Vol.1, No.2, 5-9 (2013) Open Journal of Therapy and Rehabilitation
http://dx.doi.org/10.4236/ojtr.2013.12002
Myasthenia gravis in a professional cyclist—A case
report
Hiroteru Hayashi*, Hiroki Funasaki, Kentaro Kawai, Sakiko Ito, Keishi Marumo
Department of Sports and Wellness Clinic, Jikei University School of Medici n e, Tokyo, Japan;
*Corresponding Author: hiroteru17@gmail.com
Received 2 October 2013; revised 2 November 2013; accepted 10 November 2013
Copyright © 2013 Hiroteru Hayashi et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Since myasthenia gravis affects the muscular
system, athletes suffering from the disease of-
ten have difficulty in performing or returning to
their sports activity, in which exertion of con-
tinuous muscular power is required. In this pa-
per, we present a case of a professional bicycle
rider with symptomatic MG who successfully
return to his sport activity after thymectomy,
steroid pulse therapy and aggressive rehabilita-
tion. He resumed load training, returned to com-
petitive cycling 8 months after leaving hospital
while being on 20 mg PSL/day, and won seven
victories in the top class cycling competitions.
This is the first report on a professional athlete
suffering from MG who successfully returned to
competitive sport s af ter aggressive steroid treat-
ment.
Keywords: Myasthenia Gravis; Agg ressive
Rehabilitation; Return to Sports
1. INTRODUCTION
One of characteristic symptoms of myasthenia gravis
(MG), an autoimmune disease of the neuromuscular
junction is the daily variation in fatigability. Since my-
asthenia gravis affects the muscular system, athletes suf-
fering from the disease often have difficulty in perform-
ing or returning to their spor ts activity, in which exertion
of continuous muscular power is required [1]. We pre-
sent a case of a professional bicycle rider with sympto-
matic MG who successfully return to his sport activity
after thymectomy, steroid pulse therapy and aggressive
rehabilitation. The available literature on treatment out-
comes in athletes suffering from MG is reviewed and
discussed.
2. CASE REPORT
A 22-year-old professional bicycle rider presented to
the thoracic surgery department at our hospital with a
mediastinal tumor detected on a routine medical exami-
nation. His chest X-ray, CT and MRI (Figure 1) indi-
cated thymoma and blood analysis showed increased
anti-acetylcholine receptor (anti-AchR) antibody levels
(4.1 nmol/l). A diagno sis of myasthenia gravis was made
and after removal of the tumor by video-assisted thoracic
surgery the patient was discharged from the hospital.
He had not shown any symptoms affecting his daily
life activities for few weeks after the discharge, but dif-
ficulty in head elevation and looking straight ahead de-
veloped at seven weeks following surgery. He was re-
hospitalized due to the MG remission manifested by pro-
gressive muscle weakness of his neck and tights, waning
phenomenon and increased anti-AchR antibody levels
(up to 43.0 nmol/l). The grade of MG at re-admission
was IIA type according to the Osserman classification [2]
and class IIA by the MGFA classification [3].
3. COURSE AFTER RE-ADMIS SION
(FIGURE 2)
Prednisolone (PSL) treatment was initiated and the
dose was gradually increased from 15 mg/day to 80 mg/
(a) (b)
Figure 1. Chest MRI (transverse image) before operation. (a)
T1WI; (b) T2WI. In T2WI image, a solid tumor with a low
signal intensity containing a nodular liquid inclusion can be
found in the anterior mediastinum (white arrow).
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H. Hayashi et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 5- 9
6
100
90
80
70
60
50
40
30
20
10
0
PSL (mg/day)
The amount of PSL (mg/day) Time on elevating of arm (sec)
Time on elevating of leg (sec) Time on elevating of head (sec)
Rehabilitation
start
the maximum load 100 W
for 10 min utes QMG score: O point
Leaving hospita
l
350
300
250
200
150
100
50
0
The time on elevating of arm, leg and head (sec)
0 5 10 15 20 25 30
The weeks after hospitalization (weeks)
Figure 2. Clinical course after re-hospitalization. PSL was gra-
dually increased from 15 mg/day up to 80 mg/day maximum
during one month. Then, steroid pulse therapy was started and
followed by weaning from the steroid by decreasing PSL dose
by 5 mg/day every fourth week. Rehabilitation was started from
six weeks after re-hospitalization.
day maximum; the PSL administration was continued for
one month. Steroid pulse therapy [4,5] was then started
and was followed by weaning from the steroid done by
decreasing PSL dose by 5 mg/day every fourth week.
The patient strongly wished to return to competitive cy-
cling. Although still on 80 mg/day PSL, his generally
good state allowed rehabilitation . It was initiated early in
the course of hospitalization: the initial 10 W load (me as-
ured with an ergometer) was applied for 5 min and then
gradually increased every 3rd day to reach the maximum
of 100 W for 10 min. The exercise frequency was set at 5
times/week, and each time muscular power, respiratory
rate and pulse were monitored. During rehabilitation
exercises the patient was asked to wear a mask to prevent
infection. Later, he developed a “moon face”, steroid-
induced acne and a slight rise in ocular tension in both
eyes (all lasted temporarily) but no other serious com-
plications (severe infection, crisis, etc.) were observed.
Although the QMG score [3] was 11 p oints at th e time of
admission, it improved to zero at 17 weeks.
4. COURSE AFTER DISCHARGE
Following discharge, the patient continued to take 50
mg/day PSL for total 29 weeks from the beginning of the
steroid therapy. He resumed load training, returned to
competitive cycling 8 months after leaving hosp ital while
being on 20 mg PSL/day, and won seven victories in the
top class cycling competitions. The weaning from initial
steroid dose has continued for 3 years and 5 months and
now the PSL dose has been reduced to 6 mg/ml .
5. MUSCLE STRENGTH, QUANTITY AND
CHANGES IN THE BONE DENSITY
In order to evaluate muscle strength, we measured
isokinetic strength of muscles in knee flexion and exten-
sion by Cybex (CBX-770, Cybex Co.) and cross-sec-
tional areas of the trunk and thigh muscles were assessed
for muscle quantity using abdomen and thigh CT scans.
Furthermore, bone density by DEXA method was meas-
ured and evaluated for time-related changes.
Although slight variations in muscle strength per
weight at knee extension were found, there were almost
no changes observed between the values collected at 1
and 3 months following the discharge. The muscle
streng th at knee extens ion increased ev en to 109% of th e
one-month follow-up value at the time of return to full
sports activity. On the other hand, the muscle strength at
knee flexion decreased to 86% of the one-month fol-
low-up value at 3 months following the discharge. Then,
it gradually increased in parallel to the decreasing dose
of the steroid and reached an almost equivalent value as
measured at one month following discharge at the time
of return to sports (Figure 3).
The femoral CT axial scans taken at the time of return
to sports (the upper patellar border level) demonstrated
an increase in the tissue mass of the vastus medialis, bi-
ceps femoris, semitendinosus, semimembranosus and the
sartorial muscles when the muscle cross sections were
compared with those at the time of discharge. The
amount of the tissue mass in the femoral CT axial scans
was the av erage value obtained from 3 measurements by
the PACS method and freehan d ROI selections.
The abdominal CT axial scans (at the level of inferior
margin of the 4th lumbar vertebra) showed a remarkable
PSLmg/day
Mus cular po wer per weigh tN/Kg
0
10
20
30
40
50
60
70
80
90
0
0.5
1
1.5
2
2.5
3
3.5
The am oun t of P SL
Muscular power of
knee ext ension
Muscular power of
knee flexion
Le aving hospi tal
Retur n to game
Figure 3. PSL dose and its relationship with the knee exten-
sion-and-flexion muscular power measured with a muscular
power-measuring device (CBX-770 by Cybex). Although slight
variations in muscle strength per weight at knee extension were
found, there were almost no changes observed between the
values collected at 1 and 3 months following the discharge.
Then, muscular strength gradually increased. On the other hand,
the muscle strength at knee flexion decreased at three months
following the discharge. Then, it gradually increased in parallel
to the decreasing dose of the steroid and reached an almost
equivalent value as measured at one month following discharge
at the time of return to sports.
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H. Hayashi et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 5- 9 7
decrease in visceral fat at 3 years and 3 months after re-
turn to full sport activities when compared to the value at
the time of first return (79.6 cm and 89.1 cm, respec-
tively; PACS measurement method). Moreover, although
marked tissue mass increases were not observed in cross
sections of the abdominal internal oblique, abdominal
external oblique, transverse abdominal and rectus ab-
domi n is mu s cl es , mo rp ho lo g y of th e mu sc l e tis s ue c hanged
accordingly with the overall decrease in the visceral fat
(Figures 4 and 5).
Bone mineral density was maintained within the nor-
mal range from the time of re-hospitalization until 9
months following return to competitive cycling; it reached
its minimum value of 1.292 g/cm2 at 2 months after
re-hospitalization, when the PSL dose was the highest.
Than, it gradually increased reaching YAM (young adult
mean) score of 112% (T score: 1.8) and 105% by the
contemporary comparison method (Z score: 0.7) (Figure
6).
6. DISCUSSION
Myasthenia gravis is a disease characterized by progres-
sive loss of muscle strength and easy fatigability; prog-
nosis depends on the type of disease [2,6,7]. Definite
treatment has not yet been established but administration
(a) (b)
(e)
(d)
(c
VM
SM
ST
Sa
G
Bi
Ra
PM
Oa
Ta
Figure 4. CT (transverse image s). ((a), (b), (c)). CT scans of th e
thigh at the level of superior patellar border (VM: medial vastus
muscle, Bi: biceps femoris, ST: semitendinosus, SM: semime-
mbranosus, Sa: sartorius muscles). (a) CT scan taken at the
time of discharge (PSL 50 mg/day), (b) CT scan taken at the
time of return to competitive cycling (PSL 20 mg/a day), (c) CT
scan taken 3 years and 3 months after return to full sports activ-
ity (PSL 7 mg/day); ((d), (e)) Abdomen CT scans at the level of
inferior-border L4 (Ra: rectus abdominis, Oa: inner and exter-
nal oblique, Ta: transverse muscle of abdomen, PM: greater
psoas muscles); (d) CT scan taken at the time of return to com-
petitive cycling (PSL 20 mg/day), (e) CT scan taken at 3 years
and 3 months after return to full sports activity (PSL 7 mg/day).
Increase in the muscle cross-sectional area of VM, Bi, ST, SM,
and Sa was observed. Moreover, the amount of visceral fat de-
creased. On the other hand, almost no changes were observed
in the muscle cross-sectional area of Ra, Oa and Ta.
A muscular cross-sectional
area (mm
A muscular cross-
sectional area mm
VMBi ST+S
MSaRaOa+Ta PM
At the time of leaving
hospital 1502.8 991.4 1499.2 380.2
At the time of a game
return 1743.7 1364.11912.64786612855.12482.5
After-return three years
and three months1721.7 1330.1 1998.8490.4839.42947.4 2216.8
0
500
1000
1500
2000
2500
3000
3500
Figure 5. Results of CT measurements of muscle cross-sec-
tional areas (mm2). Although each muscle cross-sectional area
had gradually increased from the time of discharge to the time
of return to full sports activity, it did not show any changes for
the following 3 years and 3 months.
PSL (mg/day )
1.36
1.35
1.34
1.33
1.32
1.31
1.3
1.29
1.28
1.27
1.26
Bone mineral density (g/cm
2
)
Leaving hospital
80
70
60
50
40
30
20
10
0
The amo unt of
PSL (mg/day)
Bone mineral
density (g/cm
2
)
2008.6 2008.8 2008.12 2009.5 2010.4
Figure 6. The PSL dose and bone density (the DEXA method).
Although bone mineral density reached its minimum value at 2
months after re-hospitalization it could be maintained within
the normal range from the time of re-hospitalization until 9
months following return to competitive cycling.
of a cholinesterase inhibitor or medium dose PSL has
been shown to induce spontaneous remission in Osser-
man classification type I and MGFA classification class
0, I cases [8]. In more advanced stages, thymectomy and
long-term PSL therapy are usually applied (cases with
Osserman classification type II and MGFA classification
class II - V complicated by thymoma); treatment results
are greatly influenced by patient compliance and side
effects of the applied therapy. The presented case was
classified as A type (Osserman) and class IIA (MGFA)
and steroid-pulse therapy was applied for 7 months to the
patient who had also undergone thymectomy.
Generally, it is difficult for a top athlete suffering fro m
and treated for MG to return to sports activity in disci-
plines that require muscular r and endurance like powe
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8
Table 1. Three reports on return to sports in MG patients.
Author Year e publication Old Sex MG classification Sports Level
Scheer BV et al. 2012 52 MaleMild generalized (MGFA IIA) Ultra marathon Recreation
Leddy JJ et al. 2000 17 MaleMild generalized Football College
Hayashi H et al. 2013 22 MaleMild generalized (Osserman IIA) (MGFA IIA)Bicycle rider Professional
race cycling. This is not only because of temporary dis-
continuation of training caused by long-term hospitaliza-
tion but also because of the nature of the disease and its
complications (ex. crisis). In many cases, side effects
[9-11] such as osteoporosis and loss of muscle strength
that might occur due to large-dose steroid therapy may
pose additional problems [1].
OPEN ACCESS
In fact, only two reports on athletes affected by MG
and their return to sports activity have been published to
date [12,13] (Table 1). In both cases, patients had mild
generalized MG (class IIA, MGFA) as in our case.
Though their sports disciplines required less muscle
strength and endurance than professional cycling (Ameri-
can football and marathon, respectively) and the level of
activity was comparatively lighter than competitive cy-
cling (one was a student practicing at a college sports
club and another trained recreationally), in both cases
full return to pre-disease sports activity was not possible.
This is the first report on successfully treated profes-
sional athlete with MG class IIA (MGFA classification)
who was able to return to his full pre-disease sports ac-
tivity following steroid-pulse treatment.
We presume that three factors played important roles
in treatment to full recovery in our case. First, patient’s
compliance was excellent and drawn by the strong desire
to return to pre-disease sports activity. Second, rehabili-
tation was initiated early, when the patient was still un-
der large doses of PSL. Therefore, loss in muscle
strength and volume could be minimized and severe
complications (e.g. crisis) avoided. Third, due to young
age of the patient, his originally high bone mineral den-
sity was maintained within the normal range during the
course of treatment. This allowed load training during
rehabilitation.
7. CONCLUSION
We report a case of a professional bicycle rider who
achieved full recovery to competitive sports after re-ac-
tivation of myasthenia gravis (type II Osserman classifi-
cation and class IIA, MGFA classification). Treatment
including steroid-pulse therapy and early rehabilitation
program started while the patient was still on high dose
steroids and during hospitalization. This is the first report
on a professional athlete suffering from MG who suc-
cessfully returned to competitive sports after aggressive
steroid treatment.
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