scholarly journals The urge to blink in Tourette syndrome

2018 ◽  
Author(s):  
Haley E. Botteron ◽  
Cheryl A. Richards ◽  
Tomoyuki Nishino ◽  
Keisuke Ueda ◽  
Haley K. Acevedo ◽  
...  

Functional neuroimaging studies have attempted to explore brain activity that occurs with tic occurrence in subjects with Tourette syndrome (TS). However, they are limited by the difficulty of disambiguating brain activity required to perform a tic, or activity caused by the tic, from brain activity that generates a tic. Inhibiting the urge to tic is important to patients’ experience of tics and we hypothesize that inhibition of a compelling motor response to a natural urge will differ in TS subjects compared to controls. This study examines the urge to blink, which shares many similarities to premonitory urges to tic. Previous neuroimaging studies with the same hypothesis have used a one-size-fits-all approach to extract brain signal putatively linked to the urge to blink. We aimed to create a subject-specific and blink-timing-specific pathophysiological model, derived from out-of-scanner blink suppression trials, to eventually better interpret blink suppression fMRI data. Eye closure and continuously self-reported discomfort were reported during five blink suppression trials in 30 adult volunteers, 15 with a chronic tic disorder. For each subject, data from four of the trials were used with an empirical mathematical model to predict discomfort from eye closure observed during the remaining trial. The blink timing model of discomfort during blink suppression predicted observed discomfort much better than previously applied models. However, so did a model that simply reflected the mean time-discomfort curves from each subject’s other trials. The TS group blinked more than twice as often during the blink suppression block, and reported higher baseline discomfort, smaller excursion from baseline to peak discomfort during the blink suppression block, and slower return of discomfort to baseline during the recovery block. Combining this approach with observed eye closure during fMRI blink suppression trials should therefore extract brain signal more tightly linked to the urge to blink.

2010 ◽  
Vol 24 (2) ◽  
pp. 76-82 ◽  
Author(s):  
Martin M. Monti ◽  
Adrian M. Owen

Recent evidence has suggested that functional neuroimaging may play a crucial role in assessing residual cognition and awareness in brain injury survivors. In particular, brain insults that compromise the patient’s ability to produce motor output may render standard clinical testing ineffective. Indeed, if patients were aware but unable to signal so via motor behavior, they would be impossible to distinguish, at the bedside, from vegetative patients. Considering the alarming rate with which minimally conscious patients are misdiagnosed as vegetative, and the severe medical, legal, and ethical implications of such decisions, novel tools are urgently required to complement current clinical-assessment protocols. Functional neuroimaging may be particularly suited to this aim by providing a window on brain function without requiring patients to produce any motor output. Specifically, the possibility of detecting signs of willful behavior by directly observing brain activity (i.e., “brain behavior”), rather than motoric output, allows this approach to reach beyond what is observable at the bedside with standard clinical assessments. In addition, several neuroimaging studies have already highlighted neuroimaging protocols that can distinguish automatic brain responses from willful brain activity, making it possible to employ willful brain activations as an index of awareness. Certainly, neuroimaging in patient populations faces some theoretical and experimental difficulties, but willful, task-dependent, brain activation may be the only way to discriminate the conscious, but immobile, patient from the unconscious one.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gonzalo Rivera-Lillo ◽  
Emmanuel A. Stamatakis ◽  
Tristan A. Bekinschtein ◽  
David K. Menon ◽  
Srivas Chennu

AbstractThe overt or covert ability to follow commands in patients with disorders of consciousness is considered a sign of awareness and has recently been defined as cortically mediated behaviour. Despite its clinical relevance, the brain signatures of the perceptual processing supporting command following have been elusive. This multimodal study investigates the temporal spectral pattern of electrical brain activity to identify features that differentiated healthy controls from patients both able and unable to follow commands. We combined evidence from behavioural assessment, functional neuroimaging during mental imagery and high-density electroencephalography collected during auditory prediction, from 21 patients and 10 controls. We used a penalised regression model to identify command following using features from electroencephalography. We identified seven well-defined spatiotemporal signatures in the delta, theta and alpha bands that together contribute to identify DoC subjects with and without the ability to follow command, and further distinguished these groups of patients from controls. A fine-grained analysis of these seven signatures enabled us to determine that increased delta modulation at the frontal sensors was the main feature in command following patients. In contrast, higher frequency theta and alpha modulations differentiated controls from both groups of patients. Our findings highlight a key role of spatiotemporally specific delta modulation in supporting cortically mediated behaviour including the ability to follow command. However, patients able to follow commands nevertheless have marked differences in brain activity in comparison with healthy volunteers.


2021 ◽  
pp. 135910452110079
Author(s):  
Shaheen Zinna ◽  
Rebecca Luxton ◽  
Efstathios Papachristou ◽  
Danai Dima ◽  
Marinos Kyriakopoulos

Objective: Children needing admission to an inpatient mental health unit often present with severe neuropsychiatric disorders characterised by complex psychopathology. We aimed to examine all admitted children with comorbid chronic tic disorder (CTD) and Tourette syndrome (TS) over a 10-year period and determine the clinical significance of these diagnoses. Method: A retrospective, naturalistic study was conducted, comparing children with and without CTD/TS in terms of co-morbid diagnoses, medication use, access to education, aggression contributing to the admission, duration of admission, functional outcomes and satisfaction with treatment. Data were analysed using Chi-square/Fisher’s exact test and t-test for categorical and continuous variables, respectively, and subsequently with unadjusted and adjusted linear and logistic regression analyses. Results: A relatively high proportion of children had co-morbid CTD/TS (19.7%). There was a significant association with co-morbid obsessive-compulsive disorder, intellectual disability and autism spectrum disorder but not attention deficit hyperactivity disorder. CTD/TS were associated with longer admissions even after adjustments for confounding but did not seem to be independently associated with other examined clinical characteristics. Conclusions: The prevalence of CTD/TS in children needing inpatient treatment is significant. In our sample, comorbid CTD/TS seem to represent a marker of overall symptom severity as evidenced by longer admissions.


2014 ◽  
Vol 45 (4) ◽  
pp. 841-854 ◽  
Author(s):  
A. J. Skilleter ◽  
C. S. Weickert ◽  
A. Vercammen ◽  
R. Lenroot ◽  
T. W. Weickert

Background.Brain-derived neurotrophic factor (BDNF) is an important regulator of synaptogenesis and synaptic plasticity underlying learning. However, a relationship between circulating BDNF levels and brain activity during learning has not been demonstrated in humans. Reduced brain BDNF levels are found in schizophrenia and functional neuroimaging studies of probabilistic association learning in schizophrenia have demonstrated reduced activity in a neural network that includes the prefrontal and parietal cortices and the caudate nucleus. We predicted that brain activity would correlate positively with peripheral BDNF levels during probabilistic association learning in healthy adults and that this relationship would be altered in schizophrenia.Method.Twenty-five healthy adults and 17 people with schizophrenia or schizo-affective disorder performed a probabilistic association learning test during functional magnetic resonance imaging (fMRI). Plasma BDNF levels were measured by enzyme-linked immunosorbent assay (ELISA).Results.We found a positive correlation between circulating plasma BDNF levels and brain activity in the parietal cortex in healthy adults. There was no relationship between plasma BDNF levels and task-related activity in the prefrontal, parietal or caudate regions in schizophrenia. A direct comparison of these relationships between groups revealed a significant diagnostic difference.Conclusions.This is the first study to show a relationship between peripheral BDNF levels and cortical activity during learning, suggesting that plasma BDNF levels may reflect learning-related brain activity in healthy humans. The lack of relationship between plasma BDNF and task-related brain activity in patients suggests that circulating blood BDNF may not be indicative of learning-dependent brain activity in schizophrenia.


2014 ◽  
Vol 72 (12) ◽  
pp. 942-948 ◽  
Author(s):  
Helvio L. Alves ◽  
Elizabeth M. A. B. Quagliato

Tourette syndrome (TS) and tic disorders represent events of familiar magnitude characterized by involuntary movements and/or vocalization. To determine the prevalence of TS/tic disorders we studied a sample of 762 subjects (388 M, 374 F), between 1992 and 1997, age 6 to 43 years old, taken out of a population of 10,155 subjects (4,918 M, 5,237 F; age: 3-56 years old). A structured 4-item questionnaire, direct interview (multistaged), >1 yr follow-up, were used. 9,565 subjects (4,614 M, 4,951 F) sent back the questionnaires, 3,354 of these (1,671 M, 1,683 F) with positive answers to tics. 42 subjects (31 M, 11 F, age: 7-21 years old, mean: 11 years old) met the DSM-III-R criteria. The total minimal prevalence of TS is 0.43%, with a 3:1 ratio male/female. The minimal prevalence of chronic tic disorder is 2.27%. The total minimal prevalence for tic disorders at all is 2.91%. No special education students participation.


2013 ◽  
Vol 25 (6) ◽  
pp. 834-842 ◽  
Author(s):  
Joseph M. Moran ◽  
Jamil Zaki

Functional imaging has become a primary tool in the study of human psychology but is not without its detractors. Although cognitive neuroscientists have made great strides in understanding the neural instantiation of countless cognitive processes, commentators have sometimes argued that functional imaging provides little or no utility for psychologists. And indeed, myriad studies over the last quarter century have employed the technique of brain mapping—identifying the neural correlates of various psychological phenomena—in ways that bear minimally on psychological theory. How can brain mapping be made more relevant to behavioral scientists broadly? Here, we describe three trends that increase precisely this relevance: (i) the use of neuroimaging data to adjudicate between competing psychological theories through forward inference, (ii) isolating neural markers of information processing steps to better understand complex tasks and psychological phenomena through probabilistic reverse inference, and (iii) using brain activity to predict subsequent behavior. Critically, these new approaches build on the extensive tradition of brain mapping, suggesting that efforts in this area—although not initially maximally relevant to psychology—can indeed be used in ways that constrain and advance psychological theory.


2020 ◽  
Author(s):  
Per Andrén ◽  
Vera Wachtmeister ◽  
Julia Franzé ◽  
Caroline Speiner ◽  
Lorena Fernández de la Cruz ◽  
...  

Background: Treatment guidelines recommend behaviour therapy (BT) as the first-line intervention for patients with Tourette syndrome (TS) and chronic tic disorder (CTD). The efficacy of BT has been documented in randomised controlled trials (RCTs), but it is unclear to what extent these results are generalisable to real-world clinical settings, and whether the therapeutic gains are maintained long-term.Methods: In this naturalistic study, 74 young people with TS/CTD (aged 6 to 17) received BT (including psychoeducation, exposure with response prevention, habit reversal training or a combination of these treatments) at a specialist clinic in Stockholm, Sweden. Data were routinely collected at baseline, post-treatment, and at 3-, 6-, and 12-month follow-ups. Measures included the clinician-rated Yale Global Tic Severity Scale (YGTSS) and the Clinical Global Impression – Improvement scale (CGI-I), amongst others.Results: Tic severity and tic-related impairment (as measured by the YGTSS) improved significantly after treatment, with large within-group effect sizes (d=1.03 for the YGTSS Total Tic Severity Score, and d=1.37 for the YGTSS Impairment Score). At post-treatment, 57% of the participants were classified as treatment responders according to the CGI-I. Both tic severity and tic-related impairment continued to improve further through the follow-up, with 75% of the participants being rated as responders 12 months after the end of treatment. Significant improvements were also observed across a range of secondary measures.Conclusions: BT is an effective and durable treatment for young people with TS/CTD in a real-world clinical setting, with effects comparable to those reported in RCTs.


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