Complex phenotype of Tourette syndrome in a ten-year-old boy (a clinical case)

Abstract

Aim. The aim of the work is to draw attention to the symptoms associated with Tourette syndrome and to examine the association with comorbid diseases. Materials and methods. A review of the scientific literature on Tourette syndrome (TS) was conducted using the following Keywords “tics”, “Tourette syndrome”, “Tourette obsessive-compulsive disorder, TOCD”, “obsessive-compulsive disorder, OCD”, “attention deficit hyperactivity disorder, ADHD” using PubMed, MEDLINE, EMBASE as search engines. Taking into account studies conducted in the last 10 years, the abstracts of 275 articles were analyzed. Articles were selected for the study based on the criterion of their close relevance to the topic. The study results covered in 49 articles were examined in more detail. A description of a TOCD clinical case was prepared from primary medical documentation with parental informed consent. Results. The prevalence of TS is quite variable, depends on epidemiological research methods and ranges from 0.3 % to 1.0 % worldwide. Given the methodological limitations of most studies, the actual prevalence may be 10 times higher. TS is a progressive disease and is characterized by regular stages. Tourette syndrome-plus is distinguished, including autoaggressive actions besides the basic symptoms of OCD and ADHD. The etiology of TS is still being studied. In particular, the impact of environmental factors is considered: infection or inflammation, perinatal complications and chronic psychosocial stress in childhood. In 70–80 % of cases, TS is a hereditary disorder, making it one of the most heritable childhood-onset neuropsychiatric diseases. Various approaches have been applied to assess the genetic architecture of TS, including candidate gene studies, segregation analysis, linkage analysis, cytogenetics, copy number variants (CNV), rare variation studies, genome-wide association studies (GWAS), and whole exome sequencing (WES). Currently, there is no specific laboratory or genetic test for TS diagnosis. Pharmacological treatments are available but often ineffective; behavioral and surgical treatments are under development. The clinical case of TS in a 10-year-old boy is described with an onset at the age of 7 years following frequent infections, manifested as cephalocaudal motor tics and several vocal tics (coprolalia, echolalia) with a progression to obsessive-compulsive behavior (mysophobia, compulsive skin picking, self-hitting, self-biting, repetitive compulsions). The presented clinical case is of great interest from the viewpoint of somewhat belated diagnosis of TOCD syndrome, as well as indicates the need to continue the search for effective methods of diagnosis and treatment. Conclusions. The case of comorbid OCD and tic disorder is a unique endophenotype combining externalized disinhibited TS movements in parallel with internalized distress reminiscent of OCD. Clinicians should consider these features when choosing treatment methods.