ABSTRACT
Background@#and Purpose Lesions on diffusion-weighted imaging (DWI) occasionally appear on follow-up magnetic resonance imaging (MRI) among initially DWI-negative but clinically suspicious stroke patients. We established the prevalence of positive conversion in DWI-negative stroke and determined the clinical factors associated with it. @*Methods@#This retrospective, observational, single-center study included 5,271 patients hospitalized due to stroke/transient ischemic attack (TIA) in a single university hospital during 2010 to 2017. Patients without initial DWI lesions underwent follow-up DWI imaging as a routine practice. Adjusted hazard ratios (aHRs) for recurrent stroke risk according to positive conversion were determined using Cox proportional hazard regression. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for positive conversion among initially DWI-negative patients were estimated. @*Results@#In total, 694 (13.2%) patients (mean±standard deviation age, 62.9±13.7 years; male, 404 [58.2%]) were initially DWI-negative. Among them, 22.5% had positive-conversion on follow-up DWI. Positive conversion was associated with a higher risk of recurrent stroke (aHR, 3.12; 95% CI, 1.56 to 6.26). Early neurologic deterioration (aOR, 15.1; 95% CI, 5.71 to 47.66), atrial fibrillation (aOR, 6.17; 95% CI, 3.23 to 12.01), smoking (aOR, 3.76; 95% CI, 2.19 to 6.63), pre-stroke dependency (aOR, 1.62; 95% CI, 1.15 to 2.27), objective hemiparesis (aOR, 4.39; 95% CI, 1.90 to 10.32), longer symptom duration (aOR, 2.17; 95% CI, 1.57 to 3.08), high cholesterol (aOR, 4.70; 95% CI, 1.78 to 12.77), National Institutes of Health Stroke Scale score (aOR, 1.44; 95% CI, 1.08 to 1.91), and high systolic blood pressure (aOR, 1.01; 95% CI, 1.00 to 1.02) were associated with a higher incidence of lesions with delayed appearance. Regarding the location of lesions on follow-up DWI, 34.6% and 21.2% were in the cortex and brainstem, respectively. @*Conclusions@#In DWI-negative stroke/TIA, positive conversion is associated with a higher risk of recurrent stroke. DWI-negative stroke with factors related to positive conversion may require follow-up MRI for a definitive diagnosis.
ABSTRACT
BACKGROUND: Existing laryngoscopes are designed to be handled by the left hand, whereas most healthcare professionals are right-handed. However, controlling the laryngoscope device requires considerable strength and refinement to control the blade. We examined the usefulness of a right-handed laryngoscope to validate its clinical applicability. METHODS: One hundred sixty-four patients for general anesthesia were involved. Laryngoscopy was performed twice for each patient, once using a conventional left-handed Macintosh No. 3 laryngoscope and once using a right-handed one, by 25 right-handed and 18 left-handed laryngoscopists. The perpendicular distance from the tip of the maxillary incisor to the flange of each blade was measured when the maximum visibility of the glottis was obtained. We compared the distances, chances of directly contacting the tooth, laryngoscopic views and subjective feeling of difficulty in handling device between the two laryngoscopes. RESULTS: For the right-handed laryngoscopists, distance varied significantly between the two laryngoscopes (5.0 ± 3.5 and 5.7 ± 3.7 mm [mean ± standard deviation] for the conventional and right-handed laryngoscopes, respectively [P < 0.001]). The right-handed laryngoscope was associated with a decreased chance of directly contacting the teeth (P = 0.001). Additionally, the right-handed laryngoscope provided a better view than the conventional one (P = 0.005). Conversely, most of the left-handed laryngoscopists felt that the procedure using a conventional laryngoscope was easier than with a right-handed one. CONCLUSIONS: When a right-handed laryngoscopist uses a right-handed laryngoscope, a better laryngoscopic view and a reduced chance of blade contact with the teeth can be achieved.