This news item caught my eye just yesterday.
A middle-aged lady had her hair washed seven times (the stylist was trying to get the colouring right) while leaning back over the edge of the sink.
Many mechanisms and factors might lead to a ‘vascular event’ in this situation, potentially causing a stroke.
What do we mean by a vascular event?
The vertebral arteries, which connect the heart’s freshly oxygenated blood to the base of the brain, have to wind their way up through the vertebrae of the neck and then loop – in an odd way – around the top vertebrae before going up into the brain.
Any direct pressure on the artery, which is especially likely to happen as it loops, can cause a reflex contraction of the muscular coat of the artery. Temporary stress like this won’t usually cause a problem – perhaps just momentary dizziness?
But what if this pressure was combined with excessive stretching, torsion or abrasion? This might just happen when the neck twists and tightens around the artery, and is more likely if there is degenerative change in the neck due to trauma or age.
A small tear in the artery in the inner muscular coat of the artery can sometimes lead to a dissection. This, apart from causing pain, can potentially rupture into the internal space of the artery just where the high-pressure blood flows. A stroke might develop from this, generally after some delay (at least a few hours).
The moral of the story? If you are over fifty, always have your hair washed leaning forward over the sink, and never backwards.