Stroke/TIA Tom Bedwell tab1g11@soton.ac.uk
The Plan Definitions Anatomy Recap Aetiology Pathology Syndromes Brocas / Wernickes Investigations Management Prevention & Prognosis TIAs
Key Definitions Transient Ischaemia Attack: Clinical syndrome. Neurological dysfunction.. Disruption of blood supply. Stroke: Clinical syndrome. Neurological Dysfunction. or death. Disruption of blood supply. infarction haemorrhage intracerebral longstanding hypertension (lenticulostriate arteries) subarachnoid Complicated stroke: Stroke w/ maximal deficit <6 hours Minor stroke: Stroke symptoms resolved w/o significant deficit <1 week
Arterial Anatomy Recap Everyone grab a piece of paper
Of Ischaemic Strokes: 5-10% occur in the ACA 65-75% occur in the MCA 20-30% in VA/PCA What do these regions supply? ACA medial aspect of cerebral hepsiphere MCA lateral aspect of cerebral hemisphere Vertebral Arteries supply the vetrolateral aspect of the medulla forming the Basillar Artery which supply the cerebellum and brainstem. PCA occipital lobe of cerebral hemisphere
NB - These are really easy marks for Intermediates. Don t let Norman down. Aetiology Risk Factors
Ischaemic Stroke Thrombus forms in arteries damaged by valve defects, vasculitis or arterial dissection Non-Atheromatous Disease Thrombus forms in small penetrating intracerebral arteries that are damaged by longstanding hypertension Arterial Atherosclerosis Vessel Occlusion Small-vessel Occlusion (Lacunar Stroke) Thrombus forms on a pre-existing plaque or within the ICA or other intracranial vessels Cardioembolism Cardiac thrombus forms due to AF or recent MI and travels to the cerebral circulation
Stenoses & Plaque Position 1. Origin of Common Carotid artery 2. Origin of Internal Carotid artery 3. Origin of Vertebral artery 4. Subclavian artery
Colliquetive (Liquefactive) Necrosis Occlusion of the artery Hypoxic neurons Disintegration of brain tissue MØs arrive to phagocytose debris Cyst formation
Signs & Symptoms TACS: Total Anterior Circulation Syndrome Vessel: Hemiparesis Homonymous Hemianopia Higher dysfunction PACS: Partial Anterior Circulation Syndrome Vessel: Hemiparesis Leg > Arm Mutism Incontinence Disinhibition Vessel: 2/3 Signs = PACS Hemiparesis Arm > Leg Sensory Deficit Hemianopia Higher Dysfunction LACS: Lacunar Anterior Circulation Syndrome Occlusion to deep arteries supplying internal capsule Pure Motor Pure Sensory Pure Sensorimotor POCS: Posterior Circulation Syndrome Vessel: = CN Palsies + Visual = DANISH-PR
Do not forget your anatomy!
Broca s vs Wernicke s Broca s Wernicke s
Investigations Three main aims: (1) confirm the diagnosis (2) distinguish ischaemia from haemorrhage (3) identify underlying cause of stroke e.g. AF or atherosclerosis etc. Blood Tests FBCs, Renal Function, Lipids, Glucose etc. ECG looking for arrhythmias or recent ischaemias Cardiac Doppler USS look for Carotid artery stenosis CT Brain (Confirm & Distinguish) URGENT IS PATIENT IS A CANDIDATE FOR THROMBOLYSIS MRI occasionally used in diagnostic difficulty more sensitive than CT for ischaemic strokes but slower and less widely available
Differences Between Scans:
Please note, this is a boring slide, full of boring (but necessary) but still boring information. Acute Management 1. Resuscitate! ABCDE + OXYGEN 2. Glucose & BP 3. CT/MRI Urgent: high risk of haemorrhage, thrombolysis is considered or unusual presentation Non-urgent (<24hours) Diffusion weighted MRI is most sensitive for an acute infarct but CT will rule out haemorrhage 4. Thrombolysis - Consider if 18-80yrs & Sx onset <4.5hours 5. Assess Swallowing (NBM + Keep Hydrated) 6. Keep Relatives and/or Patient informed 7. Antiplatelets: Aspirin 300mg ONCE HAEMORRHAGE EXCLUDED 8. Admission to Stroke Unit or Haemorrhage = Neurosurgeons
Prevention & Prognosis Primary Prevention (before a stroke) Control risk factors, e.g. DM, BP, Lipids etc. Folate supplements etc. Secondary Prevention (preventing further strokes) Antiplatelet agents after stroke (C/I d Haemorrhage) If embolic or AF= Warfarin (INR aim 2-3) Treat other causes e.g. Carotid Artery Stenosis or Valve replacements etc. Prognosis Overall 60,000/yr Survivors require care! BIOPSYCHOSOCIAL! Rehabilitation
TIAs Consciousness preserved Hemiparesis & aphasia commonest Clinical evidence of embolus Carotid arterial bruit, AF, difference between L & R brachial BP etc. Special Syndromes: Amaurosis Fugax indicates ICA stenosis Sudden transient loss of vision in one eye (emboli retinal arteries) Benign in migraine Transient global amnesia Episodes of confusion/amnesia last for several hours Presumed posterior circulation ischaemia Prognosis: after 5 years 30% will stroke (1/3 after Y1) and 15% will MI. Anterior Circulation strokes are often more serious
Cheers!