Management of Myasthenia Gravis in E.N.T. Practice K. K. DESARDA
Myasthenia gravis is neuro-muscular disorder characterised by marked weakness and fatiguability of muscles affecting the motor apparatus at Myoneural junction. Management of this disease in ENT practice has been outlined. This disorder involves all age groups and any muscles in the body, but the disease shows special affinity for muscles innervated by bulbar nuclei (face, lips, eyes, tongue and neck). It is because of this affection, patients of this disorder see first Otolaryngologists.
phagia, dyspnoea, dysphonia, hoarseness, diplopia and ptosis, mimiking the presentation of bulbar palsy, crieopharyngeal and nasopharyngeal malignancies, with neurological involvements. The correct diagnosis and investigations importance are stressed.
The cause of the myasthenia gravis is not known, but it is said to be of metabolic disorder. Thymus gland abnormalities have been described in some patients. It has also been said that myasthenia gravis is an autoimmune disease, since multiple autoantibodies have been found in the sera of patients of this disorder. The women are more often affected than men and the disease appears between 20 and 40 years of age.
Case Report CASE : 1 : A 40 year old man was referred by his practitioner to ENT OPD for the complaints of difficulty in swallowing, heaviness of speech and inability to open the eye. The symptoms were progressing as the day is to advance. The detailed examination of nose, pharynx, nasopharynx and larynx did not reveal any abnormality except weak movements of palate (soft), pharyngeal wall and vocal cords. There was no evidence of any malignancy etc. Routine blood, urine X-ray chest, ECG and lipid profiles were within normal limits. The only positive findings were ptosis, diplopia and marked fatiguability. The nasal regurgitation, nasal twang was noted. His speech was dysarthric and had difficulty in swallowing even liquids. By morning he was almost normal. A provisional diagnosis of Myasthenia gravis was made and confirmed by positive neostigmine test.
About 20 cases of proved myasthenia gravis were being treated at K.E.M. Hospital, Pune since 1970. Out of this, 3 patients required Thymectomy, 2 patients went into respiratory failure and had to be subjected for tracheostomy and subsequently on respirator, but ultimately died. 14 cases were managed on medical therapy eg. Neostigmine, alternate day steroids and supportive therapy. The interesting 3 cases which were presented to our department are briefed below, for their oropharyngeal complaints like dysK. K. Desarda, Hon. Associate Consultant ENT Surgeon, K.E.M. Hospital, Pune411 011. Acknowledgement
I am thankful to the Chief Medical Officer—Dr. Mrs. B. J. Coyaji for permitting me to publish this paper. 102
Fig. 1. X.ray chest (P.A view) showing huge shadow in mediastinum.
CASE : 2 : A 40 year old female was admitted to medical ward for difficulty in breathing, hoarseness of voice and difficulty in swallowing. Routine ENT examination was done. Her nose, nasopharynx, larynx looked normal except for weakness in palatal movements, pharyngeal musculature and sluggish mobility of the cords. She
Fig. 2. X-ray chest (Lat. view) of the same patient.
Indian Journal of Otolaryngology, Volume 37, No. 3, September, 1985
MANAGEMENT OF MYASTHENIA GRAVIS IN ENT PRACTICE—DESARDA had ptosis and diplopia. Fundi were normal. Routine blood, urine, serum electrolyte studies did not reveal any abnormality. X-ray chest revealed huge shadow in the mediastirum suggestive of Thymoma. Provisional diagnosis of my asthenia gravis was confirmed by positive neostigmine test. Clinical photograph is enclosed (PA/Lat. view).
CASE : 3 : A 35 year old female
was attending ENT clinic for slurring of speech, nasal regurgitation and change of voice for 6 weeks. She is to feel fine in the mornings, but as the day advanced, her symptoms used to be progressive and at the end of the day, she used to be dyspnoeic and dysphonic with marked fatiguability in articulation. Routine ENT examination did not reveal any marked abnormality except weakness in palatal movements, nasal twang, and weak movements of vocal cords. Routine haemogram, urine, X-ray chest did not reveal any abnormality. A provisional diagnosis of myasthenia gravis was made and confirmed by positive neostigmine test. Clinical Presentation Most of these patients who present first to otoloryngologist for their naso-or-pharyngeal symptoms. Their clinical presentation is as follows Occular Symptoms : Ptosis, diplopia or both. b) Oro-pharyngeal symptom dysDysphagia, dysarthria, pnoea. c) Weakness of muscles of mastication and facial muscles. d) Nasal twang (nasal speech) and nasal regurgitation and marked fatiguability in articulation. e) Pharyngeal musculature weakness may cause dysphagia for liquids and solids. f) Laryngeal muscle weakness may casue dyspnoea, dysa)
phonia and hoarseness of voice and weak cough reflex. g) Involvement of respiratory muscle may cause respiratory stridor. Diagnosis It is based on detail history, clinical course of the disease and clinical examination and laboratory investigation. The positive finding like ptosis, diplopia, facial weakness and progressive fatiguability in chewing, swallowing, speaking etc. The diagnosis is confirmed by positive neostigmine test. The hysteria, dissiminated sclerosis, bulbar lesions, and polymyositis do mimic the picture of myasthenia gravis and should be excluded by appropriate tests and laboratory investigations. It is also stressed that malignancy of oropharyngeal, nasopharyngeal spaces should be kept in mind in valuating the diagnosis. The importance of positive neostigmine test is the main stay in the diagnosis of the myasthenia gravis. Management
Medical Treatment : Most of these patients are well maintained on medical drugs regime. 1. Neostigmine bromide 15 mg orally four times/day and may be increased upto 180 mg/day. 2. Edrophonium chloride (TensiIon) 10 mg I/v may relieve myasthenic weakness in 20 to 30 seconds. 25-30 mg I/m daily gives relief for several honrs. 3. Ephenrine sulphate : 12 mg/ day. The side effects of these drugs like abdominal cramps, nausea, vomiting may be prevented by adding atropine like drug. 4. Corticosteroids and corticotropine : Encouraging results have been reported. Alternative day steroids orally is the recommended therapy. Surgical treatment : Myasthenia gravis with Thymus tumor can ve subjected for Thymectomy in females under 40 years, where medical treatment has failed. Complete remission may occur in 1/3rd
Indian Journal of Otolaryngology, Volume 37, No. 3, September, 1985
of patients. The surgical result in man is uncertain. Deep Xray therapy : Those patients whose medical treatment has failed and those who have refused surgery, may be subjected for deep X-ray therapy (3000 R) to thymus in 10 to 12 divided doses. Partial remission may occur in half the patients. Emergency treatment : The Myasthenic crisis is an emergency and should be attended to immediately. Sudden inability to breath or swallow may occur any time. These patients should carry 2 ampules of 0.5 mg of Neostigmine methysulphate to be given immediately S/c or I/m if severe symptoms develop. Progressive and potentially dangerous respiratory stridor may take place and will require immediate emergency tracheostomy. Therefore a set of tracheostomy, oxygen and suction unit should be kept near the patient. If these facilities are not available, then the patient should be transferred to intensive care unit for magagement where respirator facilities will be available. During this emergency treatment body fluids and electrolytes should be maintained. As regards, the prognosis of this condition is always guarded. The spontaneous remission occur frequently but relapse is the rule. Myasthenic crisis and sudden death may occur. The most critical period following the onset is two years. References
1. Brumner N G. (1972). 'Corticosteroids in Myasthenia Gravis. Neurology 22, IO2.
Utterback R. A. (1973). 'Maintenance of ARTH in Myasthenia Gravis'. New England Journal Med.
2. Cape C. A.,
27, 253.
3. Kreal et al. (1967). 'Role of Thymcctomy in the management of Myasthenia Gravis'. Ann. Surnery 165,111. 4. Warmohs J.R., Engel V'I.K. (1972). 'Benefit from alternate prednisone in Myasthenia Gravis'. Nev. England J Med. 17,286.
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