“…Transient focal neurological conditions at high altitude, without cerebral edema, are uncommon but often very alarming to both the individual and group members. Reported in the literature are a variety of transient focal neurological signs presenting at high altitude, without associated acute mountain sickness or other concurrent illness, including dysphasia, 1 lateral rectus palsy? hemiplegia,3 unilateral paresthesia, aphasia,4 cortical blindness,s and other visual disturbances such as scotomata.…”