By using NIR spectroscopy to monitor blood flow in the brains of six climbers scaling Mount Kilimanjaro in Tanzania, German medical researchers have identified a possible way to prevent the headaches that are a common feature of altitude sickness. This work appears in the latest issue of Journal of Near Infrared Spectroscopy.
Peter Stein, at the department of anesthesiology, intensive care medicine and pain therapy at University Hospital Frankfurt, and his colleagues accompanied six climbers as they scaled Mount Kilimanjaro. They attached NIR electrodes to the climbers’ foreheads while they slept to monitor haemoglobin concentrations in the blood supply to the brain.
Stein wanted to discover whether abnormal breathing patterns observed in climbers sleeping at high altitudes was reducing the supply of oxygen to the brain, potentially worsening the effects of altitude sickness. The team used NIR spectroscopy to analyse haemoglobin concentrations.
‘The lack of oxygen at high altitude causes the climbers to hyperventilate, which leads to a decline of CO2 in the blood,’ explained Peter Stein, who is in the department of anesthesiology, intensive care medicine and pain therapy at University Hospital Frankfurt. ‘The decline of CO2 leads to episodes of hypoventilation or even apnoea when the conscious breathing control subsides during sleep. As a consequence the oxygen level drops, causing an arousal and subsequent hyperventilation.’
The researchers discovered that those climbers experiencing the most extreme periodic changes in haemoglobin concentrations in the brain as they slept were also those that suffered most from headaches at high altitudes. This suggests that one simple approach to preventing these headaches is to find ways to stop the abnormal breathing that occurs when sleeping at high altitudes.
‘Our experiments reveal a pathomechanism contributing to the aetiology of the most common symptom of altitude sickness: headache,’ said Stein. ‘I hope that based on our findings it will be possible to develop new therapeutic approaches that help to increase comfort and safety for climbers in the future.’