Tactile processing in children and adolescents with obsessive–compulsive disorder

Abstract

Many obsessive-compulsive disorder (OCD) patients experience sensory phenomena, such as bodily sensations and "just-right" perceptions accompanying compulsions. We studied tactile processing in OCD by psychophysical experiments targeting the somatosensory cortex. Thirty-two children and adolescents with OCD (8 tic-related, 19 with sensory phenomena (SP)) and their sex- and age-matched controls participated in the study. After clinical assessments, two questionnaires were completed for sensory problems (Sensory Profile and Touch Inventory for Elementary-School-Aged Children). The psychophysical experiments consisted of five tasks: simple reaction time, choice reaction time, dynamic (detection) threshold, amplitude discrimination, and amplitude discrimination with single-site adaptation. The tactile stimuli were sinusoidal mechanical vibrations (frequency: 25 Hz) applied on the fingertips. Just-noticeable differences (JNDs) were found in amplitude discrimination tasks. There was no difference between the OCD group and controls in detection thresholds. However, the OCD group (especially young males) had worse amplitude discrimination (i.e., higher JNDs) than controls. Young OCD participants had reduced adaptation than young controls. Tic-related OCD participants and those with SP had higher detection thresholds than those without. Additionally, the OCD group reported more problems than controls in the Emotional/Social subset of the Sensory Profile questionnaire. The discrimination results show altered tactile processing in OCD at suprathreshold levels. This can be explained by a scaling factor modifying the sensory signal with decreasing slope at higher input levels to achieve normal Weber fractions internally. Quadratic discriminant analysis gave the best positive (76%) and negative (60%) predictive values for classifying individuals (into "OCD" or "control" groups) based on psychophysical data alone.

Sensory Habituation as a Shared Mechanism for Sensory Over-Responsivity and Obsessive–Compulsive Symptoms

“…This finding is consistent with previous reports of high correlations between self-reported SOR and OCS in healthy adults (Dar et al, 2012;Taylor et al, 2014;Ben-Sasson and Podoly, 2017). The difference between selfreported sensory questionnaire and physiological measures that was found in the current study is also consistent with other studies that found that reporting sensitivity does not necessarily imply actual physiological sensitivity (Belluscio et al, 2011;Güçlü et al, 2015). In order to understand whether the results support the relation between habituation and OC symptoms, results must be examined in several contexts.…”

“…Some studies examined whether individuals with OCD have lower neurological thresholds and are therefore more sensitive to stimuli. However, those studies found no differences between tactile and olfactory stimuli-detection thresholds of individuals with OCD and those of healthy controls (Belluscio et al, 2011;Güçlü et al, 2015). Moreover, the subjective intensity near threshold was similar to normal, despite noting that faint stimuli were generally more bothersome (Belluscio et al, 2011).…”

“…Audition is the most commonly reported bothersome modality among individuals with SOR (Royeen and Fortune, 1990;Ben-Sasson et al, 2009). Although other sensory modalities, such as tactile and olfactory, were found to be involved in OCD (e.g., Güçlü et al, 2015), our study focused on the auditory modality because it is often observed in OCD (Buhlmann et al, 2007;Buse and Roessner, 2016) and it is feasible to quantify in an experimental design. Auditory SOR can be expressed by sensitivity to specific sounds (e.g., breathing and electronic devices), background noises (e.g., air conditioner and people talking), or sensitivity to the intensity of the sound (e.g., loud tones and noisy environments).…”

Vibrotactile Sensitivity of the Glabrous Hand and Perioral Face in Neurotypical Children and Adults

“…These data will add to our understanding of somatosensory vibrotactile sensitivity from childhood through age 35 years. Moreover, expanded application of VDT measures has clear clinical applications in children and adults with neurological issues, including peripheral mechanosensory neuropathy, and central somatosensory processing disorders [9][10][11][12][13][14].…”

“…Psychophysical detection of the rate of amplitude modulation of tactile stimuli discriminates ASD from neurotypical control children [26]. Children (ages 7-18 years) with obsessive compulsive disorder showed impaired amplitude discrimination adaptation and elevated just noticeable differences (JNDs) to tactile stimuli (25Hz vibration) delivered to the fingertips on the nondominant hand [13].…”