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Importance The current assessment of visual field loss in diseases such as glaucoma is affected by the subjectivity of patient responses and the lack of portability of standard perimeters. Objective To describe the development and initial validation of a portable brain-computer interface (BCI) for objectively assessing visual function loss. Design, Setting, and Participants This case-control study involved 62 eyes of 33 patients with glaucoma and 30 eyes of 17 healthy participants. Glaucoma was diagnosed based on a masked grading of optic disc stereophotographs. All participants underwent testing with a BCI device and standard automated perimetry (SAP) within 3 months. The BCI device integrates wearable, wireless, dry electroencephalogram and electrooculogram systems and a cellphone-based head-mounted display to enable the detection of multifocal steady state visual-evoked potentials associated with visual field stimulation. The performances of global and sectoral multifocal steady state visual-evoked potentials metrics to discriminate glaucomatous from healthy eyes were compared with global and sectoral SAP parameters. The repeatability of the BCI device measurements was assessed by collecting results of repeated testing in 20 eyes of 10 participants with glaucoma for 3 sessions of measurements separated by weekly intervals. Main Outcomes and Measures Receiver operating characteristic curves summarizing diagnostic accuracy. Intraclass correlation coefficients and coefficients of variation for assessing repeatability. Results Among the 33 participants with glaucoma, 19 (58%) were white, 12 (36%) were black, and 2 (6%) were Asian, while among the 17 participants with healthy eyes, 9 (53%) were white, 8 (47%) were black, and none were Asian. The receiver operating characteristic curve area for the global BCI multifocal steady state visual-evoked potentials parameter was 0.92 (95% CI, 0.86-0.96), which was larger than for SAP mean deviation (area under the curve, 0.81; 95% CI, 0.72-0.90), SAP mean sensitivity (area under the curve, 0.80; 95% CI, 0.69-0.88; P = .03), and SAP pattern standard deviation (area under the curve, 0.77; 95% CI, 0.66-0.87; P = .01). No statistically significant differences were seen for the sectoral measurements between the BCI and SAP. Intraclass coefficients for global and sectoral parameters ranged from 0.74 to 0.92, and mean coefficients of variation ranged from 3.03% to 7.45%. Conclusions and Relevance The BCI device may be useful for assessing the electrical brain responses associated with visual field stimulation. The device discriminated eyes with glaucomatous neuropathy from healthy eyes in a clinically based setting. Further studies should investigate the feasibility of the BCI device for home-based testing as well as for detecting visual function loss over time.

Author(s): Chien, Yu-Yi; Lin, Fang-Cheng; Zao, John K; Chou, Ching-Chi; Huang, Yi-Pai; Kuo, Heng-Yuan; Wang, Yijun; Jung, Tzyy-Ping; Shieh, Han-Ping D | Abstract: ObjectiveInteractive displays armed with natural user interfaces (NUIs) will likely lead the next breakthrough in consumer electronics, and brain-computer interfaces (BCIs) are often regarded as the ultimate NUI-enabling machines to respond to human emotions and mental states. Steady-state visual evoked potentials (SSVEPs) are a commonly used BCI modality due to the ease of detection and high information transfer rates. However, the presence of flickering stimuli may cause user discomfort and can even induce migraines and seizures. With the aim of designing visual stimuli that can be embedded into video images, this study developed a novel approach to induce detectable SSVEPs using a composition of red/green/blue flickering lights.ApproachBased on the opponent theory of colour vision, this study used 32 Hz/40 Hz rectangular red-green or red-blue LED light pulses with a 50% duty cycle, balanced/equal luminance and 0°/180° phase shifts as the stimulating light sources and tested their efficacy in producing SSVEP responses with high signal-to-noise ratios (SNRs) while reducing the perceived flickering sensation.Main resultsThe empirical results from ten healthy subjects showed that dual-colour lights flickering at 32 Hz/40 Hz with a 50% duty cycle and 180° phase shift achieved a greater than 90% detection accuracy with little or no flickering sensation.SignificanceAs a first step in developing an embedded SSVEP stimulus in commercial displays, this study provides a foundation for developing a combination of three primary colour flickering backlights with adjustable luminance proportions to create a subtle flickering polychromatic light that can elicit SSVEPs at the basic flickering frequency.

Objective Primary quadriceps weakness/atrophy is a rare disorder with variable etiologies; therefore, this disorder has been regarded as a clinical syndrome rather than a distinct entity. However, three affected patients of a Taiwanese family demonstrate a uniform pattern of quadriceps weakness and atrophy, their clinical manifestations and pattern of inheritance may suggest a new disease entity. Patients and Methods Three patients in a Taiwanese kindred with selective quadriceps weakness and atrophy, which began after age 40 years, were examined. To disclose the confines of this disorder, muscle CT scans, electromyography, nerve conduction studies and muscle biopsies were performed; and to unravel and better understand the nature of this disorder, histopathological, ultrastructural, immunocytochemical and genetic studies were carried out. Results In two patients with long-standing disease, muscle imaging showed marked atrophy and fat replacement of the anterior thigh muscles and electromyography showed a mixture of myopathic and neuropathic changes. Muscle histopathology on the mildly affected tibialis anterior showed myopathic changes with myofibrillar degeneration and secondary neurogenic alterations. Immunocytochemical staining was not diagnostic but excluded the dystrophinopathies and other well-known muscular dystrophies. Conclusion All previously identified diseases resulting in quadriceps weakness and atrophy have been ruled out and the present disorder appears to be a new disease entity of autosomal dominant late onset quadriceps myopathy.

The short-term effects after experimental partial and total denervation on histochemical fiber type profiles were studied in rat soleus muscles by the myofibrillar ATPase stain. In 58 control soleus muscles, a total of 155788 fibers were counted, comprising type 1 (75.1%), type 2A (13.3%), type 2B (1.4%) and type 2C (10.3%), respectively. In 34 animals with total denervation, including 17 with soleus nerve resection at 1cm before entering the soleus muscle and 17 with total sciatic neurectomy, the proportion of type 1 fiber was decreased in denervated muscles to 39.1% 5 weeks after the procedures. In parallel with a decrease in type 1 fiber proportion, undifferentiated type 2C fibers increased, thereby suggesting muscle fiber type dedifferentiation taking place in totally denervated muscle. In contrast, 24 muscles with partial denervation showed a decreased proportion of type 1 fibers at the initial stage followed by an increase in type 1 fiber to 89.0% 5 weeks after denervation, resulting from an active reinnervating process.

The effects of partial and total denervation on muscle fibers were studied in rat soleus muscles by quantitative computer imaging analysis. Within 5 weeks after denervation, there was a progressive reduction of the soleus muscle weight in total denervation groups but a gradual recovery beginning in the third week and reaching 75% of the control in the fifth week in the partial denervation group. The reduction of muscle mass was mainly due to the replacement of large and medium-sized fibers by small atrophic fibers.In totally denervated muscles, cross-sectional fiber area showed a rapid decline after denervation, but the shape of fiber size distribution was nearly normal. On the other hand, partially denervated muscles showed an asymmetrical fiber size distribution with a shift toward large fibers. In control and totally denervated muscles, mean fiber area strongly correlated with the standard deviation from the mean, but in partially denervated muscles, this strong correlation no longer existed and was replaced by larger standard deviations. It is concluded that only partially denervated muscles show significant variations in fiber size.

Signal analysis is a field of study that attempts to extract information features from various physical phenomena. Fourier transform (FT), wavelet transform (WT), and Hilbert-Huang transformation (HHT) are the 3 major approaches used in signal analysis (Huang et al., 1998) (Yan & Gao, 2007). FT is a global energy-frequency distribution approach that is suitable for analyzing linear, strictly periodic, and stationary signals. In contrast, HHT is a good method for analyzing non-linear and non-stationary signals, such as those associated with wind, earthquakes, electrocardiographs (ECGs), and electroencephalograms (EEGs). This method can also used to describe the local features of dynamic signals, and illustrate the energy-frequency-time distribution of these signals. The 2 principal steps employed in HHT are empirical mode decomposition (EMD) and Hilbert spectral analysis, EMD is used to decompose local signals to finite data sets, which are referred to as intrinsic mode functions (IMFs), and Hilbert transforms (HTs) are used in conjunction with the obtained IMFs to determine the instantaneous frequencies (IFs), time-frequency-energy distributions of the local time signals. A number of studies have been performed to elucidate various aspects of signal analysis. Cohen reviewed the fundamental ideas, methods, and characteristics of the time-frequency analysis approaches employed until 1989 (Cohen, 1989). Blanco et al., used the Gabor transform (GT) time-frequency analysis approach to facilitate identification of the source of epileptic seizures (Blanco et al., 1997). The GT approach is similar to the fast FT approach, but GT offers the advantage of allowing the analysis of the frequencies and their time evolution. Blanco et al., adopted GT to achieve maximal concentration of the time and frequency characteristics for epilepsy and obtain accurate information on the time evolution of the frequency epileptic activity. Tzallas et al., used short-time Fourier transform and 12 different time-frequency distributions for studying epilepsy classification problems and discussed the obtained sensitivity, accuracy, and selectivity results, and the characteristic data features for the detection of epilepsy (Tzallas et al., 2009). However, they did not use the HHT-based time-frequency analysis approach to define epileptic sharps. Sharabaty et al., used the HHT signal-analysis approach to determine the alpha and theta localizations for estimation of the vigilance level, and

Background: Clinical outcome of internal carotid artery (ICA) occlusion is highly variable and the reason is uncertain. Aim: To study the predictive factors of clinical outcome and stroke recurrence in patients with ischemic stroke associated with unilateral atherosclerosis-related ICA occlusion. Settings and Design: Prospective study in neurology department of a single hospital. Materials and Methods: We prospectively studied 66 patients who suffered from first-ever ischemic stroke associated with unilateral atherosclerosis-related ICA occlusion over a period of two years. The end point was death or stroke recurrence. Statistical Analysis: Chi-square or Fisher's exact test was used to analyze predictors of early functional outcome. Multivariate analysis was used to analyze predictors of death or stroke recurrence within two years. Result: Higher age (³70 years) predicted a worse functional outcome ( P = 0.049). Total anterior circulation syndrome (TACS) was associated with a poor functional outcome ( P < 0.001), but lacunar syndrome had a better outcome ( P = 0.001). Stroke in evolution predicted a poor outcome ( P = 0.001), while those with symptom improvement had a better outcome ( P = 0.016). Pneumonia predicted a poor outcome ( P = 0.021). Five patients expired and 22 patients suffered from recurrent stroke in the following 24 months. Previous transient ischemic attack (TIA) and anemia were associated with a higher risk of death or recurrent stroke within two years ( P = 0.036, P = 0.012). Conclusion: High age, TACS, stroke in evolution and pneumonia were predictors for poor functional outcome. Previous TIA and anemia were predictors for death and recurrent stroke within two years.

Background/PurposeDespite effective vaccine programs, tetanus is occasionally observed in adults. We reviewed clinical presentation data for adult patients with tetanus in the post-vaccine era in Taiwan.MethodsWe retrospectively reviewed the medical records of all adult patients (age >18 years) discharged from Chang-Gung Memorial Hospital at Lin-Ko (CGMHLK) after treatment for tetanus between January 1996 and July 2005. Data regarding demographic characteristics, clinical manifestation, treatment, and outcome were collected. To assess the features for different age groups, patients were divided into those aged ≥65 years and those aged