Central macular thickness in patients with sickle cell disease and no signs of retinopathy: a cross-sectional study of Jordanian patients

ObjectivesTo measure central macular thickness in Jordanian patients with sickle cell disease who did not have retinopathy and compare the findings with age- and sex-matched controls using spectral domain optical coherence tomography (SDOCT).MethodsIn this cross-sectional study, participants underwent visual acuity testing, slit-lamp bio-microscopy, dilated ophthalmoscopy, and SDOCT imaging to measure central macular thickness. Macular quadrant measurements and thickness difference indexes (TDIs) were compared between groups.ResultsTwenty eyes with sickle cell disease and 20 control eyes were enrolled. The median visual acuity in both groups was 20/20. The mean macular thickness was significantly lower in eyes with sickle cell disease than in matched controls (mean difference, 22.15 ± 6.44 µm). Peripheral quadrants were all significantly thinner in eyes with sickle cell disease, especially in superior and temporal quadrants. TDIs were lower in eyes with sickle cell disease than in control eyes.ConclusionsEyes with sickle cell disease that had no clinical evidence of retinopathy exhibited significantly lower central macular thickness in all quadrants, compared with eyes in age- and sex-matched controls. SDOCT is a non-invasive imaging modality that can detect preclinical changes in eyes with sickle cell disease and can be used to screen and monitor the disease process.     

Reduction of heart sound interference from lung sound signals using empirical mode decomposition technique

During the recording time of lung sound (LS) signals from the chest wall of a subject, there is always heart sound (HS) signal interfering with it. This obscures the features of lung sound signals and creates confusion on pathological states, if any, of the lungs. A novel method based on empirical mode decomposition (EMD) technique is proposed in this paper for reducing the undesired heart sound interference from the desired lung sound signals. In this, the mixed signal is split into several components. Some of these components contain larger proportions of interfering signals like heart sound, environmental noise etc. and are filtered out. Experiments have been conducted on simulated and real-time recorded mixed signals of heart sound and lung sound. The proposed method is found to be superior in terms of time domain, frequency domain, and time–frequency domain representations and also in listening test performed by pulmonologist.     

Sleep spindle activity correlates with implicit statistical learning consolidation in untreated obstructive sleep apnea patients

Objective/BackgroundThe aim of this study was to examine the relationship between overnight consolidation of implicit statistical learning with spindle frequency EEG activity and slow frequency delta power during non-rapid eye movement (NREM) sleep in obstructive sleep apnea (OSA).Patients/MethodsForty-seven OSA participants completed the experiment. Prior to sleep, participants performed a reaction time cover task containing hidden patterns of pictures, about which participants were not informed. After the familiarisation phase, participants underwent overnight polysomnography. 24 h after the familiarisation phase, participants performed a test phase to assess their learning of the hidden patterns, expressed as a percentage of the number of correctly identified patterns. Spindle frequency activity (SFA) and delta power (0.5–4.5 Hz), were quantified from NREM electroencephalography. Associations between statistical learning and sleep EEG, and OSA severity measures were examined.ResultsSFA in NREM sleep in frontal and central brain regions was positively correlated with statistical learning scores (r = 0.41 to 0.31, p = 0.006 to 0.044). In multiple regression, greater SFA and longer sleep onset latency were significant predictors of better statistical learning performance. Delta power and OSA severity were not significantly correlated with statistical learning.ConclusionsThese findings suggest spindle activity may serve as a marker of statistical learning capability in OSA. This work provides novel insight into how altered sleep physiology relates to consolidation of implicitly learnt information in patients with moderate to severe OSA.     

Quantitative electroencephalography during rapid eye movement (REM) and non‐REM sleep in combat‐exposed veterans with and without post‐traumatic stress disorder

Sleep disturbances are a hallmark feature of post‐traumatic stress disorder (PTSD), and associated with poor clinical outcomes. Few studies have examined sleep quantitative electroencephalography (qEEG), a technique able to detect subtle differences that polysomnography does not capture. We hypothesized that greater high‐frequency qEEG would reflect ‘hyperarousal’ in combat veterans with PTSD (n = 16) compared to veterans without PTSD (n = 13). EEG power in traditional EEG frequency bands was computed for artifact‐free sleep epochs across an entire night. Correlations were performed between qEEG and ratings of PTSD symptoms and combat exposure. The groups did not differ significantly in whole‐night qEEG measures for either rapid eye movement (REM) or non‐REM (NREM) sleep. Non‐significant medium effect sizes suggest less REM beta (opposite to our hypothesis), less REM and NREM sigma and more NREM gamma in combat veterans with PTSD. Positive correlations were found between combat exposure and NREM beta (PTSD group only), and REM and NREM sigma (non‐PTSD group only). Results did not support global hyperarousal in PTSD as indexed by increased beta qEEG activity. The correlation of sigma activity with combat exposure in those without PTSD and the non‐significant trend towards less sigma activity during both REM and NREM sleep in combat veterans with PTSD suggests that differential information processing during sleep may characterize combat‐exposed military veterans with and without PTSD.     

Can nurses exclude middle-ear effusion without otoscopy in young asymptomatic children in primary care?

Objective. Scandinavian guidelines recommend controlling middle-ear effusion (MEE) after acute otitis media. The study aim was to determine whether nurses without otoscopic experience can reliably exclude MEE with tympanometry or spectral gradient acoustic reflectometry (SG-AR) at asymptomatic visits. Design. Three nurses were taught to perform examinations with tympanometry and SG-AR. Pneumatic otoscopy by the study physician served as the diagnostic standard. Setting. Study clinic at primary health care level. Patients. A total of 156 children aged 6–35 months. Main outcome measures. Predictive values (with 95% confidence interval) for tympanometry and SG-AR, and the clinical usefulness, i.e. the proportion of visits where nurses obtained the exclusive test result from both ears of the child. Results. At 196 visits, the negative predictive value of type A and C1 tympanograms (tympanometric peak pressure > −200 daPa) was 95% (91–97%). Based on type A and C1 tympanograms, the nurse could exclude MEE at 81/196 (41%) of visits. The negative predictive value of SG-AR level 1 result was 86% (79–91%). Based on SG-AR level 1 results, the nurse could exclude MEE at 29/196 (15%) of visits. Conclusion. Tympanograms with tympanometric peak pressure > −200 daPa (types A and C1) obtained by nurses are reliable test results in excluding MEE. However, these test results were obtained at less than half of the asymptomatic visits and, thus, the usefulness of excluding MEE by nurses depends on the clinical setting.     

频域光学相干断层扫描检测原发性开角型青光眼视盘及黄斑参数的影响因素分析

目的 利用频域光学相干断层扫描（SD-OCT）检测健康对照和早中期原发性开角型青光眼（POAG）患者的视盘及黄斑参数,分析其相关影响因素。方法 选择2015年9月至2018年8月在我科就诊的早中期POAG患者40例（40眼）,其中20~39岁者20例、60~79岁者20例;纳入同期在我科就诊的40名（40眼）健康对照,其中20~39岁者20名、60~79岁者20名。受试者均接受全面的眼科检查,并利用SD-OCT测量所有受试者视盘周围视网膜神经纤维层（pRNFL）厚度、黄斑区平均神经节细胞层联合内丛状层（GCL-IPL）厚度、黄斑区最薄GCL-IPL厚度和黄斑区平均整体厚度。结果 健康对照组和早中期POAG组黄斑区平均GCL-IPL厚度及最薄GCL-IPL厚度均随年龄增长而变薄,差异均有统计学意义（P<0.05,P<0.01）;两组黄斑区平均整体厚度随着年龄的增长均无明显变化。在健康对照组,年龄因素对pRNFL厚度影响不大,20~39岁者与60~79岁者pRNFL厚度差异无统计学意义（P>0.05）。在早中期POAG组,20~39岁者和60~79岁者pRNFL平均厚度、上方厚度、下方厚度和颞侧厚度与健康对照组同年龄者相比均变薄,且60~79岁者上述pRNFL厚度与20~39岁者相比更薄,差异均有统计学意义（P<0.01）;早中期POAG组pRNFL鼻侧厚度在20~39岁者与60~79岁者之间差异无统计学意义（P>0.05）,与健康对照组同年龄者相比差异亦无统计学意义（P>0.05）。结论 SD-OCT测量的pRNFL厚度与POAG有关,可作为早期诊断POAG的检测指标。