Search results
Results from the WOW.Com Content Network
AVMs are more common in males than females, although in females pregnancy may start or worsen symptoms due to the increase in blood flow and volume it usually brings. [31] There is a significant preponderance (15–20%) of AVM in patients with hereditary hemorrhagic telangiectasia (Osler–Weber–Rendu syndrome). [6]
The heart failure is due to the size of the arteriovenous shunt that can steal 80% or more of the cardiac output, with large volumes of blood under high pressure returning to the right heart and pulmonary circulation and sinus venosus atrial septal defects. [4] [5] It is also the most common cause of death in such patients. [6]
The epidemiology of cranial venous outflow obstruction is not well-studied, and the condition is likely underdiagnosed due to the nonspecific nature of its symptoms. However, it is known to affect individuals of all ages, with a higher prevalence in females and individuals with anatomical venous disorders (varicose veins), certain risk factors ...
The deep venous system is primarily composed of traditional veins inside the deep structures of the brain, which join behind the midbrain to form the great cerebral vein (vein of Galen). This vein merges with the inferior sagittal sinus to form the straight sinus which then joins the superficial venous system mentioned above at the confluence ...
Posterior cerebral artery syndrome is a condition whereby the blood supply from the posterior cerebral artery (PCA) is restricted, leading to a reduction of the function of the portions of the brain supplied by that vessel: the occipital lobe, the inferomedial temporal lobe, a large portion of the thalamus, and the upper brainstem and midbrain. [1]
Brain herniation is associated with hyperventilation, extensor rigidity, pupillary asymmetry, pyramidal signs, coma and death. [10] Hemorrhage into the basal ganglia or thalamus causes contralateral hemiplegia due to damage to the internal capsule. [7] Other possible symptoms include gaze palsies or hemisensory loss. [7]
Brain ischemia has been linked to a variety of diseases or abnormalities. Individuals with sickle cell anemia, compressed blood vessels, ventricular tachycardia, plaque buildup in the arteries, blood clots, extremely low blood pressure as a result of heart attack, and congenital heart defects have a higher predisposition to brain ischemia in comparison to the average population.
The lack of blood flow results in cell death and subsequent breakdown of the blood vessel walls, leading to bleeding. While this bleeding can result in further injury, it is itself a marker for injury that has already occurred. Most intraventricular hemorrhages occur in the first 72 hours after birth. [9]