Myasthenia gravis in a professional cyclist—A case report

doi:10.4236/ojtr.2013.12002

Paper Menu >>

Journal Menu >>

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: [email protected]

Received 2 October 2013; revised 2 November 2013; accepted 10 November 2013

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).

H. Hayashi et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 5- 9

100

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

350

300

250

200

150

100

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

PSL（mg/day）

Mus cular po wer per weigh t（Nｍ/Kg）

0.5

1.5

2.5

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.

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）

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

２

）

A muscular cross-

sectional area （mm

２

）

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

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

)

Leaving hospital

The amo unt of

PSL (mg/day)

Bone mineral

density (g/cm

)

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

H. Hayashi et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 5- 9

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.

REFERENCES

[1] American Academy of Pediatrics. Committee on Sports

Medicine and Fitness (1994) Medical conditions affecting

sports participation. Pediatrics, 94, 757-760.

[2] Osserman, K.E., et al. (1971) Studies in myasthenia gra-

vis—Review of a twenty-year experience in over 1200

patients. Mount Sinai Journal of Medicine, 38, 497-537.

[3] Jaretzki 3rd, A., et al. (2000) Myashenia gravis: Recom-

mendation for clinical research standards. Task Force of

the Medical Scientific Advisory Board of the Myasthenia

Gravis Foundation of America. The Annals of Thoracic

Surgery, 70, 327-334.

http://dx.doi.org/10.1016/S0003-4975(00)01595-2

[4] Lindberg, C., et al. (1998) Treatment of myasthenia gra-

vis with methylprednisolone pulse: A double blind study.

Acta Neurologica Scandinavica, 97, 370-373.

h ttp :/ /dx .d oi .org/ 10. 1111/j .1600-0404.1998.tb05968.x

[5] Arsura, E., et al. (1985) High-dose intravenous methyl-

prednisolone in myasthenia gravis. Archives of Neurology,

42, 1149-1153.

http://dx.doi.org/10.1001/archneur.1985.04060110031011

[6] Grober, M., et al. (1998) Self-care actions to manage fa-

tigue among myasthenia gravis patients. Journal of Neu-

roscience Nursing, 30, 191-199.

http://dx.doi.org/10.1097/01376517-199806000-00007

[7] Oosterhuis, H.J. (1981) Observation of the natural history

of myasthenia gravis and the effect of thymectomy. An-

nals of the New York Academy of Sciences, 377, 678-690.

h ttp :/ /dx .d oi .org/ 10. 1111/j .1749-6632.1981.tb33766.x

[8] Masaoka, A., et al. (1996) Extended thymectomy for my-

asthenia gravis patients: A 20-year review. The Annals of

Thoracic Surgery, 62, 853-859.

http://dx.doi.org/10.1016/S0003-4975(96)00376-1

[9] Sghirlanzoni, A., et al. (1984) Myasthenia gravis: Pro-

longed treatment with steroids. Neurology, 34, 170-174.

http://dx.doi.org/10.1212/WNL.34.2.170

[10] Pascuzzi, R.M., et al. (1984) Long-term corticosteroid

treatment of myasthenia gravis: Report of 116 patients.

Annals of Neurology, 15, 291-298.

http://dx.doi.org/10.1002/ana.410150316

[11] Kanda, F., et al. (2001) Steroid myopathy; pathogenesis

and effects of growth hormone and insulin-like growth

factor-I administration. Hormone Research, 56, 24.

http://dx.doi.org/10.1159/000048130

[12] Leddy, J.J. , et al. (2000) Myasthenia gravis in a collegiate

football player. Medicine & Science in Sports & Exercise,

H. Hayashi et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 5- 9 9

32, 1975-1979.

http://dx.doi.org/10.1097/00005768-200012000-00001

[13] Scheer, B.V., et al. (2012) Myasthenia gravis and endur-

ance exercise. American Journal of Physical Medicine &

Rehabilitation, 91, 725-727.

http://dx.doi.org/10.1097/PHM.0b013e31824663c6