营养支持对重症肌无力患者呼吸功能的影响

目的探讨营养支持在治疗重症肌无力患者中的应用价值。方法对78例MG患者常规治疗基础上给予肠内营养乳剂进行营养支持15d,记录患者肠内营养治疗前后营养指标（肱三头肌皮皱厚度、上臂肌困、白蛋白、肌酐、尿素氮、氮平衡）、呼吸功能指标（最大吸气压、最大呼气压、残气量、最大通气量、呼吸肌耐力）及临床肌无力严重度的变化情况。将治疗前后的上述指标进行分析比较。结果MG患者肠内营养支持治疗15d后,患者各项营养指标中,血浆白蛋白、肌酐水平和氮平衡均较营养支持前明显升高（P〈0．01）,血尿素氮（BUN）水平较营养支持前明显下降（P〈0．01）;I型MG患者的肺功能状况已经较健康对照有所下降;经常规治疗和营养支持后,各型MG患者的肺功能状况以及临床肌无力严重度均有所改善。结论对MG患者,合理的肠内营养支持治疗可以改善机体的营养状态,改善患者肺功能及临床症状。     

重症肌无力患者红细胞免疫功能的变化

为了探讨重症肌无力（ＭＧ）患者红细胞免疫功能的变化，我们测定了２０１例ＭＧ患者外周血ＲＢＣ－Ｃ３ｂ受体花环率（ＲＢＣ－Ｃ３ｂＲＲ）和ＲＢＣ－ＩＣ花环率（ＲＢＣ－ＩＣＲ）和５０名正常人进行对照。结果为ＭＧ患者的ＲＢＣ－Ｃ３ｂＲＲ（７．５８±３．４％）明显低于正常对照组（１２．８７±５．０７％）（Ｐ＜０．０１），ＲＢＣ－ＩＣＲ（５．８３±４．６２％）稍高于正常对照组（５．０３±３．８４％）（Ｐ＞０．０５），ＭＧ全身型组ＲＢＣ－Ｃ３ｂＲＲ（５．２５±１．８５％）明显低于眼肌型组（８．５９±３．１９％）（Ｐ＜０．０１），强的松治疗前组（７．９８±４．０１％）与治疗后组（１１．６４±４．３５％）有明显差异（Ｐ＜０．０１），强的松治疗前后ＲＢＣ－ＩＣＲ的变化无统计学意义。上述结果表明ＭＧ患者红细胞免疫粘附功能低下与ＭＧ发病有一定的相关性。ＭＧ的发病不仅有体液免疫功能障碍，还可能有红细胞免疫功能障碍，我们的资料为ＭＧ免疫病原学发病机理提供了一项新的实验依据，也可为免疫治疗ＭＧ评定疗效提供客观辅助指标。     

重症肌无力伴发特发性甲状旁腺功能减退症二例

重症肌无力(MG)是自身免疫性疾病,常伴发甲状腺功能亢进、类风湿关节炎、系统性红斑狼疮、多发性肌炎、多发性硬化等其他自身免疫疾病,而伴发特发性甲状旁腺功能减退症(I HP)的报道较少。作者医院收治的3000余例MG患者中有2例伴有手足搐搦症状,最后均诊断为I HP。     

OssermanⅡA和ⅡB型重症肌无力患者呼吸肌功能的研究

本文运用肺功能仪测定２７例ＯｓｓｅｒｍａｎⅡＡ和ⅡＢ型ＭＧ患者呼吸肌功能，根据临床上有无呼吸困难分为两组进行统计分析，通过应用Ｔｅｎｓｉｌｏ前后的实测值与预计值差异的比较，结果显示本组患者均存在不同程度的呼吸肌无力，呼吸肌力可用胆碱脂酶抑制剂改善。     

重症肌无力合并甲状腺功能亢进一例

目的探讨重症肌无力(MG)合并甲状腺功能亢进临床特点及诊治,增进对此类疾病的认识。方法报道1例MG合并甲状腺功能亢进的临床资料,结合文献进行分析。结果 MG合并甲状腺功能亢进同时治疗效果更好。结论 MG和甲状腺功能亢进的关联是自身免疫性疾病在人体不同组织系统中针对相同抗原决定簇的损伤,临床医生应该注意到两种疾病同时存在的可能性。     

重症肌无力患者静息态脑功能研究

目的探索重症肌无力(MG)患者的静息态脑功能情况。方法选择30例MG患者,以及性别、年龄和文化程度相匹配的20例正常对照组(NC)进行静息态功能磁共振成像(rs-fMRI)扫描。采用局部一致性(ReHo)方法,分析计算MG组和NC组的ReHo改变的脑区,并比较两组间ReHo值差异,从而探索MG患者脑功能ReHo的变化情况。结果与NC相比,MG组在双侧小脑、双侧尾状核等脑区ReHo值下降。结论可通过静息态功能磁共振的角度研究MG患者的脑功能变化。     

儿童重症肌无力伴甲状腺功能亢进88例临床分析

目的研究儿童重症肌无力(MG)伴甲状腺功能亢进症(甲亢)的临床特点及治疗.方法对88例儿童MG伴甲亢患者的临床资料和治疗方法进行回顾性研究,并与同时期成人MG伴甲亢患者进行比较.结果男性35例,女性53例;就诊时MG患者Ⅰ型72例,ⅡA型8例,ⅡB型6例,Ⅳ型2例;先有甲亢后有MG18例,先有MG后有甲亢34例,MG和甲亢同时发生36例;合并癫痫6例,伴胸腺增生16例;经过治疗60.23%的患者痊愈,7.95%的患者无效.结论儿童与成年人MG合并甲亢患者在性别上发病无统计学差异,而临床类型分布不同,儿童组以Ⅰ型多见;两种疾病的发生顺序不同,儿童先发生甲亢者较少,成人组先发生甲亢者多见.儿童MG伴甲亢患者的临床表现复杂,诊断较难,容易误诊和漏诊,提高对本病的认识是改善预后的关键.     

糖皮质激素治疗对重症肌无力患者补体的影响

目的检测糖皮质激素治疗重症肌无力(MG)患者血清补体水平的变化,以探讨其和糖皮质激素治疗间的关系。方法对MG患者进行糖皮质激素规范化治疗,检测患者治疗前后血清补体水平,并计算其治疗前后补体水平的差值,分析患者补体水平变化和糖皮质激素之间的关系。结果(1)治疗前糖皮质激素治疗组(GMG)和非糖皮质激素治疗组(NGMG)C3水平差异无统计学意义(P>0.05),两组均较非MG患者对照组(NC)明显降低(P<0.01);治疗后GMG组和NGMG组C3水平增高但仍低于NC组(P<0.01),同组治疗前后比较,结果GMG组治疗后浓度增高明显(P<0.05),而NGMG组和NC组(P>0.05)浓度改变无统计学意义。(2)治疗前后3组C5水平变化不明显(P>0.05)。结论糖皮质激素可使MG患者血清C3浓度增高,对C5浓度影响不明显。     

重症肌无力患者血浆对乙酰胆碱受体功能的影响

ＴＥ６７１细胞能特异性地表达乙酰胆碱受体（ＡＣｈＲ）。本研究利用此特性，观察了重症肌无力（ＭＧ）患者血浆对ＡＣｈＲ功能的影响。结果表明，已去除补体的ＭＧ患者血浆，室温下孵育ＴＥ６７１细胞仅２ｈ，对ＡＣｈＲ功能就有抑制作用，与ＰＢＳ对照组比较总体抑制率为６３％。提示ＭＧ发病机制中除抗体对ＡＣｈＲ破坏、溶解、促进降解外，ＭＧ患者血清（也许是其中的ＡＣｈＲａｂ）对ＡＣｈＲ的Ｎａ￣＋通道有直接阻断作用。     

Mitochondrial function in myasthenia gravis

We determined the respiration rate, respiratory control and ADP/O ratios, with different substrates in mitochondria isolated from 2 patients with myasthenia gravis and compared them with normal human muscle. In all cases studied, a severe alteration of the respiratory control with variable derangement of oxidative phosphorylation was found. This abnormality of mitochondrial metabolism was referred to by Luft as 'loosely coupled' and was reported in other neuromuscular diseases. In our opinion this defective oxidative metabolism is nonspecific.     

Lymphocyte function in myasthenia gravis.

Mitogen-induced blastoid transformation of peripheral blood lymphocytes from patients with myasthenia gravis was studied using a microplate culture technique and evaluated with 3H-thymidine incorporation. It was found that both phytohaemagglutinin and pokeweed mitogen responses decreased significantly in patients with myasthenia gravis. In myasthenic crisis, indices of stimulation by phytohaemagglutination became very low. The autologous plasma neither inhibited nor facilitated mitogenic responses of lymphocytes. The decreased mitogen responsiveness of lymphocytes suggests that part of the T lymphocyte function is subnormal in myasthenia.     

Ⅰ型重症肌无力患者呼吸功能状况评估

目的研究Ⅰ型重症肌无力(MG)患者的呼吸功能状况与健康人的差异,并对比研究应用抗胆碱酯酶药后患者肺功能状况的改变.方法46例MG患人和50例健康人,分别行肺功能(肺活量、第1秒用力呼气量、用力肺活量、1秒率、吸气量、最大呼吸流量容积曲线、最大通气量、残气容积)、和血气分析(pH、PaCO2、PaO2)和血氧饱和度(SaO2)检测.MG患者在检测肺功能之后平静休息30 min以上,肌注抗胆碱酯酶药(新斯的明1 mg)后30 min再次检测肺功能.结果(1)MG患者肺功能状况显著低于健康人,但其动脉血气水平和SaO2与健康人比较无显著性差异;(2)MG患者在应用新斯的明之后肺功能状况有明显的改善.结论MG患者尽管平静状态下无呼吸困难,但呼吸功能状况已有潜在性损害,当有肺部感染、需要麻醉手术治疗等情况时,应密切注意其肺功能状况.     

Left ventricular long-axis function in myasthenia gravis

Abstract   Myasthenia gravis (MG) primarily affects skeletal muscles, but influence on cardiac function has been suggested. The aim of this study was to assess left ventricular long-axis function in MG patients compared to healthy controls, and to examine whether any MG-related heart involvement was influenced by the acetylcholine-esterase inhibitor pyridostigmine. We found that early diastolic atrioventricular-plane velocity and tissue Doppler peak systolic strain was lower in MG patients than in controls before pyridostigmine. The differences disappeared following administration of pyridostigmine. Also, tissue velocities at systole and early diastole tended to be lower in patients before pyridostigmine. In multivariate analyses adjusting for between-group differences in blood pressure, MG was no longer associated with lower longaxis function. Conventional echocardiographic measures of left ventricular diastolic and systolic function did not differ between groups. In conclusion, this study, using modern tissue Doppler imaging as well as conventional echocardiography, could not demonstrate definite MG-related cardiac involvement in a group of MG patients without known cardiac disease, but indicates that pyridostigmine-responsive MG-related alterations in cardiac muscle function exist in MG patients.     

Prednisone-induced worsening of neuromuscular function in myasthenia gravis

In patients with myasthenia gravis who received single doses of prednisone orally (40 to 100 mg), we found acute inhibition of neuromuscular function as manifest by increased decremental responses to repetitive nerve stimulation, reduced twitch tension, and lowered maximum voluntary contraction strength. The time course of these changes correlated with plasma methylprednisolone levels, implying direct drug effects on neuromuscular function.     

Assessment of esophageal function in patients with myasthenia gravis

Background: Myasthenia gravis (MG) is an autoimmune disease in which impairment of neuromuscular transmission results in a pathological fatigability of striated muscles. Dysphagia is a common symptom in MG. It is caused by a weakness of the striated muscles in the pharynx and esophagus. The purpose of our study was to evaluate the role of esophageal scintigraphy in the assessment of esophageal function in MG. Methods: In 15 patients with clinically proven MG (oculopharyngeal manifestation in 6/15 patients, generalized weakness in 9/15 patients) esophageal transit was investigated scintigraphically with a multiple swallow test protocol. 10/15 patients had a history of dysphagia. Patients were studied twice: under baseline conditions, and immediately after pharmacological stimulation with 10 mg of edrophonium chloride (EC), a short-acting acetylcholinesterase inhibitor. Results: Under baseline conditions all patients showed an impaired esophageal function (emptying [%]= 58 % ± 21; normal range > 85 %). In 14/15 individuals esophageal transit improved after administration of EC (emptying [%]= 75 % ± 18; p < 0.01), reaching the normal range in 6 patients. One patient showed no effect attributable to EC. Conclusions: Esophageal transit is often compromised in MG. Functional abnormalities may be also present in patients without a history of dysphagia. Inhibition of cholinesterase positively affects striated muscles in the pharynx and upper esophagus, thus improving esophageal transit. Esophageal scintigraphy may be considered as a simple, non-invasive method for diagnosing impairment of esophageal function in MG and to monitor the changes under pharmacological stimulation. Received: 20 August 2002, Received in revised form: 11 December 2002, Accepted: 18 December 2002 Correspondence to Rainer Linke, MD     

Influence of temperature on neuromuscular transmission in myasthenia gravis

Summary The effect of local cooling was studied in 28 patients with myastenia gravis. We stimulated the ulnar nerve with single stimuli and trains at 3/s for 2s and at 50/s for 1.5s. The compound muscle action potential (MAP), the muscle twitch and the isometric tetanic force of the adductor pollicis were registered. 1. At 3/s stimulation the pathological decrement of the MAP decreased after slight cooling. 2. The amplitude of the single MAP was higher at lower temperature when compared to normal temperature. The same increase is however to be found in healthy subjects. 3. After slight cooling, the maximum tetanic force was higher. However, the decrement of the force was higher also, therefore ruling out a practicable application of cooling for the patient. 4. After severe cooling (18–22°C) the tetanic force was much lower and in many cases a complete failure of the neuromuscular transmission occured.

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Zusammenfassung Der Einfluß lokaler Kühlung wurde an 28 Patienten mit Myasthenia gravis untersucht. Wir reizten den N. ulnaris mit einzelnen Impulsen und mit Serien von 3/s für 2s und von 50/s für 1.5s. Das Summenaktionspotential (MAP), die Muskelzuckung und die isometrische tetanische Kraft des Adduktor pollicis wurden registriert. 1. Bei Reizung mit 3/s war das pathologische Dekrement des MAP nach leichter Kühlung geringer. 2. Die Amplitude des MAP war größer. Diese Amplitudenzunahme tritt jedoch auch bei Gesunden nach Kühlung auf. 3. Nach leichter Kühlung war die maximale tetanische Kraft größer. Jedoch nahm die Kraft während der Reizung nach dem Maximum wieder schnell ab. Der praktische Nutzen einer Kühlung ist deshalb für den Patienten gering. 4. Nach starker Kühlung (18–22°C) war die maximale tetanische Kraft sehr niedrig. In vielen Fällen kam es zu einem vollständigen Versagen der neuromuskulären Impulsübertragung.

     

Seronegative myasthenia gravis

Of 221 patients with myasthenia gravis, 18.5% had no detectable antibodies to acetylcholine receptor. Seven of 14 patients (50%) with only ocular symptoms for more than 2 years were seronegative, and 25 of 145 (17%) patients with generalized myasthenia were seronegative. The clinical characteristics of seronegative patients did not differ from patients with high antibody titers. No seronegative patient had a thymoma, but that difference did not reach statistical significance. Lack of serum antibodies did not preclude favorable response to thymectomy or plasmapheresis.     

Juvenile myasthenia gravis

Juvenile myasthenia gravis shares a similar pathophysiologic origin with adult myasthenia gravis, but there are important differences, mostly relating to epidemiology, presentation, and therapeutic decision making. Gender ratios and the proportion of seropositive patients differ in the pre‐ and postpubertal age groups. The diagnostic evaluation is similar to that in adults, although special techniques are sometimes necessary to perform single‐fiber electromyography in younger patients. Therapeutic decisions in affected children and adolescents are complicated by the greater long‐term consequences of using steroids, and thus other interventions, such as intravenous immunoglobulin (IVIg) and plasmapheresis, may play a greater therapeutic role in this population than in adults. Steroid‐sparing agents may contribute to the management of refractory cases, but they should be used with caution due to the risk of malignancy. Muscle Nerve, 2008