Introduction
Tourette Syndrome and Chronic Tic Disorder (TS/CTD) are complex neuropsychiatric disorders in which patients present with multiple motor or vocal tics. In many patients with TS/CTD, attentional problems are present and ADHD is the most common condition that co-occurs with TS/CTD, occurring in about 50% of patients (Greimel et al., 2011). These attentional problems can range from mild to severe and can impact the patient’s ability to complete tasks, sustain attention, and keep track of personal items. Sensory hypersensitivity (SH; the tendency to be sensitive to subtle stimuli that most people would no longer attend to after habitation has occurred) is also commonly present in patients with TS/CTD (Belluscio et al., 2011). Patients with sensory hypersensitivity have difficulty tuning out otherwise neutral stimuli such as the tag in their shirt or the voices of people around them. In addition, patients with TS/CTD often experience a premonitory urge before a tic which some patients describe as a feeling of itchiness, pressure, tenseness, or energy. These tics and premonitory urges can also be distracting (Kane, 1994).
The observation that SH can distract one from a cognitively demanding task suggested the approach we used in a small pilot study to attempt to quantify SH by examining the effects of a tactile stimulus on reaction time during a sustained attention task (Panagopoulos et al., 2013). The present study was designed to improve on some of the earlier methods and to compare subjects with TS/CTD to tic-free controls, with the goal of quantifying the extent to which sensory hypersensitivity in patients with TS/CTD affects sustained attention. To do this, participants with and without TS/CTD performed an attention task in the presence and absence of a subtle sensory stimulus.
Methods
Ethical approval
This study was approved by the Washington University Human Research Protection Office (IRB), proposal # 201108081.
Participants
A convenience sample of 14 adults with TS/CTD and 14 tic-free adults participated in the study. Subjects completed a questionnaire that included age, sex, and the question, “Have you ever been diagnosed with any of the following,” with check boxes for ADHD (Attention-Deficit/Hyperactivity Disorder), learning disorder, atopic (allergic) dermatitis, OCD (Obsessive-Compulsive Disorder), Tourette syndrome, other tic disorder, and other neurological illness (to be specified by the respondent). All participants also completed the 26-item Adult Sensory Questionnaire (ASQ), developed to screen for sensory defensiveness in adults (Kinnealey et al., 1995), and the ADHD Rating Scale (Barkley, 1998; Magnusson et al., 2006). Subjects endorsing tics also rated symptom severity for the past week using the Yale Global Tic Severity Scale (YGTSS; Leckman et al., 1989), the Yale-Brown Obsessive Compulsive Scale (Goodman et al., 1989a,b), and the Premonitory Urge for Tics Scale (PUTS; Woods et al., 2005). These data were collected using REDCap electronic data capture tools hosted at Washington University (Harris et al., 2009). For tic subjects, the Diagnostic Confidence Index (DCI) was also completed; the DCI assesses typical historical features of TS (Robertson et al., 1999).
Choice reaction time task
The subjects were seated at a fixed distance in front of a laptop computer in a darkened room. All subjects then performed a 12-minute choice reaction time task consisting of pressing one key on a computer keyboard when the capital letter ‘S’ appeared on the screen and pressing another key when the numeral 5 appeared on the screen. They were instructed to respond as quickly and accurately as possible with the right hand. The task consisted of 11 blocks; the first was a 2-minute OFF condition and the remaining blocks were each 1 minute long alternating between the ON and the OFF condition. Throughout the ON condition, a 4.74N von Frey hair was held against a point previously marked on the subject’s ankle, with ~1 Hz mild increases of pressure to just bend the von Frey hair. During the OFF condition, the von Frey hair was absent. E-Prime® 2 software was used to present stimuli and to collect all task data (www.pstnet.com/eprime.cfm; Schneider et al., 2002a,b).
Dataset 1.A revised method for measuring distraction by tactile stimulation: Subject characteristics and task data.
Subject_data2.csv: This file includes demographic and diagnostic data for each subject. Legend: Group = self-reported diagnosis (1=TS/CTD, 2=control). ADHD hx = self-reported history of Attention-Deficit/Hyperactivity Disorder. OCD hx = self-reported history of Obsessive-Compulsive Disorder. ASQ = total score on the Adult Sensory Questionnaire. ASQ Pure = score from a subset of ASQ items (#1, 2, 4–14, 17, 23) that the authors felt were less likely to be affected by psychiatric comorbidity. See Methods for remaining abbreviations. task_data.7z: This file contains a text file for each subject with output from ePrime® including accuracy and reaction time data for the attention task session for each subject. The file can be opened by 7-Zip, free and open source archiving software (http://www.7-zip.org/).Data availability
F1000Research: Dataset 1. A revised method for measuring distraction by tactile stimulation: Subject characteristics and task data, 10.5256/f1000research.4944.d34156 (Schechter et al., 2014).
Author contributions
All authors contributed to conception of the study and design of the experiments. JRS and DJG carried out the research. JRS and KJB prepared the first draft of the manuscript. All authors were involved in the revision of the draft manuscript and have agreed to the final content.
Competing interests
No competing interests were disclosed.
Grant information
This project was supported by National Institutes of Health (NIH) grants K24 MH087913, K01 MH104592, P30 CA091842, UL1 TR000448, the Siteman Comprehensive Cancer Center, and a Tourette Syndrome Association fellowship (DJG). The content is solely the responsibility of the authors and does not necessarily represent the official view of the funders.
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
F1000 recommendedReferences
- Barkley RA:
Attention deficit/hyperactivity disorder: A handbook for diagnosis and treatment. 2nd edition. New York; Guilford Press; 1998. Reference Source
- Belluscio BA, Jin L, Watters V, et al.:
Sensory sensitivity to external stimuli in Tourette syndrome patients.
Mov Disord.
2011; 26(14): 2538–2543. PubMed Abstract
| Publisher Full Text
| Free Full Text
- Harris PA, Taylor R, Thielke R, et al.:
Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support.
J Biomed Inform.
2009; 42(2): 377–381. PubMed Abstract
| Publisher Full Text
| Free Full Text
- Goodman WK, Price LH, Rasmussen SA, et al.:
The Yale-Brown Obsessive Compulsive Scale. I. Development, use and reliability.
Arch Gen Psychiatry.
1989a; 46(11): 1006–1011.PubMed Abstract
| Publisher Full Text
- Goodman WK, Price LH, Rasmussen SA, et al.:
The Yale-Brown Obsessive Compulsive Scale. II. Validity.
Arch Gen Psychiatry.
1989b; 46(11): 1012–1016. PubMed Abstract
| Publisher Full Text
- Greimel E, Wanderer S, Rothenberger A, et al.:
Attentional performance in children and adolescents with tic disorder and co-occurring attention-deficit/hyperactivity disorder: new insights from a 2 × 2 factorial design study.
J Abnorm Child Psychol.
2011; 39(6): 819–28. PubMed Abstract
| Publisher Full Text
| Free Full Text
- Kane MJ:
Premonitory urges as “attentional tics” in Tourette’s syndrome.
J Am Acad Child Adolesc Psychiatry.
1994; 33(6): 805–808. PubMed Abstract
| Publisher Full Text
- Kinnealey M, Oliver B, Wilbarger P:
A phenomenological study of sensory defensiveness in adults.
Am J Occup Ther.
1995; 49(5): 444–451. PubMed Abstract
| Publisher Full Text
- Leckman JF, Riddle MA, Hardin MT, et al.:
The Yale Global Tic Severity Scale: initial testing of a clinician-rated scale of tic severity.
J Am Acad Child Adolesc Psychiatry.
1989; 28(4): 566–573. PubMed Abstract
| Publisher Full Text
- Magnusson P, Smari J, Sigurdardottir D, et al.:
Validity of self-report and informant rating scales of adult ADHD symptoms in comparison with a semistructured diagnostic interview.
J Atten Disord.
2006; 9(3): 494–503. PubMed Abstract
| Publisher Full Text
- Panagopoulos VN, Greene DJ, Campbell MC, et al.:
Towards objectively quantifying sensory hypersensitivity: a pilot study of the “Ariana effect”.
PeerJ.
2013; 1: e121. PubMed Abstract
| Publisher Full Text
| Free Full Text
- Robertson MM, Banerjee S, Kurlan R, et al.:
The Tourette syndrome diagnostic confidence index: development and clinical associations.
Neurology.
1999; 53(9): 2108–2112. PubMed Abstract
| Publisher Full Text
- Schechter JR, Greene DJ, Koller JM, et al.:
Dataset 1. A revised method for measuring distraction by tactile stimulation: Subject characteristics and task data.
F1000Research.
2014. Data Source
- Schneider W, Eschman A, Zuccolotto A:
E-Prime Reference Guide. Pittsburgh: Psychology Software Tools Inc. 2002a. Reference Source
- Schneider W, Eschman A, Zuccolotto A:
E-Prime User’s Guide. Pittsburgh: Psychology Software Tools Inc. 2002b. Reference Source
- Woods DW, Piacentini J, Himle MB, et al.:
Premonitory Urge for Tics Scale (PUTS): Initial psychometric results and examination of the premonitory urge phenomenon in youths with Tic disorders.
J Devel Behav Pediatr.
2005; 26(6): 397–403. PubMed Abstract
| Publisher Full Text
Schechter JR, Greene DJ, Koller JM, Black KJ: The effects of tactile stimulation on the attentional performance of ... Continue reading A preliminary analysis of these data was presented at a student research symposium:
Schechter JR, Greene DJ, Koller JM, Black KJ: The effects of tactile stimulation on the attentional performance of subjects with Tourette syndrome. Mind-Brain-Behavior Research Symposium, Washington University Department of Psychology, University City, MO, 29 Apr 2014. Archived at F1000Posters 2014; 5:492 (http://f1000.com/posters/browse/summary/1095670).
Schechter JR, Greene DJ, Koller JM, Black KJ: The effects of tactile stimulation on the attentional performance of subjects with Tourette syndrome. Mind-Brain-Behavior Research Symposium, Washington University Department of Psychology, University City, MO, 29 Apr 2014. Archived at F1000Posters 2014; 5:492 (http://f1000.com/posters/browse/summary/1095670).