[Characteristics of low frequency repetitive nerve stimulation in patients with myasthenia gravis and its correlation with clinical features].

Objective: To investigate the characteristics of low frequency repetitive nerve stimulation (RNS) in patients with myasthenia gravis (MG) and analyze the correlation between RNS results and clinical characteristics. Methods: The clinical and electrophysiological data of 107 MG patients who were admitted to Guangdong Provincial People's Hospital and underwent electromyography (EMG) between September 2015 to September 2020 were retrospectively reviewed. The characteristics of low frequency RNS in ocular MG and generalized MG patients were analyzed. Patients were divided into RNS-negative group and RNS-positive group according to the RNS results. The clinical features, serological and thymic CT findings, thymic pathology were collected and compared. Binary logistic regression analysis was used to analyze the related factors of low frequency RNS. Results: Generalized MG (73.0%, 46/63) showed a lower positive rate of low frequency RNS compared to ocular MG (34.1%, 15/44) (P<0.001). In generalized MG, the positive rate of low frequency RNS in accessory nerve (68.3%, 43 cases) and facial nerve (52.4%, 33 cases) was higher than that in ulnar nerve (14.3%, 9 cases) (P<0.001). The decrease rate of compound muscle action potential (CMAP) in facial nerve (32%±11%) was higher than that in ocular muscle type (22%±7%) in RNS-positive group (P=0.011). Patients with positive facial nerve RNS were more likely to involve the throat muscles than those with negative result [22 cases (52.4%) compared with 17 cases (26.2%), P=0.006]. RNS-positive group showed a significantly higher quantitative myasthenia gravis (QMG) score than that of negative group (P<0.001). In ocular MG, patients with positive RNS showed a later onset (P=0.021), higher acetylcholine receptor (AChR) antibody-positive rate (P=0.03) and QMG score (P<0.001). Additionally, In generalized MG, patients with positive RNS showed a significantly higher AChR antibody-positive rate (P=0.023) and QMG score (P<0.001). The logistic regression analysis showed that QMG score [OR(95%CI)=1.66(1.36-2.03), P<0.001] and positive AChR antibody [OR(95%CI)=5.45(1.28-23.14), P=0.022] were independently related to abnormal RNS. Conclusions: Low frequency RNS is more sensitive in generalized MG. The stimulation of facial and accessory nerves increases the positive rate of RNS in MG patients. Abnormal results of low frequency RNS tend to be combined with positive AChR antibody and higher QMG score, reflecting the severity of muscle weakness. Therefore, serological examination and early intervention are required for those with abnormal RNS.

Quality of questionnaires for the assessment of otitis media with effusion in children.

OBJECTIVES: Audiometric tests provide information about hearing in otitis media with effusion (OME). Questionnaires can supplement this information by supporting clinical history-taking as well as potentially providing a standardized and comprehensive assessment of the impact of the disease on a child. There are many possible candidate questionnaires. This study aimed to assess the quality and usability of parent / child questionnaires in OME assessment. DESIGN AND MAIN OUTCOME MEASURES: Fifteen, published questionnaires, commonly used in audiological departments (Auditory Behaviour in Everyday Life (ABEL), Children's Auditory Performance Scale (CHAPS), Children's Home Inventory for Listening Difficulties (CHILD), Children's Outcome Worksheets (COW), Evaluation of Children's Listening and Processing Skills (ECLiPS), Early Listening Function (ELF), Fisher's Auditory Problem Checklist (FAPC), Hearing Loss 7 (HL-7), Listening Inventory for Education- Revised (LIFE-R Student), Listening Inventory for Education UK Individual Hearing Profile (LIFE-UK IHP), LittlEARS Auditory Questionnaire (LittlEARS), Listening Situations Questionnaire (LSQ), Otitis Media 6 (OM-6), Quality of Life in Children's Ear Problems (OMQ-14), Parents' Evaluation of Aural/Oral Performance of Children (PEACH) were assessed according to the following 8 criteria: conceptual clarity, respondent burden, reliability, validity, normative data, item bias, ceiling/ floor effects, and administrative burden. RESULTS: ECLiPS, LittlEARS and PEACH scored highest overall based on the assessment criteria established for this study. None of the questionnaires fully satisfied all 8 criteria. Although all questionnaires assessed issues considered to be of at least adequate relevance to OME, the majority had weaknesses with respect to the assessment of psychometric properties, such as item bias, floor/ceiling effects or measurement reliability and validity. Publications reporting on the evaluation of reliability, validity, normative data, item bias and ceiling/floor effects were not available for most of the questionnaires. CONCLUSIONS: This formal evaluation of questionnaires, currently available to clinicians, highlights three questionnaires as potentially offering a useful adjunct in the assessment of OME in clinical or research settings. These were the ECLiPS, which is suitable for children aged 6 years and older, and either the LittlEARS or the PEACH for younger children. The latter two are narrowly focused on hearing, whereas ECLiPS has a broader focus on listening, language and social difficulties.

A rare PAX6 mutation in a Chinese family with congenital aniridia.

Aniridia is an autosomal dominant disorder characterized by the complete or partial loss of the iris and is almost associated with mutations in the paired box gene 6 (PAX6). We examined three generations of a Chinese family with congenital aniridia and observed genetic defects. Exons of PAX6 from 12 family members were amplified by polymerase chain reaction, sequenced, and compared with reference sequences in NCBI reference sequence database (http://www.ncbi.nlm.nih.gov/nuccore/NG_008679.1?from=5001&to=38170&report=genbank). A rare mutation c.2T>A (M1K) in exon 4 of PAX6 was identified in all affected family members but not in unaffected family members. Our results suggest that the c.2T>A (M1K) mutation may be responsible for the pathogenesis of congenital aniridia in this family. To our knowledge, this is the first report of the M1K mutation in PAX6 in a Chinese family with this disease and the second report worldwide.

A novel mutation of PAX6 identified in a Chinese twin family with congenital aniridia complicated with nystagmus.

Genetic variations within the paired box gene 6 (PAX6) gene are associated with congenital aniridia. To detect the genetic defects in a Chinese twin family with congenital aniridia and nystagmus, exons of PAX6 were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database. Six members from the family of three generations were included in the study. The twins' father presented with congenital aniridia, nystagmus and cataract at birth, while the twins presented with congenital aniridia and nystagmus. A novel mutation c.888 insA in exon 10 of PAX6 was identified in all affected individuals. This study suggests that the novel mutation c.888 insA is likely responsible for the pathogenesis of the congenital aniridia and nystagmus in this pedigree. To the best of our knowledge, this is the first report of this mutation in PAX6 gene in pedigree with aniridia. Furthermore, no PAX6 gene defect was reported in twins with congenital aniridia.

Modified transseptal approach in endoscopic transsphenoidal pituitary surgery.

OBJECTIVE: Transsphenoidal pituitary surgery is commonly performed via a direct transostial approach with a posterior septectomy. However, a technique via an endoscopic transseptal route has been described that avoids a posterior septectomy, but it comes with its own disadvantages. METHODS: This paper describes a modification, and discusses its pros and cons. RESULTS: The initial incision in the mucosa is placed level with the anterior middle turbinate. The mucoperichondrial flap is raised ipsilaterally until the sphenoid sinus ostium. An incision is made at the osseocartilaginous junction, and the contralateral mucoperichondrial flap is raised. The bony septum and posterior aspect of this flap is excised. The size and position of this window can be adapted. At the end of the operation, the lateralised intact mucoperichondrial flap is moved back to the midline. CONCLUSION: Excision or deflection of the cartilaginous septum is not required. It maintains an intact septal mucosa on one side and avoids a septal perforation.

Effect of insulin infusion on electrocardiographic findings following acute myocardial infarction: importance of glycaemic control.

AIMS: To determine the effects of insulin infusion and blood glucose levels during acute myocardial infarction (AMI) on electrocardiographic (ECG) features of myocardial electrical activity. METHODS: ECGs at admission and 24 h were examined in a randomized study of insulin infusion vs. routine care for AMI patients with diabetes or hyperglycaemia. Results were analysed according to treatment allocation and also according to average blood glucose level. RESULTS: ECG characteristics were similar at admission in both groups. Patients allocated to conventional treatment had prolongation of the QT interval (QTc) after 24 h but those receiving infused insulin did not. In patients with a mean blood glucose in the first 24 h > 8.0 mmol/l, new ECG conduction abnormalities were significantly more common than in patients with mean blood glucose