Update on attention-deficit/hyperactivity disorder and tic disorders: a review of the current literature

Additive and Interactive Effects of Attention-Deficit/Hyperactivity Disorder and Tic Disorder on Brain Connectivity

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and persistent tic disorder (PTD) are two neurodevelopmental disorders that frequently co-occur. Contributions of each disorder to cognitive and behavioral deficits have been reported. In this paper, we tested 3 models of pathophysiology for the two disorders (additive, interactive, and phenotypic) using resting-state connectivity associated with each disorder separately and together.

METHODS

Participants were 148 children (55 with ADHD only, 33 with ADHD and PTD, 27 with PTD only, and 33 healthy control subjects) at ages 8 to 12 years. Following diagnostic interviews and behavioral assessment, participants underwent a 128-channel electroencephalography recording. Resting-state, cortical source-level effective connectivity was analyzed across the 4 groups using a 2 × 2 factorial design with factors of ADHD (with/without) and PTD (with/without).

RESULTS

ADHD diagnosis was the primary driver of cognitive and behavioral deficits, while deficits associated with PTD were primarily with thought problems and internalizing problems when compared with controls. Subadditive effects were observed in co-occurring ADHD+PTD for parent-rated behavioral problems and cognitive functions. Aberrant effective connectivity was primarily associated with ADHD, more specifically with lower posterior and occipital-frontal connectivity, while children with PTD exhibited greater left postcentral to precuneus connectivity. Weaker ADHD-related connectivity was associated with more severe behavioral problems, including internalizing behaviors, thought problems, and working memory deficits.

CONCLUSIONS

Similar to general behavioral deficits, aberrant resting-state neural connectivity in pediatric ADHD and PTD combines additively in co-occurring cases. The findings of this study support ADHD as a focus of treatment in comorbid cases, given the driving role of ADHD in both behavioral and neurophysiological deficits.

Tic Disorder of Children Analyzed and Diagnosed by Magnetic Resonance Imaging Features under Convolutional Neural Network

This work aimed to explore the analysis and diagnosis of children with tic disorder by magnetic resonance imaging (MRI) features under convolutional neural network (CNN), to provide a certain reference basis for clinical identification. A total of 45 children diagnosed with tic disorder in hospital from January 2018 to June 2020 were selected as the research subjects. A total of 30 normal children were selected as the control group. MRI images were collected, and CNN was constructed for image processing. The results showed that the convolutional neural network could significantly improve the speed of MRI reconstruction and can improve the diagnostic accuracy. Compared with normal children, the metabolites in children with tic disorder were slightly increased, but there was no statistical significance (P > 0.05). The results of the Yale score showed that the proportion of children with moderate illness was significantly greater than that of children with mild and severe illness. In short, the pathological changes of tic disorder were effectively discovered by MRI based on CNN algorithms, which can provide a reference for clinical identification.

The relationship between allergic diseases and tic disorders: A systematic review and meta-analysis

This systematic review aims to 1) explore the association between tic disorders (TD) and allergic diseases (AD), 2) judge whether patients with a diagnosis of TD are prone to suffer from a specific AD, by compiling the literature and analyzing the evidence. A literature search was conducted in PubMed and Embase database on February 24, 2021. The inclusion criteria for the literature were all comparative studies that reported TD patients were diagnosed with allergic illness as well. We identified that TD is positively associated with asthma, allergic rhinitis and allergic conjunctivitis, respectively. Especially, provisional tic disorder (PTD) patients might be more likely to suffer from these three AD, although it is still difficult to accurately predict which specific AD is prone to be accompanied by a specific TD. Shared genetic and etiological factors are suggested responsible for the AD-TD association. Large prospective cohort studies in future might shed light on a deep understanding of the relationship between immune disorders and tics.

Assessment and Management of Tic Disorders in Pediatric Primary Care Settings

Purpose of Review

Pediatricians and other primary care providers are often the first and sole healthcare clinicians of patients who present with tics. However, limited primary care pediatric training in neuropsychiatric concerns, as well as perceived lack of comfort and preparation, make it challenging for these clinicians to confidently identify and manage tic disorders.

Recent Findings

Current empirical findings of tic disorder management relevant to pediatric physicians, including assessment, psychoeducation, behavioral interventions, psychotropic medications, and alternative treatments are reviewed.

Summary

This article discusses neuropsychiatric and medical complexities of tic disorder assessment, with particular emphasis on differential and comorbid diagnoses. Tiered referral recommendations, based on symptom severity, impairment, and consideration of comorbid conditions, are provided. Future directions for tic management, including dissemination of evidence-based treatments of tic disorders and multidisciplinary teams within pediatric primary care settings, are included.

Decreased transfer of value to action in Tourette syndrome

OBJECTIVE

Tourette syndrome is a neurodevelopmental disorder putatively associated with a hyperdopaminergic state. Therefore, it seems plausible that excessive dopamine transmission in Tourette syndrome alters the ability to learn based on rewards and punishments. We tested whether Tourette syndrome patients exhibited altered reinforcement learning and corresponding feedback-related EEG deflections.

METHODS

We used a reinforcement learning task providing factual and counterfactual feedback in a sample of 15 Tourette syndrome patients and matched healthy controls whilst recording EEG. The paradigm presented various reward probabilities to enforce adaptive adjustments. We employed a computational model to derive estimates of the prediction error, which we used for single-trial regression analysis of the EEG data.

RESULTS

We found that Tourette syndrome patients showed increased choice stochasticity compared to controls. The feedback-related negativity represented an axiomatic prediction error for factual feedback and did not differ between groups. We observed attenuated P3a modulation specifically for factual feedback in Tourette syndrome patients, representing impaired coding of attention allocation.

CONCLUSION

Our findings indicate that cortical prediction error coding is unaffected by Tourette syndrome. Nonetheless, the transfer of learned values into choice formation is degraded, in line with a hyperdopaminergic state.

Questioning the long-term stability of the additive model in comorbid CTD+ADHD - The transition from childhood to adulthood

Background

A previous study (Roessner et al. 2007) found psychopathological evidence of an additive model of the comorbid group with Chronic Tic Disorders and Attention Deficit Hyperactivity Disorder (CTD+ADHD), which demanded clinical interventions aimed primarily at the factor ADHD. This 14-year follow-up study tested whether this childhood additive model can also be found in young adulthood and whether ADHD remains the most impairing factor.

Methods

92 patients (22.8% girls) from Roessner et al. (2007) were re-investigated as young adults at the age of 24 years, broken down into four groups: CTD-only (n = 22), CTD+ADHD (n = 23), ADHD-only (n = 24), and controls (n = 23). The Adult Behavior Checklist (ABCL) was used as an equivalent parent-report instrument to the Child Behavior Checklist (CBCL) applied 14 years ago. Statistically, 2x2 factorial design was completed.

Results

From the point of view of parents, the factors CTD and ADHD in young adults contributed almost equally to psychopathological problems and showed many interactions, i.e. an interactive model was supported. In addition, the ADHD factor was no longer the leading problem for psychosocial impairment in the adult CTD+ADHD group.

Conclusion

The additive model of CTD+ADHD seems to exist no longer in young adults, nor may the childhood predominance of the factor ADHD in comorbid CTD+ADHD. Thus, treatment priority should be decided by clinicians on a case-by-case basis depending on the most impairing disorder of each patient.

Neurobiology of the Premonitory Urge in Tourette's Syndrome: Pathophysiology and Treatment Implications

Motor and vocal tics are relatively common motor manifestations identified as the core features of Tourette's syndrome (TS). Although traditional descriptions have focused on objective phenomenological observations, such as anatomical location, number and frequency of tics, patients' first-person accounts have consistently reported characteristic subjective correlates. These sensory phenomena are often described as a feeling of mounting inner tension or urge to move ("premonitory urge"), which is transiently relieved by tic expression. This article reviews the existing literature on the clinical and neurobiological aspects of the premonitory urge in patients with TS, with focus on its pathophysiology and possible treatment implications.

Tourette syndrome and consciousness of action

BACKGROUND

Tourette syndrome (TS) is a neuropsychiatric disorder characterized by the chronic presence of multiple motor tics and at least one vocal/phonic tic since childhood. Tics typically change and vary in both intensity and severity over time, with remission and exacerbation common. In the vast majority of patients, tic expression is characteristically accompanied by discomforting bodily sensations, known as sensory phenomena or premonitory urges.

METHODS

We reviewed the existing literature on premonitory urges associated with the sense of voluntariness of action in TS.

RESULTS

Although the wish to move is perceived by the patient as involuntary, the decision to release the tic is often perceived by the patient as a voluntary capitulation to the subjective urge. Most patients with TS can exert a degree of control over the urge and constantly try to inhibit the movement. Based on these features, it has been suggested that tics performed in response to an urge to move should be classified as 'unvoluntary', as opposed to voluntary or involuntary acts. However, recent experimental data suggest that the brain areas involved in the generation of the wish to act show considerable overlap between healthy subjects and patients with TS.

DISCUSSION

The simultaneous presence of both voluntary and involuntary aspects in the expression of tic symptoms by patients with TS is consistent with the hypothesis that tics can have the same neurophysiologic substrate as voluntary acts, even though they are misperceived as being involuntary. This reinforces the view of TS as a hyperkinetic movement disorder primarily affecting the conscious experience of action.

Factors associated with newly diagnosed tic disorders among children in Taiwan: a 10-year nationwide longitudinal study

Increased attention has been paid to tic disorders clinically, yet relatively few studies have probed potential factors that account for the occurrence of tic disorders in the general population. In this study, we used data derived from the Taiwan's National Health Insurance Research Database to examine an array of factors related to the diagnosis of tic disorders and to further probe gender heterogeneity in clinical manifestation. Poisson regression analyses were applied to model the effects of birth cohort, period, and age, separately, on tic disorders. A total of 880 newly diagnosed tic disorders were identified from 2002 to 2009 among 100,516 youngsters in the study dataset who were born between 1997 and 2005. The results showed that a significant increase in the adjusted incidence rate ratio (IRR) was observed when age increased, with the highest adjusted IRR found at age 8-9 years. Compared to the time period from 2002 to 2005, an elevated IRR was found in the time period from 2006 to 2009 (adjusted IRR: 1.37; 95% CI: 1.05-1.80). Boys tended to be more likely to receive their initial diagnosis from psychiatrists and have higher comorbid attention-deficit/hyperactivity disorder (ADHD), as compared with their girl counterparts. In conclusion, the findings indicate that the effects of age and period, respectively, influence the occurrence of newly diagnosed tic disorders. Gender difference and higher frequent comorbid ADHD in boys than in girls were observed in this study.

Clinical considerations for the management of pediatric patients with attention-deficit/hyperactivity disorder

Introduction: Attention-deficit/hyperactivity disorder (ADHD) is a chronic health condition presenting with symptoms of hyperactivity, impulsivity, and/or inattention in early childhood, adolescence and adulthood. Many patients will persist with associated symptoms throughout their life and may require long term treatment to maintain adequate control.

Objective: The purpose of this article is to review the current literature in regards to diagnosis, treatment, and management of ADHD in the pediatric and adolescent population.

Methods: A search was conducted using PubMed, Medline, Ovid, and CINHAL with a focus on studies and reviews in the English language from 2008 – 2013, featuring pediatric/adolescent patients across the ages of 4–17 years using the terms: “management”, “attention-deficit”, “hyperactivity”, and “treatment.” Literature referenced prior to the five-year time frame outlined herein provided foundational information on diagnostics and medications.

Discussion: Stimulants, in conjunction with behavioral therapy, are standard first line treatments used in ADHD. While stimulant medications have been shown to be effective in treating symptoms associated with ADHD, there are a variety of concerns that may prevent their use. These concerns are related to adverse consequences, many of which are not supported by concrete evidence. Other pharmacotherapy options such as norepinephrine reuptake inhibitors and selective alpha-2 adrenergic agonists are typically reserved as second line options. The use of novel and emerging complementary therapies will also be explored.

Conclusion: Patients diagnosed with ADHD must be thoroughly evaluated when making decisions regarding treatment. Many studies and reviews support the efficacy of pharmacotherapy in treatment of ADHD; however, there is insufficient evidence regarding long-term safety of the medications. Further research is warranted to evaluate current treatment options and associated risks and benefits to guide the clinician in optimal management of these patients.

The psychopathological spectrum of Gilles de la Tourette syndrome

Gilles de la Tourette syndrome (GTS) holds a unique status as quintessentially neuropsychiatric condition at the interface between neurology (movement disorder) and psychiatry (behavioural condition). This is a reflection of the common observation that the vast majority of patients present with behavioural problems in association with the motor and vocal tics which define GTS. The present article focuses on the relationship between GTS and obsessive-compulsive disorder (OCD), attention-deficit and hyperactivity disorder (ADHD), affective disorders (both major depression and bipolar affective disorder), and personality disorders. Over the last decade, converging lines of research have pointed towards the concept of a 'GTS spectrum', encompassing motor phenomena and behavioural symptoms, with important implications for the clinical management of patients.