1,720,977 research outputs found
Evidence of different neural pathways for motor and vocal tic-like expressions in monkeys
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Oral δ9-tetrahydrocannabinol improved refractory gilles de la tourette syndrome in an adolescent by increasing intracortical inhibition: a case report
No full textObjective: To describe the clinical course of the Delta 9-tetrahydrocannabinol (Delta 9-THC) treatment of a boy with Gilles de la Tourette Syndrome (TS) and comorbid attention-deficit/hyperactivity disorder (ADHD) in relation to Delta 9-THC plasma levels and intracortical inhibition measured by transcranial magnetic stimulation. Methods: The clinical course and pharmacological and neurophysiological measures are reported in a 15-year-old boy with treatment refractory TS plus ADHD leading to severe physical and psychosocial impairment. Results: Administration of Delta 9-THC improved tics considerably without adverse effects, allowing parallel stimulant treatment of comorbid ADHD. Along with the Delta 9-THC treatment, intracortical inhibition was increased, reflected in the enhanced short-interval intracortical inhibition and the prolongation of the cortical silent period. Conclusions: Our observation suggests that Delta 9-THC might be a successful alternative in patients with severe TS refractory to classic treatment. Particularly in the case of stimulant-induced exacerbation of tics, Delta 9-THC might enable successful treatment of comorbid ADHD. The enhancement of intracortical inhibition might be mediated by modulating release of several neurotransmitters including dopamine and gamma-aminobutyric acid. Further studies are needed to substantiate our findings
Quality and temporal properties of premonitory urges in patients with skin picking disorder
No full textSkin picking is a newly recognized obsessive-compulsive spectrum disorder in DSM-5. Similar to some repetitive behaviors in Gilles de la Tourette syndrome (GTS) and obsessive-compulsive disorder (OCD), premonitory urges are assumed to play a critical role in maintaining skin picking behavior, by creating a vicious cycle. The present study is the first to investigate the quality of premonitory urges, as well as the temporal relationship between urges and skin picking behavior in individuals with skin picking disorder. Quality and intensity of premonitory urges was assessed in 15 individuals with skin picking. Urge quality was assessed with the translated University of São Paulo Sensory Phenomena Scale (USP-SPS). Urge intensity was assessed continuously over 20 min using a computer-based tool. Participants were instructed either a) to pick freely or b) to suppress their skin picking behavior. Skin picking events during the free and suppression condition were recorded on video and coded manually. Regarding the types of urges, individuals with skin picking reported mainly physical urge sensations (80%), visual ”just-right” feelings (80%), and urge-only sensations (80%) similar to urges reported by GTS and OCD patients. Moreover, the data showed a strong temporal relationship between the intensity of premonitory urges and the emergence of skin picking behavior (R2 = .23) that was weakened when skin picking was suppressed (R2 = .06). The results suggest that skin picking behavior is maintained by premonitory urges and that this vicious cycle of negative reinforcement can be, at least partially, broken by suppressing skin picking behavior
Help or hurt? How attention modulates tics under different conditions
No full textTourette syndrome is a neuropsychiatric developmental disorder, characterized by tics that are often preceded by an increasingly uncomfortable urge to move. Tic frequency can increase when patients pay attention to their tics, if tics are not suppressed. This study investigates how attentions modulates urge intensity, tic frequency and arousal during free ticcing and tic suppression.Tic frequency (video recording), urge intensity (rating scale) and pupil width (pupillometry as a measure of arousal) were assessed in 23 patients with Tourette syndrome (mean age 33.48 ± 12.37; 14 male) during five attention conditions: 1) baseline, 2) watching own tics in a live video-feedback, 3) watching own tics in a previously recorded video, 4) thinking about situations that can trigger tics and 5) thinking about specific, non-tic related stimuli (distraction condition) during: a) free ticcing and b) tic suppression tic states.Urge intensity and tic frequency increased in the free ticcing condition when patients viewed their own tics live and when they thought about tic-triggering situations. In the tic suppression condition, tic frequency increased when patients watched a video of their tics, thought about their tics or were distracted. Pupil width increased significantly during the live feedback and the video condition compared to baseline in both tic states.Paying attention to own tics can be detrimental when tics are not suppressed. In contrast, paying attention to other stimuli appears detrimental when tics are suppressed, as would be the case during most current behavioural therapy techniques. However, results point to high emotional arousal and patients feeling uncomfortable when seeing themselves tic. The results also suggest that urge intensity is modulated by changes in attention in the same manner as tics and may drive change in tic frequency during free ticcing
Premotor transcranial direct current stimulation (tDCS) affects primary motor excitability in humans
No full textRecent studies have shown that repetitive transcranial magnetic stimulation (rTMS) over the premotor cortex (PM) modifies the excitability of the ipsilateral primary motor cortex (M1). Transcranial direct current stimulation (tDCS) is a new method to induce neuroplasticity in humans non-invasively. tDCS generates neuroplasticity directly in the cortical area under the electrode, but might also induce effects in distant brain areas, caused by activity modulation of interconnected areas. However, this has not yet been tested electrophysiologically. We aimed to study whether premotor tDCS can modify the excitability of the ipsilateral M1 via cortico-cortical connectivity. Sixteen subjects received cathodal and anodal tDCS of the PM and eight subjects of the dorsolateral prefrontal cortex. Premotor anodal, but not premotor cathodal or prefrontal tDCS, modified selectively short intracortical inhibition/intracortical facilitation (SICI/ICF), while motor thresholds, single test-pulse motor-evoked potential and input-output curves were stable throughout the experiments. Specifically, anodal tDCS decreased intracortical inhibition and increased paired-pulse excitability. The selective influence of premotor tDCS on intracortical excitability of the ipsilateral M1 suggests a connectivity-driven effect of tDCS on remote cortical areas. Moreover, this finding indirectly substantiates the efficacy of tDCS to modulate premotor excitability, which might be of interest for applications in diseases accompanied by pathological premotor activity
Phenotypic spectrum of PINK1-associated parkinsonism in 15 mutation carriers from 1 family
No full textThe phenotypic spectrum of PINK1-associated Parkinsonism was studied in a family with homozygous (n = 4) or heterozygous (n = 3) PINK1 mutations. All homozygous mutation carriers were definitely affected; the heterozygous carriers were asymptomatic but displayed unequivocal signs of probable or possible Parkinsonism. This finding suggests a role not only of homozygous but also of heterozygous PINK1 mutations in the development of parkinsonian signs and underlines the necessity to carefully investigate family members of affected mutation carriers. (C) 2006 Movement Disorder Society
Treatment of Tourette syndrome with attention training technique—a case series
No full textThe existing therapeutic strategies of Tourette syndrome (TS) do not lead to sufficient improvement in a significant number of patients. Recently published studies show that paying attention to tics increases whereas directing attention away decreases tic frequency. The aim of the present case series in three patients with TS was to investigate the effect of attention training technique (ATT) on TS symptoms. ATT is a technique derived from metacognitive therapy that aims on training patients to consciously (re-)focus their attention away from themselves. Friedman’s chi-square test indicated a trend regarding the reduction of tic frequency and tic severity and a significant reduction of positive metacognitions from pre-baseline to follow-up. Reliable Change Indices (RCIs) are given for each measure and patient. Given the small number of patients, further studies including randomized controlled trials appear warranted
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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