Höjdhjärnödem

Höjdhjärnödem, also known as high-altitude cerebral edema (HACE), is a serious medical condition that can occur in people who ascend to high altitudes too quickly. It is a form of acute mountain sickness (AMS) and is characterized by swelling of the brain due to increased pressure. This swelling is thought to be caused by the body's response to lower oxygen levels at high altitudes, leading to dilation of blood vessels in the brain and increased fluid leakage.

Symptoms of HACE typically develop within 12 to 72 hours of reaching a high altitude, often above 3,000 meters (9,800 feet). Early symptoms can include severe headache, nausea, vomiting, and loss of appetite, which are also common to milder forms of AMS. However, as HACE progresses, neurological symptoms become more pronounced. These can include confusion, disorientation, ataxia (loss of coordination and balance), difficulty walking in a straight line, drowsiness, and even coma or death if left untreated.

The most effective treatment for HACE is immediate descent to a lower altitude. Once at a lower elevation, oxygen therapy and medications such as dexamethasone, a corticosteroid that reduces brain swelling, can be administered. Acetazolamide, a medication that aids in acclimatization, may also be used as a preventative measure or in the early stages of AMS. Prevention is key, and this involves gradual ascent, adequate hydration, and avoiding strenuous activity in the initial days at high altitude. Individuals with a history of HACE should be particularly cautious when traveling to high elevations.