Inter-hemispheric EEG coherence analysis in Parkinson's disease : Assessing brain activity during emotion processing

Parkinson’s disease (PD) is not only characterized by its prominent motor symptoms but also associated with disturbances in cognitive and emotional functioning. The objective of the present study was to investigate the influence of emotion processing on inter-hemispheric electroencephalography (EEG) coherence in PD. Multimodal emotional stimuli (happiness, sadness, fear, anger, surprise, and disgust) were presented to 20 PD patients and 30 age-, education level-, and gender-matched healthy controls (HC) while EEG was recorded. Inter-hemispheric coherence was computed from seven homologous EEG electrode pairs (AF3–AF4, F7–F8, F3–F4, FC5–FC6, T7–T8, P7–P8, and O1–O2) for delta, theta, alpha, beta, and gamma frequency bands. In addition, subjective ratings were obtained for a representative of emotional stimuli. Interhemispherically, PD patients showed significantly lower coherence in theta, alpha, beta, and gamma frequency bands than HC during emotion processing. No significant changes were found in the delta frequency band coherence. We also found that PD patients were more impaired in recognizing negative emotions (sadness, fear, anger, and disgust) than relatively positive emotions (happiness and surprise). Behaviorally, PD patients did not show impairment in emotion recognition as measured by subjective ratings. These findings suggest that PD patients may have an impairment of inter-hemispheric functional connectivity (i.e., a decline in cortical connectivity) during emotion processing. This study may increase the awareness of EEG emotional response studies in clinical practice to uncover potential neurophysiologic abnormalities

Trapeziometacarpal total joint arthroplasty: The effect of capsular release on range of motion

It has been suggested that trapeziometacarpal total joint arthroplasty be combined with complete release of the joint capsule to prevent ligament tethering and implant dislocation. Our goal was to evaluate the consequences of capsular release on range of motion. Trapeziometacarpal joint motion was measured with a 3D motion tracking system in seven fresh frozen human cadaver hands before and after capsular release and total joint arthroplasty with subsequently longer neck lengths. Relative to the native trapeziometacarpal joint with intact joint capsule, mean flexion-extension was significantly increased after the arthroplasty with released capsule and lengthening up to 6 mm. Mean abduction-adduction did not increase significantly. Total joint replacement combined with capsular release increases the trapeziometacarpal joint's range of motion, but not beyond the limits of most trapeziometacarpal implant designs. Lengthening of the implant neck progressively decreases the excess motion.status: publishe

First demonstration of highly TM reflective and highly polarisation selective diffraction gratings (GIRO-gratings) for long wavelength VCSELs.

Abstract—We present experimental results on surface relief gratings in GaAs and InP with high reflectivity (>85%) and po-larization selectivity to normal incidence from the semiconductor side. The potential for polarization stabilization with a reduced mirror complexity for long-wavelength VCSEL’s is discussed. Index Terms — Grating reflectors, semiconductor lasers, surface-emitting lasers. I

First demonstration of highly reflective and highly polarization selective diffraction gratings (GIRO-gratings) for long-wavelength VCSEL's.

Abstract—We present experimental results on surface relief gratings in GaAs and InP with high reflectivity (>85%) and po-larization selectivity to normal incidence from the semiconductor side. The potential for polarization stabilization with a reduced mirror complexity for long-wavelength VCSEL’s is discussed. Index Terms — Grating reflectors, semiconductor lasers, surface-emitting lasers. I