High altitude ataxia--its assessment and relevance.

Ataxia at altitude is reviewed in relation to acute mountain sickness (AMS). The cause of ataxia occurring at altitude is unknown but may be hypoxia affecting basal ganglia and hindbrain activity. Ataxia is an important sign of high altitude cerebral edema (HACE) but is less well-established as a clinical feature of AMS.

The sharpened Romberg test for assessing ataxia in mild acute mountain sickness.

Objective: To evaluate the Sharpened Romberg Test (SRT) as a measure of ataxia in subjects with mild acute mountain sickness in order to determine its sensitivity and specificity.

Methods: The SRT was performed in 23 subjects during ascent to 5260 m.

Results: The SRT was more often abnormal than the traditional heel-to-toe test, and at the highest altitude it was related to higher median Lake Louise symptom scores with predictive values of 60% sensitivity and 89% specificity.

Ataxia at altitude measured on a wobble board.

Objective: To establish a simple measure of ataxia for use at high altitude.

Methods: Twenty healthy subjects took part in a trek to 5005 m. At 5 different altitudes on the route, they undertook a balance test using a wobble board.