Hüfner K, Brugger H, Kuster E, Dünsser F, Stawinoga AE,
Turner R, Tomazin I, Sperner-Unterweger B. Isolated psychosis during exposure to
very high and extreme altitude - characterisation of a new medical entity. Psychol
Med. 2017 Dec 5:1-8. doi: 10.1017/S0033291717003397. [Epub ahead of print]
Abstract
BACKGROUND:
Psychotic episodes during exposure to very high or extreme
altitude have been frequently reported in mountain literature, but not
systematically analysed and acknowledged as a distinct clinical entity.
METHODS:
Episodes reported above 3500 m altitude with possible psychosis
were collected from the lay literature and provide the basis for this
observational study. Dimensional criteria of the Diagnostic and Statistical
Manual of Mental Disorders were used for psychosis, and the Lake Louise Scoring
criteria for acute mountain sickness and high-altitude cerebral oedema (HACE).
Eighty-three of the episodes collected underwent a cluster analysis to identify
similar groups. Ratings were done by two independent, trained researchers (κ
values 0.6-1). Findings Cluster 1 included 51% (42/83) episodes without
psychosis; cluster 2 22% (18/83) cases with psychosis, plus symptoms of HACE or
mental status change from other origins; and cluster 3 28% (23/83) episodes
with isolated psychosis. Possible risk factors of psychosis and associated
somatic symptoms were analysed between the three clusters and revealed
differences regarding the factors 'starvation' (χ2 test, p = 0.002),
'frostbite' (p = 0.024) and 'supplemental oxygen' (p = 0.046). Episodes with
psychosis were reversible but associated with near accidents and accidents (p =
0.007, odds ratio 4.44).
CONCLUSIONS:
Episodes of psychosis during exposure to high altitude are
frequently reported, but have not been specifically examined or assigned to
medical diagnoses. In addition to the risk of suffering from somatic mountain
illnesses, climbers and workers at high altitude should be aware of the
potential occurrence of psychotic episodes, the associated risks and respective
coping strategies.
________________________________________________________________________
From the article
‘I first met Jimmy on the Balcony, a cold windswept snow
shelf high up on the southeast ridge of Mount Everest. At an altitude of more
than 8200 meters our introduction had been brief, with little more than a
muffled “hello” and a few words of encouragement passing between us. Over my
right shoulder, obscured by the bulky oxygen mask and the rim of down that
smothered my face, I was sure I could see Jimmy moving lightly in the darkness.
But despite him remaining close by me for the rest of the day, I didn't see him
again’…
We analysed the distribution of accidents and near accidents
across the clusters: 12% (5/42) of cases were associated with accidents or near
accidents in the PSYNO cluster, 59% (10/17, one missing) in PSYPLUS and 22%
(5/23) in PSYISO (χ2 test, p = 0.001, z-test < 0.05 for PSYNO a, PSYPLUS b,
PSYISO a). Overall, episodes without psychosis (cluster 1) were compared with
episodes with psychosis (clusters 2 + 3). The latter were associated with a
higher number of near accidents and accidents [cluster 1 12% (5/42), clusters 2
+ 3 38% (15/40, one missing), χ2 test, p = 0.007, OR 4.44]. Episodes where
individuals were considered to display symptomology congruent with AMS were not
associated with a higher number of accidents or near accidents compared with
episodes without AMS [acute mountain sickness] [28% (11/40) v. 21% (9/42, one missing), χ2 test, p =
0.522, OR 1.28]. While episodes where individuals were considered to display
symptomology congruent with HACE showed higher number of accidents and near
accidents compared with episodes without HACE [42% (8/19) v. 19% (12/63, one
missing), χ2 test, p = 0.04, OR 3.09]…
In conclusion, psychosis can occur at very high and extreme
altitude, and reportedly in the absence of other signs and symptoms of HACE [high altitude cerebral edema].
Isolated HA psychosis should thus be considered a distinct and separate
HA-related syndrome. It is important to inform subjects who intend to go to HA
about the possibility of psychosis, in addition to the well-recognised somatic
HA disorders. This should be part of the information campaign for HA
travellers. Cognitive strategies (e.g. reality testing, Smailes et al. 2015)
should be considered and practiced beforehand. This information has the
potential to increase safety at HA, especially when with a partner or in a
group. These findings are not only important for climbers and mountaineers but
also for occupational HA work. To better describe HA psychosis, to determine
its incidence, risk and trigger factors, treatment and patient's outcome, a
prospective observational study should be performed. Additionally, in vitro
studies could further ameliorate knowledge of the underlying pathophysiology.
Since isolated psychosis at altitude shows some clinical features similar to
schizophrenia, it could potentially serve as a reversible model of the disease;
thus aiding in the investigation of pathophysiological concepts or new
treatments for schizophrenia and related disorders.
Brugger P, Regard M, Landis T, Oelz O. Hallucinatory
experiences in extreme-altitude climbers. Neuropsychiatry Neuropsychol
Behav Neurol. 1999 Jan;12(1):67-71.
Abstract
OBJECTIVE:
This study attempted a systematic investigation of
incidence, type, and circumstances of anomalous perceptual experiences in a
highly specialized group of healthy subjects, extreme-altitude climbers.
BACKGROUND:
There is anecdotal evidence for a high incidence of
anomalous perceptual experiences during mountain climbing at high altitudes.
METHOD:
In a structured interview, we asked eight world-class
climbers, each of whom has reached altitudes above 8500 m without supplementary
oxygen, about hallucinatory experiences during mountain climbing at various
altitudes. A comprehensive neuropsychological, electroencephalographic, and
magnetic resonance imaging evaluation was performed within a week of the
interview (8).
RESULTS:
All but one subject reported somesthetic illusions
(distortions of body scheme) as well as visual and auditory
pseudohallucinations (in this order of frequency of occurrence). A
disproportionately large number of experiences above 6000 m as compared to
below 6000 m were reported (relative to the total time spent at these different
altitudes). Solo climbing and (in the case of somesthetic illusions)
life-threatening danger were identified as probable triggers for anomalous
perceptual experiences. No relationship between the number of reported
experiences and neuropsychological impairment was found. Abnormalities in
electroencephalographic (3 climbers) and magnetic resonance imaging (2
climbers) findings were likewise unrelated to the frequency of reported
hallucinatory experiences.
CONCLUSIONS:
The results confirm earlier anecdotal evidence for a
considerable incidence of hallucinatory experiences during climbing at high
altitudes. Apart from hypoxia, social deprivation and acute stress seem to play
a role in the genesis of these experiences.
"During the last few minutes [before the ascent had to
be given up], I had the feeling that another person was climbing with me. He
[although I 'knew' he was a man, I had no idea who he could have been] was
always approximately 5 m behind me, and although I clearly saw that nobody was
there, I continued to look over my shoulder again and again. The stronger I
felt his being there, the stronger I noticed an 'empty feeling,' a distinct
'hollowness' of my body" (subject 5, climbing behind two companions at an
altitude of 8300 m; exhausted but not in danger)....
"Despite the fog, I clearly saw these people. [...] I
could make out individual faces and decided that I had never seen them before
in my life" (subject 2, during a solo climb at an altitude between 5000
and 6000 m)....
"First I saw two horses, later on, just one horse but
this time with a rider on its back. In this person, I recognized a remote
acquaintance" (subject 1, describing an experience at an altitude of 4500
m).
"I heard someone speaking French. The voice seemed to
emanate from within my own body, and I heard myself responding. It was in
French too—amazing, if you consider that I do not speak French at all..."
(subject 1, solo climb below 6000 m)...
"For a few minutes, I heard some friends talk about
technical problems or issues relating to our present situation. The voices were
quite normal in loudness and intelligibility. I did not try to take part in the
conversation" (subject 3, while resting at an altitude of approximately
7500 m).
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