Sensory Hypersensitivity Severity and Association with Obsessive-Compulsive Symptoms in Adults with Tic Disorder

Tourette syndrome and obsessive-compulsive disorder: A comprehensive review of structural alterations and neurological mechanisms

Currently, it is possible to study the pathogenesis of Tourette's syndrome (TS) in more detail, due to more advanced methods of neuroimaging. However, medical and surgical treatment options are limited by a lack of understanding of the nature of the disorder and its relationship to some psychiatric disorders, the most common of which is obsessive-compulsive disorder (OCD). It is believed that the origin of chronic tic disorders is based on an imbalance of excitatory and inhibitory influences in the Cortico-Striato-Thalamo-Cortical circuits (CSTC). The main CSTCs involved in the pathological process have been identified by studying structural and neurotransmitter disturbances in the interaction between the cortex and the basal ganglia. A neurotransmitter deficiency in CSTC has been demonstrated by immunohistochemical and genetic methods, but it is still not known whether it arises as a consequence of genetically determined disturbances of neuronal migration during ontogenesis or as a consequence of altered production of proteins involved in neurotransmitter production. The aim of this review is to describe current ideas about the comorbidity of TS with OCD, the involvement of CSTC in the pathogenesis of both disorders and the background of structural and neurotransmitter changes in CSTC that may serve as targets for drug and neuromodulatory treatments.

Exploring sensory sensitivity, cortical excitability, and habituation in episodic migraine, as a function of age and disease severity, using the pattern-reversal task

BACKGROUND

Migraine is a cyclic, neurosensory disorder characterized by recurrent headaches and altered sensory processing. The latter is manifested in hypersensitivity to visual stimuli, measured with questionnaires and sensory thresholds, as well as in abnormal cortical excitability and a lack of habituation, assessed with visual evoked potentials elicited by pattern-reversal stimulation. Here, the goal was to determine whether factors such as age and/or disease severity may exert a modulatory influence on sensory sensitivity, cortical excitability, and habituation.

METHODS

Two similar experiments were carried out, the first comparing 24 young, episodic migraine patients and 28 healthy age- and gender-matched controls and the second 36 middle-aged, episodic migraine patients and 30 healthy age- and gender-matched controls. A neurologist confirmed the diagnoses. Migraine phases were obtained using eDiaries. Sensory sensitivity was assessed with the Sensory Perception Quotient and group comparisons were carried out. We obtained pattern-reversal visual evoked potentials and calculated the N1-P1 Peak-to-Peak amplitude. Two linear mixed-effects models were fitted to these data. The first model had Block (first block, last block) and Group (patients, controls) as fixed factors, whereas the second model had Trial (all trials) and Group as fixed factors. Participant was included as a random factor in both. N1-P1 first block amplitude was used to assess cortical excitability and habituation was defined as a decrease of N1-P1 amplitude across Blocks/Trials. Both experiments were performed interictally.

RESULTS

The final samples consisted of 18 patients with episodic migraine and 27 headache-free controls (first experiment) and 19 patients and 29 controls (second experiment). In both experiments, patients reported increased visual hypersensitivity on the Sensory Perception Quotient as compared to controls. Regarding N1-P1 peak-to-peak data, there was no main effect of Group, indicating no differences in cortical excitability between groups. Finally, significant main effects of both Block and Trial were found indicating habituation in both groups, regardless of age and headache frequency.

CONCLUSIONS

The results of this study yielded evidence for significant hypersensitivity in patients but no significant differences in either habituation or cortical excitability, as compared to headache-free controls. Although the alterations in patients may be less pronounced than originally anticipated they demonstrate the need for the definition and standardization of optimal methodological parameters.

Sensory Over-responsivity: A Feature of Childhood Psychiatric Illness Associated With Altered Functional Connectivity of Sensory Networks

BACKGROUND

Sensory over-responsivity (SOR) is recognized as a common feature of autism spectrum disorder. However, SOR is also common among typically developing children, in whom it is associated with elevated levels of psychiatric symptoms. The clinical significance and neurocognitive bases of SOR in these children remain poorly understood and actively debated.

METHODS

This study used linear mixed-effects models to identify psychiatric symptoms and network-level functional connectivity (FC) differences associated with parent-reported SOR in the Adolescent Brain Cognitive Development (ABCD) Study, a large community sample (9 to 12 years of age) (N = 11,210).

RESULTS

Children with SOR constituted 18% of the overall sample but comprised more than half of the children with internalizing or externalizing scores in the clinical range. Controlling for autistic traits, both mild and severe SOR were associated with greater concurrent symptoms of depression, anxiety, obsessive-compulsive disorder, and attention-deficit/hyperactivity disorder. Controlling for psychiatric symptoms and autistic traits, SOR predicted increased anxiety, attention-deficit/hyperactivity disorder, and prodromal psychosis symptoms 1 year later and was associated with FC differences in brain networks supporting sensory and salience processing in datasets collected 2 years apart. Differences included reduced FC within and between sensorimotor networks, enhanced sensorimotor-salience FC, and altered FC between sensory networks and bilateral hippocampi.

CONCLUSIONS

SOR is a common, clinically relevant feature of childhood psychiatric illness that provides unique predictive information about risk. It is associated with differences in brain networks that subserve tactile processing, implicating a neural basis for sensory differences in affected children.

Sensory processing difficulties in psychiatric disorders: A meta-analysis

In clinical practice, many individuals with psychiatric disorders report difficulties in sensory processing, including increased awareness or sensitivity to external stimuli. In this meta-analysis, we examined the sensory processing patterns of adolescent and adult individuals with a broad spectrum of different psychiatric conditions. A systematic search in various databases resulted in the inclusion of 33 studies (N=2008), all using the Adolescent/Adult Sensory Profile (AASP). By comparing diagnostic subgroups to the corresponding reference group of the AASP, we detected a general pattern of sensory processing, indicating elevated levels of low registration, sensory sensitivity and sensory avoiding and lowered sensory seeking behavior in patients with different types of psychiatric disorders. The majority of effect sizes were large to very large. In conclusion, sensory processing difficulties can be considered as a non-specific transdiagnostic phenotype associated with a broad spectrum of psychiatric conditions. Further research into the relevance and role of sensory processing difficulties in psychiatric disorders may improve long-term prognosis and treatment.

Tourette syndrome research highlights from 2020

We present here research from 2020 relevant to Tourette syndrome (TS). The authors briefly summarize a few reports they consider most important or interesting.

Sensory over-responsivity and obsessive-compulsive disorder: Measuring habituation and sensitivity through self-report, physiological and behavioral indices

Individuals with obsessive-compulsive disorder (OCD) may report Sensory Over Responsivity (SOR), but evidence for specific shared mechanism is limited. This study investigated a habituation-sensitivity mechanism in individuals with OCD (n = 30). Sensory habituation and sensitivity were compared with a neurotypical sample, divided to high (n = 30) and low (n = 30) obsessive-compulsive symptoms (HOCS and LOCS). Participants completed self-report sensory questionnaires and a physiological protocol measuring Electro Dermal Activity (EDA) while presenting aversive and neutral sounds in two conditions: Aversive stimuli followed by neutral stimuli (AVfirst), or neutral stimuli followed by aversive stimuli (NEfirst). In addition, participants could shorten the stimulus duration by pressing a key. LOCS differed from HOCS and OCD in most sensory self-report scores, with no significant difference between OCD and HOCS. HOCS had no significant differences in habituation patterns across conditions, while OCD had no differences in habituation patterns in AVfirst (p = .08) but significantly slower habituation patterns to the NEfirst neutral stimuli (p < .001). Condition order determined sensitivity for LOCS (AVfirst p = .017; NEfirst p = .045) but not for OCD and HOCS. HOCS and OCD shortened aversive stimuli by key pressing more than LOCS, with no significant difference between OCD and HOCS. The habituation process of individuals with OCD and HOCS was more influenced by stimulus type than by condition order, which might be due to a cognitive bias of prediction. Individuals with elevated OCS have difficulty relying upon sensory input to respond adaptively to the environment. This process can explain the avoidant behavior and complains of individuals with OCD not being able to ignore and to habituate to the sensory environment. These evidence warrants design of psychoeducation and intervention methods for relying on prior sensory information to improve functioning in individuals with OCD and SOR.

Cross-disorder comparison of sensory over-responsivity in chronic tic disorders and obsessive-compulsive disorder

BACKGROUND

Sensory over-responsivity (SOR) refers to excessively intense and/or prolonged behavioral responses to environmental stimuli typically perceived as non-aversive. SOR is prevalent in several neurodevelopmental disorders, including chronic tic disorders (CTDs) and obsessive-compulsive disorder (OCD). Few studies have examined the extent and clinical correlates of SOR across disorders, limiting insights into the phenomenon's transdiagnostic clinical and biological relevance. Such cross-disorder comparisons are of particular interest for CTDs and OCD given their frequent co-occurrence.

OBJECTIVE

We sought to compare the magnitude of SOR between adults with CTD and adults with OCD and to identify the clinical factors most strongly associated with SOR across these disorders.

METHODS

We enrolled 207 age- and sex-matched participants across four diagnostic categories: CTD without OCD (designated "CTD/OCD-"; n = 37), CTD with OCD ("CTD/OCD+"; n = 32), OCD without tic disorder ("OCD"; n = 69), and healthy controls (n = 69). Participants completed a self-report battery of rating scales assessing SOR (Sensory Gating Inventory, SGI), obsessive-compulsive symptoms (Dimensional Obsessive-Compulsive Scale, DOCS), inattention and hyperactivity (Adult ADHD Self-Report Screening Scale for DSM-5, ASRS-5), anxiety (Generalized Anxiety Disorder-7), and depression (Patient Health Questionnaire-9). CTD participants were also administered the Yale Global Tic Severity Scale (YGTSS). To examine between-group differences in SOR, we compared SGI score across all groups and between pairs of groups. To examine the relationship of SOR with other clinical factors, we performed multivariable linear regression.

RESULTS

CTD/OCD-, CTD/OCD+, and OCD participants were 86.7%, 87.6%, and 89.5%, respectively, more likely to have higher SGI total scores than healthy controls. SGI total score did not differ between CTD/OCD-, CTD/OCD+, and OCD groups. In the regression model of log-transformed SGI total score, OCD diagnosis, DOCS score, and ASRS-5 score each contributed significantly to model goodness-of-fit, whereas CTD diagnosis and YGTSS total tic score did not.

CONCLUSION

SOR is prevalent in adults with CTD and in adults with OCD but does not significantly differ in magnitude between these disorders. Across CTD, OCD, and healthy control adult populations, SOR is independently associated with both obsessive-compulsive and ADHD symptoms, suggesting a transdiagnostic relationship between these sensory and psychiatric manifestations. Future cross-disorder, longitudinal, and translational research is needed to clarify the role and prognostic import of SOR in CTDs, OCD, and other neurodevelopmental disorders.

Altered Interoceptive Sensibility in Adults With Chronic Tic Disorder

BACKGROUND

Interoception refers to the sensing, interpretation, integration, and regulation of signals about the body's internal physiological state. Interoceptive sensibility is the subjective evaluation of interoceptive experience, as assessed by self-report measures, and is abnormal in numerous neuropsychiatric disorders. Research examining interoceptive sensibility in individuals with chronic tic disorders (CTDs), however, has yielded conflicting results, likely due to methodologic differences between studies and small sample sizes.

OBJECTIVE

We sought to compare interoceptive sensibility between adults with CTD and healthy controls, adjusting for co-occurring psychiatric symptoms, and to examine the relationship of interoceptive sensibility with other CTD clinical features, in particular, premonitory urge.

METHODS

We recruited adults with CTDs and sex- and age-matched healthy controls to complete the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), as well as a battery of measures assessing psychiatric symptoms prevalent in CTD populations. CTD participants additionally completed scales quantifying tic severity, premonitory urge severity, and health-related quality of life. We conducted between-group contrasts (Wilcoxon rank-sum test) for each MAIA-2 subscale, analyzed the effect of psychiatric symptoms on identified between-group differences (multivariable linear regression), and examined within-group relationships between MAIA-2 subscales and other clinical measures (Spearman rank correlations, multivariable linear regression).

RESULTS

Between adults with CTD (n = 48) and healthy controls (n = 48), MAIA-2 Noticing and Not-Worrying subscale scores significantly differed. After adjusting for covariates, lower MAIA-2 Not-Worrying subscale scores were significantly associated with female sex (β = 0.42, p < 0.05) and greater severity of obsessive-compulsive symptoms (β = -0.028, p < 0.01), but not with CTD diagnosis. After adjusting for severity of tics and obsessive-compulsive symptoms, a composite of MAIA-2 Noticing, Attention Regulation, Emotional Awareness, Self-Regulation, Body Listening, and Trusting subscales (β = 2.52, p < 0.01) was significantly associated with premonitory urge.

CONCLUSION

Study results revealed three novel findings: adults with CTD experience increased anxiety-associated somatization and increased general body awareness relative to healthy controls; anxiety-associated somatization is more closely associated with sex and obsessive-compulsive symptoms than with CTD diagnosis; and increased general body awareness is associated with greater severity of premonitory urges.