Sex can be mind-blowing, literally

Having sex or drinking coffee are just two of a number of activities that can temporarily raise the risk of rupturing a brain aneurysm - which can in turn lead to a stroke.

An aneurysm is a weakness in a blood vessel, in this case in those found in the brain. This weakness can balloon under pressure, which can cause the vessel to burst. This can result in a stroke caused by bleeding at the base of the brain.

It is estimated that 2% of the population have aneurysms in the brain. These rarely rupture, but Dutch scientists from the University Medical Center in Utrecht have identified a range of behaviours that can increase the risk of this happening.

The risk factors identified are (with the figure in brackets showing the percentage of brain hemorrhages that can be attributed to the factor):

• Coffee consumption (10.6 percent)
• Vigorous physical exercise (7.9 percent)
• Nose blowing (5.4 percent)
• Sexual intercourse (4.3 percent)
• Straining to defecate (3.6 percent)
• Cola consumption (3.5 percent)
• Being startled (2.7 percent)
• Being angry (1.3 percent)

Drinking alcohol can also increase the risk for a short period of time.

Commenting on the results, study leader Monique H.M. Vlak said: "All of the triggers induce a sudden and short increase in blood pressure, which seems a possible common cause for aneurysmal rupture."

Difficult to spot

Few people with aneurysms have any symptoms, making it difficult to identify those who should take preventive action. However, with the increasing use of neuro-imaging techniques, more incidental aneurysms are being detected.

In these cases the patients can take measures to reduce their risk, "reducing caffeine consumption or treating constipated patients with unruptured IAs with laxatives may lower the risk of subarachnoid hemorrhage" Vlak said.

The results of the study are published in Stroke: Journal of the American Heart Association.

This article was published on Fri 6 May 2011