The Evaluation of a Mobile Device to Measure Ataxia With High Altitude Exposure
Condition: Hypoxia
MeSH terms: Ataxia; Hypoxia
Study type: Interventional

Summary: 
      With exposure to high altitude some individuals will develop acute mountain sickness (AMS).
      Current evaluation of AMS can make it difficult to rule out other possible conditions.
      Evaluation of ataxia, as measured by the performance of a coordinated task, can aide in the
      correct diagnosis of AMS. The investigators have developed novel finger-tapping tasks on a
      mobile device to assess both reaction time and accuracy. The proposed research will evaluate
      the utility of this tool in assessing human acclimatization to hypoxia.
    

Detailed description: 
      Introduction: Hypoxia is the reduction in partial pressure of oxygen that occurs with
      exposure to altitude. Individuals acclimatize at different rates and to different degrees
      meaning that those who are slow to make the necessary physiological adjustments will develop
      signs and symptoms of acute mountain sickness (AMS). AMS is marked by headache,
      gastrointestinal disturbances, insomnia, fatigue and ataxia, which can be evaluated using
      subjective questionnaires such as the Lake Louise Score (LLS). Evaluation of AMS by solely
      using subjective questionnaires can make differential diagnosis of other possible pathologies
      difficult. Ataxia is characterized by poor coordination in the absence of significant
      weakness. Ataxia can be assessed with the performance of a coordinated task. The
      investigators have developed a novel finger-tapping task on a mobile device to assess both
      reaction time and accuracy. The proposed research will evaluate the utility of this tool in
      assessing human acclimatization to hypoxia, which could ultimately serve as a novel,
      objective methodology in the diagnosis of AMS.

      Hypothesis: (1) When exposed to simulated altitude (equivalent to 4200m above sea level),
      subjects will exhibit diminished coordination relative to a sham exposure. (2) Reaction time
      of novel coordination tasks will positively correlate with heart rate, balance, and LLS. (3)
      Accuracy of novel coordination tasks will negatively correlate with heart rate, balance, and
      LLS.

      Methods: A repeated-measures design with a familiarization trial, a hypoxic trial, and a sham
      trial will be used. Sixteen healthy adults will be exposed to normobaric hypoxia in the
      investigator's chamber, simulating an elevation of 4200m above sea level. Subjects will be
      measured for pulse oxygen saturation, heart rate, and will complete the LLS, the Balance
      Error Scoring System (BESS), as well as two electronic finger tap coordination tasks prior
      to, and at 5 minutes, 4, and 12 hours into the altitude chamber exposure.

      Outcomes: This research will enhance the investigators understanding of the relationship
      between coordination, balance, and acclimatization to hypoxia. It will allow us to validate a
      new objective tool in the measurement of acclimatization with exposure to hypoxia.
    

Intervention name(s): AMS Monitor App; Lake Louise Score; Balance Error Scoring System; Heart Rate & Pulse Oxygen Saturation
Intervention type(s): Device; Other; Other; Other
Intervention description(s): Participants will complete a novel coordination task performed on an android phone.; Participants will complete a questionnaire to assess acclimatization to hypoxia.; Participants will complete a series of static stance positions to evaluate their ability to maintain balance.; Participants will have their heart rate and pulse oxygen saturation continuously monitored throughout the entire exposure.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Other
Keywords: hypoxia; ataxia