Ischemic
Ischemic stroke, the most common is caused by a blockage of a blood vessel in the brain, usually caused by thrombosis or emboli from a proximal arterial source or the heart, that leads to the brain being starved of oxygen. The neurologic signs and symptoms must last longer than 24 hours or the brain infarction is demonstrated, mainly by imaging techniques. Transient ischemic attack (TIA) also called a mini-stroke. This is a condition in which the blood flow to a region of the brain is blocked, but blood flow is quickly restored and the brain tissue can fully recover. The symptoms are only transient, leaving no sequelae, or long-term deficits. In order to diagnose this entity, all neurologic signs and symptoms must have been resolved within 24 hrs without evidence of brain infarction on brain imaging. Hemorrhagic
Subarachnoid haemorrhage occurs when blood leaks out of damaged vessels into the cerebrospinal fluid in the subarachnoid space around the brain. The most common cause of a subarachnoid hemorrhage is an aneurysm rupture due to the weakened blood vessel walls and increased wall stress. The neurologic symptoms are produced by the blood mass effect on neural structures, from the toxic effects of blood on the brain tissue, or by the increasing of intracranial pressure. Intracerebral haemorrhage is bleeding directly into the brain rather than around the brain. Causes and risk factors include hypertension, blood thinning medications, trauma, and arteriovenous malformations. Diagnosis
Diagnoses of cerebrovascular disease may include:
medical history
physical exam
neurological examination.
Usually, a capillary bed separates arteries from veins, which protects the veins from the higher blood pressures that occur in arteries. In arteriovenous malformations, arteries are directly connected to veins, which increases the risk of venous rupture and hemorrhage. Arteriovenous malformations in the brain have a 2–4% chance of rupture each year. However, many arteriovenous malformations go unnoticed and are asymptomatic throughout a persons lifetime. A germinal matrix hemorrhage is bleeding into the brain of premature infants caused by the rupture of fragile blood vessels within the germinal matrix of premature babies. The germinal matrix is a highly vascularized area within an unborn infants brain from which brain cells, including neurons and glial cells, originate. Infants are at most risk to germinal matrix hemorrhages when they are born prematurely, before 32 weeks. The stresses exposed after birth, along with the fragile blood vessels, increase risk of hemorrhage. Signs and symptoms include flaccid weakness, seizures, abnormal posturing, or irregular respiration.CADASIL is an inherited disorder caused by mutations in the Notch 3 gene located on chromosome 19. The Notch 3 gene codes for a transmembrane protein whose function is not well-known. However, the mutation causes accumulation of this protein within small to medium-sized blood vessels. This disease often presents in early adulthood with migraines, stroke, mood disturbances, and cognitive deterioration. MRI shows white matter changes in the brain and also signs of repeated strokes. The diagnosis can be confirmed by gene testing.