Anti aging guide

Stroke and the Brain

 

 

How common are strokes and what causes it?

A stroke is the result of a disturbance of the blood supply to a part of the brain. Each part of the brain has its own function, and those functions contained within the damaged area will be seriously affected. About 15 pep cent of strokes are caused by cerebral haemorrhage, which is a rupture of a blood vessel with destruction of brain tissue by the ensuing torrent of blood. A large majority of strokes, about 80 per cent, are caused by the blood supply being drastically diminished by atherosclerosis (resulting in cerebral infarction) with or without the formation of a thrombosis (clot). Sometimes a clot travels upwards from the heart or from an ulcerated area in the carotid artery in the neck. It will be readily appreciated that there are many different kinds of stroke, depending on which of these underlying mechanisms is responsible and on the area of the brain affected. It will also be appreciated that the onset is typically sudden but that the effects are long-lasting. Stroke is a chronic disability with an acute onset.

The number of strokes occurring annually per 100 000 population has fallen substantially in the USA and, to a lesser extent, in other developed countries during the past quarter century. Mortality rates have also fallen in these countries but have risen sharply in Eastern Europe. This decline in Western Europe, North America, Australia, and New Zealand seems to have come to an end, so that stroke remains the third leading cause of death after coronary heart disease and lung cancer in the UK. Perhaps more importantly, it continues to cause immeasurable suffering to victims and their families and an enormous amount of dependency and utilization of hospital and nursing-home bed days.

Cerebral haemorrhage is mainly caused by high blood pressure although a rarer cause is an inborn weakness in the wall of one of the arteries supplying the brain. Cerebral infarction is caused by atherosclerosis but sometimes it is a sudden fall in blood pressure, perhaps due to a heart attack, that reduces a precarious blood supply through a narrowed vessel to a level insufficient to keep that particular part of the brain alive.

The main risk factors for atherosclerosis are as follows:

  •  age
  •  high blood pressure (and therefore obesity and heavy alcohol use)
  •  smoking
  •  diabetes
  •  raised blood cholesterol.
Posted by Carol Hudgens - May 6, 2012 at 2:41 pm