Motion sickness: physiopathology, therapeutic and rehabilitation

Abstract: Technological evolution of modern transports significantly increases motion sickness symptoms occurrence. Motion sickness is defined by a set of four main symptoms that regularly appear: facial pallor, cold sweats,nausea and vomiting. Other additional signs such as dizziness, headache, fatigue and postural instability can be also observed. One of the most established theories to explain in which circumstances motion sickness arises is the ‘sensory conflict’ theory. This theory postulates that motion sickness originates from a sensory mismatch between actual versus expected invariant patterns of vestibular, visual and somatosensory inputs. It has been accepted that the vestibular system influences individual motion sickness susceptibility since patients with bilateral vestibular deficit have greatly reduced susceptibility or do not become motion sick at all. This sensory mismatch leads to an activation of vestibule-autonomic pathways, which have been shown to be also involved in producing nausea and vomiting during motion sickness and those that generate illness after ingestion of toxins. The characteristics of movements that induce motion sickness have been defined: otolith stimulations around 0.2 Hz are involved probably because the signals at this frequency are ambiguous and difficult to interpret by the brain in terms of inclination or translational movements perception. Other factors such as vestibular reflex characteristics, gender, age are involved; strong smells, temperature are often reported. Preventive and curative pharmacological treatments are the same as 30 years ago. New pharmacological classes without undesirable side effects have to be tested on humans. Behavioral measures can be useful