NPL4_MDSA30220_2023_Cerebrovascular_Disease_PH_notes.pdf

Stroke and Cerebrovascular Disease MDSA30220 Neurology in Health & Disease Dr Peter Holloway 06/04/2023 Objectives After this lecture you should be able to To classify the different types of stroke – To outline and discuss the causes and mechanisms and consequences of stroke Impact Stroke :One of th...

Stroke and Cerebrovascular Disease MDSA30220 Neurology in Health & Disease Dr Peter Holloway 06/04/2023 Objectives After this lecture you should be able to To classify the different types of stroke – To outline and discuss the causes and mechanisms and consequences of stroke Impact Stroke :One of the leading causes of death and disability in the western world. Ireland 2nd leading cause of death (2019) unchanged from 2009 (in England it dropped from 3rd to 5th over the same period) 2/3 of global stroke burden in middle and low income countries – Higher rates in Asian and African populations than European (also more intracranial vascular disease) Increasing risk with age but ¼ are 95% of the time Stroke is a clinical diagnosis (scans only to rule out haemorrhage and pseudostroke and shouldn’t slow down time to intervention) Vessels Blood vessels are tubes Tubes fail in 2 ways – Blockage Ischaemia – Leakage Haemorrhage Mechanisms/Types Cerebrovascular Disease - Ischaemic (blockages) 85% - Occlusion: Reduced blood flow– ischaemia +/- infarction - Focal (stroke-causing): - Embolic (maximal at outset, risk of later haemorrhagic transformation) - NB Cardiac, aortic arch and extracranial vessels and cardiac NB European - Thrombotic (evolves) - Large vessel stenosis (atheroma branch points) Small vessel stenosis (lipohyalinosis/arteriosclerosis-hypertension, DM, NB Asian and African, vasculitis) - Global (stroke and encephalopathy causing): Hypoperfusion-shockglobal - Haemorrhagic (leakages) 10-15% - Haemorrhage – Secondary to rupture of a blood vessel or aneurysm disruption and possible secondary ischaemia due vasospasm or SOL decreased perfusion pressure - Intracerebral 7-10% - Sub-arachnoid haemorrhage 5% Venous and sinus thrombosis 2 Wks) - Removal of necrotic tissue - - Loss of normal organized appearance CNS structure - - Gliosis Global Cerebral Ischaemia: Laminar necrosis Hypertensive Cerebrovascular Disease Effects: 1. Hypertensive encephalopathy(rare) oedema, headaches, nausea & vomiting, agitation and seizures 2. Massive hypertensive intracerebral haemorrhage 3. Lacunar infarcts LACUNAR INFARCT: Lacunar = “lake-like” Usually a few millimeters in size (