View source for Space motion sickness

==Background==
*Space motion sickness (SMS)  is a common condition experienced by 60-80% of astronauts during the first 2-3 days of spaceflight. 
*Current research indicates that SMS is caused by conflicting sensory-motor control inputs from visual and tactile senses with inputs coming from the vestibular organs in the inner ear. <ref> Legner K. Humans in Space & Space Biology. Seminars of the United Nations Programme on Space Applications. 2003.</ref>
*SMS is a part of a larger constellation of symptoms known as Space Adaptation Syndrome (SAS) <ref>https://humanresearchroadmap.nasa.gov/Evidence/medicalConditions/Space_Motion_Sickness_(Space_Adaptation).pdf
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*Space motion sickness is very likely to occur during space flight and, without treatment, may lead to dehydration and decreased mission readiness.
*Similar symptoms to SMS can occur on return to earth gravity, pretreatment of these conditions is recommended. 


==Clinical Features==
*Symptoms can vary between astronauts but typically include:
**Nausea
**Vomiting
**Loss of Appetite
**Dizziness
**Malaise
**Sweating
*Duration: Astronauts generally recover within 3-5 days


==Differential Diagnosis==
{{Space medicine}}
{{Vertigo DDX}}

==Evaluation==
*Comprehensive review of the astronaut's medical history, focusing on any previous experiences with motion sickness, vestibular function tests, and monitoring symptoms during the initial phase of spaceflight. 
*Pre-flight training and simulations may help anticipate susceptibility.

===Workup===
*Tracking the onset, duration, and intensity of symptoms through self-reported logs and medical assessments.
*Physiological measurements 
**Heart Rate
**Blood Pressure
**Blood Glucose
**Urine Output.

===Diagnosis===
*Diagnosis is primarily clinical, based on the presence of characteristic symptoms in the context of spaceflight. 
*It is supported by the absence of alternative explanations for the symptoms. 
*Early identification is crucial for effective management.
*Occurs during the first 3-5 days of spaceflight
*If symptoms start later or continue past 5 days look for alternative diagnosis. 

==Management==
*Preventative Countermeasures
**Non-Pharmacological
***Tilt-transition devices  <ref>Harm D. L., Parker D. E. (1994). Preflight adaptation training for spatial orientation and space motion sickness. J. Clin. Pharmacol. 34, 618–627. 10.1002/j.1552-4604.1994.tb02015.x </ref>
***Autogenic feedback training exercises <ref>Cowings P. S., Toscano W. B. (2000). Autogenic-feedback training exercise is superior to promethazine for control of motion sickness symptoms. J. Clin. Pharmacol. 40, 1154–1165. 10.1177/009127000004001010</ref> 
***Virtual Reality training <ref> Stroud K. J., Harm D. L., Klaus D. M. (2005). Preflight virtual reality training as a countermeasure for space motion sickness and disorientation. Aviat. Space Environ. Med. 76, 352–356. </ref> 
***Head or body rotation exercises <ref> Reschke M. F., Somers J. T., Ford G. (2006). Stroboscopic vision as a treatment for motion sickness: strobe lighting vs. shutter glasses. Aviat. Space Environ. Med. 77, 2–7. </ref>
***Galvanic Vestibular Stimulation <ref> Dilda V., Morris T. R., Yungher D. A., MacDougall H. G., Moore S. T. (2014). Central adaptation to repeated galvanic vestibular stimulation: implications for pre-flight astronaut training. PLoS ONE 9, e0112131. </ref>
**Pharmacological
***Scopolamine
****Fewest side effects, current recommendation
****Transdermal 1mg 12 hrs prior to flight, Q72h
****Intramuscular 0.3-0.5mg Q6h
****Oral 0.3-0.5mg
***[[Promethazine]] 25mg IM or per rectum (oral absorption is less predictable due to microgravity induced ileus)
***Promethazine/ephedrine 25mg/25mg (Oral)
****Most effective, higher side effects
***Meclizine 25-50mg (Oral)
*Symptomatic Treatment
**Antihistamines: inhibit vestibular stimulation and vestibular-cerebellar pathways
***Meclizine (Antivert) 25mg PO QID
***Diphenhydramine (Benadryl) 25-50mg IM, IV, or PO q4hr
**Anticholinergics
***Scopolamine transdermal patch 0.5mg (behind ear) QID
**Antidopaminergics
***Metoclopramide 10-20 IV or PO TID
**Benzodiazepines
***Diazepam 2.5-10 mg q6h PRN
**IV Hydration

==Disposition==
*Most cases of space motion sickness resolve within a few days as the astronaut's body adapts to the space environment. 
*Continuous monitoring and supportive care are provided to ensure the well-being of the affected individual. 
*Astronauts typically recover fully and can continue with their mission activities without long-term effects.


==See Also==
*[[Space Medicine]]
*[[Space Adaptation Syndrome]]
*[[Vertigo]]
*[[Labrynthitis]]


==External Links==


==References==
<references/>

[[Category: Space Medicine]]