Manual Therapy, Posturology & Rehabilitation Journal
Manual Therapy, Posturology & Rehabilitation Journal
Research Article

Pulmonary function and respiratory muscle strength in myasthenia gravis.

Oliveira, Ezequiel Fernandes; Nacif, Sergio Roberto; Fonseca, Nina Teixeira; Apostolico, Nadua; Urbano, Jessica Julioti; Guimarães, Letícia Lopes; Perez, Eduardo de Araujo; Cavalcante, Valéria; Bulle, Acary Sousa; Oliveira, Luis Vicente Franco

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Introduction: Myasthenia gravis (MG) is a neuromuscular autoimmune disease of unknown etiology, characterized by generalized muscle weakness and fatigue, especially after repetitive physical activities, with consequent improvement after rest. The MG follows a slowly progressive course, which can be fatal failure of the ventilatory muscles. The manifestations of the respiratory system are generally attributed to the weakness of the diaphragm and also accessory muscles of ventilation. Objetive: The objective was to evaluate the volumes and lung capacities and maximum pressure ventilation in patients with clinically stable MG. Methods: This is an observational study involving 15 patients (2 men) with MG. Subjects were recruited consecutively and screened for eligibility using the standardized protocol. Results: Spirometry, only two patients showed abnormalities of respiratory pattern, being a moderate restrictive pattern (50-60% predicted), and another patient with the congenital form showed a severe restrictive pattern. Not obstructive patterns were observed. Our results of spirometry showed an average value of FVC: 3.15 ± 0.77 and FEV1: 2.64 ± 0.65. Regarding the maximum pressure generated by the ventilatory muscles, the average value for the MIP was 45.5 cmH2O among women and the value of 56 cmH2O for men was observed. To MEP it was observed the average value of 45 cmH2O for women and 55 cmH2O for men. Conclusion: We conclude that patients with MG have lower values of maximal inspiratory and expiratory ventilatory associated with normal lung function values.


Myasthenia Gravis, spirometry, maximal ventilatory pressures.


1. Vincent A, Palace J, Hilton-Jones D. Myasthenia gravis. Lancet. 2001;357:2122-8.

2. Neewsom-Davis J. Autoantibody-mediated channelopathies at the neuromuscular junction. Neuroscientist. 1997;3:337-46.

3. Grob D. Natural history of myasthenia gravis. En: Engel AG, editor. Myasthenia gravis and myasthenic disorder. Oxford: Oxford University Press. Contemporary Neurological Series; 1999. p. 131-45.

4. Muñoz-Fernández C, Díez-Tejedor E, Frank A, Pino JM, Barreiro P. Maximal respiratory pressure in myasthenia gravis. Relation to single fiber electromyography. Acta Neurol Scand. 2001;103:392-5.

5. Osserman KE, Genkins G. Studies in myasthenia gravis: review of twenty-year experience in over 1,200 patients. Mt Sinai J Med. 971;38:497-537.

6. Mier-Jedrzejowicz A, Brophy C, Green M. Respiratory muscle function in myasthenia gravis. American Review of Respiratory Disease. 1988;138:867-873.

7. Marlowe FI, D’Angelo AJ. Respiratory failure as the initial presentation of myasthenia gravis. Ear Nose Throat J. 1989;68:472-73.

8. Foulks MCJ. Myasthenia gravis presenting as laryngeal stridor after exposure to chlorine gas. South Med J. 1981;74:1423-24.

9. Díez Tejedor E, Pinto JM, Frank A, Blanco C, Cruz Martínez A. Valoración de la función muscular respiratoria (presiones respiratórias máximas) en la miastenia gravis. Neurología. 1990;5:310-4.

10. García Río F, Prados C, Díez Tejedor E, Díaz Lobato S, Álvarez- Sala R, Villamor J, et al. Breathing pattern and central ventilatory drive in mild and moderate generalised myasthenia gravis. Thorax. 1994;49:703-6.

11. Spinelli A, Marconi G, Gorini M, Pizzi A, Scano G. Control of breathing in patients with myasthenia gravis. Am Rev Respir Dis. 1992;145:1359-66.

12. Miller M, Hankinson J, Brusasco V, Burgos F, Casaburi R, Coates A, et al. Standardisation of spirometry. Eur Respir J. 2005; 26:319–338.

13. Pereira CAC. II Consenso Brasileiro de Espirometria. J Pneumol. 2002; 28(supl3):S1-S82.

14. Pellegrino R, Viegi G, Brusasco V, Crapo R, Burgos F, Casaburi R, et al. Interpretative strategies for lung function tests. Eur Respir J. 2005;26:948–968.

15. Fabbri L, Pauwels R, Hurd S. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary updated 2003. COPD. 2004;1:105–141.

16. Magnani KL, Cataneo AJM. Respiratory muscle strength in obese individuals and influence of upper-body fat distribution. Med J. 2007;125(4):215-219.

17. Neder JA, Andreoni S, Lerario MC, Nery LE. Reference values for lung function tests. II. Maximal respiratory pressures and voluntary ventilation. Braz J Med Biol Res. 1999;32:719-27.

18. Ambrosino N, Opasich C, Crotti P, Cobelli F, Tavazzi L, Rampulla C. Breathing pattern, ventilatory drive and respiratory muscle strenght in patients with chronic heart failure. Eur Respir J. 1994;7:17-22.

19. Grob D, Arsura EL, Brunner NG, Namba T. The course of myasthenia gravis and therapies affecting outcome. Ann NY Acad Sci. 1987;505:472–99.

20. Somnier FE, Keiding N, Paulson OB. Epidemiology of myasthenia gravis in Denmark. A longitudinal and comprehensive population survey. Arch Neurol. 1991;48:733–9.

21. Saraiva, PAP, Assis JL, Marchiori PE. Evaluation of the Respiratory function in Myasthenia gravis. Arq. Neuropsiquiatr. 1996;54(4):601-607.

22. Heliopoulos I, Patlakas G, Vadikolias K, Artemis N, kleopa KA, Maltezos E, et al. Maximal voluntary ventilation in myasthenia gravis. Muscle Nerve. 2003;27:715–719.

23. Fregonezi GFA, Regiane-Resqueti V, Pradas J, Vigil L, Casan P. Relación entre función pulmonar y calidad de vida relacionada con la salud en la miastenia gravis generalizada. Arch Bronconeumol. 2006;42(5):218-24.

24. Keenan SP, Alexander D, Road JD, Ryan CF, Oger J, Wilcox PG. Ventilatory muscle strength and endurance in myasthenia gravis. Eur Respir J. 1995;8:1130–1135.

25. McCool FD, Conomos P, Benditt JO, Cohn D, Sherman CB, Hoppin FG Jr. Maximal inspiratory pressures and dimensions of the diaphragm. Am J Respir Crit Care Med. 1997;155:1329-1334.

26. Krachman S, Criner GJ. Hypoventilation Syndromes. Clinics in Chest Medicine. 1998;19(1):139-155.

27. Heritier F, Rahm F, Pasche P, Fitting JW. Sniff nasal inspiratory pressure. A non-invasive assessment of inspiratory muscle strength. Am J Respir Crit Care Med. 1994;150:1678-1683.

28. Fiz JA, Carreras A, Rosell A, Montserrat JM, Ruiz J, Morera JM. Measurement of maximal expiratory pressure: effect of holding the lips. Thorax. 1992;47:961-63.

29. Fiz JA, Carreras A, Aguilar J, Gallego M, Morera J. Effect of order on the performance of maximal inspiratory and expiratory pressures. Respiration. 1992;59:288-290.

30. Rubinstein I, Slutsky AS, Rebuck AS, McClean PA, Boucher R, Szeinberg A, et al. Assessment of maximal expiratory pressure in healthy adults. J Appl Physiol. 1988;64(5):2215-2219.

31. Larson JL, Covey MK, Vitalo CA, Alex CG, Patel M, Kim MJ. Maximal inspiratory pressure. Learning effect and testretest reliability in patients with chronic obstructive pulmonary disease. Chest. 1993;104:448-453.

32. Karvonen J, Saarelainen S, Nieminen MM. Measurement of respiratory muscle forces based on maximal inspiratory and expiratory pressures. Respiration. 1994;61:28-31.

33. Wen AS, Woo MS, Keens TG. How many maneuvers are required to measured maximal inspiratory pressure accurately? Chest. 1997;111:802-07.

34. Munõz-Fdez C, Díez-Tejedor E, Frank A, Pino JM, Pérez C, Barreiro P. Maximal respiratory pressures in myasthenia gravis. Relation to single fiber electromyography. Acta Neurol Scand. 2001;103:392–395.

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