13 research outputs found
Low-frequency repetitive transcranial magnetic stimulation modulates evoked-gamma power, event-related potentials, and behavior in autism spectrum disorders.
Evidence suggests that cortical minicolumns are reduced in size and increased in number in individuals with autism spectrum disorder (ASD), especially in the dorsolateral prefrontal cortex (DLPFC). More specifically minicolumns in individuals with ASD are narrower and contain less peripheral, neuropil space; this may cause an increase in the ratio of cortical excitation to inhibition and adversely affect the functional distinctiveness of minicolumnar activation. A lack of cortical inhibition may cause signal/sensory amplification which can impair functioning, raise physiological stress, and adversely affect social interaction in patients with ASD. Additionally, the DLPFC forms a circuit interconnected with many areas of cortex (e.g., anterior cingulate, orbitofrontal) and is involved in selecting a possible range of responses while suppressing inappropriate ones. Low-frequency (:\u27SlHz) repetitive transcranial magnetic stimulation (rTMS) has been shown to increase inhibition of stimulated cortex by the activation of inhibitory circuits. The baseline hypothesis was that individuals with ASD would show electroencephalopgrahic (EEG) and event-related potential (ERP) evidence of amplified cortical activity at early and late stages of visual processing as well as impaired indices of selective attention. The second hypothesis was that low-frequency rTMS would reduce augmented cortical responses at early stage and late stages of visual processing and improve selective attention and behavior in ASD. The baseline findings indicate both ERP and evoked gamma activity are amplified and indiscriminative in ASD at early stages of visual processing which may reflect decreased \u27signal to noise\u27 due to decreased cortical inhibitory processing. Additionally, individuals with ASD showed evidence of compromised selective attention, and had a significantly higher rate of motor response errors. After low-frequency rTMS individuals with ASD showed significant reductions in augmented ERP responses at very early stages of visual processing and showed significant improvement in discriminatory EEG gamma activity. There was also evidence of improved ERP indices of selective attention and significant reductions in irritability and repetitive behavior. TMS has the potential to become an important therapeutic tool in ASD treatment and has shown significant benefits in treating core symptoms of ASD with few, if any side effects
Musically Induced Emotions: Subjective Measures of Arousal and Valence
This study was designed to investigate whether US participants would experience the same emotions when listening to specific pieces of music as were labeled by participants in a previous study done in the Netherlands. It examined whether musical excerpts would fall into quadrants of serene, happy, agitated, and sad created by an interaction of the dimensions of arousal (calm-excited) and valence (unpleasant-pleasant) and whether the mean scores would fall within quadrant positions similar to those in the previous study. Participants heard 12 musical excerpts and responded by turning dials depicting different degrees of arousal and valence. After one of the pieces of music was reallocated to a different category, they experienced 3 of the 4 emotions as did earlier participants. Implications for the study of emotion in music and its use in music therapy and music medicine are discussed. © 2011, SAGE Publications. All rights reserved
Low-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS) Affects Event-Related Potential Measures of Novelty Processing in Autism
Distal radius fractures and risk of incident neurocognitive disorders in older adults : a retrospective cohort study
Introduction: Distal radius fractures (DRF) are associated with increased risk of subsequent fractures and physical decline in older adults. This study aims to evaluate the risk cognitive decline following DRF and potential for timely screening and intervention. Methods: A cohort of 1046 individuals 50–75 years of age with DRF were identified between 1995 and 2015 (81.5% female; mean age 62.5 [± 7.1] years). A control group (N = 1044) without history of DRF was matched by age, sex, and fracture date (i.e., index). The incidence of neurocognitive disorders (NCD) in relation to DRF/index was determined. Group comparisons were adjusted by age and comorbidity measured by the Elixhauser index. Results: The DRF group had a greater incidence of NCD compared to the control group (11.3% vs. 8.2%) with a 56% greater relative risk (HR = 1.56, 95% Cl: 1.18, 2.07; p = 0.002) after adjusting for age and comorbidity. For every 10-year age increase, the DRF group was over three times more likely to develop a NCD (HR = 3.23, 95% Cl: 2.57, 4.04; p < 0.001). Conclusion: DRF in adults ages 50 to 75 are associated with increased risk of developing neurocognitive disorders. DRF may represent a sentinel opportunity for cognitive screening and early intervention. Summary: Distal radius fractures (DRF) have been associated with greater risk of future fractures and physical decline. This study reports that DRF are also associated with greater risk of developing neurocognitive disorders in older adults. Timely intervention may improve early recognition and long-term outcomes for older adults at risk of cognitive decline
N-acetylaspartate normalization in bipolar depression after lamotrigine treatment.
ObjectivesThe aim of the present study was to examine N-acetylaspartate (NAA), a general marker of neuronal viability, and total NAA (tNAA), the combined signal of NAA and N-acetylaspartylglutamate, in bipolar depression before and after lamotrigine treatment. Given that NAA is synthesized through direct acetylation of aspartate by acetyl-coenzyme A-l-aspartate-N-acetyltransferase, we hypothesized that treatment with lamotrigine would be associated with an increase in NAA level.MethodsPatients with bipolar depression underwent two-dimensional proton magnetic resonance spectroscopy of the anterior cingulate at baseline (n = 15) and after 12 weeks of lamotrigine treatment (n = 10). A group of age-matched healthy controls (n = 9) underwent scanning at baseline for comparison.ResultsAt baseline, patients with bipolar depression had significantly lower NAA [mean standard deviation (SD) = 1.13 (0.21); p = 0.02] than controls [mean (SD) = 1.37 (0.27)]. Significant increases in NAA [mean (SD) = 1.39 (0.21); p = 0.01] and tNAA [mean (SD) = 1.61 (0.25); p = 0.02] levels were found after 12 weeks of lamotrigine treatment.ConclusionsThese data suggest an NAA deficit in bipolar depression that is normalized after lamotrigine treatment. Future research is warranted to evaluate whether baseline NAA level is a potential biomarker for identifying lamotrigine response patterns and whether this functional brain change has an associated clinical response