University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

197

Pages:

3
Author:

Mariam A.

Embolisation     Atherosclerosis of the carotid arteries, arch of the aorta, and the heart, may cause thrombus formation and embolise to occlude a cerebral vessel. The most common cardiac cause of thrombus formation is atrial fibrillation (10 – 30% of all strokes). Other causes of embolisation: o Mural thrombosus development in severe heart failure. o Mural thrombosis in an aneurysm complicating an anterior myocardial infarction. o Endocarditis complicating valvular heart disease or thrombus complicating a prosthetic valve. Emboli tend to become lodged in large arteries. Small vessel disease  Lacunar infarcts are caused by small vessel disease seen primarily in hypertension, diabetes and old age.  The pathology is known as lipohyalinosis.  Affects small penetrating arteries and arterioles that originate from the base of the brain and supply the basal ganglia, thalamus, deep white matter, and the brainstem. Intracranial haemorrhage  Comprises intracerebral haemorrhage and subarachnoid haemorrhage.  Types of haemorrhage: o Extradural/epidural: between periosteum and periosteal dura; usually caused by tears in arteries. o Subdural: between meningeal dura and arachnoid mater; usually caused by tears in bridging veins that cross the subdural space. o Parenchymal: inside brain tissue.  Causes: o Hypertension. o Cerebral amyloid angiopathy. o Vascular malformations. o Trauma. o Bleeding secondary to a tumour or infarction.    Hypertensive. o Burst and bleed. o Can occur in cerebellum, subthalamic areas, pons and under the cortex. Arteriovenous malformation. o Direct connection between artery and vein. o Can burst and cause spontaneous haemorrhages. Venous sinus thrombosis. o Often seen in pregnancy, dehydration, infection. Stroke syndromes  Symptoms depend on which artery, and hence which area of brain, was affected.  Middle cerebral artery stroke. o Dysphasia. o Dyspraxia. o Neglect. o Visuospatial disturbances, including field defects. o Parietal lobe signs.  Anterior cerebral artery stroke. o Less than 3% of all cerebral infarcts involve cerebral artery territory. o Weakness and sensory loss in contralateral leg. o May have cognitive, behavioural and emotional disorders.  Vertebrobasilar artery. o Dysarthria. o Diplopia. o Ataxia. o Paralysis. o Vertigo. o Vomiting. o Coma. o Dysphonia. o Dysphagia. o Cranial nerve signs. o Horner’s syndrome. Loss of coordination.