Neurology Flashcards
Stroke (ischaemic, haemorrhage) definition
Ischaemic stroke = vascular occlusion or stenosis cuts off blood supply to the brain
- most common type of stroke (87%)
Haemorrhagic stroke = vascular rupture, resulting in intraparenchymal and/or subarachnoid haemorrhage - bleeding in brain causes stroke
- 13% of strokes
Stroke aetiology
Risk factors both
- age >55
- family history
- HTN, T2DM
- smoking
Ischaemic
- Afib
- history of: TIA, stroke
- sickle cell disease
Haemorrhagic
- male
- asian/black
- alcohol
- anticoagulant use
Stroke pathophysiology
Other types = subarachnoid haemorrhage and cavernous sinus thrombosis
Stroke clinical manifestations
Ischaemic - key
- vision loss
- unilateral muscle weakness (often face, arm, leg)
- impaired language function (aphasia)
- impaired coordination (ataxia)
Ischaemic - other
- sensory loss
- headache
- diplopia
- dysarthria
- gaze paresis
- arrhythmia
Haemorhhagic
- visual disturbance (homonymous hemianopia - visual field loss on the left or right side of the vertical midline on the same side of both eyes may be due to haemorrhage in visual pathways, diplopia may result from brain stem haemorrhage)
- photophobia
- unilateral muscle weakness/paralysis (often face, arm, leg)
- dysarthria/dysphasia
- ataxia
- sensory loss
Stroke uncommon clinical manifestations
Both
- vertigo
- nausea/vomiting
- coma
Ichaemic
- neck/facial pain
Haemorrhagic
- gaze paresis
Stroke 1st line investigations
Both
- non-contrast CT head
- serum glucose - hyperglycemia associated with worse prognosis, hypo
= stroke mimc
- serum electrolytes - exclude electrolyte disturbance
- serum urea and creatinine - exclude renal failure
- FBC - exclude thrombocytopenia
- ECG - may indicate MI
Ischamic
- cardiac enzymes - exclude MI
- PT and PTT - exclude coagulopathy
Haemorrhagic
- liver func
- clotting screen - exclude coagulopathy
Stroke general investigations
Both: serum toxicity screen - exclude alcohol/drug causes
Ischaemic
- CT/MRI - show areas at risk of subsequent infarction
- US - shows carotid stenosis
Stroke management
INITIAL - suspected ischaemic/haemorrhagic stroke
- first line stabilize and refer to hyperacute/acute stroke unit
- consider endotracheal intubation
- give supplementation oxygen only if oxygen saturation drops below 93%
ACUTE - confirmed ischaemic stroke
- 1st line - monitor: consciousness (Glasgow coma scale), blood glucose, BP, oxygen saturation, hydration, temperature (antipyretic high temp), cardiac rhythm and rate, intracranial pressure
- IV alteplase
- mechanical thrombectomy and antiplatelet drug (aspirin)
- venous thromboembolism prophylaxis and high intensity statin (atorvastatin)
ACUTE - confirmed haemorrhagic stroke
- 1st line - monitor (as above) and immediate referral to neurosurgery assessment
- rapid BP control
- reversal of anticoagulation
- warfarin/vit K antagonist reversal (prothrombin complex concentrate, phytomenadione)
- dibigatran reversal (idarucizumab)
- factor Xa reversal (prothrombin complex concentrate)
- venous thromboembolism prophylaxis
Transient ischaemic attack (TIA) definition
Focal, sudden onset, neurological deficit lasing <24 hours, with complete clinical recovery
15% of first strokes are preceded by TIA
Transient ischaemic attack epidemiology
M > F
Black ethnicity is at greater risk due to their hypertension and atherosclerosis predisposition
20, 000 people have a TIA
Risk factors
- age
- hypertension
- smoking
- diabetes
- heart disease - valvular, ischaemic or AF
- past TIA
- peripheral arterial disease
Transient ischaemic attack aetiology
Inadequate cerebral or ocular blood supply due to
- reduced blood flow
- ischaemia
- embolism associated with disease of: blood vessels, heart or blood
Reduced blood flow can be caused by
- atherothromboembolism from the carotid artery
- small vessel occlusion
- cardioembolism resulting in microemboli from
- mural thrombus post-MI or in AF
- valve disease
- prosthetic valve
- hyperviscocity eg polycythaemia, sickles cell anaemia, extremely raised white cell count, myeloma
Transient ischaemic attack pathophysiology
Common cause is from cerebral ischaemia - lack of O2 and nutrients to the brain - cerebral dysfunction
- ischaemia is short lived, with symptoms only lasting a maximum if 5-15 mins after onset and then resolves before irreversible cell death occurs
Gradual progression of symptoms suggests a different pathology eg demyelination, tumour or migraine
90% of TIA’s affect the anterior circulation (carotid artery)
10% affect posterior circulation (vertebrobasilar artery)
Transient ischaemic attack clinical manifestations
Sudden loss of function with complete recovery
Stroke symptoms (focal neurological deficit)
- slurred speech
- facial droop
Transient ischaemic attack other diagnostic features
Associated with both anterior and posterior circulation TIAs
- unilateral weakness/paralysis
Associated with anterior circulation TIAs
- dysphasia
- amaurosis fugax
Aossictaed with anterior circulation TIAs
- ataxia, vertigo, loss of balance
- homonymous hemianopia
- diplopia
Transient ischaemic attack investigations
First line:
Blood glucose - exclude hypoglycaemia
FBC/platelet count = normal
PT/PTT/INR - exclude coagulopathy
Fasting lipid profile - normal or hyperlipidemia
Serum electrolytes - exclude electrolyte disorders
ECG - evaluate atrial fibrillation and other arrhythmias (rule out MI)
CT angiography - look for stenosis
Transient ischaemic attack differential diagnosis
Impossible to differentiate from a stroke until there is a full recovery
Hypoglycaemia
Labyrinthine disorders - labyrinthitis/vestibular neuronitis, BPPV, Meniere’s disease
Migrainous aura
- typical - visual symptoms, sensory symptoms, dysphagia
- atypical - motor weakness “hemiplegic migraine”
Mass lesions
- sundural hematoma
- cerebral abscess
- tumours
Postictal weakness (also known as Todd’s paralysis)
Transient ischaemic attack management
INITIAL - for suspected transient ischaemic attack 1st line - antiplatelet therapy Primary: aspirin Secondary: clopidogrel Referral
ACUTE - confirmed TIA 1st line - Antiplatelet therapy Primary: clopidogrel Secondary: aspirin
High intensity statin - atorvastain - simvastatin Anticoagulant - LMW heparin - direct thrombin inhibitor - factor Xa inhibitor
Subarachnoid, subdural, extradural haemorrhage definition
EDH - bleeding external to dura
SDH - bleeding beneath the dural membrane
SAH - bleeding within the subarachnoid space
Subarachnoid, subdural, extradural haemorrhage epidemiology
EDH - adolescents/young adults
- 10% severe head injuries -> EDH
SDH
- elderly
- blood thinning medication
- haemophilia
- epilepsy
- alcoholics (chronic alcohol consumption can gradually cause brain to shrink and make blood vessels more vulnerable to damage
SAH - uncommon
Subarachnoid, subdural, extradural haemorrhage risk factors
SAH
- smoking
- high blood pressure
- excessive alcohol consumption
- a family history of the condition
- some rarer conditions, such as autosomal dominant polycystic kidney disease (ADPKD)
Subarachnoid, subdural, extradural haemorrhage aetiology
EDH
- head strike (sport/motor vehicle accident)
- fractured temporal or parietal damaging the middle meningeal artery or vein
SDH
- usually trauma causes tearing of subdural cortical bridging veins = blood between dura matter
SAH
- after trauma where cortical surface vessels are damaged
- non-traumatic follows the rupture of a cerebral (Terry) aneurysm = blood in circle of willis cisterns and fissures
- less common - brain tumour; encephalitis; vasculitis
Subarachnoid, subdural, extradural haemorrhage pathophysiology
SDH
Bleeding into the subdural space caused by damage to cranial vessels/brain.
As blood starts to build up, it can place pressure on the brain (intracranial hypertension) -> brain damage
SAH
A brain aneurysm is a bulge in a blood vessel, caused by weakness in the blood vessel wall, usually at a point where the vessel branches off. As blood passes through the weakened vessel, the pressure causes a small area to bulge outwards like a balloon and rupture
Subarachnoid, subdural, extradural haemorrhage clinical manifestations
EDH
- initial loss of consciousness -> lucid interval -> second loss of consciousness
- hemiparesis
- nausea/vomiting
- unequa pupils
- bradycardia
SDH
- level of consciousness gradually decreases
- gradual increase of headache and confusion/slurred speech
- confusion
- double vision
- seizures
SAH
- extremely painful headache
- thunderclap headache, maximum severity within seconds, worse ever, potential focal symptoms/coma as a result of aneurysms
- sight problems
Subarachnoid, subdural, extradural haemorrhage management
EDH
- expident evacuation via a craniotomy
- ABC/2 (haemorrhage volume measurement method)
- give oxygen
- a full trauma assessment must be made
- intravenous (IV) fluids may be required to maintains the circulation and preserve cerebral perfusion
- if IC pressure is raised -> osmotic diuretics (IV mannitol)
- Burr holes may be required to evacuate a hematoma
SDH
- conservative (monitor with serial CT)
- surgical - craniotomy (main treatment after severe head injury); burr holes (main treatment for hematomas)
SAH - nimodipine - analgesioa anticonvulsant (phenytoin) - antiemetic (promethazine) - surgery - neurosurgical clippings, endovascular coiling