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. [1]
- SMS is a part of a larger constellation of symptoms known as Space Adaptation Syndrome (SAS) [2]
- 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
- Anemia of spaceflight
- Bone loss of spaceflight
- Contact dermatitis of spaceflight
- Ocular foreign body (microgravity)
- Ebullism syndrome
- Interpersonal conflicts in spaceflight
- Nitrogen tetroxide toxicity
- Hydrazine toxicity
- Pulmonary disorders of spaceflight
- Sleep disorders of spaceflight
- Space adaptation syndrome
- Space dentistry
- Space motion sickness
- Spaceflight headache
- Spaceflight testicular torsion
- Spaceflight urinary retention
- Spaceflight urinary tract infection
Vertigo
- Vestibular/otologic
- Benign paroxysmal positional vertigo (BPPV)
- Traumatic (following head injury)
- Infection
- Ménière's disease
- Ear foreign body
- Otic barotrauma
- Otosclerosis
- Neurologic
- Cerebellar stroke
- Vertebrobasilar insufficiency
- Lateral Wallenberg syndrome
- Anterior inferior cerebellar artery syndrome
- Neoplastic: cerebellopontine angle tumors
- Basal ganglion diseases
- Vertebral Artery Dissection
- Multiple sclerosis
- Infections: neurosyphilis, tuberculosis
- Epilepsy
- Migraine (basilar)
- Other
- Hematologic: anemia, polycythemia, hyperviscosity syndrome
- Toxic
- Chronic renal failure
- Metabolic
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
- 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)
- Scopolamine
- 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
- Antihistamines: inhibit vestibular stimulation and vestibular-cerebellar pathways
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
External Links
References
- ↑ Legner K. Humans in Space & Space Biology. Seminars of the United Nations Programme on Space Applications. 2003.
- ↑ https://humanresearchroadmap.nasa.gov/Evidence/medicalConditions/Space_Motion_Sickness_(Space_Adaptation).pdf
- ↑ 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
- ↑ 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
- ↑ 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.
- ↑ 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.
- ↑ 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.