Comprehensive systematic review summary: Treatment of tics in people with Tourette syndrome and chronic tic disorders

Objective To systematically evaluate the efficacy of treatments for tics and the risks associated with their use. Methods This project followed the methodologies outlined in the 2011 edition of the American Academy of Neurology\u27s guideline development process manual. We included systematic reviews and randomized controlled trials on the treatment of tics that included at least 20 participants (10 participants if a crossover trial), except for neurostimulation trials, for which no minimum sample size was required. To obtain additional information on drug safety, we included cohort studies or case series that specifically evaluated adverse drug effects in individuals with tics. Results There was high confidence that the Comprehensive Behavioral Intervention for Tics was more likely than psychoeducation and supportive therapy to reduce tics. There was moderate confidence that haloperidol, risperidone, aripiprazole, tiapride, clonidine, onabotulinumtoxinA injections, 5-ling granule, Ningdong granule, and deep brain stimulation of the globus pallidus were probably more likely than placebo to reduce tics. There was low confidence that pimozide, ziprasidone, metoclopramide, guanfacine, topiramate, and tetrahydrocannabinol were possibly more likely than placebo to reduce tics. Evidence of harm associated with various treatments was also demonstrated, including weight gain, drug-induced movement disorders, elevated prolactin levels, sedation, and effects on heart rate, blood pressure, and ECGs. Conclusions There is evidence to support the efficacy of various medical, behavioral, and neurostimulation interventions for the treatment of tics. Both the efficacy and harms associated with interventions must be considered in making treatment recommendations

Parent and self-report health-related quality of life measures in young patients with Tourette syndrome

Tourette syndrome is a neurodevelopmental disorder characterized by tics and comorbid behavioral problems. This study compared child- and parent-reported quality of life and everyday functioning. We assessed 75 children with Tourette syndrome, of which 42 (56%) had comorbid conditions (obsessive-compulsive disorder = 25; attention-deficit hyperactivity disorder = 6; both comorbidities = 4). All patients completed psychometric instruments, including the Gilles de la Tourette Syndrome-Quality of Life Scale for Children and Adolescents (child report) and the Child Tourette's Syndrome Impairment Scale (parent report). Data were compared for patients with pure Tourette syndrome, Tourette syndrome + obsessive-compulsive disorder, Tourette syndrome + attention-deficit hyperactivity disorder, and Tourette syndrome + both comorbidities. There were no group differences in quality of life. However, there were differences for total, school, and home activities impairment scores. Children and parents may not share similar views about the impact of Tourette syndrome on functioning. The measurement of health-related quality of life in Tourette syndrome is more complex in children than adults

Interactions and charge fractionalization in an electronic Hong-Ou-Mandel interferometer

We consider an electronic analog of the Hong-Ou-Mandel (HOM) interferometer, where two single electrons travel along opposite chiral edge states and collide at a Quantum Point Contact. Studying the current noise, we show that because of interactions between co-propagating edge states, the degree of indistinguishability between the two electron wavepackets is dramatically reduced, leading to reduced contrast for the HOM signal. This decoherence phenomenon strongly depends on the energy resolution of the packets. Insofar as interactions cause charge fractionalization, we show that charge and neutral modes interfere with each other, leading to satellite dips or peaks in the current noise. Our calculations explain recent experimental results [E. Bocquillon, et al., Science 339, 1054(2013)] where an electronic HOM signal with reduced contrast was observed.Comment: 5 pages, 2 figure

Separation of neutral and charge modes in one dimensional chiral edge channels

Coulomb interactions have a major role in one-dimensional electronic transport. They modify the nature of the elementary excitations from Landau quasiparticles in higher dimensions to collective excitations in one dimension. Here we report the direct observation of the collective neutral and charge modes of the two chiral co-propagating edge channels of opposite spins of the quantum Hall effect at filling factor 2. Generating a charge density wave at frequency f in the outer channel, we measure the current induced by inter-channel Coulomb interaction in the inner channel after a 3-mm propagation length. Varying the driving frequency from 0.7 to 11 GHz, we observe damped oscillations in the induced current that result from the phase shift between the fast charge and slow neutral eigenmodes. We measure the dispersion relation and dissipation of the neutral mode from which we deduce quantitative information on the interaction range and parameters.Comment: 23 pages, 6 figure