Stroke Andy Ritson. Definition Focal neurological deficit of cerebrovascular origin lasting >24...

Stroke

Andy Ritson

Definition

• Focal neurological deficit of cerebrovascular origin lasting >24 hours

• <24 hours = TIA

• Two types:

– Ischaemic

– Haemorrhagic

Ischaemic stroke

Pathophysiology

• Usually thrombotic embolus

• Origins:– Heart (AF, MI)– Carotids (atherosclerosis)

• Lodges distally occluding blood supply and hence ↓O2 delivery to cerebral tissue

Ischaemic Cascade

• Failure of ATP dependant Na+/K+ pump – depolarisation

• Glutamate toxicity

• Ca2+ influx into cells

• Initiating wide spread destructive effects

• Progressive infarction

Risk Factors• Atherosclerosis:

– Smoking– Diabetes– Hypercholesterolaemia– Age– SE Asian heritage

• Thrombosis:– Oral Contraceptive Pill– Polycythaemia– Thrombophilia– Vasculitis

• Cardiac:- MI- AF- Valvular heart disease

- Previous Stroke / TIA

Clinical Picture• Related to neuroanatomy:

ClassificationPartial Anterior

Total Anterior Posterior Lacunar

Signs 2 of the following: motor or sensory deficit; higher cortical dysfunction, hemianopia

Motor or sensory deficit, higher cortical dysfunction and hemianopia

Isolated hemianopia, brainstem signs and cerebellar ataxia

Motory or sensory deficit only

Arteries affected

Ant. or middle cerebral

Ant. or middle cerebral

Post. cerebral, basillar or vertebral

Any deep penetrating artery

Higher cortical functions: Speech disturbances and visual-spatial disturbances.

Brainstem signs: Heart rate, blood pressure, breathing, swallowing, digestion, eye movements, speech and body movement.

Cerebellar signs: nystagmus, truncal ataxia, co-ordination problems etc

ACUTE MANAGEMENT• Airway

– Protected– Swallowing?

• Breathing– Adequate on air?

• Circulation– Fluid replacement if BP ↓– Do not routinely treat hypertension

• Disablility– GCS– Pupils

• Exposure– Sustained other injuries with fall?– Concomitant pathologies?

• GLUCOSE!

Investigations:• CT Scan:

– Rule out HAEMORRHAGE– Exclude tumour– Evidence of early ischaemic changes

• Bloods – FBC, U+E, Glucose, Coagulation, ESR

• Cardiac– ECG– Echo– Carotid doppler US

• CXR – heart size, lung pathology, tumours

Thrombolysis

• Administered <4.5hrs of symptom onset

• Recombinant tissue Plasminogen Activator (rtPA) = “alteplase”

• Binds to fibrin and activates plasminogen → cleaves fibrin → degrades thrombus

• Also give Aspirin 300mg

Contraindications• Extremes of age (>80 or <18)

• Previous severe disability / terminal illness

• Hx ICH / neoplasm or AV malformation

• Stroke / prev head trauma (3/12)

• Platelets ↓or INR > 1.5

• Pregnancy / Recent Childbirth (2 weeks)

• Recent MI (1 month)

• Active Bleeding / Acute Trauma

• Major Surgery (2 weeks)

Complications• Dysphagia

– Malnutrition / Medications– Aspiration pneumonia

• Immobility– Muscle wasting and contractures– Pressure sores → ulceration → infection– Falls– Osteoporosis

• Incontinence– Skin integrity– Retention of Urine– Catheterisation → UTI

• Epilepsy• Depression• Death

Secondary Prevention• Antiplatelet

– Aspirin 300mg (2/52) then 75mg

• Statin

• BP (aggressive if DM)

• Carotid Endarterectomy

• Lifestyle

Case 1

An 81 year old woman is found collapsed on her bedroom floor by the sheltered housing warden the day after a trip to her bingo. A CT scan of the brain reveals an area of ischaemia in the left parietal cortex, consistent with a recent cerebral infarct. She is badly bruised and has an obvious weakness on the right side of her body. She is confused and her speech sounds slurred.

• An 81 year old woman is found collapsed on her bedroom floor by the sheltered housing warden the day after a trip to her bingo. A CT scan of the brain reveals an area of ischaemia in the left parietal cortex, consistent with a recent cerebral infarct. She is badly bruised and has an obvious weakness on the right side of her body. She is confused and her speech sounds slurred.

a. What is the definition of a stroke?

A rapidly developing focal neurological deficit of vascular origin lasting over 24 hours or causing death

b. Suggest 4 risk factors for stroke?

• Hypertension• Atrial fibrillation • Diabetes mellitus• Smoking• Previous TIA/stroke• Increasing Age• Oral contraceptive pill use• Coagulopathy• Sedentary lifestyle• Hypercholesterolaemia• Raised haematocrit• Cocaine use• Male• Asian descent

c. The CT scan of the brain showed an area of ischaemia. Explain the pathogenesis of this cause of stroke.

• Narrowing of the supplying blood vessels (thrombus, embolus) causes reduced blood flow (and thus oxygen and glucose) to an area of the brain.

• There is a central area of necrosis surrounded by a penumbra that may be salvageable if blood supply is re-established.

• There is an initiation of the ischaemic cascade that causes inflammation and oedema that results in tissue damage.

• This leads to glutamate toxicity and cell membrane permeability changes thus activating destructive enzymes.

d. Given this lady’s symptoms, which is the most likely artery to have been affected by this stroke?

• Left Middle Cerebral Artery

e. List 4 significant non-neurological complications of stroke.

• Aspiration pneumonia• DVT/PE due to immobility• Communication difficulties due to dysphasia and

dysarthria• Depression• Bed sores due to immobility• Urinary incontinence

f. This patient shows slow improvement over the next three months. Outline 2 management options that the OT would be able to help with in cases like this.

• Home assessment and adaptations where appropriate

• Physical and cognitive deficit screen and provision of aids where needed

Past paper 2

While working as a FY1 on a medical ward you are asked to assess Mrs FK, a 75 year old woman, who was admitted to hospital one week previously with a sudden onset of weakness in the right arm and leg. On examination you confirm the weakness and also find that the muscle tone in the right arm and leg is increased. Sensation is decreased on the right side. Although she can talk, she sometimes has difficulty finding the words she wants.

While working as a FY1 on a medical ward you are asked to assess Mrs FK, a 75 year old woman, who was admitted to hospital one week previously with a sudden onset of weakness in the right arm and leg. On examination you confirm the weakness and also find that the muscle tone in the right arm and leg is increased. Sensation is decreased on the right side. Although she can talk, she sometimes has difficulty finding the words she wants.

a. What changes do you expect in the tendon reflexes on the right side?

Hyper-reflexive (brisk)

b. What is the mechanism of this alteration to the reflexes?

Loss of descending inhibitory input to the reflex arc resulting in an uninhibited reflex response.

c. What do you expect the right plantar reflex to be?

Up going

d. Which cranial nerve is the one most likely to be affected?

Trigeminal (CN 5)

e. What visual field abnormality might you expect to find on examination?

Homonymous hemianopia

Over the next 24 hours the patient’s condition deteriorates. A CT scan confirms an infarct in the left middle cerebral artery territory. Her husband calls you aside and asks you to write in her notes that she should not be resuscitated if she stops breathing.

f. Which 2 articles of the Human Rights Act are most applicable when considering these issues?

Article 2 – right to lifeArticle 3 – protection from mistreatment

e. Having established the diagnosis, what three issues do you need to take

into considerationbefore writing a “Do Not Resuscitate” order?

• Has the DNR order been discussed with the patient and family• Does the patient have capacity to make the decision• Would resuscitation likely to be successful and beneficial for the patient

Haemorrhagic strokes

Pathology

• Aneurysms• Arteriovenous formation• Trauma• Blood coagulation disorders• Vessel erosion by tumours

Types

• Extradural• Subdural• Intracerebral• Subarachnoid

Case 1Case 1

• 18 year old male presents to ED after being hit on the head with a bottle 3 hours previously

What would you do?

– ABCDE– History: slightly drowsy after injury, but has

resolved, no LoC– O/E: GCS 15, no focal neurology, large

parietal haematoma

Deteriorates after another hour

ExtraduralExtradural

• Laceration of MMA by fracture of temporal or parietal bones

• Features:– Lucid interval followed by GCS– Deterioration is due to ICP– May get UMN signs

• Management:– ABCDE CT Surgeons

Case 2Case 2

• 87 year old demented female has fallen out of bed that morning

What would you do?

– ABCDE– History: headache, “more confused”, AF,

vomited – O/E: GCS 13, drowsy, dysphasic

Therefore:

- Bloods and CT

Acute SubduralAcute Subdural

• Shearing of veins crossing the subdural space

• Associations:– Trauma, alcohol, anticoagulation

• Features:– Progressively GCS– Signs of ICP

• Management:– ABCDE CT Surgeons

Chronic SubduralChronic Subdural

• Similar to ASDH, but insidious

• Fluctuating consciousness

• Personality change

• Sleepiness

• Unsteadiness

• Features of raised ICP

• Almost always very old or very young

Case 3Case 3

• 48 year old male presents to the ED after a night out

• What would you do?– ABCDE– History: friends says he collapsed, had been

using cocaine– O/E: GCS 12, Babinski positive on the right,

right hemi-paresis– CT and bloods

Intra-cerebralIntra-cerebral

• Rupture of small intracerebral vessels:– Spontaneous = “haemorrhagic stroke”

• Features:– Neurology dependent on location– ICP (blood + oedema)

• Associations:– Hypertension– AVM, bleeding disorders, drugs

• Management:– ABCDE CT ?Surgeons

Case 4Case 4

• 48 year old female presents with “worst headache of my life”

• What would you do?– ABCDE– History: instantaneous severe occipital

headache, vomited 3 times, has polycystic kidneys

– O/E: GCS 12, Kernig’s positive, hypertensive, pyrexial

SubarachnoidSubarachnoid• 80% ruptured aneurysm, 5% AVM• Associations:

– Smoking, alcohol, hypertension– Polycystic kidney disease, family history,

bleeding disorders

• Features:– Thunderclap headache, vomiting, GCS, neck

stiffness, pyrexia, Kernig’s sign, BP

• Management:– ABCDE CT Nimodipine Surgeons