The treatment of tics

Pharmacological therapy for Tourette syndrome: What medicine can do and cannot do

Tourette syndrome (TS) is a frequently observed developmental neuropsychological disorder occurring in children. The pathophysiology involves both genetic and environmental factors. In this review, clinical characteristics, pathophysiology, and treatment approaches based on the pathophysiology of TS are presented. The pathophysiology is the acceleration of developmental decrement of dopamine (DA) activity at the terminal of nigro-striatal (NS)-DA system causing DA D2 receptor up-ward regulation. Serotonergic neurons involving in development of the biphasic sleep-wake-rhythm, and locomotion may be involved. Pharmacological treatments constitute an important part in managing TS. Small dose of levodopa and aripiprazole showed the good effect controlling the tics, without side effects. Intervention with enhancing the day time activity and keeping the regular sleep-wake-rhythm, and encouraging locomotion are important. The data from Yoshiko Nomura Neurological Clinic for Children regarding the clinical features and outcomes, medication effects, and OCD and outcomes are shown. To discuss about the environmental factor, how the COVID-19 pandemic affected the TS patients is also presented.

Centromedian-Parafascicular Complex Deep Brain Stimulation for Tourette Syndrome: A Retrospective Study

Deep brain stimulation (DBS) of the thalamic centromedian/parafascicular (CM-Pf) complex has been reported as a promising treatment for patients with severe, treatment-resistant Tourette syndrome (TS). In this study, safety and clinical outcomes of bilateral thalamic CM-Pf DBS were reviewed in a series of 12 consecutive patients with medically refractory TS, 11 of whom met the criteria of postsurgical follow-up at our institution for at least 2 months. Five patients were followed for a year or longer. Consistent with many patients with TS, all patients had psychiatric comorbidities. Tic severity and frequency were measured by using the Yale Global Tic Severity Scale (YGTSS) over time (average, 26 months) in 10 subjects. One patient was tested at 2-week follow-up only and thus was excluded from group YGTSS analysis. Final YGTSS scores differed significantly from the preoperative baseline score. The average (n=10) improvement relative to baseline in the total score was 54% (95% CI, 37-70); average improvement relative to baseline in the YGTSS Motor tic, Phonic tic, and Impairment subtests was 46% (95% CI, 34-64), 52% (95% CI, 34-72), and 59% (95% CI, 39-78), respectively. There were no intraoperative complications. After surgery, 1 subject underwent wound revision because of a scalp erosion and wound infection; the implanted DBS system was successfully salvaged with surgical revision and combined antibiotic therapy. Stimulation-induced adverse effects did not prevent the use of the DBS system, although 1 subject is undergoing a trial period with the stimulator off. This surgical series adds to the literature on CM-Pf DBS and supports its use as an effective and safe therapeutic option for severe refractory TS.

Centromedian-parafascicular deep brain stimulation induces differential functional inhibition of the motor, associative, and limbic circuits in large animals

BACKGROUND

Deep brain stimulation (DBS) of the centromedian-parafascicular (CM-Pf) thalamic nuclei has been considered an option for treating Tourette syndrome. Using a large animal DBS model, this study was designed to explore the network effects of CM-Pf DBS.

METHODS

The combination of DBS and functional magnetic resonance imaging is a powerful means of tracing brain circuitry and testing the modulatory effects of electrical stimulation on a neuronal network in vivo. With a within-subjects design, we tested the proportional effects of CM and Pf DBS by manipulating current spread and varying stimulation contacts in healthy pigs (n = 5).

RESULTS

Our results suggests that CM-Pf DBS has an inhibitory modulating effect in areas that have been suggested as contributing to impaired sensory-motor and emotional processing. The results also help to define the differential neural circuitry effects of the CM and Pf with evidence of prominent sensorimotor/associative effects for CM DBS and prominent limbic/associative effects for Pf DBS.

CONCLUSIONS

Our results support the notion that stimulation of deep brain structures, such as the CM-Pf, modulates multiple networks with cortical effects. The networks affected by CM-Pf stimulation in this study reinforce the conceptualization of Tourette syndrome as a condition with psychiatric and motor symptoms and of CM-Pf DBS as a potentially effective tool for treating both types of symptoms.

Treatment options for Tourette syndrome

Tics are commonly observed in children, and Tourette Syndrome (TS) represents one end of the spectrum of tic disorders. This article reviews the treatment options for TS.

The auspicious role of the 5-HT3 receptor in depression: a probable neuronal target?

The serotonergic mechanisms have been successfully utilized by the majority of antidepressant drug discovery programmes, while the search for newer targets remains persistent. The present review focused on the serotonin type-3 receptor, the only ion channel subtype in the serotonin family. Behavioural, neurochemical, electrophysiological and molecular analyses, including the results from our laboratory, provided substantial evidence that rationalizes the correlation between serotonin type-3 receptor modulation and rodent depressive-like behaviour. Nevertheless, the reports on polymorphism of serotonin type-3 receptor genes and data from clinical studies (on serotonin type-3 receptor antagonists) were insufficient to corroborate the involvement of this receptor in the neurobiology of depression. The preclinical and clinical studies that have contradicted the antidepressant-like effects of serotonin type-3 receptor antagonists and the reasons underlying such disagreement were discussed. Finally, this critical review commended the serotonin type-3 receptor as a candidate neuronal antidepressant drug target.

Neurosurgical strategies for Gilles de la Tourette's syndrome

Tourette's syndrome (TS) is a neurological disorder characterized by motor and vocal tics that typically begin in childhood and often are accompanied by psychiatric comorbidities. Symptoms of TS may be socially disabling and cause secondary medical complications. Pharmacological therapies remain the mainstay of symptom management. For the subset of patients in whom TS symptoms are medically recalcitrant and do not dissipate by adulthood, neurosurgery may offer an alternative treatment strategy. Greater understanding of the neuroanatomic and pathophysiologic basis of TS has facilitated the development of surgical procedures that aim to ameliorate TS symptoms by lesions or deep brain stimulation of cerebral structures. Herein, the rationale for the surgical management of TS is discussed and neurosurgical experiences since the 1960s are reviewed. The necessity for neurosurgical strategies to be performed with appropriate ethical considerations is highlighted.

Tic exacerbation and precipitation during atomoxetine treatment in two children with attention-deficit hyperactivity disorder

Stimulants have been the mainstay of treatment for children with Attention-deficit/hyperactivity Disorder (ADHD). However, stimulants have been controversially purported to precipitate and exacerbate tics. Atomoxetine, a selective norepinephrine inhibitor, was introduced as a safe non-stimulant alternative treatment for ADHD children with comorbid tics or TS. We are presenting two children with ADHD, in which atomoxetine, at relatively low doses, exacerbated and precipitated tics. The diagnoses of ADHD and tic disorder were based on clinical observations and standardized rating scales. Case 1, an 8-year-old boy, had history of stimulant-induced tics. This child was placed on atomoxetine reported to be safe for patients with tics. This patient's tic control was adequate prior to atomoxetine treatment. However, while on atomoxetine, the patient promptly experienced tic exacerbation. Case 2, a 6-year-old boy, had no previous history of stimulant therapy and was receiving citalopram due to a comorbid anxiety disorder. Atomoxetine was initiated for the treatment of ADHD with improvement in the ADHD symptoms. But, upon a mild dose increase, the patient presented tic precipitation consisting primarily of neck twitches. Both cases experienced a decrease in tic activity when atomoxetine was discontinued, but tics did not fully resolve, causing psychosocial disturbance. Atypical neuroleptics were used with good results. Periodic assessments of the need for continued neuroleptic treatment were emphasized. These two children exemplify atomoxetine's potential to exacerbate and precipitate tics in children with ADHD. Independent controlled studies are needed to determine if atomoxetine should be used in children with ADHD and comorbid tic disorders or TS.

Mechanisms of dopaminergic and serotonergic neurotransmission in Tourette syndrome: clues from an in vivo neurochemistry study with PET

Tourette syndrome (TS) is a neuropsychiatric disorder with childhood onset characterized by motor and phonic tics. Obsessive-compulsive disorder (OCD) is often concomitant with TS. Dysfunctional tonic and phasic dopamine (DA) and serotonin (5-HT) metabolism may play a role in the pathophysiology of TS. We simultaneously measured the density, affinity, and brain distribution of dopamine D2 receptors (D2-R's), dopamine transporter binding potential (BP), and amphetamine-induced dopamine release (DA(rel)) in 14 adults with TS and 10 normal adult controls. We also measured the brain distribution and BP of serotonin 5-HT2A receptors (5-HT2AR), and serotonin transporter (SERT) BP, in 11 subjects with TS and 10 normal control subjects. As compared with controls, DA rel was significantly increased in the ventral striatum among subjects with TS. Adults with TS+OCD exhibited a significant D(2)-R increase in left ventral striatum. SERT BP in midbrain and caudate/putamen was significantly increased in adults with TS (TS+OCD and TS-OCD). In three subjects with TS+OCD, in whom D2-R, 5-HT2AR, and SERT were measured within a 12-month period, there was a weakly significant elevation of DA rel and 5-HT2A BP, when compared with TS-OCD subjects and normal controls. The current study confirms, with a larger sample size and higher resolution PET scanning, our earlier report that elevated DA rel is a primary defect in TS. The finding of decreased SERT BP, and the possible elevation in 5-HT2AR in individuals with TS who had increased DA rel, suggest a condition of increased phasic DA rel modulated by low 5-HT in concomitant OCD.

Botulinum Toxin in Ophthalmology

Since its introduction into clinical medicine in 1980, botulinum toxin has become a major therapeutic drug with applications valuable to many medical sub-specialties. Its use was spearheaded in ophthalmology where its potential applications have expanded to cover a broad range of visually related disorders. These include dystonic movement disorders, strabismus, nystagmus, headache syndromes such as migraine, lacrimal hypersecretion syndromes, eyelid retraction, spastic entropion, compressive optic neuropathy, and, more recently, periorbital aesthetic uses. Botulinum toxin is a potent neurotoxin that blocks the release of acetylcholine at the neuromuscular junction of cholinergic nerves. When used appropriately it will weaken the force of muscular contraction, or inhibit glandular secretion. Recovery occurs over 3 to 4 months from nerve terminal sprouting and regeneration of inactivated proteins necessary for degranualtion of acetylcholine vesicles. Complications are related to chemodenervation of adjacent muscle groups, injection technique, and immunological mechanisms.

Contemporary assessment and pharmacotherapy of Tourette syndrome

To develop a guide to clinical assessment and pharmacotherapy for children and adults with Tourette syndrome (TS), we reviewed published literature over the past 25 years to identify original articles and reviews on the assessment and pharmacological treatment of Tourette syndrome, attention-deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). The literature search also included a survey of reviews published in book chapters. The assessment section was compiled from several reviews. Pharmacological treatments were classified into those with strong empirical support (as evidenced by two positive placebo-controlled studies for tics, OCD, or ADHD in TS samples); modest empirical support (one positive placebo-controlled study), or minimal support (open-label data only). We conclude that accurate diagnosis, including identification of comorbid conditions, is an essential step toward appropriate treatment for patients with TS. In many patients with TS, symptom management requires pharmacotherapy for tics or coexisting conditions. The evidence supporting efficacy and safety for medications used in patients with TS varies. But this evidence offers the best guide to clinical practice.

Patient selection and assessment recommendations for deep brain stimulation in Tourette syndrome

In response to recent publicity regarding the potential use of deep brain stimulation (DBS) for reducing tic severity in Tourette's syndrome (TS), the Tourette Syndrome Association convened a group of TS and DBS experts to develop recommendations to guide the early use and potential clinical trials of DBS for TS and other tic disorders. The goals of these recommendations are to ensure that all surgical candidates are (1) fully informed about the risks, benefits, and alternative treatments available; (2) receive a comprehensive evaluation before surgery to ensure that DBS is clearly the appropriate clinical treatment choice; and (3) that early clinical experience will be documented publicly to facilitate rational decision-making for both clinical care and future clinical trials.

Botulinum toxin type A injections: Adverse events reported to the US Food and Drug Administration in therapeutic and cosmetic cases

BACKGROUND

Botulinum toxin type A (BTA) (Botox) received Food and Drug Administration (FDA) approval for therapeutic treatment of strabismus and blepharospasm in 1989, cervical dystonia in 2000, and cosmetic treatment of glabellar wrinkles (Botox Cosmetic) in 2002. In 2002 alone there were approximately 1.1 to 1.6 million patients using cosmetic BTA. Our objective was to review adverse event (AE) reporting to the FDA after BTA administration.

METHODS

We reviewed all (therapeutic and cosmetic use) serious (per FDA regulations) AEs reported to the FDA for the 13.5 years since licensure of the product (December 1989-May 2003) and nonserious AEs reported from December 2001 to November 2002. AEs are reported to the FDA through the MedWatch system.

RESULTS

We reviewed 1437 AE reports; 406 followed therapeutic use of BTA (217 serious and 189 nonserious) and 1031 followed cosmetic use (36 serious and 995 nonserious). Reported AEs occurred predominantly in female patients, with a median age of 50 years. In the year December 2001 to November 2002, when both serious and nonserious reports were evaluated, the proportion of reports classified as serious was 33-fold higher for therapeutic than for cosmetic cases. The 217 serious AEs reported in therapeutic cases involved a wide spectrum of events and included all 28 reported deaths. Among cosmetic users, no deaths were reported and, of the 36 serious AEs, 30 were included as possible complications in the FDA-approved label. The remaining 6 serious AEs did not display a pattern suggesting a common causal relationship to BTA. Among the 995 cosmetic cases reported to have nonserious AEs, most commonly noted were lack of effect (623, 63%), injection site reaction (190, 19%), and ptosis (111, 11%).

CONCLUSIONS

Serious AEs were more likely to be reported for therapeutic than for cosmetic use, which may be related to higher doses, complicated underlying diseases, or both. Among cosmetic cases, few serious AEs were reported, and these were predominantly events that were previously recognized in clinical trials of BTA for the labeled use. This study is limited primarily by the incomplete nature of AE reporting by clinicians. Numerous departures from FDA-approved recommendations for drug dose, dilution, handling, site of injection, and storage were noted in these AE reports.

Clinical characteristics of adult patients with tics and/or Tourette's syndrome

OBJECTIVE

This study was conducted to describe the natural course of tic disorders over a long period of time in Japanese adults patients with Tourette's syndrome (TS) in terms of symptomatology.

METHODS

An extensive literature on TS cases was reviewed selectively and 31 TS patients (mean age: 31.4 years; sex: 28 males and 3 females) at our outpatient clinic were examined. The mean follow-up period of the patients was 7.6 years (SD: 8.1; 0 to 26). All the data available for this study, including medical charts, were examined systematically by two experienced child psychiatrists.

RESULTS

The adult patients with tic disorders could be classified into the four groups: group A - tics only, group B - tics + comorbidities, group C - comorbidities only and group D - sub-clinical (remission) cases. Our 31 subjects consisted of 10 patients (32.3%) for group A, 14 (45.2%) for group B, 7 (22.6%) for group C, and 0 for group D.

CONCLUSIONS

Further investigation into the natural course and clinical characteristics of adult TS needs to be done in order to acquire a better understanding of the broad spectrum of TS and to make improvements to the treatment for this illness.

Neurology of Tourette's syndrome (TS) TS as a developmental dopamine disorder: a hypothesis

The favorable effect of dopamine (DA) depletors or DA receptor blockers suggested the state of increased transmission of DA system as the pathophysiology of Tourette's syndrome (TS). We have analysed the neurological signs of TS and evaluated the role of levodopa on the symptoms of TS. The data were compared with age-matched patients with Hereditary Progressive Dystonia (HPD) with marked diurnal fluctuation. Neurological examination of 81 drug naive TS patients revealed the clumsiness of rapid alternating pronation-supination movements of the arms and induced rigidity in the contralateral arm, which responded to the oral levodopa, and suggested hypofunction of the nigrostriatal (NS)-DA system. Postural asymmetry or scoliosis and abnormal tilting response suggested the asymmetric involvement of DA. The rotation to the side of less affected DA neuron on stepping with closed eyes suggested DA receptor supersensitivity. The favourable effects of a small dose of levodopa on these signs suggest the existence of DA receptor supersensitivity, because a small dose of levodopa is considered to alleviate the supersensitized DA receptors.

Pharmacological management of tics in patients with TS

This article reviews the evidence published in the English language literature concerning the pharmacological treatment of tics in patients with Tourette Syndrome. The focus is on the efficacy and safety of the current treatments. A clinical approach to pharmacological management of Tourette Syndrome patients is outlined.