IPLab:Lab 3:Brain Infarction
Eight years prior to his demise, this 48-year-old black male had a dissecting aortic aneurysmA dissecting aortic aneurysm occurs when an intimal tear allows blood--under very high pressure--to enter the media and thus to separate the intima from the adventitia. The separation occurs longitudinally and amounts to the formation of a blood-filled canal parallel to the aortic lumen which may run the entire length of the aorta. The word aneurysm usually refers to an abnormal dilatation of a localized segment of artery. Since marked dilatation of the aorta is not a prominent feature of a dissecting lesion, aortic dissection is now the preferred term.. The first portion of the aortic arch was dilated with an associated aortic valve insufficiencyAortic insufficiency refers to the inability of the aortic valve to close properly, thus allowing regurgitation of blood into the left ventricle during diastole -- i.e., volume overload. Disease of the aortic valve leaflets is a common cause of insufficiency.. The defect was repaired and a mechanical prosthetic valveProsthetic heart valves are a common source of emboli (blood clots) which may lodge in arteries of the brain and lead to infarction. was implanted. One year prior to his terminal admission, the patient experienced a catastrophic cerebrovascular accidentA cerebrovascular accident (CVA) is known as a stroke in layman's terms. The most common cause of CVAs, by far, is a brain infarction resulting from reduced blood flow secondary to a thrombotic embolus (blood clot). (CVA) with left hemiparesisSlight paralysis or weakness affecting one side of the body. and obtundationObtunded patients will have mental blunting with mild to moderate reduction in alertness and a diminished sensation of pain.. The patient experienced severe neurologic sequelae from this CVA and was eventually transferred to a nursing home where he was bedbound and required an indwelling urinary catheter. The patient developed a urinary tract infection and was transferred to the hospital. The patient's condition deteriorated and he died 6 weeks after admission with a urinary tract infection and pneumoniaIn alcoholics, aspiration pneumonia is common--bacteria enter the lung via aspiration of gastric contents..
Autopsy showed the expected findings in the aorta and in a 760-gramA normal heart weighs 300 grams (range: 270 to 360 grams). heart. The mechanical valve showed some deterioration and there was old thrombotic material adherent to the valve, which was probably the source of the emboliPlural of embolus. An embolus is something that blocks the blood flow in a blood vessel. It may be a gas bubble, a blood clot, a fat globule, a mass of bacteria, or other foreign body. It usually forms somewhere else and travels through the circulatory system until it gets stuck. which caused the patient's CVA. The patient's 1250-gram brainA normal brain weighs 1400 grams (range: 1100 to 1700 grams). showed extensive old infarctions in at least three different areas, with the largest (12.5 x 5.5 cm) in the distribution of the right middle cerebral artery.
Thrombotic occlusionAn occlusion is a blockage. of cerebral arteries due to atherosclerosis. The carotid arteries, the origin of the middle cerebral artery, and either end of the basilar artery are the most common sites of thrombusA thrombus is a solid mass resulting from the aggregation of blood constituents within the vascular system..
Infarction resulting from thrombotic material from the prosthetic heart valve.
- eMedicine Medical Library: Ischemic Stroke
- eMedicine Medical Library: Acute Aortic Dissection
- eMedicine Medical Library: Prosthetic Heart Valves
- Merck Manual: Overview of Stroke (CVA)
- Merck Manual: Thrombotic Disorders
- Merck Manual: Aortic Dissection
- Love S, Barber R, Wilcock GK. Neuronal death in brain infarcts in man. Neuropathol Appl Neurobiol 2000 Feb;26A normal partial thromboplastin time is 28 to 37 seconds.(1):55-66.