Motor excitability in bilateral moyamoya vasculopathy and the impact of revascularization.

OBJECTIVE: Motor cortical dysfunction has been shown to be reversible in patients with unilateral atherosclerotic disease after cerebral revascularization. Moyamoya vasculopathy (MMV) is a rare bilateral stenoocclusive cerebrovascular disease. The aim of this study was to analyze the corticospinal excitability and the role of bypass surgery in restoring cortical motor function in patients by using navigated transcranial magnetic stimulation (nTMS). METHODS: Patients with bilateral MMV who met the criteria for cerebral revascularization were prospectively included. Corticospinal excitability, cortical representation area, and intracortical inhibition and facilitation were assessed by nTMS for a small hand muscle (first dorsal interosseous) before and after revascularization. The clinically and/or hemodynamically more severely affected hemisphere was operated first as the leading hemisphere. Intra- and interhemispheric differences were analyzed before and after direct or combined revascularization. RESULTS: A total of 30 patients with bilateral MMV were examined by nTMS prior to and after revascularization surgery. The corticospinal excitability was higher in the leading hemisphere compared with the non-leading hemisphere prior to revascularization. This hyperexcitability was normalized after revascularization as demonstrated in the resting motor threshold ratio of the hemispheres (preoperative median 0.97 [IQR 0.89-1.08], postoperative median 1.02 [IQR 0.94-1.22]; relative effect = 0.61, p = 0.03). In paired-pulse paradigms, a tendency for a weaker inhibition of the leading hemisphere was observed compared with the non-leading hemisphere. Importantly, the paired paradigm also demonstrated approximation of excitability patterns between the two hemispheres after surgery. CONCLUSIONS: The study results suggested that, in the case of a bilateral chronic ischemia, a compensation mechanism between both hemispheres seemed to exist that normalized after revascularization surgery. A potential role of nTMS in predicting the efficacy of revascularization must be further assessed.

The Frankfurt Patient Safety Climate Questionnaire for General Practices (FraSiK): analysis of psychometric properties.

BACKGROUND Safety culture has been identified as having a major impact on how safety is managed in healthcare. However, it has not received much attention in general practices. Hence, no instrument yet exists to assess safety climate-the measurable artefact of safety culture-in this setting. This study aims to evaluate psychometric properties of a newly developed safety climate questionnaire for use in German general practices. METHODS The existing Safety Attitudes Questionnaire, Ambulatory Version, was considerably modified and enhanced in order to be applicable in general practice. After pilot tests and its application in a random sample of 400 German practices, a first psychometric analysis led to modifications in several items. A further psychometric analysis was conducted with an additional sample of 60 practices and a response rate of 97.08%. Exploratory factor analysis with orthogonal varimax rotation was carried out and the internal consistency of the identified factors was calculated. RESULTS Nine factors emerged, representing a wide range of dimensions associated with safety culture: teamwork climate, error management, safety of clinical processes, perception of causes of errors, job satisfaction, safety of office structure, receptiveness to healthcare assistants and patients, staff perception of management, and quality and safety of medical care. Internal consistency of factors is moderate to good. CONCLUSIONS This study demonstrates the development of a patient safety climate instrument. The questionnaire displays established features of safety climate and additionally contains features that might be specific to small-scale general practices.