Shinshu Med J, 65⑸：259～265, 2017

A Case of Cerebral Infarction with Favorable Outcome that
Occurred while Climbing a 2400m Mountain―Successful Prehospital Emergency Medical Serviceof Mountain Rescue―
Hiroshi Takayama
Department of Emergency and Critical Care Medicine, Shinshu University School of Medicine

Here we report a case of ischemic stroke in a 55-year-old man climbing a mountain 2400m above see levelalone who successfully recovered after treatment with reperfusion therapy. He experienced an ischemic stroke
on a snowfield at an altitude of 2400m while climbing the 3180m Mt. Yarigatake in May. A nearby climber
reported the incident by cellular phone. The patient was rescued by a Nagano Prefecture Emergency
Management Air Corps helicopter and transported to our hospital 1 h after stroke onset. On arrival, his National
Institutes of Health Stroke Scale (NIHSS) score was 25. At 2 h 9 min after onset, the recombinant tissue
plasminogen activator alteplase was administered intravenously and his NIHSS score improved to 2. The patient
was transferred to another hospital on day 19 after onset with a modified Rankin Scale score of 2 and a Barthel
Index score of 100. He returned to work 78 days after onset. This is the first case report in Japan about thesuccessful treatment of cerebral infarction that occurred on a mountain at 2400m. While good weather andvarious other favorable conditions helped to improve the patient’s prognosis, other factors, such as the goodcommunication infrastructure and the coordination between the aeromedical service system and hospital, playeda major role in mountain rescue of this patient. Shinshu Med J 65 : 259―265, 2017
(Received for publication November 22, 2016 ; accepted in revised form June 23, 2017)
Key words : mountain rescue helicopter, stroke, rt-PA

Ⅰ Introduction

in weather and getting lost, but also injuries andillness. Illness was the fourth most common cause atMountaineering accidents are becoming increas­

7.6% (232 persons). The prefecture with the mostingly frequent in Japan. In 2015, a record high of

accidents was Nagano1）. According to Nagano Pre­

2508 persons across Japan were involved in moun­fectural Police statistics in 2015, 32 persons (11.7%)

taineering accidents. One prominent trend is the

had accidents caused by illness2）.

increase in middle-aged and elderly adults in this

There are few reports of stroke during mountaingroup. Adults aged≥40 years accounted for 76.7% ofclimbing in the medical literature3）-6）. Noguchi et al.

persons involved in all mountaineering accidents,

reported 3 cases of cerebral ischemia. One case was

91.6% of those died or went missing. Causes ofdiagnosed as having cerebral infarction by autopsy,

mountaineering accidents include not only factors

and the others were considered transient ischemic

specific to mountain climbing, for example, changes

attacks. However, we were unable to find any re­ports of treatment in patients with stroke occurring＊

Corresponding author : Hiroshi Takayama
Department of Emergency and Critical Care Medicine,
Shinshu University School of Medicine, 3-1-1 Asahi,
Matsumoto, Nagano 390-8621, Japan
E-mail : takayama@shinshu-u.ac.jp

No. 5, 2017

during mountain climbing.
The prognosis of patients with cerebral infarction
has improved in recent years due to the introductionof thrombolysis and endovascular therapy. However,259

Hiroshi Takayama

Mt Yarigatake 3180m
the scene of the accident 2400m

Shishu University Hospital

Shinshu Matsumoto Airport
25km
map date©2017 Google,ZENRIN
Fig. 1

Map of Mt. Yarigatake and the surrounding area.

it is important to perform these treatments at an

The physical examination on admission showed

early stage, which makes it difficult to realize their

Glasgow Coma Scale of E4V1M5, respiratory rate ofbenefits when the patient cannot be rapidly trans­

21 breaths/min, oxygen saturation of arterial blood

ported to a medical facility.

measured by pulse oximeter (SpO2) of 96% (with O2

Here we report a case of cerebral infarction occur­

8 L/min supplement), blood pressure of 136/86 mmHg,

ring on a snowy mountain with successfully treat­heart rate of 74 beats/min (regular) and body tem­

ment. The effective communication infrastructure

perature of 32.5℃ (tympanic). The thoracic andand coordination between the aeromedical service

abdominal findings were normal. Global aphasia, andsystem and hospital contributed to the success.

no anisocoria (right pupil 3.5 mm, left 3.5 mm) were

Ⅱ

Case

observed. Light reflex was prompt in both eyes.
Right hemiparesis and right hemispatial neglect

A 55-year-old man collapsed while climbing Mt.

were observed but eye deviation and sensory distur­

Yarigatake (Fig. 1) alone in May 2013. nearby climb­

bance were not observed. National Institute ofer witnessed the event and immediately reported it

Health Stroke Scale (NIHSS) score was 25 points.

by calling 119 (the emergency number in Japan) at

Blood examinations, plain chest X-ray, and electro­

9 : 22A.M. A Nagano Prefecture Emergency Manage­

cardiogram showed no abnormal results. Non-

ment Air Corps helicopter was dispatched to thecontrast brain CT revealed no high density area.

location and spotted the patient on a snowfield at an

Early ischemic changes were not observed (Fig. 2).

altitude of about 2400m (Table 1). A crew member

A diagnosis of cerebral infarction was made.

was lowered on a hoist, rescued the patient, andThe patient was initially hypothermic, but bodybrought him into the helicopter. The patient wastemperature soon increased with normal warming

transported to the Advanced Emergency and Criti­

procedures. There was no obvious association be­

cal Care Center at Shinshu University Hospital.

tween level of consciousness and body temperature.

260

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A case of cerebral infarction while climbing a 2400m mountain
Table 1Timelinetimeelapsed timeevent

9 : 220 : 009 : 52
10 : 05
10 : 11

0 : 30
0 : 40
0 : 46

The patient had a stroke and collapsed on the snow. Other climber nearby the patient
watched him and did emergency call with his cellular phone.
Nagano prefectural rescue helicopter “Alps” took off from Shinshu Matsumoto Airport
Alps arrived at the site.

10 : 22

1 : 00

10 : 30
11 : 31

1 : 082 : 09Fig. 2

Aips rescued the patient.
Alps transported the patient to advanced emergency and critical care center of Shinshu
university
NIHSS was 25 points. CT scan was taken and no high density area was found.
tPA was administrated.

Brain CT scan. High density area and early ischemic changes were absent.

We could contact his family by telephone before his

criteria for careful administration for alteplase (se­arrival at the hospital and so knew his past history.

vere renal failure, uncontrollable diabetes, etc.).

The patient had no allergy history and a health check­

Informed consent was obtained without delay be­

up reportedly indicated suspected Wolff-Parkinson-

cause we could talk with his family by telephone.

White syndrome but he did not take any medicine.

Intravenous administration of alteplase was started

The patient had an active lifestyle, including com­approximately 2 h 9 min after the onset of cerebral

peting in triathlons, and had considerable mountaininfarction. (Table 1)

climbing experience. The patient had no contraindi­

Symptoms promptly improved after the start ofcations for thrombolysis, for example no intracranialadministration. The patient’s NIHSS score improved

hemorrhage on CT, no history of intracranial hemor­

to 2 points, and his only remaining symptoms wererhage, and so on. He had an NIHSS score of 25 andmild dysarthria, mild aphasia, and Barré’s sign (onlyexhibited severe neurologic symptoms, but had no

pronator drift of the right upper arm).

contraindications for alteplase and did not meet
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After thrombolysis, diffusion-weighted brain mag­
261

Hiroshi Takayama

Fig. 3 Brain magnetic resonance imaging. Diffusion-weighted imaging showed a highintensity area along the left middle cerebral artery.

netic resonance (MR) imaging showed high-inten­

was 100 points, indicating no impact on activities ofsity areas in the left corona radiata, the left parietal

daily living. The only remaining symptoms were

lobe, and the left temporal lobe (Fig. 3). Brain MR

mild sensory aphasia and reduction in high orderangiography showed stenosis of the distal branch ofbrain function (e.g., attention deficit). He was trans­

the left middle cerebral artery, but no encasement offerred to a hospital close to his home for the purpose

any other area, including the carotid artery (Fig. 4).

of rehabilitation for high order brain function. He

On the basis of neurologic and MR imaging findings

was discharged after 75 days and returned to workof the infarcted area, it was concluded that the initial

78 days after onset.

obstruction occurred at the main trunk of the middle
cerebral artery ; remnants of the thrombus were

Ⅲ

Discussion

found at the distal branch after thrombolysis andThis is the first report from Japan of successful

reperfusion was achieved by administering alteplase.

treatment by thrombolytic therapy of a patient who

No abnormalities such as a left atrial thrombus orexperienced cerebral infarction while climbing apatent foramen ovale were observed on transthorac­

snowy mountain alone. Mt. Yarigatake, where thisic or transesophageal echocardiography. Moreover,stroke occurred, is a mountain in the southern partarrhythmias such as atrial fibrillation and deltaof Japan’s Northern Alps and is the fifth highest

waves were not observed while the patient was

peak in Japan at 3180m in altitude. It is not easy to

hospitalized. The absence of atherosclerotic lesions

climb in May because the snow cap is not yet melt­in the carotid artery and aorta indicated that theed. The direct distance to the scene of stroke from

cerebral infarction was more likely cardioembolic

Shinshu-Matsumoto Airport and our hospital is 32

than atherothrombotic, so administration of dabiga­

km, and it would probably take≥10 hrs to reach thetran was started on the day after admission.

point on the mountain from the trailhead on foot.

On day 19 after onset, the patient’s Barthel Index
262

In this case, the patient was climbing this snowy
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A case of cerebral infarction while climbing a 2400m mountain

Fig. 4 Brain magnetic resonance angiogram. Left is magnetic resonance angiogramsource image. Narrowing of the left middle cerebral artery is evident (arrow).

mountain at an altitude of 2400m alone when thehelpful in this case, as we were able to prepare thestroke occurred. A mountain is a harsh environment

necessary procedures such as CT because we could

for medical care, making it difficult to manage se­anticipate the need for intravenous administration of

2）
7）
-9）

vere medical emergencies. The good communi­

alteplase before the patient arrived at the hospital.

cation infrastructure, aeromedical service system,

Areas where mountaineering accidents are likely

and successful coordination with the hospital wereto occur need to have emergency centers with heli­

the reason for this good outcome.

ports so that patients can be transported directly toThis incident was reported by cellular phone. The

the hospital after being rescued by helicopter. Shin­area of Mt. Yarigatake near where the incident oc­

shu University Hospital has an Advanced Emergen­curred was within the wireless coverage area. Thiscy and Critical Care Center and a roof heliport on

is because NTT Docomo built a cellular phone basethe premises. It has accepted patients transported

station at Jonen hut in the Northern Alps, which has

by helicopter after becoming ill or injured in abeen operating every year between May and No­

mountaineering accident

vember since 2002. At present, more than 60% ofPrompt treatment can improve the functional

mountaineering accident reports are made by cellu­

prognosis for cerebral infarction. According to clini­lar phone. In some cases, 110 or 119 operators cancal studies and postmarketing surveillance fromtrack report locations using GPS, which makes it

Japan, 33% to 37% of patients who undergo throm­

10）easier to find the ill or injured person .

bolysis with rt-PA have a favorable outcome (0-1 on

Emergency Management Air Corps helicopters

the modified Rankin scale)11）-13）. However, few pa­

can communicate directly with the hospital using

tients receive the thrombolysis14）-17）. Shiotsuki et al

the fire radio communication system. This allows thereported that it was only used in an estimated 4.6%

hospital to begin preparing for the expected situa­of all patients with cerebral infarction18）.

tion before admission of the patient. This was also
No. 5, 2017

A smooth transition from the mountain rescue and263

Hiroshi Takayama

pre-hospital emergency care to acute-phase treat­

the hospital may likely not receive sufficient infor­

ment and successful reperfusion of the obstructedmation about the patient before arrival. Measures

cerebral artery by prompt administration of rt-PA

for providing prompt medical treatment to patientswere carried out. All of this contributed to the favor­

transported by prefectural police helicopter after aable outcome in this case despite the stroke occur­

mountaineering accident should be considered in thering while the patient was climbing a snowy moun­future.

tain alone.

Ⅳ Conclusion

In recent years, the main method of rescuing peo­
ple involved in a moderate to severe mountaineering

We treated a patient who experienced cerebral in­

accident has shifted from ground teams to helicopter

farction while climbing a 3000m class mountain alone

teams. The number of helicopter rescues for moun­in early spring and obtained a favorable outcome.

taineering accidents has been increasing year by

Factors that contributed to this outcome were theyear. Of the 300 mountaineering accidents in Nagano

good communication infrastructure, the aeromedical

prefecture in 2013, a helicopter was dispatched forservice system, and effective coordination with the

243 (81%), and 230 patients were admitted to a hospi­

accepting hospital. We hope that information about

tal emergency department.

this case will contribute to the recovery of other pa­

Crewmembers aboard prefectural police helicop­
ters, which perform 80% of helicopter rescues, taketients who experience an acute event such as cere­bral infarction while mountain climbing.

rescue training courses on first aid. However, theirmain duty is search and rescue, so they are limited

Acknowledgments : We sincerely thank the Nagano

in their ability to make medical observations andPrefecture Emergency Management Air Corps.

provide care. In addition, these teams cannot com­municate directly with the accepting hospital

No author of this paper has any conflict of interest

through prefectural police radio, which means thatto declare.

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