Chinese Journal of Physiology

ORIGINAL ARTICLE
Year
: 2021  |  Volume : 64  |  Issue : 5  |  Page : 225--231

Visual hallucinations in 246-km mountain ultra-marathoners: An observational study


Ming-Kun Huang1, Kuo-Song Chang2, Wei-Fong Kao3, Li-Hua Li4, Chorng-Kuang How5, Shih-Hao Wang6, Yen-Kuang Lin7, Yuh-Shyan Hwang8, Ding-Kuo Chien9, Yu-Hui Chiu10 
1 Department of Emergency Medicine, Mackay Memorial Hospital; Department of Electronic Engineering, National Taipei University of Technology, Taipei; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
2 Department of Emergency Medicine, Mackay Memorial Hospital; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
3 Department of Emergency and Critical Care Medicine, Taipei Medical University Hospital; Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
4 Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital; Program of Medical Biotechnology, Taipei Medical University, Taipei, Taiwan
5 Department of Emergency Medicine, Taipei Veterans General Hospital; Department of Emergency Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei; Department of Emergency Medicine, Kinmen Hospital, Ministry of Health and Welfare, Kinmen, Taiwan
6 Leader Clinic, Taipei, Taiwan
7 Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan, Taiwan
8 Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan
9 Department of Emergency Medicine, Mackay Memorial Hospital, Taipei; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
10 Department of Emergency Medicine, Mackay Memorial Hospital; Department of Medicine, Mackay Medical College, New Taipei City; Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan

Correspondence Address:
Dr. Yu-Hui Chiu
Department of Emergency Medicine, Mackay Memorial Hospital, Taipei
Taiwan

Ultra-marathons are typically held over harsh terrains such as mountains, deserts, or other wilderness, and place severe demands on the physical and psychological capabilities of participants. Adventure-race competitors commonly report hallucinations. The goal of this study was to gain insight into visual hallucinations (VHs) during a mountain ultra-marathon. Thirty-one Taiwanese runners who participated in the 2018 Run Across Taiwan Ultra-Marathon, which spans 246 km with an altitude difference of 3266 m and an overall cut-off time of 44 h, volunteered for this study. Self-reported questionnaires on sleep duration, hallucinatory experiences, clinical symptoms of cold- and heat-related illnesses, and the 2018 Lake Louise Acute Mountain Sickness (AMS) Score were recorded prerace, during the summit, immediately postrace, and 3-days postrace. Hematological samples were collected 1 week before, immediately after, and 3 days after the race. Eight ultra-marathoners (six males and two females; seven finishers and one withdrawer) were recruited. Three out of eight (37.5%) subjects (two males and one female) reported experiencing VHs during the last 60 km. Three out of five (60%) lower-ranked subjects experienced VHs. All eight runners slept for <30 min during the race. None of the runners presented with headache either during or after the race to meet the criteria for AMS. None of the runners suffered an abnormal thermoregulatory response or a hypoglycemic episode throughout the ultra-marathon. The changes in blood osmolality immediately postrace were subclinical, despite being statistically significant. Among the three runners with VHs, none presented with severe dehydration or dysnatremia immediately postrace. High-altitude exposure, hyper/hypothermia, dehydration, dysnatermia, or hypoglycemia did not seem to contribute to hallucination onset in our subjects during the event. VHs of ultra-marathoners may be associated with excessive physical exertion and sleep deprivation.


How to cite this article:
Huang MK, Chang KS, Kao WF, Li LH, How CK, Wang SH, Lin YK, Hwang YS, Chien DK, Chiu YH. Visual hallucinations in 246-km mountain ultra-marathoners: An observational study.Chin J Physiol 2021;64:225-231


How to cite this URL:
Huang MK, Chang KS, Kao WF, Li LH, How CK, Wang SH, Lin YK, Hwang YS, Chien DK, Chiu YH. Visual hallucinations in 246-km mountain ultra-marathoners: An observational study. Chin J Physiol [serial online] 2021 [cited 2021 Dec 3 ];64:225-231
Available from: https://www.cjphysiology.org/article.asp?issn=0304-4920;year=2021;volume=64;issue=5;spage=225;epage=231;aulast=Huang;type=0