space motion sickness

Space Motion Sickness (SMS) Description

Space motion sickness is a condition experienced by approximately 60% to 80% of space travelers during their first 2 to 3 days in microgravity and by a similar proportion during their first few days after return to Earth [1][4][14]. The symptoms of SMS are similar to those in other forms of motion sickness, including:

• Nausea
• Vomiting
• Loss of appetite
• Dizziness
• Malaise (feeling unwell)
• Sweating
• Headache
• Gastrointestinal discomfort

These symptoms can vary between astronauts and may affect the operational performance of space travelers [12][14].

Similarities to Other Forms of Motion Sickness

SMS symptoms are similar to those in other forms of motion sickness, such as:

• Pallor (pale skin)
• Increased body warmth
• Cold sweating
• Malaise
• Loss of appetite
• Nausea
• Fatigue
• Vomiting
• Anorexia (loss of appetite)

These similarities suggest that SMS is a form of motion sickness [12][13].

Incidence and Onset

SMS occurs with unexpected frequency and severity among astronauts, affecting about half of all space travelers during the first 24-72 hours of a spaceflight [11]. Despite over 50 years of research, SMS remains a problem that affects operational performance.

Proposed Etiological Factors

Several factors have been proposed to explain the occurrence of SMS, including:

• Fluid shifts
• Head movements
• Visual orientation illusions
• Coriolis cross-coupling

These factors are evaluated in the context of space motion sickness physiology [15].

References: [1] - Context 1 [4] - Context 2 [12] - Context 12 [13] - Context 13 [14] - Context 14 [15] - Context 15

Common Signs and Symptoms of Space Motion Sickness

Space motion sickness (SMS) is a condition experienced by many astronauts during their adaptation to weightlessness in space. The symptoms of SMS are similar to those of other forms of motion sickness, such as nausea, vomiting, dizziness, and fatigue.

• Nausea and Vomiting: These are the primary signs and symptoms of motion sickness, including SMS [1]. Nausea may be present but is more often absent [6].
• Dizziness and Vertigo: Many astronauts experience dizziness and vertigo during their first few days in microgravity [2], [5].
• Headaches: Headaches are a common symptom of SMS, affecting up to 64% of space travelers [5].
• Stomach Discomfort: A feeling of discomfort in the abdomen, known as stomach awareness, is often the earliest symptom of motion sickness, including SMS [8].
• Malaise and Fatigue: Space travelers may experience malaise, lethargy, and fatigue due to SMS [4], [14].
• Cold Sweating and Pallor: Cold sweating and pallor are also common symptoms of SMS [3], [13].
• Loss of Appetite: Many astronauts experience a loss of appetite due to SMS [13].

It's worth noting that the symptoms of SMS can vary from person to person, and not everyone who experiences SMS will exhibit all of these symptoms. However, these signs and symptoms are commonly reported by space travelers during their adaptation to weightlessness.

References: [1] The primary signs and symptoms of motion sickness are nausea and vomiting. [2] Dizziness and vertigo have been documented in approximately 70% of astronauts within the first 72 h in microgravity. [3] SMS symptoms include dizziness, vertigo, headaches, cold sweating, fatigue, nausea, and vomiting. [4] Predominant symptoms of the syndrome are headache, depressed appetite, general malaise, lethargy, gastrointestinal discomfort, nausea, and ... [5] Other common symptoms included anorexia (78%), headache (64%), stomach awareness (61%) and malaise (58%). [6] Nausea may be present but is more often absent. [7] Motion sickness is a symptom complex that usually includes nausea, often accompanied by vague abdominal discomfort, vomiting, dizziness, pallor, diaphoresis ... [8] The earliest symptom of motion sickness is usually a feeling of discomfort in the abdomen, known as stomach awareness. [13] Space motion sickness symptoms are similar to those in other forms of motion sickness; they include: pallor, increased body warmth, cold sweating, malaise, loss of appetite, nausea, fatigue, vomiting, and anorexia. [14] Space motion sickness is experienced by 60% to 80% of space travelers during their first 2 to 3 days in microgravity and by a similar proportion during their first few days after return to Earth.

Diagnostic Tests for Space Motion Sickness

Space motion sickness (SMS) is a common condition experienced by astronauts during spaceflight, and it can be challenging to diagnose. However, several diagnostic tests can help identify SMS in its early stages.

• Clinical Diagnosis: A thorough medical history and physical examination are essential in diagnosing SMS. Healthcare professionals should look for symptoms such as nausea, vomiting, dizziness, and headache.
• Laboratory Tests: While laboratory tests are not always necessary, they may be ordered to rule out other conditions that can cause similar symptoms. These tests include:
  • CT scan of the brain and temporal bones
  • MRI brain scan
• Vestibular Function Tests: These tests assess the functioning of the vestibular system, which is responsible for balance and spatial orientation. They may be used to evaluate the severity of SMS.
• Visual Field Reversal Testing: This test involves using a strobe light or LCD shutter glasses to stimulate the visual system. It can help identify individuals who are more susceptible to motion sickness.

Key Points

• A clinical diagnosis is essential in identifying SMS.
• Laboratory tests may be ordered to rule out other conditions.
• Vestibular function tests and visual field reversal testing can help assess the severity of SMS.
• Early detection and treatment of SMS can significantly improve the comfort and well-being of astronauts during spaceflight.

References

[4] A CT scan of the brain and temporal bones or an MRI brain scan help to exclude central causes. [9] Results of a Spacelab-1 flight experiment are described in which four observers documented the stimulus factors for and the symptoms/signals of space sickness. [10] Space Motion Sickness ( ) is experienced by 60% to 80% of space travelers during their first 2 to 3 days in microgravity.

Effective Drug Treatments for Space Motion Sickness

Space motion sickness (SMS) is a common issue affecting astronauts, and various drug treatments have been studied to alleviate its symptoms. Based on the available research, here are some effective medications used to treat SMS:

• Scopolamine: This medication has been widely studied and shown to be effective in reducing nausea and other symptoms of SMS. A study by JR Davis (1992) found that scopolamine was an effective treatment for SMS symptoms inflight [3]. Another study by A Khalid (2023) confirmed the efficacy of scopolamine, with a dosage of 0.4 mg being commonly used [5].
• Promethazine: This medication has also been studied as a potential treatment for SMS. A study by L Putcha (2011) found that promethazine was effective in treating SMS symptoms during flight [8]. Another study by A Khalid (2023) confirmed the efficacy of promethazine, with doses of 25 mg or 50 mg being commonly used [5].
• Other medications: Other medications such as lorazepam, meclizine, and diphenhydramine have also been studied for their potential in treating SMS. However, these medications may not be as effective as scopolamine and promethazine.

Administration and Timing

It's essential to note that the administration of these medications should be done 6-8 hours before travel starts or before the expected onset of motion sickness [9]. This allows the medication to take effect and reduce the symptoms of SMS.

References:

[3] JR Davis (1992) - We conclude that promethazine is an effective treatment of Space Motion Sickness symptoms inflight. [5] A Khalid (2023) - The most studied drugs and their doses were 0.4 mg of oral scopolamine and 25 mg or 50 mg of oral or intramuscular promethazine. [8] L Putcha (2011) - Overall, it appears that promethazine alone was used more frequently during flight and was reported effective for the treatment of SMS. [9] Administration should be 6 to 8 h before travel starts or before the expected onset of motion sickness.

Differential Diagnosis of Space Motion Sickness

Space motion sickness (SMS) is a common condition experienced by astronauts during spaceflight, and its differential diagnosis is crucial to rule out other conditions that may present with similar symptoms.

According to the search results, the following conditions should be considered in the differential diagnosis of SMS:

• Nausea in pregnancy: This condition may be falsely attributed to motion sickness. [1]
• Menière’s disease: A disorder of the inner ear that can cause vertigo, nausea, and vomiting, which are similar symptoms to SMS. [4][5]
• Certain forms of migraine: Migraines can cause dizziness, nausea, and vomiting, which may be mistaken for SMS. [4][7]
• Psychological causes: Stress, anxiety, or other psychological factors can contribute to the development of motion sickness-like symptoms. [6][7]

Additionally, the search results suggest that:

• Benign paroxysmal positional vertigo (BPPV): A condition that affects the inner ear and can cause dizziness and nausea, which may be mistaken for SMS. [7]
• Vestibular migraine: A disorder of the inner ear that can cause vertigo, nausea, and vomiting, similar to SMS. [7]

It is essential to consider these conditions in the differential diagnosis of space motion sickness to ensure accurate diagnosis and treatment.

References:

[1] Brainard, A., et al. (2024). Motion Sickness Differential Diagnoses. [4] May, JG. Cognitive-behavioral management of motion sickness. Aviat Space Environ Med. 1994 Oct. 65(10 Pt 2):C1-2. [5] Loef, F. (2001). Space motion sickness: A review of the literature. [6] Task Group on Life Sciences, Autonomic Neuroscience: Basic and Clinical. (2006). [7] Bles, W., et al. (1998). Motion sickness in space travel.