Clinical Analysis Of 322 Myasthenia Gravis Patients

Objective: Myasthenia gravis(MG)is the most common neuromuscular junction diseases, with variety of clinical manifestations, and easily missed or misdiagnosed. The aim of this study is to give epidemiological investigation and provide clinical guidance for medical staff, through retrospective study on the incentives, clinical characteristics, and treatment regimens of MG patients.Methods: Retrospective analysis on the chinical data of 322 patients who had hospitalized in the Second Hospital of Hebei Medical University and diagnosed with MG between 1st October 2013 to 30 th December 2004, including their gender, age, initial symptoms, clinical classification, supplementary examinations, treatment and efficacy.Result: The MG patients in this study had some regional representation, of which 94.72%(305/322)were Hebei people, and 57.76%(186/322)lived in Shijiazhuang.The study included 149 cases of male patients(46.27%), 173 cases of female patients(53.73%), and the ratio of male to female was 0.86:1. The minimum age of first episode was 1 year 7 months old, the largest was 83 years old, the average age was 45.63 years old and the median age was 48 years old. It showed a peak in male patients aged between 50 to 69 years, two incidence peaks in female patients between 20 to 29 years and 40 to 49 years, and the second peak was more significant.The main factors induced and aggravated patients’ condition was upper respiratory tract infection(36 / 322, 11.18%).The symptoms at onset of 322 MG patients were: ptosis(unilateral and bilateral), diplopia, limb weakness(upper, lower, unilateral and bilateral limb weakness), dysphagia, chew weakness, barylaia, and difficulties in elevating their heads and breathing, their constituent ratio was 50.62%, 12.73%, 18.94%, 7.14%, 0.93%, 7.76%, 0.62% and 1.24%.The proportions of patients in different clinical classifications were as follows: 7.14% were children type, 2.48% were juvenile type, and the rate of adult Osserman typeⅠ, ⅡA, ⅡB, Ⅲ, Ⅳand Ⅴwas 24.84%, 6.83%, 45.96%, 8.70%, 4.04% and 0.00%. Simple external ophthalmoplegia in pediatric patients occupied the largest proportion(78.26%, 18/23), while the juvenile MG patients also often accompanied with external ophthalmoplegiaThe positive rate of neostigmine test in 159 MG patients was 98.11%.Two hundered and twenty-one cases(86.67%)had a decremental response with amplitude at slow rates in 255 patients with repetitive nerve stimulation examination. All juvenile patients’ tests were positive, while adult Osserman type patients had the lowest positive rate(72.86%).ⅠOnly 9 adult patients had the serum acetylcholine receptor antibody test before given drug therapy, in which only 4 patients was positive.Thyroid hormones or antibodies in the serum thyroid function tests were abnormal accounted for 50%(64/128) out of 128 patients, in which 9 cases were diagnosed with hyperthyroidism, 4 with hypothyroidism, and 24 cases(18.75%) only shows higher TPOAb. Adult Osserman typeⅡB accounted for the highest proportion in patients concomitant with thyroid dysfunction(31/64,48.44%); Patients with age of first episode between 60 to 69 years are more likely associated with the onset of thyroid dysfunction(16/64, 12.50%).In the patients who had the thymic radiology included 19 chest X-ray and 243 thymic CT examinations, 91 MG patients(32.27%) were found with abnormal thymus gland, and adult Osserman typeⅡB accounted for the highest proportion(20/52, 38.46%). 32 MG patients(82.05%) were found with thymoma in 39 cases with previous thymectomy.Thirty cases experienced MG crisis, including 29 myasthenic crisis and 1 cholinergic crisis. The study showed the incidence of MG crisis was 9.32%, rescue-rate was 80%, and the mortality rate was 10%. In patients experienced MG crisis, adult Osserman typeⅡB and Ⅲaccounted for a large proportion(22 / 30,73.33%) and 73.33%(22/30) patients had thymic abnormalities.Young patients showed better effect than elderly patients when given simple medication therapy; adult Osserman type Ⅲtreatment outcome was the worst. The efficacy was better when patients had no thymic abnormalities. Only 5 patients with thymic abnormalities choosed the thymectomy while hospitalization, in which 4 patient’s condition improved when discharged. Bad treatment outcome was showed in patients with disease aggravated or relapse after thymectomy.Fifty-two patients were repeatedly hospitalized, 25 cases of male and 27 cases of female(53.73%) included, and the ratio of male to female was 0.93: 1. 21 patients concomitanted with thymic abnormalities and 19 patients with thyroid dysfunction in this study, in which 30 cases(57.69%) were adult Osserman typeⅡB.Conclusion: MG is a treatable disease, of which clinical characteristics have large individual differences and patients often concomitanted with thyroid dysfunction and thymic abnormalities, so individualized therapy should be given. We have few special and regional MG clinical characteristics in China, and large sample size and regional statistical study is needed currently. Fully aware of the clinical features of MG has positive significance to early diagnosis and treatment and reducing the morbidity and mortality.