion of occipital cortex
What would cause a homonymous quadrantanopias?
superior: lesion of the inferior optic radiations in the temporal lobe (Meyer’s loop)
inferior: lesion of the superior optic radiations in the parietal lobe
mnemonic = PITS (Parietal-Inferior, Temporal-Superior)
what would cause a bitemporal hemianopia?
lesion of optic chiasm
upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma
what are the adverse effects of Levodopa?
Usually combined with a decarboxylase inhibitor (e.g. carbidopa or benserazide) to prevent peripheral metabolism of L-dopa to dopamine
reduced effectiveness with time (usually by 2 years)
no use in neuroleptic induced parkinsonism
Adverse effects
dyskinesia
‘on-off’ effect
postural hypotension
cardiac arrhythmias
nausea & vomiting
psychosis
reddish discolouration of urine upon standing
where would the stoke be if there is Contralateral hemiparesis and sensory loss, lower extremity > upper
Anterior cerebral artery
where would the stroke be if there was Contralateral hemiparesis and sensory loss, upper extremity > lower
Contralateral homonymous hemianopia
Aphasia
middle cerebral artery
what symptoms would you have if you had a posterior cerebral artery stroke?
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
what is weber’s syndrome?
a stoke to the branches of the posterior cerebral artery that supply the midbrain
Ipsilateral CN III palsy
Contralateral weakness of upper and lower extremity
what symptoms would you get if there was a posterior inferior cerebellar artery stroke?
lateral medullary syndrome, Wallenberg syndrome
Ipsilateral: facial pain and temperature loss
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus
What symptoms would you get if you had an anterior inferior cerebellar artery ?
lateral pontine syndrome
Symptoms are similar to Wallenberg’s, but:
Ipsilateral: facial paralysis and deafness
what symptoms would you get if you had a retinal/ophthalmic artery stroke?
Amaurosis fugax
what symptoms would you get with a basilar artery stroke?
locked in syndrome
How does lacunar stroke present?
present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia
strong association with hypertension
common sites include the basal ganglia, thalamus and internal capsule
what does the dorsal column-medial lemniscal pathway carry?
the sensory modalities of fine touch, vibration and proprioception
In the spinal cord, information travels via the dorsal (posterior) columns. In the brainstem it is transmitted through the medial lemniscus
the fibres decussate (cross to the other side of the CNS in the medulla oblongata)
what does the anterior lateral system carry ?
Anterior spinothalamic tract – carries the sensory modalities of crude touch and pressure.
Lateral spinothalamic tract – carries the sensory modalities of pain and temperature.
they enter the spinal cord asked 1-2 vertebral levels and synapse at the tip of the dorsal horn - an area known as the substantial gelatinous. These fibres decussate within the spinal cord and then form two distinct tracts:
Crude touch and pressure fibres – enter the anterior spinothalamic tract.
Pain and temperature fibres – enter the lateral spinothalamic tract.
what are the spinal tracts that carry unconscious proprioceptive information?
The tracts that carry unconscious proprioceptive information are collectively known as the spinocerebellar tracts.
Posterior spinocerebellar tract – Carries proprioceptive information from the lower limbs to the ipsilateral cerebellum.
Cuneocerebellar tract – Carries proprioceptive information from the upper limbs to the ipsilateral cerebellum.
Anterior spinocerebellar tract – Carries proprioceptive information from the lower limbs. The fibres decussate twice – and so terminate in the ipsilateral cerebellum.
Rostral spinocerebellar tract – Carries proprioceptive information from the upper limbs to the ipsilateral cerebellum.
what is subacute combined degeneration of the spinal cord?
Subacute combined degeneration of the spinal cord is due to vitamin B12 deficiency resulting in impairment of the dorsal columns, lateral corticospinal tracts and spinocerebellar tracts..
Recreational nitrous oxide inhalation may also result in vitamin B12 deficiency → subacute combined degeneration of the spinal cord.
What are the features of subacute combined degeneration of the spinal cord?
dorsal column involvement
distal tingling/burning/sensory loss is symmetrical and tends to affect the legs more than the arms
impaired proprioception and vibration sense
lateral corticospinal tract involvement
muscle weakness, hyperreflexia, and spasticity
upper motor neuron signs typically develop in the legs first
brisk knee reflexes
absent ankle jerks
extensor plantars
spinocerebellar tract involvement
sensory ataxia → gait abnormalities
positive Romberg’s sign
what are the features of autonomic neuropathy?
impotence, inability to sweat, postural hypotension
postural hypotension e.g. drop of 30/15 mmHg
loss of decrease in heart rate following deep breathing
pupils: dilates following adrenaline instillation
what are the causes of autonomic neuropathy?
diabetes
Guillain-Barre syndrome
multisystem atrophy (MSA), Shy-Drager syndrome
Parkinson’s
infections: HIV, Chagas’ disease, neurosyphilis
drugs: antihypertensives, tricyclics
craniopharyngioma
what can cause brain abscess?
Brain abscesses may result from a number of causes including, extension of sepsis from middle ear or sinuses, trauma or surgery to the scalp, penetrating head injuries and embolic events from endocarditis
how will brain abscess present?
symptoms will depend on site of access
headache
fever
focal neurology - e.g. oculomotor nerve palsy or abducens nerve palsy secondary to raised intracranial pressure
other features associated with raised intracranial pressure - nausea, papilloedema, seizures
how do you manage a brain access?
surgery
a craniotomy is performed and the abscess cavity debrided
the abscess may reform because the head is closed following abscess drainage.
IV antibiotics: IV 3rd-generation cephalosporin + metronidazole
intracranial pressure management: e.g. dexamethasone
what features indicate a diagnosis of MND?
asymmetric limb weakness is the most common presentation of ALS
the mixture of lower motor neuron and upper motor neuron signs
wasting of the small hand muscles/tibialis anterior is common
fasciculations
the absence of sensory signs/symptoms
vague sensory symptoms may occur early in the disease (e.g. limb pain) but ‘never’ sensory signs
Other features
doesn’t affect external ocular muscles
no cerebellar signs
abdominal reflexes are usually preserved and sphincter dysfunction if present is a late feature
how is an acute ischaemic stroke managed?
CBGs, hydration, sats and temp should be maintained within normal limits
Blood pressure should not be lowered in the acute phase unless there are complications e.g. hypertensive encephalopathy or are they being considered for thrombolysis - blood pressure control should be considered for patients who present with an acute ischaemic stroke, if they present within 6 hours and have systolic blood pressure > 150mmHg.
Aspirin 300mg as soon as hemorrhagic stroke has been excluded
Anticoagulants should not be started until 14 days have passed from the onset of an ischaemic stroke
if the cholesterol is > 3.5 mmol/l patients should be commenced on a statin. Many physicians will delay treatment until after at least 48 hours due to the risk of haemorrhagic transformation
Thrombolysis
Thrombectomy
what is the criteria for thrombolysis for acute ischaemic stroke?
it is administered within 4.5 hours of onset of stroke symptoms
haemorrhage has been definitively excluded (i.e. Imaging has been performed)
The 2023 National Clinical Guideline for Stroke broadened the potential inclusion criteria:
patients with an acute ischaemic stroke, regardless of age or stroke severity, who were last known to be well more than 4.5 hours earlier, should be considered for thrombolysis with alteplase if:
treatment can be started between 4.5 and 9 hours of known onset, or within 9 hours of the midpoint of sleep when they have woken with symptoms, AND
they have evidence from CT/MR perfusion (core-perfusion mismatch) or MRI (DWI-FLAIR mismatch) of the potential to salvage brain tissue
this should be irrespective of whether they have a large artery occlusion and require mechanical thrombectomy.
there are specific criteria in the guidelines that determine the imagine criteria that determine whether thrombolysis should be performed
Blood pressure should be lowered to 185/110 mmHg before thrombolysis.
What are the contraindicaitions to thrombolysis?
Absolute
- Previous intracranial haemorrhage
- Seizure at onset of stroke
- Intracranial neoplasm
- Suspected subarachnoid haemorrhage
- Stroke or traumatic brain injury in preceding 3 months
- Lumbar puncture in preceding 7 days
- Gastrointestinal haemorrhage in preceding 3 weeks
- Active bleeding
- Oesophageal varices
- Uncontrolled hypertension >200/120mmHg
Relative
- Pregnancy
- Concurrent anticoagulation (INR >1.7)
- Haemorrhagic diathesis
- Active diabetic haemorrhagic retinopathy
- Suspected intracardiac thrombus
- Major surgery / trauma in the preceding 2 weeks
What is thrombectomy?
Mechanical thrombectomy is an exciting new treatment option for patients with an acute ischaemic stroke. NICE incorporated recommendations into their 2019 guidelines. It is important to remember the significant resources and senior personnel to provide such a service 24 hours a day. NICE recommend that all decisions about thrombectomy take into account a patient’s overall clinical status:
NICE recommend a pre-stroke functional status of less than 3 on the modified Rankin scale and a score of more than 5 on the National Institutes of Health Stroke Scale (NIHSS)
When should thrombectomy offered?
Offer thrombectomy as soon as possible and within 6 hours of symptom onset, together with intravenous thrombolysis (if within 4.5 hours), to people who have:
acute ischaemic stroke and
confirmed occlusion of the proximal anterior circulation demonstrated by computed tomographic angiography (CTA) or magnetic resonance angiography (MRA
Offer thrombectomy as soon as possible to people who were last known to be well between 6 hours and 24 hours previously (including wake-up strokes):
confirmed occlusion of the proximal anterior circulation demonstrated by CTA or MRA and
if there is the potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume
Consider thrombectomy together with intravenous thrombolysis (if within 4.5 hours) as soon as possible for people last known to be well up to 24 hours previously (including wake-up strokes):
who have acute ischaemic stroke and confirmed occlusion of the proximal posterior circulation (that is, basilar or posterior cerebral artery) demonstrated by CTA or MRA and
if there is the potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume
what is the secondary prevention in ischaemic stroke?
clopidogrel plus MR dipyridamole in people who have had an ischaemic stroke
Carotid endarterectomy is recommend if the patient has suffered a stroke or TIA in the carotid territory and is not severely disabled
should only be considered if the stenosis > 50%
It should be performed asap - within 7 days
What would a lesion in the parietal lobe cause?
sensory inattention
apraxias
astereognosis (tactile agnosia)
inferior homonymous quadrantanopia
Gerstmann’s syndrome (lesion of dominant parietal): alexia, acalculia, finger agnosia and right-left disorientation
What would a lesion in the occipital lobe cause?
homonymous hemianopia (with macula sparing)
cortical blindness
visual agnosia
What would a lesion in the temporal lobe cause?
Wernicke’s aphasia: this area ‘forms’ the speech before ‘sending it’ to Brocas area. Lesions result in word substituion, neologisms but speech remains fluent
superior homonymous quadrantanopia
auditory agnosia
prosopagnosia (difficulty recognising faces)
What would a lesion in the frontal lobe cause?
expressive (Broca’s) aphasia: located on the posterior aspect of the frontal lobe, in the inferior frontal gyrus. Speech is non-fluent, laboured, and halting
disinhibition
perseveration
anosmia
inability to generate a list
What would a lesion in the cerebellum cause?
midline lesions: gait and truncal ataxia
hemisphere lesions: intention tremor, past pointing, dysdiadokinesis, nystagmus
What is Acalculia?
Acalculia refers to an acquired impairment in numerical and calculation abilities. It is most commonly associated with lesions in the parietal lobe, particularly on the dominant (usually left) side. The parietal lobe plays a crucial role in processing numerical information and performing calculations. Thus, a glioma in this area would likely disrupt these functions, leading to acalculia.
what is the mechanism of action of pyridostigmine?
Pyridostigmine is a long-acting acetylcholinesterase inhibitor that reduces the breakdown of acetylcholine in the neuromuscular junction, temporarily improving symptoms of myasthenia gravis
what is neuroleptic malignant syndrome?
Neuroleptic malignant syndrome is a rare but dangerous condition seen in patients taking antipsychotic medication. It carries a mortality of up to 10% and can also occur with atypical antipsychotics. It may also occur with dopaminergic drugs (such as levodopa) for Parkinson’s disease, usually when the drug is suddenly stopped or the dose reduced.
what are the features of Neuroleptic malignant syndrome?
It occurs within hours to days of starting an antipsychotic (antipsychotics are also known as neuroleptics, hence the name) and the typical features are:
pyrexia
muscle rigidity
autonomic lability: typical features include hypertension, tachycardia and tachypnoea
agitated delirium with confusion
A raised creatine kinase is present in most cases. Acute kidney injury (secondary to rhabdomyolysis) may develop in severe cases. A leukocytosis may also be seen
How is Neuroleptic malignant syndrome managed?
stop antipsychotic
patients should be transferred to a medical ward if they are on a psychiatric ward and often they are nursed in intensive care units
IV fluids to prevent renal failure
dantrolene may be useful in selected cases
thought to work by decreasing excitation-contraction coupling in skeletal muscle by binding to the ryanodine receptor, and decreasing the release of calcium from the sarcoplasmic reticulum
bromocriptine, dopamine agonist, may also be used
what is the mechanism of action on lamotrigine and what are the adverse effects?
Mechanism of action
sodium channel blocker
Adverse effects
Stevens-Johnson syndrome
What is the diagnostic criteria of a migraine?
The International Headache Society has produced the following diagnostic criteria for migraine without aura:
A At least 5 attacks fulfilling criteria B-D
B Headache attacks lasting 4-72 hours* (untreated or unsuccessfully treated)
C Headache has at least two of the following characteristics:
1. unilateral location*
2. pulsating quality (i.e., varying with the heartbeat)
3. moderate or severe pain intensity
- aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs)
D During headache at least one of the following: - nausea and/or vomiting*
- photophobia and phonophobia
E Not attributed to another disorder (history and examination do not suggest a secondary headache disorder or, if they do, it is ruled out by appropriate investigations or headache attacks do not occur for the first time in close temporal relation to the other disorder)
Migraine with aura (seen in around 25% of migraine patients) tends to be easier to diagnose with a typical aura being progressive in nature and may occur hours prior to the headache. Typical aura include a transient hemianopic disturbance or a spreading scintillating scotoma (‘jagged crescent’). Sensory symptoms may also occur
what migraine symptoms are atypical and may prompt further investigation?
motor weakness
double vision
visual symptoms affecting only one eye
poor balance
decreased level of consciousness.
what is Ramsay hunt syndrome?
Ramsay Hunt syndrome (herpes zoster oticus) is caused by the reactivation of the varicella zoster virus in the geniculate ganglion of the seventh cranial nerve.
what are the symptoms of Ramsay hunt syndrome?
auricular pain is often the first feature
facial nerve palsy
vesicular rash around the ear
other features include vertigo and tinnitus
what is the management of Ramsay Hunt syndrome?
oral aciclovir and corticosteroids are usually given
what is Hoffmans sign?
To elicit it, the examiner should flick the patients distal phalanx (usually of the middle finger) to cause momentary flexion. A positive sign is exaggerated flexion of the thumb.
A positive Hoffmans sign is a sign of upper motor neuron dysfunction and points to a disease of the central nervous system
What is degenerative cervical myelopathy?
Degenerative cervical myelopathy (DCM) is caused by compression (pinching) of the spinal cord in the neck.
How does degenerative cervical myelopathy present?
Early symptoms are often subtle and can vary in severity day to day, making the disease difficult to detect initially. However as a progressive condition, worsening, deteriorating or new symptoms should be a warning sign.
DCM symptoms can include any combination of :
Pain (affecting the neck, upper or lower limbs)
Loss of motor function (loss of digital dexterity, preventing simple tasks such as holding a fork or doing up their shirt buttons, arm or leg weakness/stiffness leading to impaired gait and imbalance
Loss of sensory function causing numbness
Loss of autonomic function (urinary or faecal incontinence and/or impotence) - these can occur and do not necessarily suggest cauda equina syndrome in the absence of other hallmarks of that condition
Hoffman’s sign: is a reflex test to assess for cervical myelopathy. It is performed by gently flicking one finger on a patient’s hand. A positive test results in reflex twitching of the other fingers on the same hand in response to the flick.
how would you investigate for degenerative cervical myelopathy?
An MRI of the cervical spine is the gold standard test where cervical myelopathy is suspected. It may reveal disc degeneration and ligament hypertrophy, with accompanying cord signal change.
How is degenerative cervical myelopathy managed?
urgent referral for assessment by spinal services.
Importance of early treatment
Any existing spinal cord damage can be permanent. Early treatment (within 6 months of diagnosis) offers the best chance of a full recovery
Currently, decompressive surgery is the only effective treatment.
What is an essential tremor?
Essential tremor (previously called benign essential tremor) is an autosomal dominant condition which usually affects both upper limbs
Features
postural tremor: worse if arms outstretched
improved by alcohol and rest
most common cause of titubation (head tremor)
what is the management of an essential tremor?
propranolol is first-line
primidone is sometimes used
What are the adverse effects of sodium valproate?
teratogenic
P450 inhibitor
gastrointestinal: nausea
increased appetite and weight gain
alopecia: regrowth may be curly
ataxia
tremor
hepatotoxicity
pancreatitis
thrombocytopaenia
hyponatraemia
hyperammonemic encephalopathy: L-carnitine may be used as treatment if this develops
what kind of drug is ondasatron?
Where does it act?
5-HT3 antagonists are antiemetics used mainly in the management of chemotherapy-related nausea. They mainly act in the chemoreceptor trigger zone area of the medulla oblongata.
What are the teratogenic effects of epilepsy medications?
sodium valproate
carbamazepine
Phenytoin
lamotrigine
Sodium valproate: associated with neural tube defects
carbamazepine: often considered the least teratogenic of the older antiepileptics
phenytoin: associated with cleft palate
lamotrigine: studies to date suggest the rate of congenital malformations may be low. The dose of lamotrigine may need to be increased in pregnancy
It is advised that pregnant women taking phenytoin are given vitamin K in the last month of pregnancy to prevent clotting disorders in the newborn
which anti-epileptic medications can be taken when breast feeding?
Breast feeding is generally considered safe for mothers taking antiepileptics with the possible exception of the barbiturates
What is lateral medullary syndrome?
where is the leasion and what ate the symtoms?
Lateral medullary syndrome - PICA lesion - cerebellar signs, contralateral sensory loss & ipsilateral Horner’s
Lateral medullary syndrome, also known as Wallenberg’s syndrome, occurs following occlusion of the posterior inferior cerebellar artery.
Cerebellar features
ataxia
nystagmus
Brainstem features
ipsilateral: dysphagia, facial numbness, cranial nerve palsy e.g. Horner’s
contralateral: limb sensory loss
How does an anterior inferior cerebellar artery lesion present?
The AICA lesions are less well known and have been purported to cause central vestibular loss and hearing loss, since the inner ear, lateral pons and anterior inferior cerebellum are supplied.
What featrues suggest a diagnosis of Parkinson’s disease rather than drug-induced parkinsonism?
Rigidity and rest tremor are uncommon in drug-induced parkinsonism. Masked face and flexed posture can be seen in both conditions. Bilateral symptoms are more common in drug-induced parkinsonism. Restlessness of arms and legs (akathisia) is a common side-effect of antipsychotics.
What is parkinsons?
a progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the substantia nigra. 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.
Features of parkinsons?
Bradykinesia (short shuffling steps with reduced arm swing)
Tremor - 3-5Hz most marked at rest, worse when stressed or tired, improves on voluntary movement, typicall pill rolling
Rigidity - lead pip, cogwheel.
Other characteristic features
mask-like facies
flexed posture
micrographia
drooling of saliva
psychiatric features: depression is the most common feature (affects about 40%); dementia, psychosis and sleep disturbances may also occur
impaired olfaction
REM sleep behaviour disorder
fatigue
autonomic dysfunction:
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
What is acute disseminated encaphalomyelitis?
Acute disseminated encephalomyelitis (ADEM) is an autoimmune demyelinating disease of the central nervous system. It may also be termed post-infectious encephalomyelitis. The aetiology is not fully understood and it can occur following infection with a bacterial or viral pathogen. Common infections include measles, mumps, rubella and varicella, however this list is not exhaustive.
Symptoms of acute disseminated encephalomyelitis?
what would MRI show?
After a lag time of between a few days to 2 months, there is an acute onset of multifocal neurological symptoms with rapid deterioration. Non-specific signs such as headache, fever, nausea and vomiting may also accompany the onset of illness. Motor and sensory deficits are frequent and there may also be brainstem involvement including oculomotor defects.
It is found on T2-weighted MRI imaging which reveals poorly-defined hyperintensities in the subcortical white matter. These lesions can develop throughout the course of the illness and hence serial MRIs may be required.
*** MRI Findings - For MRCP - Herpes - Temporal lobes
ADEM - Subcortical white matter
management of acute disseminated encaphalomyelitis?
Management involves intravenous glucocorticoids and the consideration of IVIG where this fails.
Features of Brown-Sequard syndrome?
ipsilateral weakness below lesion
ipsilateral loss of proprioception and vibration sensation
contralateral loss of pain and temperature sensation
What is a craniopharyngioma?
a common brain tumor in children and often mimics pituitary adenoma due to the presence of a bitemporal hemianopia in this group of patients. Craniopharyngioma is derived from the Rathke’s pouch and it often invades the pituitary and hypothalamus. The ventromedial area of the hypothalamus is often involved.
Guillain barre syndrome poor prognostic features?
Poor prognostic features
age > 40 years
poor upper extremity muscle strength
previous history of a diarrhoeal illness (specifically Campylobacter jejuni)
high anti-GM1 antibody titre
need for ventilatory support
causes of both upper and lower motor neurone signs?
Motor neurone disease
Subacute combined degeneration of the spinal cord
Syphilitic tabes dorsalis
Friedreich’s ataxia
Dual pathology
Myelopathy affecting the exiting roots
Peripheral neuropathy: demyelinating vs. axonal
Demyelinating pathology
Guillain-Barre syndrome
chronic inflammatory demyelinating polyneuropathy (CIDP)
amiodarone
hereditary sensorimotor neuropathies (HSMN) type I
paraprotein neuropathy
Axonal pathology
alcohol
diabetes mellitus*
vasculitis
vitamin B12 deficiency*
hereditary sensorimotor neuropathies (HSMN) type II
- may also cause a demyelinating picture
What would be seen on NCS in axonal vs demyelinating pathology?
Axonal
normal conduction velocity
reduced amplitude
Demyelinating
reduced conduction velocity
normal amplitude
what is neuromyelitis optica?
Neuromyelitis optica (NMO) is a monophasic or relapsing-remitting demyelinating CNS disorder Although previously thought to be a variant of multiple sclerosis, it is now recognised to be a distinct disease, particularly prevalent in Asian populations. It typically involves the optic nerves and cervical spine, with imaging of the brain frequently normal. Vomiting is also a common presenting complaint.
Features of Neuromyeitis optica?
Diagnosis requires bilateral optic neuritis, myelitis and 2 of the following 3 criteria:
1. Spinal cord lesion involving 3 or more spinal levels
2. Initially normal MRI brain
3. Aquaporin 4 positive serum antibody
NMO-IgG seropositive status (The NMO-IgG test checks the existence of antibodies against the aquaporin 4 antigen.)
Management on Neuromyelitis optica?
treatment of acute attacks
high-dose IV methylprednisolone
maintenance therapy for attack prevention
long-term monoclonal antibody therapy, e.g. eculizumab, ravulizumab (antibody target = complement C5), inebilizumab (antibody target = CD19 on B cells) or satralizumab (antibody target = IL-6 receptor)
How does phenytoin cause folate deficiency ?
Phenytoin is a well-known cause of folate deficiency through multiple mechanisms including reduced absorption, increased metabolism, and reduced cellular uptake
what is given to prevent vasospasm in SAH?
vasospasm is prevented using a course of oral nimodipine
what peripheral neuropathies are predominatley motor loss and what is predominately sensory loss?
Predominately motor loss
Guillain-Barre syndrome
porphyria
lead poisoning
hereditary sensorimotor neuropathies (HSMN) - Charcot-Marie-Tooth
chronic inflammatory demyelinating polyneuropathy (CIDP)
diphtheria
Predominately sensory loss
diabetes
uraemia
leprosy
alcoholism
vitamin B12 deficiency
amyloidosis
Causes of tinnitus?
what drugs cause tinnitus?
Aspirin/NSAIDs
Aminoglycosides
Loop diuretics
Quinine
What is Hemiballism?
Hemiballism occurs following damage to the subthalamic nucleus. Ballisic movements are involuntary, sudden, jerking movements which occur contralateral to the side of the lesion. The ballisic movements primarily affect the proximal limb musculature whilst the distal muscles may display more choreiform-like movements
Symptoms may decrease whilst the patient is asleep.
Antidopaminergic agents (e.g. Haloperidol) are the mainstay of treatment
What area of the brain does hemiballismus affect?
Subthalamic nucleus of the basal ganglia lesions
What is CADASIL?
what is the mutation seen ?
CADASIL (also known as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is the most common cause of hereditary cerebral small-vessel disease and vascular cognitive impairment in young adults.
NOTCH3 mutation on chromosome 19.
How to interpret Rinne and Webers tests?
What is Renne’s test?
tuning fork is placed over the mastoid process until the sound is no longer heard, followed by repositioning just over external acoustic meatus
‘positive test’: air conduction (AC) is normally better than bone conduction (BC)
‘negative test’: if BC > AC then conductive deafness
What is Weber’s test?
tuning fork is placed in the middle of the forehead equidistant from the patient’s ears
the patient is then asked which side is loudest
in unilateral sensorineural deafness, sound is localised to the unaffected side
in unilateral conductive deafness, sound is localised to the affected side
