Stroke is a collective name for brain damage caused by a blood clot or bleeding in the brain. A stroke leads to a lack of oxygen in the brain which causes you to suddenly lose various functions such as speech, movement, feeling and vision. It can be life-threatening and therefore immediate hospital care is required.
Here you can read more about diseases and disorders that have to do with stroke and blood vessels in the brain.
A pulmonary artery hernia on the brain's vascular tree means that part of a pulmonary vein has weakened and expanded. If the hernia breaks, you may have brain bleeding inside or outside the brain, that is, a form of stroke. How it will go depends, among other things, on how much bleeding is and what part of the brain is affected.