Sleep disordered breathing in children receiving vagus nerve stimulation therapy

ObjectiveThe effects of vagus nerve stimulation (VNS) on sleep disordered breathing (SDB) have been reported in limited case series. Detailed studies, particularly in the pediatric population, have not been performed. The primary purpose of this study is to describe clinical characteristics, polysomnographic findings, and management of children treated with VNS.MethodsA retrospective review of medical records and polysomnography data was performed in patients ages 0–20 years old receiving VNS therapy for refractory epilepsy at Cincinnati Children's Hospital Medical Center.Results22 subjects met the inclusion criteria. 50% were male. The mean age at the time of VNS insertion was 8.4 ± 4.0 years. The mean age at the first PSG was 10.6 ± 4.3 years. Common presentations to sleep clinics included snoring (77.3%), frequent nighttime awakening (68.1%), and parasomnias (63.6%). The median apnea-hypopnea index (AHI) was 4.5/hr (IQR 3.0–13.1) and the median obstructive index (OI) was 4.1/hr (1.5–12.8). Obstructive sleep apnea (OSA) was diagnosed after VNS insertion in 19 patients (86.4%), 8 of which (36.3%) had severe OSA. Six patients (27.3%) had significant hypoventilation. For management, 6 patients (27.2%) were treated with bilevel PAP, 3 patients (13.6%) with CPAP, 2 patients (9.1%) with ventilator, 4 patients (18.2%) with upper airway surgeries, and 9 patients (40.9%) received medications only.ConclusionsSDB is common in pediatric patients with medically refractory epilepsy managed with VNS who were referred to sleep medicine clinics. Both OSA and nocturnal alveolar hypoventilation are relatively common in this population. Management of SDB often involves the use of positive airway pressure therapy or upper airway surgeries. Further studies are needed to assess the prevalence, risk factors, and the effect of treatments on epilepsy control. This study highlights the need for screening of SDB prior to and following VNS implantation.     

Sleep disordered breathing in a cohort of patients with sporadic inclusion body myositis

ObjectiveThe aims of the study were: (1) to evaluate subjective sleep quality and daytime sleepiness in patients affected by sporadic inclusion-body myositis (IBM); (2) to define the sleep and sleep-related respiratory pattern in IBM patients.MethodsThirteen consecutive adult patients affected by definite IBM were enrolled, six women and seven men, mean age 66.2 ± 11.1 years (range: 50–80). Diagnosis was based on clinical and muscle biopsy studies. All patients underwent subjective sleep evaluation (Pittsburgh Sleep Quality Index, PSQI and Epworth Sleepiness Scale, ESS), oro-pharingo-esophageal scintigraphy, pulmonary function tests, psychometric measures, anatomic evaluation of upper airways, and laboratory-based polysomnography. Findings in IBM patients were compared to those obtained from a control group of 25 healthy subjects (13 men and 12 women, mean age 61.9 ± 8.6 years).ResultsDisease duration was >10 years in all. Mean IBM severity score was 28.8 ± 5.4 (range 18–36). Dysphagia was present in 10 patients. Nine patients had PSQI scores ? 5; patients had higher mean PSQI score (IBM: 7.2 ± 4.7, Controls: 2.76 ± 1.45, p = 0.005); one patient (and no controls) had EES > 9. Polysomnography showed that IBM patients, compared to controls, had lower sleep efficiency (IBM: 78.8 ± 12.0%, Controls: 94.0 ± 4.5%, p < 0.001), more awakenings (IBM: 11.9 ± 11.0, Controls: 5.2 ± 7.5, p = 0.009) and increased nocturnal time awake (IBM: 121.2 ± 82.0 min., Controls: 46.12 ± 28.8 min., p = 0.001). Seven Patients (and no controls) had polysomnographic findings consistent with sleep disordered breathing (SDB).ConclusionData suggest that sleep disruption, and in particular SDB, might be highly prevalent in IBM.SignificanceData indicate that IBM patients have poor sleep and high prevalence of SDB.     

Sleep disordered breathing and subclinical impairment of respiratory function are common in sporadic inclusion body myositis

Relatively little is known about frequency and extent of respiratory problems in sporadic inclusion body myositis (IBM). To address this issue a study of peripheral muscle and respiratory function and related symptoms was performed in a cohort with biopsy-proven IBM. Dyspnoea, daytime sleepiness, dysphagia, spirometry, respiratory muscle strength, arterial blood gas tensions and ventilation during sleep were assessed. Sixteen patients were studied (10 males; age 68.1 ± 9.9 years; disease duration 11.9 ± 5.0 years; body mass index 28.5 ± 4.0 kg/m²). Four reported excessive daytime sleepiness; 8 had at least mild dysphagia; forced vital capacity was <80% predicted normal in 7; sniff nasal inspiratory pressure was reduced in 3; daytime hypoxemia was present in 9 and hypercapnia in one. Sleep study was performed in 15 and revealed sleep disordered breathing (apnoea–hypopnoea index 23.4 ± 12.8 (range 7–50.3) events/h) in all. There were no consistent relationships between respiratory function impairment, occurrence of sleep disordered breathing, and severity of peripheral muscle weakness. Thus, asymptomatic impairment of respiratory function was common and sleep disordered breathing observed in all patients tested, irrespective of daytime respiratory function. This suggests respiratory function testing, including sleep study, should be performed routinely in IBM, irrespective of peripheral muscle function or other disease severity parameters.     

非胸腺瘤性眼外肌麻痹起病重症肌无力胸腺切除时机探讨

目的比较非胸腺瘤性眼外肌麻痹起病重症肌无力(ocular onset myasthenia gravis,OMG-O)患者于不同病程行胸腺切除后病情缓解与向全身型重症肌无力(GMG)转化的差异,以期对手术时机进行探讨。方法采用双向队列研究方法,对作者医院2005年1月至2017年9月因药物治疗效果不佳而行胸腺切除的86例OMG-O患者,按起病至手术时间间隔分为早手术组(≤1年)、晚手术组(>1年),比较两组患者不同随访时间理想状态(干预后状态达到轻微异常及更好)率、GMG转化率的差异。结果 (1)与早手术组比较,晚手术组少年MG(<18岁)比例较高,起病至手术时间间隔、起病至使用激素时间间隔、激素用药时间较长(均P <0.05)。(2)与晚手术组比较,早手术组术后第3年理想状态率高(P=0.029),而第2、4~8年理想状态率有升高趋势,但差异无统计学意义(P>0.05)。(3)9例术后发生GMG转化,起病至发生GMG转化时间中位数17.8个月,其中6例(66.7%)在3年内发生GMG转化。早手术组与晚手术组间GMG转化率比较,差异无统计学意义(12.5%比8.7%;χ~2=0.049,P=0.825)。结论对于药物治疗无效或不耐受的OMG-O患者,早期行胸腺切除手术疗效较好;但即使手术,仍有可能发生GMG转化,约1/2患者于起病后1.5年内发生,约2/3于起病后3年内发生。     

Tongue force in patients with myasthenia gravis

OBJECTIVES: The aim was to study tongue force in patients with bulbar myasthenia gravis and compare it with that of patients with ocular myasthenia gravis, patients in clinical remission who previously suffered from bulbar myasthenia gravis, and healthy subjects. MATERIAL AND METHODS: Tongue force was measured with a tongue force transducer in cranial and lateral directions, which coincide with the directions in which the tongue exerts force during swallowing, speech, and mastication. RESULTS: Tongue force in lateral direction was significantly decreased in patients with bulbar myasthenia gravis. In addition, our findings suggest an incomplete recovery of lateral tongue force in the patients of the remission group. CONCLUSION: Our tongue force measurements may be useful for longitudinal evaluation of therapy in individual patients and also in studies of therapy efficacy in matched groups of patients if the influence of factors such as age, dental state, and sex is taken into account.     

Thymectomy in late-onset myasthenia gravis

Two cases of late-onset myasthenia gravis were successfully treated by thymectomy using a sternal splitting technique, in spite of the fact that no thymomas could be detected preoperatively. One patient was seriously ill, the other patient responded to medical treatment. Thymolipoma and malignant thymoma, respectively, were removed from the patients. It is stressed that not all thymomas produce antibodies to striated muscles and that CT-scan of the mediastinum is of limited value in the diagnosis of thymoma. It is suggested that patients with late-onset myasthenia gravis be offered thymectomy, even in the absence of detectable thymomas.     

Thymolipoma in patients with myasthenia gravis: report of two cases and review

Two cases of simultaneous occurrence of myasthenia gravis (MG) and thymolipoma are described and 4 previously reported cases are reviewed. In all 6 cases, thymectomy was performed. Pre- and postoperatively, the clinical status of the patients was similar to that of late-onset MG without thymolipoma. It is possible that simultaneous occurrence of MG and thymolipoma may be coincidental.     

Sympathetic skin response in patients with myasthenia gravis★ A comparative analysis

BACKGROUND: The examination of sympathetic skin response is an important index for assessing the autonomic nerve function, and patients with myasthenia gravis are always accompanied by dysautonomia. Therefore, it will be important to know whether sympathetic skin response can be used as the index for the clinical evaluation of myasthenia gravis. OBJECTIVE: To investigate the diagnostic value of sympathetic skin response in the damage of autonomic nerve function of patients with myasthenia gravis. DESIGN: A case-controlled comparative observation. SETTING: Department of Neurology and Room of Nerve Electromyogram, the Affiliated Hospital of North Sichuan Medical College. PARTICIPANTS: Thirty outpatients or inpatients with myasthenia gravis were selected from the Department of Neurology, the Affiliated Hospital of North Sichuan Medical College from May 2006 to May 2007, including 9 males and 21 females, aged 8–72 years with a mean age of (28±5) years old. They were all accorded with the diagnostic standards of myasthenia gravis, accompanied by different severity of autonomic nerve symptoms, including poor skin nutrition, sweating of hands and feet, pyknocardia, persistent hypotension, abdominal pain, constipation, etc. They all had not taken any drug affecting the autonomic nerve function before the examination. Informed consents were obtained from all the patients. Meanwhile, 30 healthy physical examinees were enrolled as the normal control group, including 10 males and 20 females, aged 10–75 years with a mean age of (31±5) years old. Approval was obtained from the hospital ethic committee. METHODS: After admission, the patients were examined with sympathetic skin response using DANTEC keypoint 2.0 electromyography evoked potential apparatus (Danmark). The changes of the latency and wave amplitude of sympathetic skin response were observed. The subjects in the normal control group were examined with the same methods at physical examination. Abnormality was judged by the disappearance of wave form, latency longer than that in the normal control group by Mean±2.5SD, or wave amplitude lower than the average value in the normal control group by 50%. MAIN OUTCOME MEASURES: The results of the latency and wave amplitude of sympathetic skin response were compared between the patients with myasthenia gravis and normal controls. RESULTS: All the 30 patients with myasthenia gravis and 30 healthy physical examinees were involved in the final analysis of results. There were no significant differences between the left and right upper and lower limbs in both the myasthenia gravis group and normal control group (P > 0.05). In the myasthenia gravis group, the abnormal rate of sympathetic skin response was 37% (11/30), the latency was prolonged and the wave amplitude was decreased as compared with those in the normal control group, and there were significant differences (P < 0.01). CONCLUSION: Sympathetic skin response can be used as an electrophysiological index for judging the damages of autonomic nerve function in patients with myasthenia gravis.     

重症肌无力患者的注意网络功能研究

目的探讨重症肌无力(myasthenia gravis,MG)患者注意功能是否受损及其受损特点,并进一步分析其影响因素,对MG注意缺陷的可能神经机制进行推测。方法选取安徽医科大学第一附属医院门诊及住院的MG确诊患者26例,并选取来自同期健康体检中的健康查体者40名作为对照。比较两组简易精神状态检查量表(mini-mental state examination,MMSE)评分、数字广度(digit span,DS)、词语流畅性(verbal fluency test,VFT)、抑郁自测量表(self-rating depression scale,SDS)评分差异,采用注意网络测验(attention network test,ANT)方法对受试者的注意功能受损情况进行检测。结果 MG和对照组间MMSE、DS、VFT、SDS评分差异无统计学意义(均P0.05);两组间ANT总平均反应时间(RT)及总平均正确率差异无统计学意义(均P0.05);MG组的定向网络效率与对照组比较减低(t=-4.198,P0.01),而两组间警觉网络与执行网络差异比较无统计学意义(均P0.05)。结论 MG患者存在注意功能损害,表现为定向网络异常,而警觉网络与执行控制网络保留正常,提示患者可能存在中枢胆碱能系统损害,推测MG患者存在认知功能障碍。     

Thymectomy in myasthenia gravis a review

The role of thymectomy in the management of myasthenia gravis is reviewed in the light of the published data and of a personal series. The patients in whom the operation is most successful are non thymomatous patients aged between 10 and 40 years with an MG history of less than 3 years. There is no sex prevalence. Lasting improvement may be expected. There are no proven correlations between biological indices like the germinal centers in the thymus and/or AChR antibody titers and the postoperative course of the disease. Complete removal of the thymus seems to be crucial and hence the transsternal approach is preferred. The operation, less effective in patients with thymona than in those with an active thymus, is nonetheless necessary to in these patients prevent putative damage to surrounding organs from thymona infiltration. Why thymectomy should be effective in patients with an active thymus and not in those with a thymona may be revealed by in vitro studies of the interactions between thymic cells and peripheral B cells, now in progress.

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Sommario Viene rivisto alla luce dei dati della letteratura e della casistica personale il ruolo della timectomia nella terapia della miastenia. Dei pazienti non portatori di timoma i migliori risultati si ottengono in quelli di età fra i 10 e i 40 anni con una durata della malattia minore di tre anni. Non vi è prevalenza di sesso. Ci si può attendere un miglioramento duraturo. Non vi sono prove di una correlazione tra gli indici biologici germinativi quali i centri germinali nel timo e o il titolo degli anticorpi contro i ricettori acetilcolinici e il decorso post-operatorio della malattia. É fondamentale la completa asportazione del timo e perciò è preferibile la scelta della tecnica di approccio transternale. Nei pazienti con timoma la timectomia è meno efficace ma l'intervento è necessario per evitare danni derivanti dall'infiltrazione del timoma sugli organi circostanti. Il perché della efficacia della timectomia nei pazienti con un timo attivo ma non in quelli con timoma potrà essere chiarito dagli studi in vitro sulle interazioni tra cellule timiche e quelle periferiche B, studi che sono ormai in stadio avanzato.

     

Psychiatric disturbances associated with myasthenia gravis

Seventy-four myasthenic patients (54 F, 20 M; mean age 49.6 years) were evaluated using the diagnostic criteria of the DSM-III in order to investigate the prevalence of psychiatric disturbances in this order. Fifty-one had had thymectomies, of whom 28 females had hyperplasia, two females and five males had involution of the thymus, and 10 females and six males had thymomata. Psychiatric disturbances were observed in 38 subjects (51%), in particular, adjustment disorders with depressed mood and mixed emotional features (19%) (22% including adjustment disorder with anxious mood), affective disorders (13.5%) and personality disorders (18%).     

Changes in serum cytokine levels during plasmapheresis in patients with myasthenia gravis

Background: The effect of plasmapheresis on cytokine levels in patients with myasthenia gravis (MG) has not been well established. Methods: Cytokine levels were measured in 19 patients with MG before and after treatment with one course of double‐filtration plasmapheresis (DFP). The control group comprised 6 age‐ and sex‐matched healthy volunteers. Results: At baseline, patients with MG had higher levels of IL‐10 than normal controls. The levels of IL‐2, IL‐4, IL‐5, and tumor necrosis factor‐α were almost undetectable in MG patients. After a single session of DFP treatment, IL‐10 levels were significantly increased. After three sessions, IL‐10 levels were still higher than those at baseline. Elevated IL‐10 level was significantly associated with use of immunosuppressant drugs, thymectomy, and good response to DFP treatment. Conclusions: Interleukin‐10 might play a crucial role in the pathogenesis and perpetuation of MG.