Define infarction
An area of tissue death due to lack of oxygen. Accounts for 70-80% of strokes
What is the most common cause of infarction
Cerebral atheroclerosis Can also be caused by embolism from intra/extra cranial plaques
What are importnt predictors of stroke?
TIAs. 15% of 1st strokes are preceded by a TIA
Risk factors for stroke or TIAs are:
Smoking, DM, HTN, FH , past TIAs, OCP, PVD, Alcohol excess, Hyperviscosity e.g. Sickle cell, polycythaemia vera
Signs/Symptoms of a stroke are:
Sudden onset, FAST, Numbness, Loss of vision, Dysphagia
Signs/Symptoms of a TIAs are:
Symptoms last less than 24 hours, Amaurosis fugax (painless loss of vision in one eye that is not permanent), Carotid bruit
Vascular territories commonly affected in strokes are:
Anterior vs Posterior territory , Most common is MCA
What areas are affected in TIAs?
Any, Characteristally embolic atherogenic debris from the carotid artery travels to the opthalmic branch of the internal carotid
Investigations of stroke are:
CT/MRI (infarct vs haemorrhage), Ix for vascular risk: BP, FBC, ESR, U&E, glucose, lipids, CXR, ECG, carotid doppler
Investigations for TIA:
Carotid US, Ix for vascular risk: BP, FBC, ESR, U&E, glucose, lipids, CXR, ECG, carotid doppler
Management of a stroke is:
Aspirin +/- dipyridamole, Thrombolytics if less than 3 hours after event, +/- carotid endartectomy, Long term: treat HTN, decrease lipids, anticoagulate
Management of a TIA is:
Aspirin +/- dipyridamole, +/- carotid endartectomy, Long term: treat HTN, decrease lipids, anticoagulate
What are the 2 main subtypes of Haemorrhage
Non Traumatic, Traumatic
Name 2 causes of Non Traumatic haemorrhage
Intraparenchymal haemorrhage, Subarachnoid haemorrhage
Describe intraparenchymal haemorrhage
50% due to HTN, onset is abrupt, can cause charcot-bouchard microaneurysms (likely to rupture), Common site is the basal ganglia
Describe Subarachnoid haemorrhage
85% from ruptured berry aneurysms, most at internal bifurication, F>M, usually under 50 years of age, thunderclap headache, vomiting and LoC, Increased in PKD, Ehler’s Danlos and Aortic coarctation, Associated with vascular abnormalities including AV malformations, capillary telangiectasias, venous and cavernous angiomas, Ehlers Danlos
Name 2 Traumatic haemorrhages
Extradural Haemorrhage, Subdural Haemorrhage
Describe extradural haemorrhage
Skull Fracture, Ruptured middle meningeal artery –> rapid arterial bleed, Lucid interval –> LoC
Describe subdural haemorrhage
Prev history of minor traume –> damaged bridging veins with slow venous bleed, Often elderly/alcoholic, Associated with brain atrophy, Fluctuating consciousness
Whate are the 6 types of increased ICP?
Uncal, Central (transtentorial), Cingulate (subfalcine), Transcalvarial, Upward, Tonsillar
What can cause raised ICP?
Oedema, space occupying lesion (e.g. tumour, abscess) –> brain herniation
What are the signs/symptoms of meningism?
Headache, Stiff neck, Photophobia, +ve Kernig’s sign
What is Kernig’s sign
having the person lie flat on the back, flex the thigh so that it is at a right angle to the trunk, and completely extend the leg at the knee joint. If the leg cannot be completely extended due to pain, this is Kernig sign.
What are the signs/symptoms of viral meningitis?
Mild systemic symptoms, Not unwell, Rash is unusual
