The thymus gland in elderly patients with myasthenia gravis.

This study was undertaken to determine the amount and histologic appearance of the persistent thymic tissue removed post mortem from 20 patients over 60 years of age with myasthenia gravis. One patient died several days after thymectomy. No recognizable thymic tissue on gross examination was seen in any patient. On microscopic examination, 11 patients had no thymic tissue. The other nine patients, including the one with thymectomy, all showed marked involution of the thymus. No germinal centers were seen. The thymus glands of two additional patients, still alive after thymectomy at ages 62 and 70, showed similar findings. Marked involution of the thymus also was found in each of six elderly controls. Thymectomy is not likely to be effective treatment of the elderly myasthenic patient.     

Safety of plasma exchange therapy in patients with myasthenia gravis

Introduction: Plasma exchange (PLEX) is effective in myasthenia gravis (MG), but there are concerns about its safety. Methods: We collected data prospectively from 42 patients randomized to PLEX treatment in a comparison study with intravenous immunoglobulin (IVIg). Detailed information on the PLEX treatment methodology and adverse events are reported. Results: Forty of 42 patients completed PLEX. Ninety percent were treated in an outpatient setting. Fifty‐five percent had no complications, and 45% had mild–moderate reactions that did not require stopping treatment; the majority were citrate reactions and peripheral vascular issues that were easily treated. Fifty‐seven percent of patients responded to treatment, and 83% completed PLEX via peripheral venous access. Two patients had severe adverse events: 1 related and 1 unrelated to PLEX. Comorbid disease and age did not predict reactions. Conclusion: PLEX is safe, effective, and well tolerated in patients with MG. Our results do not raise concerns about the safety of PLEX in patients with moderate–severe MG. Muscle Nerve 47: 510–514, 2013     

Determinants of cognitive impairment in elderly myasthenia gravis patients

The relationship between myasthenia gravis (MG) and cognitive dysfunction has been a matter of debate because of the possible association between peripheral and central nervous system (CNS) cholinergic dysfunction. The aim of this study was to evaluate cognitive function in a series of elderly MG patients in comparison to matched controls. In all, 100 consecutive MG patients aged over 60 years and 31 matched control subjects underwent an extensive neuropsychological test battery to explore multiple cognitive domains. There were no differences in cognitive performances between patients and controls. Severe MG was associated with impaired attention, constructional praxis, and frontal control. Logistic regression analysis showed that advanced age, diabetes, and thyroid dysfunction were independently associated with cognitive impairment. This study does not support the hypothesis of CNS cholinergic involvement in MG. The impairments of attention, memory, and control tasks in MG are related to general visual motor slowness and to the concomitant presence of other diseases. Muscle Nerve, 2009     

Immunoadsorption therapy for myasthenia gravis.

The results of a multicentre trial were analysed to evaluate the efficacy of immunoadsorption therapy for severe generalised myasthenia gravis. Twenty patients with myasthenia gravis who were concurrently receiving high dose prednisolone and azathioprine therapy were treated with an affinity-type adsorbent, using tryptophan-linked polyvinyl alcohol gel (IM-TR), according to a standardised treatment protocol. The 20 patients received five adsorption treatments within a period of 10 days. In 11, pronounced improvement of myasthenic weakness was seen and long-term remission was maintained. The treatment was especially effective in patients with thymic hyperplasia. Circulating acetylcholine receptor (AChR) antibodies were reduced by about 60% by treating one plasma volume. There was no difference in the rate of removal of the AChR antibodies between patients with thymic hyperplasia and patients with thymoma. No serious complications occurred during 100 procedures. It was concluded that the immunoadsorption therapy with IM-TR is useful in controlling symptoms in patients with severe myasthenia gravis who are otherwise unresponsive.     

以大剂量糖皮质激素冲击为主综合治疗重症肌无力的临床观察

目的了解大剂量糖皮质激素(GC)冲击为主综合治疗重症肌无力(MG)的疗效及副作用。方法应用临床评分随访观察64例大剂量GC冲击后短程激素加综合治疗、83例大剂量GC冲击后长程激素加综合治疗和70例非GC冲击治疗患者的病情变化及副作用。结果治疗1个月时的有效率短程组为89．06％,长程组为89．16％,对照组为70．00％;改善幅度短程组为64．62％土27．06％,长程组为65．62％±27．21％,对照组为48．35％±32．09％;加用其他免疫抑制剂继续治疗6个月时,有效率依次为短程组93．76％、长程组93．98％、对照组82．85％;改善幅度短程组为72.16％±26．95％,长程组为73．06％±24.74％,对照组为56．31％±32．08％,在治疗1个月和6个月时,短程组和长程组相对评分差异均无统计学意义;GC副作用长程组明显多于短程组(P<0．05)．结论大剂量GC冲击后短程激素加综合治疗MG与大剂量GC冲击后长程综合治疗MG疗效相当,均好于对照组,但GC冲击后短程激素并综合治疗组副作用低于长程组。     

Long-term results of corticosteroid therapy in patients with myasthenia gravis.

We studied the long-term outcome of prednisone therapy in 104 patients with myasthenia gravis (MG). At the end of the follow-up period, good therapeutic results were recorded in 85 patients (81.7%), poor results in 13 (12.5%) and no significant change of MG status in 6 (5.8%). We found a correlation between the duration of treatment and the incidence of steroid side effects. The presence of thymoma and severe forms of MG were associated with relapsing disease requiring prolonged corticosteroid regimens. The age at the start of therapy did not influence significantly the response to treatment.     

Plasmapheresis therapy in myasthenia gravis

Plasmapheresis in the treatment of myasthenia gravis has led to disparate results when applied by different investigators because of considerable differences in the volume, number, and tempo of plasmaphereses and in the type and amount of concomitant immunosuppressive drug therapy. Used as short-term crisis intervention, plasmapheresis produces temporary clinical improvement and reduction in titer of antibody to acetylcholine receptor, even without accompanying drug therapy. When applied as long-term primary therapy under optimal conditions, plasmapheresis is capable of generating stable improvement in most patients. This response appears to result from a synergistic action with immunosuppressive drugs, since it is characterized by a sustained reduction in titer of antibody to acetylcholine receptor. Where clinical circumstances warrant cytotoxic immunosuppression in patients with myasthenia gravis, consideration should be given to the simultaneous employment of plasmapheresis, in order to maximize benefit to the patient from a given exposure to drug therapy.     

High-dose intravenous immunoglobulin therapy for myasthenia gravis

The objective of this open, retrospective study was to investigate whether intravenous immunoglobulin (IVIg) could induce a clinically obvious improvement in patients with generalized myasthenia gravis (MG), as judged by MG functional status. Fourteen patients with generalized MG were treated during at least one episode with 0.4 g IVIg per kilogram body weight per day for 5 consecutive days. Patients with confounding variables were excluded; this left 11 patients (16 episodes) to be further analysed. We defined improvement as at least a one-step improvement in MG functional status (according to the University of Virginia’s Modification of Osserman’s classification). Of the treatment episodes, 56% were classified as positive responses. If improvement occurred, onset of improvement started after 3 (1–12) days and peak effect was reached after 7 (4– 30) days (median and range). All four patients who required artificial ventilation could be weaned from it 8.5 (6–11) days after the start of IVIg (median and range). Of the patients treated on two occasions, only one patient had a positive response during both. In MG functional status 5, improvement was observed during five of seven episodes. None of the patients with MG functional status 3 responded. Patients with an acute relapse of MG seemed to respond equally well to IVIg compared with patients with subacute deterioration/ chronic-static state (50% versus 60%). The MG functional status at the start of IVIg and on the day of maximal improvement was compared for all episodes together, and significant improvement was noted (P = 0.0052). We did not see any serious side-effects after IVIg treatment. This retrospective analysis suggests that high-dose IVIg is an effective therapy in some patients with deterioration of generalized MG. If improvement occurs, it starts within a few days of the onset of IVIg and the effect seems to peak within 2 weeks. Received: 4 March 1997 Received in revised form: 28 August 1997 Accepted: 1 September 1997     

非手术免疫抑制疗法治疗伴胸腺瘤的重症肌无力患者的远期疗效观察

目的评价非手术的免疫抑制疗法对伴有胸腺瘤的重症肌无力（MG）的远期疗效。方法采用类固醇、化学疗法、放射疗法治疗84例MG伴胸腺瘤患者,作回顾性研究,经诊断治疗后1－21年（平均4．8年）长期随访,评价其远期有效率、存活率和存活质量。结果远期有效率为86．9％（73／84）,即31例（36．9％）获完全缓解,37例（44．0％）获药物缓解,5例（6．0％）获明显改善。5年存活率76．5％,10年存活率54．5％。完全缓解期0．5－20．0年（平均4．6年）。总病死率为13．1％（11／84）。结论非手术免疫抑制疗法治疗MG伴胸腺瘤患者远期疗效良好,从远期存活率和存活质量来看并不亚于手术疗法。死因大多仍为危象,不是瘤转移。     

重症肌无力患者电生理检查的特点

目的分析重症肌无力(myasthenia gravis,MG)患者重复神经刺激(repetitive nerve stimulation,RNS)和针电极肌电图(needle electrode electromyography,NEMG)检查结果的特点,探求电生理检查结果对于MG诊断的临床意义。方法收集2009年²013年南京鼓楼医院神经科住院的50例MG患者的电生理资料进行分析研究。结果 50例MG患者中RNS检查结果阳性者40例(80%)。其中Ⅱ、Ⅲ和Ⅳ型阳性率较高,均超过90%;而Ⅰ型阳性率远低于其余3型,仅为40%,其差异有统计学意义(P<0.01)。对不同神经RNS结果进行分析发现,刺激腋神经、面神经和尺神经时RNS阳性率分别为:60%、58%和16%;腋神经、面神经阳性率远高于尺神经,其差异有统计学意义(P<0.01)。NEMG检查结果示,58%的患者呈肌源性损害表现,且随年龄增长,异常率升高。结论 RNS技术是诊断MG可靠的电生理方法,以面神经及近端腋神经异常率较高;MG患者容易出现肌源性损害,且与年龄有关,NEMG的使用有利于发现MG患者的肌源性损害,为临床诊断和治疗提供帮助。