Central Nervous System , Vascular. URL of Article. On this page:. Quiz questions. Early CT signs in acute middle cerebral artery infarction: predictive value for subsequent infarct locations and outcome. Neurology full text - Pubmed citation. Related articles: Stroke and intracranial haemorrhage.
Promoted articles advertising. Figure 1: vascular territories Figure 1: vascular territories. Figure 2: vascular territories Figure 2: vascular territories. Figure 3: vascular territories Figure 3: vascular territories. Case 1: few hours - dense middle cerebral artery sign Case 1: few hours - dense middle cerebral artery sign.
Case 1: day 1 Case 1: day 1. Case 2 Case 2. Case 3: bilateral Case 3: bilateral. Case 4 Case 4. Case 5 Case 5. Case 6 Case 6. Case 8: extensive stroke with swelling and mass effect Case 8: extensive stroke with swelling and mass effect. Case 9 Case 9. Case with decompressive craniectomy Case with decompressive craniectomy. An embolic stroke occurs when an embolus forms in the circulatory system usually in the heart or large arteries of the upper chest and neck , dislodges and is carried to the brain, where it occludes a cerebral blood vessel ASA A haemorrhagic stroke occurs when there is a rupture in a cerebral blood vessel that causes bleeding in the brain ASA a.
The main cause of haemorrhagic strokes is hypertension, but they can also be brought on by anatomical defects such as aneurysms, arteriovenous malformations AVMs or degenerative changes occurring in arterial walls Harvard Medical School This section of the blood vessel may continue to weaken until it eventually ruptures and bleeds into the brain ASA b.
It is estimated that about five per cent of Australians have an aneurysm, but many will not rupture myDR Arteriovenous malformations AVMs occur when there is a cluster or tangle of abnormally formed blood vessels. These blood vessels bypass normal brain tissue and divert the blood from the arteries to the veins. The manifestation of a stroke will depend on many factors. When a stroke occurs, areas of the brain are deprived of their oxygen supply, causing necrosis of cerebral tissue and resulting in neurological deficits.
When a stroke occurs, it is important to take note of which brain hemisphere it has occurred in, as this will suggest the neurological deficits that have potentially occurred. Generally, the patient will experience hemiplegia on the opposite side of the area of stroke. For example, if they had a stroke in the left hemisphere of their brain, they will experience right-sided weakness or hemiplegia Eyvazzadeh It is important to note that individuals who have experienced the same type of stroke will often display different symptoms depending on precisely where and how much of the brain was deprived of oxygen and where cerebral tissue necrosis has occurred.
This is especially important to remember for those who have had an MCA stroke, as the middle cerebral artery supplies such a vast area of the brain that the deficits are dependent on the areas most damaged. The anterior cerebral artery supplies blood to most of the anterior section of the interhemispheric cortical surface of the frontal and parietal lobes Physiopedia This is quite significant considering that a second stroke is often more severe than the first Singapore National Stroke Association Therefore, implementing stroke prevention strategies, providing education and decreasing known risk factors for the individual are essential in the treatment following a stroke.
After such a large stroke, the resulting brain swelling may cause sufficient side-to-side and downward herniation of the brain that the resulting midbrain compression kills the patient. Those who survive the initial period will have a contralateral hemiplegia affecting the lower face, arm and to a lesser extent leg.
Damage to the frontal lobe motor cortex and its projections results in brisk reflexes and a dorsiflexor Babinski response. There is also contralateral hemianesthesia produced by damage to the anterior parietal lobe somatosensory cortex, and a complete contralateral homonymous hemianopsia resulting from damage to the visual radiations as they travel from the lateral geniculate nucleus to the primary visual cortex in the white matter of the posterior temporal and parietal lobes.
In addition, damage to frontal, parietal and temporal lobes near the sylvian fissure in the language-dominant hemisphere almost always the left one produces global aphasia. Although fully conscious, these patients understand nothing that is said and are unable to utter more than a few stereotyped words.
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