Stroke

Question 1

What is the neurovascular unit?

Answer 1

• Broadly describes the relationship between brain cells and their blood vessels
• Functional unit of the CNS
• Functional & structural interplay between/ among neurones, glial cells (metabolic support cells- homeostasis) and endothelial lumens (including the dynamic of the BBB)

Question 2

How do stroke symptoms occur (physiology)?

Answer 2

• Dysfunction of the neurovascular unit…
• Hypoperfusion in the endothelial lumen
• This leads to ↓ O2 & glucose
• This leads to ↓ ATP synthesis, impairing energy dependent cell processes
• Consequent action potential arrest
• Leading to absence of neuronal transmission

Question 3

What are the typical stroke syndrome features?

Answer 3

1. Sudden onset – clarify w/ pt that from a medical perspective ‘sudden’ means seconds
2. Focal – hypoperfusion occurs only in a branch of cerebrovasculature hence only the neurovascular units in the concerned vascular territory are affected
3. Predominantly negative neurological symptoms – dysfunction of the neurovascular unit is mediated by cessation of action potentials hence typical stroke symptoms reflect loss of function
4. Vascular territory hypoperfusion can explain collection of symptoms

+ 2 additional considerations:

• Symptoms do not typically migrate – slow migration can occur in migranous sensory & visual aura, rapid migration in focal seizures (Jacksonian march)
• Episodes do not stereotype – stereotyping is defined as episodic recurrence of symptoms in an identical fashion with complete resolution in between, so in a stroke repeat embolisation of the same blood vessels

Question 4

What is capsular warning syndrome?

Answer 4

• Recurrent stereotyped lacunar transient ischaemic attacks (TIAs)
• This is not true stereotyping but fluctuation of symptoms with episodes recurrent over minutes to hours
• Lenticulostriate arteries are deep branches of the middle cerebral artery
  
  • Supply deep grey matter structures including lentiform nucleus, caudate nucleus, internal capsule, basal ganglia

Question 5

What is the basal ganglia?

What is the function of the basal ganglia?

Where does the basal ganglia receive its blood supply from?

Answer 5

• Basal ganglia refer to 4 main subcortical nuclei that regulate and coordinate movement

1. Striatum = caudate nucleus + putamen
   
   1. Caudate nucleus- lateral wall of lateral ventricle, separated from putamen by internal capsule (descending white matter fibres)
2. Globus pallidus- externa and interna
3. Subthalmic nucleus
4. Substantia nigra

• Main purpose of basal ganglia- stimulate motor cortex, fine-tune the voluntary movements
  
  • Receives information from several sources including cerebral cortex
  • Basal ganglia feeds info back to the cortex via the thalamus
• Globus pallidus + putamen = lentiform nucleus
• Thalamus- stimulates basal ganglia
• Blood supply comes from middle cerebral artery
  
  • Lenticulostriate artery

Question 6

Label the following parts of the basal ganglia

Answer 6

1. Caudate nucleus
2. Putamen
3. Globus pallidus
4. Thalamus

Question 7

What is the blood supply to the thalamus?

Answer 7

• Posterior cerebral artery

Question 8

What is the blood supply of the cerebrum?

Answer 8

• The internal carotid gives rise to the anterior and medial cerebral artery
• The anterior cerebral arteries: anteromedial area of cerebrum
  
  • Runs within interhemispheric fissure
• Middle cerebral arteries: majority of lateral cerebrum
  
  • Runs within lateral sulcus (separates frontal & parietal above from temporal lobe below = lateral fissure)
  • Within this fissure some small branches are given off called striate arteries which supply the basal ganglia
• The vertebral arteries unite and form the basilar artery at the bottom of the pons, when it reaches the midbrain it terminates by splitting into the posterior cerebral arteries
• Posterior cerebral arteries: supply a mixture of the medial and lateral areas of the posterior cerebrum

Question 9

What 2 arterial sources of the circle of Willis?

Answer 9

• Internal carotid – divides to form middle and anterior cerebral artery
• Vertebral arteries (from first part of subclavian, run up through transverse foramen of cervical vertebrae) – provides the posterior circulation
• The circle of Willis is at the base of the brain around the optic chiasm and hypothalamus

Question 10

Where does the ophthalmic artery come from?

Answer 10

• Internal carotid artery
• Arise immediately after ICA passes through the cavernous sinus to enter the cranial cavity

Question 11

Describe the blood supply to the cerebellum?

Answer 11

• Branches of basilar artery-
  
  • Superior cerebellar artery
  • Anterior inferior cerebellar artery
• Branch of vertebral artery-
  
  • Posterior inferior cerebellar artery

Question 12

What signs and symptoms can dysfunction of the cerebellum produce?

Answer 12

DANISH

• Dysdiadochokinesia (difficulty carrying our rapid, alternating movements)
• Ataxia
• Nystagmus
• Intention tremor
• Slurring speech
• Hypotonia

Question 13

Describe the blood supply of the brainstem?

Answer 13

• Midbrain
  
  • From basilar artery and its branches- posterior cerebral artery, superior cerebellar artery, posterior choroidal artery, interpeduncular branches of basilar artery
• Pons
  
  • Pontine arteries from basilar artery
  • Anterior inferior cerebellar artery and superior cerebellar artery
• Medulla
  
  • Anterior spinal, posterior spinal, posterior inferior cerebellar, anterior inferior cerebellar, vertebral arteries

Question 14

What is the Oxford Community Stroke Project Classification (OCSP)? (also known as Bamford classification of ischaemic stroke)

Answer 14

• A simple clinical assessment that finds utility in assessing stroke type ie vascular territory involved, severity, aetiology & prognosis
• Imaging is not necessarily required to complete the OCSP classification
• The following criteria should be assessed:
  
  • Unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
  • Homonymous hemianopia
  • Higher cognitive dysfunction eg dysphasia
• Dysarthria doesn’t count in OCSP
• Impairment of motor and sensory function is divided into the somatic distributions of face, arm and leg

Question 15

1. What is dysphasia and what is dysarthria?
2. Suggest some causes of isolated dysarthria (slurred speech)?

Answer 15

1.

• Dysphasia- difficulty understanding or speaking language
• Dysarthria- slurring of speech

2.

• Alcohol intoxication
• Sepsis
• Lack of sleep
• Post-ictal phase

Question 16

What is a total anterior circulation stroke (TACS)?

Answer 16

• Large cortical stroke affecting the areas of the brain supplied by both middle & anterior cerebral arteries
• All 3 of the following need to be present-
  
  1. Unilateral weakness +/- sensory deficit, of the face, arm and leg
  2. Homonymous hemianopia
  3. Higher cerebral dysfunction (dysphasia, visuospatial disorder)

Question 17

What is a partial anterior circulation stroke (PACS)?

Answer 17

• A less severe form of TACS, in which only part of the anterior circulation has been compromised
• 2 of the following need to be present:
  
  • Unilateral weakness +/- sensory deficit, of the face, arm and leg
  • Homonymous hemianopia
  • Higher cerebral dysfunction (dysphasia, visuospatial disorder)

Question 18

What is a posterior circulation syndrome (POCS)?

Answer 18

• Involves damage to the area of the brain supplied by the posterior circulation (eg cerebellum and brainstem)
• 1 of the following need to be present:
  
  • Cranial nerve palsy and a contralateral motor/sensory deficit
  • Bilateral motor/ sensory deficit
  • Conjugate eye movement disorder eg horizontal gaze palsy
  • Cerebellar dysfunction eg vertigo, nystagmus, ataxia
  • Isolated homonymous hemianopia

Question 19

What is a lacunar stroke (LACS)?

Answer 19

• Subcortical stroke that occurs secondary to small vessel disease
• No loss of higher cerebral functions eg dysphasia
• 1 of the following need to be present:
  
  • Pure sensory stroke
  • Pure motor stroke
  • Sensori-motor stroke
  • Ataxic hemiparesis
  • Clumsy hand dysarthria (internal capsule)

Question 20

Suggest some stroke mimics?

Answer 20

• Classify them in 3 groups

1. Readily identifiable on brain imaging
   
   1. SoL- brain tumour, abscess
   2. Subdural haematoma
   3. Multiple sclerosis
2. Syndromically distinguishable from the stroke syndrome – there are secure clinical features to distinguish from typical stroke syndrome
   
   1. Syncope syndrome
   2. BPPV
   3. Vestibular neuronitis
   4. Transient global amnesia
   5. Bell’s palsy
3. Exclusion of stroke syndrome requires specialist stroke assessment including brain imaging (there may be clues if you have recurrent episodes)
   
   1. Migraine with aura
   2. Focal seizures
   3. Functional syndrome
   4. Hypoglycaemia

Question 21

How to describe the causes of stroke?

Answer 21

• Type of brain parenchymal damage
  
  • Infarct vs bleed
• Mechanism causing hypoperfusion
  
  • Eg embolization from carotid artery vs thrombosis vs vasoconstriction
• Disease/ pathology process primarily responsible for mechanism of hypoperfusion
  
  • Antiphospholipid syndrome, thyroid disease, AF, infective endocarditis, brain aneurysm, thrombophilia, carotid disease, fibrinolytic necrosis
• Climate in which disease process has thrived
  
  • Eg smoking causing carotid disease, uncontrolled htn causing end artery arteriosclerosis eventually culminating into fibrinolytic necrosis, or obesity as part of metabolic syndrome

Question 22

What is the commonest cause of stroke?

Answer 22

• Atrial fibrillation
• Tend to be more severe by virtue of the larger size clots from the heart in addition the dynamic of poor mobilisation of collateral circulation relative to large vessel embolization
• Risk of stroke assessed with CHA2DS2VASc score (primary prevention only)
• HASBLED to assess bleeding risk

Question 23

If AF is the cause of a patient’s stroke in whom anticoagulation is contraindicated, what other treatment options are there?

Answer 23

• Left atrial appendage closure

Question 24

What are the causes of intracranial haemorrhage?

Answer 24

• Primary (small vessel) haemorrhage
  
  • Hypertension
  • Cerebral amyloid angiopathy
• Secondary haemorrhage
  
  • Haemorrhagic transformation infarct
    
    • Venous sinus thrombosis and venous infarction
  • Tumour- glioblastoma multiforme, anaplastic astrocytoma, metastasis
  • Vascular- aneurysm, AVM, vasculitis
  • Coagulopathy, warfarin, aspirin
  • Cocaine, alcohol

Question 25

What is cerebral amyloid angiopathy (CAA)?

Answer 25

• Amyloid build up on walls in the brain
• Causes Alzheimer’s dementia, stroke

Question 26

What is the TOAST classification of stroke?

Answer 26

• Denotes 5 subtypes of ischaemic stroke, based on clinical symptoms as well as radiological and other investigation results

1. Large-artery atherosclerosis
2. Cardio-embolic
3. Small-vessel occlusion (lacunae)
4. Stroke of other determined aetiology
5. Stroke of undetermined aetiology

Question 27

What is the FAST screening tool?

Answer 27

• Face Arm Speech Test- positive if any of the following are met
  
  • NEW FACIAL WEAKNESS: Can pt smile/ has face fallen to one side
  • NEW ARM WEAKNESS: Can pt raise both arms and keep them there
  • NEW SPEECH DIFFICULTY: Can pt speak clearly & understand what you say, is their speech slurred
• Used outside hospital to screen people with sudden onset of neurological symptoms for a diagnosis of stroke or TIA
• Well known within the community

Question 28

What is the ROSIER score?

Answer 28

• A variant of the FAST screening tool
• Used by medical professionals to establish the diagnosis of a suspected stroke or TIA when pts are admitted into ED
• Looks at: LoC or syncope, seizure activity, asymmetric facial weakness, arm weakness, leg weakness, speech disturbance, visual field defect

Question 29

What is the initial mx of suspected TIA?

Answer 29

• Aspirin 300mg daily
• Supplemental O2 if their O2 sats <95%
• Offer secondary prevention in addition to aspirin as soon as TIA diagnosis is confirmed
• Refer to TIA clinic
• After specialist assessment in TIA clinic, consider MRI to determine territory of ischaemia, or to detect haemorrhage or alternative pathologies- perform on same day as assessment
• Immediate statin treatment not recommended; continue statins if they were already receiving them

Question 30

What are the indications for a head CT scan in suspected stroke?

Answer 30

• Indications for thrombolysis or thrombectomy
• On anticoagulant therapy
• Known bleeding tendency
• Depressed GCS <13
• Unexplained progressive or fluctuating symptoms
• Papilledema, neck stiffness, fever
• Severe headache at onset of stroke symptoms

Question 31

What sort of things comprise a care bundle for stroke patients?

Answer 31

• Admission to stroke unit
• Revascularisation therapy (IV alteplase, within 4.5 hrs, or thrombectomy for patients with large vessel occlusion, 6hr therapy window)
• Optimising physiology and surveillance, prevention and early intervention of complications
• Nutritional support
• Secondary prevention (antiplatelet therapy, anticoagulation, carotid endarterectomy (CEA), BP, lipid control)
• Rehabilitation

Question 32

Describe the current pathway for emergency stroke assessment in Leicestershire?

Answer 32

• 999 call
• Urgent paramedic assessment
• FAST +ve
• LRI ED- core stroke team alerted- Rapid Assessment Protocol (RAP)
• The RAP team have 5 priorities

1. Clinically confirm diagnosis, that thrombolysis is indicated, get venous access, do bloods, obs, weigh, request CT scan
2. Identify contraindications (outside of imaging)
3. Complete consent/ assent (or best interest)
4. Imaging
5. Bolus and infusion

Question 33

What is the role of the CT during assessment for thrombolysis?

Answer 33

• Exclusion of intracranial haemorrhage
• Early changes diagnostic for ischaemic stroke-
  
  • Evidence of thrombus in vessels- clotted blood is white on CT hence vessels become white
  • Effacement (swelling of brain cells) & loss of grey and white matter distinction
    
    • The failure of membrane transport à consequent intracellular fluid and electrolyte shifts results in brain cell swelling
    • Normally white matter has darkish hue on CT due to myelin, when grey matter cells absorb excess water the attenuation changes and resembles white matter à loss of grey and white matter distinction
    • Quantifying effacement & obscuration is the basis of the ASPECTS score

Question 34

Thrombolysis with alteplase is recommended for treating acute ischaemic stroke if what criteria is met?

Answer 34

• Treatment is started as soon as possible within 4.5 hrs of onset of stroke symptoms
• Intracranial haemorrhage has been excluded by appropriate imaging techniques

Question 35

Alteplase indications and contraindications?

Answer 35

• Indications:
  
  • Administered within 4.5 hours from onset of stroke symptoms
  • Disabling impairments (NIH>4, dysphasia, inability to self-care or mobilise independently, visual field defect, dysphagia)
  • No contraindication
• Contraindications: see table in image attached

Question 36

What is the ASPECTS score?

Answer 36

• (Alberta Stroke Programme Early CT Score)
• 10 point quantitative topographic CT scan score used in patients with middle cerebral artery (MCA) stroke
• Segmental assessment of the MCA vascular territory is made and 1 point is deducted from the initial score of 10 for every region involved
• Used in revascularisation therapies for patient selection and outcome prediction

Question 37

When is thrombectomy used to treat stroke?

Answer 37

• Combination with thrombolysis (if not contraindicated & within the time window)
• For ischaemic stroke
• Thrombectomy involves removal of thrombus from vessel
• NICE set out specific criteria for use of thrombectomy- Offer as soon as possible to people who were last known to be well between 6 and 24 hrs previously:
  
  • Who have acute ischaemic stroke and confirmed occlusion of the proximal anterior circulation determined by CT or MRI, 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

Question 38

How to decide the optimal imaging for stroke?

Answer 38

The 4Ps

• Pipes- exploration of blood vessels, usually via CT and sometimes MR angiography
• Parenchyma- exploration of tissue compromise in terms of cell death, usually via non contrast CT or MRI
• Perfusion and penumbra- continue the theme of tissue compromise but go beyond cell death by clarifying ‘tissue at risk’

Question 39

How to manage an intracerebral haemorrhage?

Answer 39

• Required special anticipation to address raised ICP due to haematoma expansion
  
  • Blood pressure control- offer rapid BP lowering who present within 6 hrs of symptom onset, have systolic between 150-220
    
    • Aim for systolic target 130-140 within 1hr starting treatment & maintain this bp for at least 7 days
  • Correcting clotting derangements
  • Maintaining good glycaemic control
  • Coughing, constipation- straining increases abdo pressure, urinary retention causing increase in BP- all these things can contribute to increasing haematoma expansion so pay attention to addressing those
• Pts with any of the following rarely require surgical intervention and should receive initial medical treatment: small deep haemorrhages, lobar haemorrhage w/o either hydrocephalus or rapid neurological deterioration, large haemorrhage and significant comorbidities before stroke, GCS <8 unless because of hydrocephalus
• Decompressive hemicraniectomy for clinical deficits suggesting MCA, decreased level of consciousness

Question 40

How is a decision whether to involve neurosurgeons made when someone has haemorrhagic stroke?

Answer 40

• Neurosurgery as a strategy for managing raised ICP is a balance between the following:
  
  • Surgical accessibility- is it superficial and accessible to surgical evacuation or aspiration
  • Neurological stability- GCS, previously frail?, are they likely to survive anaesthesia or improve neurologically after surgery because raised ICP has already caused irreversible harm
    
    • If hydrocephalus develops, insert ventricular drain

Question 41

When is a decompressive hemicraniectomy (DHC) indicated?

Answer 41

• For management of malignant oedema in <60years old, but otherwise biologically fit stroke pts above this cut off
  
  • Malignant oedema means a large MCA infarction
  • Acute brain swelling
• Referrals should be made within 24 hrs & surgery completed within 48 hrs

Question 42

What are some common post stroke complications?

Answer 42

• Recurrent stroke- due to unaddressed aetiological factors before cause of stroke is clarified and secondary prevention efforts optimised
• Extension of stroke- due to loss of ischaemic penumbra resulting from suboptimal physiology
• Raised ICP- due to haematoma expansion, malignant oedema, haemorrhagic transformation or hydrocephalus
• Infections- aspiration pneumonia, UTI due to incomplete bladder emptying either from constipation or bed bound posture
• Complications of immobility- VTE, constipation, bed sores
• Mood & cognitive dysfunction- can affect motivation and compliance with rehabilitation
• Post stroke pain – due to spasticity, joint dislocation, central/ neuropathic pain
• Fatigue- due to poor sleep, medications, inherent result of brain cell damage
• Spasticity, contractures, secondary epilepsy

Question 43

What is haemorrhagic transformation?

Answer 43

• A common complication of acute ischaemic stroke
• Occurs when peripheral blood extravasates across a disrupted BBB into the brain following ischaemic stroke
• Usually occurs following cardioembolic strokes and is more likely with larger infarct size

Question 44

What is hydrocephalus?

What are the symptoms and how can stroke cause it?

How to manage?

Answer 44

• Excessive volume of CSF within ventricular system of brain
• Symptoms of raised ICP- headache worse in morning, lying down, and during Valsalva; N&V; papilloedema; coma
• Haemorrhage within brain can cause obstructive hydrocephalus due to blocking outflow of CSF
• Ix- CT head is first line
• Mx- external ventricular drain (EVD) is used in acute severe hydrocephalus, inserted into right lateral ventricle & drains into a bag bedside

Question 45

What are some complications of intracranial haemorrhage?

Answer 45

• Mass effect:
  
  • Effacement/ displacement/ twisting of ventricles
  • Hydrocephalus
  • Midline shift
  • Cerebral herniation- subfalcine, uncal, tenting, coning
  • Raising ICP

Question 46

What things can be done to identify complications of stroke as early as possible?

Answer 46

• Surveillance
  
  • Daily review of EWS, obs, mood, chest, legs (DVT), bowel, urine function, progress of impairments
• Timely bloods eg CRP- infection identification and other complications such as LFTs from statins, HB drop from antithrombin therapy

Question 47

Describe some secondary prevention efforts for stroke patients?

Answer 47

• Antithrombotic therapy (antiplatelet vs anticoagulation- 2 weeks of aspirin 300mg followed by clopidogrel 75mg daily)
• BP control (average <130/80)
• Lipid control (commence statins 48 hrs after initiation of a stroke, avoid in cerebral haemorrhage)
• Glycaemic control (HbA1C <7)
• Carotid endarterectomy (symptomatic ICA >50% lumen reduction & NASCET 50-99%)
• Lifestyle- stop smoking, weight loss, optimise sleep, exercise
• Swallow and nutrition assessment
• Rehabilitation- all members of MDT such as PT, OT, SALT, dietician, social worker, stroke coordinator, neuropsychologist
• Palliative care- early recognition and referral for those suspected with poor outcome

Question 48

What sort of vascular risk factors can be optimised to reduce risk of stroke?

Answer 48

• Smoking cessation
• Maintain avg BP < 130/80
• Glycaemic control to HbA1c<7
• Total cholesterol <4 and LDL <2
• Wt loss BMI <25
• Promotion of exercise
• OSA

Question 49

What are some secondary prevention efforts for preventing stroke in pts with AF?

Answer 49

• Anticoagulation- IV or subcut heparin, warfarin, DOACs
• Left atrial appendage closure- option for stroke secondary prevention in pts with AF in whom anticoagulation is contraindicated

Question 50

What is NIHSS?

Answer 50

• National Institutes of Health Stroke Scale
• 15 item neurologic examination stroke scale used to evaluate the effect of acute cerebral infarction on the levels of consciousness, language, neglect, visual field loss, extraocular movement, motor strength, ataxia, dysarthria, sensory loss
• A trained observer rates the pt’s ability to answer Qs and perform activities
• Provides a quantitative measure of the clinical outcome in stroke
• Scoring system out of 42: score <4 is good, >22 means a significant proportion of the brain is affected, >26 is often a contraindication for thrombolysis

Question 51

What is the Modified Rankin Scale (MRS)?

Answer 51

• Used to measure the degree of disability in pts who have had a stroke
• Compared over time to check for recovery and degree of continued disability
• Score of 0 is no disability, 5 is disability requiring constant care for all needs, 6 is death
  
  • 0 = no symptoms
  1. No significant disability, able to carry out all usual activities, despite some symptoms
  2. Slight disability, able to look after own affairs w/o assistance, but unable to carry out all previous activities
  3. Moderate disability, requires some help, can walk unassisted
  4. Moderately severe disability, unable to attend to own bodily needs w/o assistance and unable to walk w/o assistance
  5. Severe disability, requires constant nursing care and attention, bedridden, incontinent
  6. Dead

Question 52

How to estimate how well a stroke patient is likely to do?

Answer 52

• Broad prognostic groups can be initially derived from NIHSS score and OCSP class
• Functional prognosis- recovery trajectory. Recovery will continue until a pt reaches their functional plateau- 3 groups
  
  1. Early, high functioning plateau – the extreme version of this is a TIA or minor stroke, signifying excellent functional prognosis.
  2. Early, low functioning plateau – the extreme version of this is a TACS with no meaningful improvement in function as time passes, signifying poor functional prognosis.
  3. Delayed & medium functioning plateau – this will likely define recovery in most moderate strokes. These patients will benefit from a chance at sustained rehabilitation efforts until a functional plateau is achieved

Question 53

What are some good and poor prognostic factors after a stroke?

Answer 53

• GOOD
  
  • Absence of coma
  • Early motor recovery
  • Continence
• POOR
  
  • Severe communication deficit
  • Old age
  • Incontinence
  • Neglect
  • No leg movement at 2 weeks
  • Severe upper limb weakness at 4 weeks

Question 54

What are the rules of driving and stroke?

Answer 54

• 4 week driving restriction for standard car licenses
• 1 year for HGV vehicles
• Residual visual field dysfunction is subjected to separate requirements before license reinstatement

Question 55

What nutritional support can be offered to stroke patients?

How can swallowing function be assessed?

Answer 55

• Unsafe swallow function-
  
  • Tube assisted enteral feeding is temporary pending safe swallow function
• Assessing swallowing- video fluoroscopy and flexible endoscopic evaluation of swallowing (FEES)
• Prolonged use/ commencement of parenteral feeding is best avoided when pts are approaching end of life- no real improvement to QoL or preventing death
• If patients are unable to swallow adequate food/ fluids orally by 4 weeks from stroke onset- gastrostomy feeding can be considered

Question 56

What rehabilitation therapies are offered to stroke patients?

Answer 56

• Mobility, ADLs, speech and cognitive therapy
• Managing spasticity- including orthotic prosthesis and botulinum toxin therapy
• Environmental modifications

Question 57

What are your differentials for a TIA?

Answer 57

• Hypoglycaemia
• Migraine aura
• Focal epilepsy (symptoms spread over seconds & often include twitching & jerking)
• Hyperventilation
• Retinal bleeds
• Rare mimics- malignant htn, MS, intracranial tumours, peripheral neuropathy, phaeochromocytoma, somatization

Question 58

Suggest some causes of isolated peripheral neural dysfunction?

Answer 58

• Dysarthria- peripheral vocal apparatus, facial/tongue/ throat muscles
• Vertigo- vestibular dysfunction (rather than cerebellum)
• Diplopia- external ocular muscles, peripheral cranial nerve dysfunction (rather than pons)
• Peripheral motor/ sensory dysfunction- eg in dermatomal distribution- can be sudden, focal, predominantly negative but won’t fit into a cerebral vascular territory

Question 59

70 year old woken up at 4am with dizziness described as the room spinning around, associated vomiting, further episodes on turning left (resulting in staying in bed)- cause of presentation? What diagnostic assessment does he need? Treatment?

Answer 59

• BPPV
• Positive Dix-Hallpike test will confirm diagnosis
• Epley manoeuvre is a therapeutic procedure, additional vestibular exercises

Question 60

45 year old presents with sudden onset dizziness, described as room spinning around, associated vomiting, Dix-Hallpike is negative, Head thrust test is positive to the right- cause of presentation?

Answer 60

• Vestibular neuronitis- common presentation of sudden onset vertigo that may bring suspicion of stroke
• Head thrust test confirms diagnosis

Question 61

Usually well 58 year old referred to TIA clinic with ‘acute confusion’. Pt currently has no recollection of events, wife reports he was asking same Qs repeatedly, otherwise talking appropriately and no other signs of focal symptoms. Able to make cup of tea during the episode, all completely resolved within 2 hours, neurological examination normal. What is the likely cause for his presentation? Describe a bit about why/ how this happens.

Answer 61

• Transient global amnesia – dysfunction of episodic memory which is the memory of event. 3 steps to episodic memory: registration, storage, retrieval
  
  • When something first happens, brain registers the events = registration
  • The brain stores the memory it has registered = storage
  • If after a week, you can remember certain things eg recognise a voice = retrieval
  • Other types of memory are preserved eg biographic memory (who you are, where you are), procedural memory (eg making cup of tea)
• During TGA they are unable to register events hence ask the same questions again and again
• It can last a few hours

Question 62

39 year old female, gradual onset blurring of vision on right side, 20 mins later right sided pins and needles slowly migrating from fingers up arm and later affecting face and evolving to become numbness. Associated difficulty concentrating and expressing himself verbally and dull frontal headache similar in past. Is this a stroke or a stroke mimic? Describe a bit about why/ how these symptoms have occurred

Answer 62

• This is migraine with aura
• Visual, sensory, cognitive, speech aura all present in this pt
• The physiological phenomenon underlying migranous aura is cortical spreading depression and the brain location undergoing CSD explains the nature of the aura. The spreading nature explains why migraine aura are gradual in evolution and separate auras tend to evolve sequentially as CSD moves from one brain location to another

Question 63

Migraine with aura: how does it happen and why do aura occur?

Answer 63

• Physiologically characterised by cortical spreading depression or aura activity
• Hence gradual onset, migratory and sequential onset of migraine aura symptoms
• CSD involves altered but continuing brain cell activity- TIA involves cessation of action potentials
• +/- headache
• Visual aura (occipital lobe) is the most common but others are possible- tinnitus & dysphasia (temporal lobe), pines and needles/ transient cognitive disturbance (parietal lobe), unsteadiness/ dizziness/ collapse/ hemiparesis (cerebellum, brainstem)
• Explore triggers

Question 64

• Explore triggers

What is functional syndrome?

Answer 64

• Functional neurological disorder describes neurological symptoms such as limb weakness, tremor, numbness, blackouts
• Caused by a problem with the functioning of the nervous system
• Symptoms-
  
  • Motor dysfunction- eg functional limb weakness/ paralysis, movement disorders including tremor, spasms (dystonia), myoclonus (jerky movements), gait disorder, dysphonia
  • Sensory dysfunction- eg altered sensation, visual symptoms including loss of vision or diplopia
  • Episodes of altered awareness- eg blackouts, non-epileptic seizures
• Exact cause is unknown
• Mx- holistic approach: physiotherapy for motor symptoms, CBT, occupational therapy, speech therapy

Question 65

Suggest some possible stroke chameleons & what do we mean by this?

Answer 65

• Chameleons- when stroke syndrome presentations deviate from the typical presentation
• Venous infarcts- gradual onset, preponderance for seizure activity
• Small cortical strokes- peripheral nerve lesions
• Limb shaking TIA- can appear like a focal seizure- classically due to carotid low flow
• Occipital strokes- predominant confusion, unexplained delirium- rule out other causes of delirium (should be visual field loss)
• Stroke amnestic syndromes
• Stroke mimicking vestibular dysfunction

Question 66

What are the layers of the meninges?

Answer 66

• The meninges cover the brain and the spinal cord- there are three layers
  
  • Dura mater (outermost)
  • Arachnoid mater
  • Pia mater (innermost- tightly adhered to surface of brain & spinal cord, followed gyri & fissures)

Question 67

Where is the subarachnoid space?

Answer 67

• Underneath the arachnoid mater
• Contains cerebrospinal fluid- cushion to brain
• Arachnoid mater projections (arachnoid granulations_ allow CSF to re-enter the circulation via dural venous sinuses

Question 68

What is an extradural haemorrhage, how do they present?

Answer 68

• Acute presentation, young men, 90% have skull fracture
• Limited by sutures, bi-convex, hyperdense
• Outer layer (periosteum) lacerates, inner layer (meningeal) is intact
• Blood collects between naked bone and inner layer of dura mater

Question 69

What are the sources of an extradural bleed?

Answer 69

• Meningeal vessels
• Dural sinus

Question 70

What is a subdural haemorrhage?

Sources of bleed?

Classic presentation?

Answer 70

• Dissection of subdural space- haematoma spreads around the brain, between arachnoid and dura- arachnoid intact
• Convex, not crescentic
• Sources of bleed- torn bridging veins
• Classic presentation- middle age, severe trauma, bleeding can be rapid, localised, hyperdense

Question 71

How do strokes involving the anterior cerebral artery classically present?

Answer 71

• Contralateral hemiparesis and sensory deficits
• Lower extremities affected worse than upper

Question 72

How do strokes involving the middle cerebral artery classically present?

Answer 72

• Contralateral hemiparesis and sensory loss
• Upper extremities affected worse than lower
• Contralateral homonymous hemianopia may be present
• Aphasia may be present

Question 73

How do strokes involving the posterior cerebral artery present?

Answer 73

• Contralateral homonymous hemianopia with macular sparing
• Visual agnosia

Question 74

What is Weber’s syndrome?

Answer 74

• Branches of the posterior cerebral artery that supply the midbrain become blocked
• Ipsilateral CN III palsy
• Contralateral weakness of upper and lower extremity

Question 75

What is lateral medullary syndrome?

Answer 75

• AKA Wallenberg syndrome
• Most commonly due to blockage of the posterior inferior cerebellar artery, causing ischaemia of the lateral part of the medulla oblongata in the brainstem
• Ipsilateral facial pain and temperature loss
• Contralateral limb/ torso pain and temperature loss
• Ataxia and nystagmus
• Loss of temperature sensation and pain from the involvement of the lateral spinothalamic tract

Question 76

How would a stroke involving the anterior inferior cerebellar artery present?

Answer 76

• = Lateral pontine syndrome
• Symptoms similar to lateral medullary syndrome- this artery supplies the pons and the cluster of signs is known as the lateral pontine syndrome
• In addition to the findings of lateral medullary syndrome, ipsilateral facial paralysis and deafness would be expected

Question 77

How does a stroke involving the retinal or ophthalmic artery present?

Answer 77

• Amaurosis fugax

Question 78

Locked in syndrome is a result of stroke in which artery?

Answer 78

• Basilar artery

Question 79

What is Broca’s aphasia?

Answer 79

• Lesion of the inferior frontal gyrus
• Expressive aphasia where the patient’s speech is non-fluent and halting, repetition is impaired
• They can comprehend commands as language comprehension remains relatively intact
• Caused by infarcts to the superior division of the left MCA
• Broca sounds like ‘broken’ as the patient’s word flow is broken

Question 80

What is conduction aphasia?

Answer 80

• Affecting the arcuate fasciculus, the connection between Wernicke’s and Broca’s area
• Speech fluent, repetition poor
• Comprehension relatively intact

Question 81

What is Wernicke’s aphasia?

Answer 81

• Lesion of the superior temporal gyrus
• Speech fluent, comprehension abnormal, impaired ability to repeat back phrases
• = Receptive aphasia
• Commonly secondary to an ischaemic stroke affecting the inferior left MCA
• Word salad

Question 82

What is global aphasia?

Answer 82

• Both Wernicke’s and Broca’s areas are damaged
• Impairment of language production, comprehension and repetition
• Poor stuttering word flow with poor comprehension
• May be able to communicate w/ facial gestures or movements

Question 83

How do lacunar strokes present?

Answer 83

• Either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia
• Strong association with hypertension
• Common sites include the basal ganglia, thalamus and internal capsule

Question 84

What is the first line radiological investigation for suspected stroke?

Answer 84

• Non-contrast CT head scan
• The Question to answer is is this an ischaemic stroke or a haemorrhagic stroke
  
  • Rarely a third pathology such as a tumour may be detected
• This allows us to decide whether to thrombolyse the patient

Question 85

What are the CT head findings for ischaemic and haemorrhagic stroke?

Answer 85

• Acute ischaemic stroke
  
  • May show areas of low density in the grey and white matter of the territory
    
    • These changes may take time to develop
  • Other signs include the hyperdense artery sign corresponding with the responsible arterial clot
    
    • This tends to be visible immediately
• Acute haemorrhagic stroke
  
  • Typically show areas of hyperdense material (blood) surrounded by low density (oedema)

Question 86

Why do we do a non-contrast CT in suspected stroke?

Answer 86

• To rule out intracerebral haemorrhage
• Adding contrast is unnecessary and could make any haemorrhages less easy to see
• A contrast CT scan would therefore NOT be done in the acute investigation of stroke

Question 87

What urgent investigation needs to be performed when a patient initially presents w/ a focal neurological deficit for which you suspect TIA?

Answer 87

• Blood sugar
• Hypoglycaemia can lead to focal neurological symptoms
• Especially important in diabetic pts

Question 88

Possible features of TIA?

Answer 88

• Similar to stroke but features resolve within ~1hr
• Unilateral weakness or sensory loss
• Aphasia or dysarthria
• Ataxia, vertigo or loss of balance
• Visual problems
  
  • Amaurosis fugax
  • Diplopia
  • Homonymous hemianopia

Question 89

How is TIA defined?

Answer 89

• Tissue-based- a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischaemia, w/o acute infarction
• (Used to be time-based)