Mycoplasma pneumoniae infection and Tourette's syndrome

What every psychiatrist should know about PANDAS: a review

The term Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infections (PANDAS) was coined by Swedo et al. in 1998 to describe a subset of childhood obsessive-compulsive disorders (OCD) and tic disorders triggered by group-A beta-hemolytic Streptococcus pyogenes infection. Like adult OCD, PANDAS is associated with basal ganglia dysfunction. Other putative pathogenetic mechanisms of PANDAS include molecular mimicry and autoimmune-mediated altered neuronal signaling, involving calcium-calmodulin dependent protein (CaM) kinase II activity. Nonetheless the contrasting results from numerous studies provide no consensus on whether PANDAS should be considered as a specific nosological entity or simply a useful research framework. Herein we discuss available data that could provide insight into pathophysiology of adult OCD, or might explain cases of treatment-resistance. We also review the latest research findings on diagnostic and treatment.

Mycoplasma pneumoniae infection and obsessive-compulsive disease: a case report

It has been demonstrated that obsessive-compulsive disease and/or tic syndromes in children may be triggered by an antecedent infection especially with group A beta-hemolytic streptococci, and this subgroup of children has been designated by the acronym PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections). Other infectious agents such as viruses and bacteria have also been reported to be associated with the acute onset or dramatic exacerbation of obsessive-compulsive disease or Tourette syndrome, and another acronym, PITAND (pediatric infection-triggered autoimmune neuropsychiatric disorder) has appeared in the literature. The involvement of other infectious agents such as Mycoplasma pneumoniae has been described in single case reports. We describe a case of a 5.5-year-old boy who suddenly developed obsessive-compulsive disease symptoms during a M. pneumoniae pneumonia. After treatment with oral clarithromycin, all his obsessive-compulsive disease symptoms disappeared. To our knowledge, this is the first report that shows the association between Mycoplasma pneumoniae infection and obsessive-compulsive disease.

Tourette's syndrome: clinical features, pathophysiology, and therapeutic approaches

Tourette's syndrome (TS) is a disorder characterized by simple and complex motor tics, vocal tics, and frequently obsessive-compulsive symptoms, its onset occurs before the age of 21. Typically, TS shows a waxing and waning course, but a chronification of the tics, even during later life, is often observed, TS mainly occurs in boys, and shows genetic heritability with differing penetrance. The pathological mechanism is still unclear. Neuroanatomical and neuroimaging studies, as well as effective treatment using antipsychotics, suggest that a disturbance of the dopaminergic system in the basal ganglia plays an important role in the pathogenesis of TS, Several possibly causative mechanisms of the disturbed dopaminergic neurotransmission are discussed, with the main emphasis on the-infection-triggered- inflammatory immune process, Extrapyramidal movement disorders are known to occur as a symptom of poststreptococcal disease, such as in Sydenham's chorea. Cases of childhood TS are proposed to be caused by such a post-streptococcal mechanism, being part of a spectrum of childhood neurobehavioral disorders termed pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS), The overlap between TS and PANDAS is discussed, and a critical view of the PANDAS concept is presenter], The therapeutic implications of the different pathological mechanisms are described, taking into consideration not only the acute or chronic natures of different infections, but also an autoimmune process, Moreover, therapeutic strategies using typical and atypical antipsychotics, and also experimental therapies such as repetitive transcranial magnetic stimulation and deep brain stimulation, are critically discussed.

Tourette syndrome and tic disorders: a decade of progress

OBJECTIVE

This is a review of progress made in the understanding of Tourette syndrome (TS) during the past decade including models of pathogenesis, state-of-the-art assessment techniques, and treatment.

METHOD

Computerized literature searches were conducted under the key words "Tourette syndrome," "Tourette disorder," and "tics." Only references from 1996-2006 were included.

RESULTS

Studies have documented the natural history of TS and the finding that tics usually improve by the end of the second decade of life. It has also become clear that TS frequently co-occurs with attention-deficit/hyperactivity disorder), obsessive-compulsive disorder, and a range of other mood and anxiety disorders. These comorbid conditions are often the major source of impairment for the affected child. Advances have also been made in understanding the underlying neurobiology of TS using in vivo neuroimaging and neurophysiology techniques. Progress on the genetic front has been less rapid. Proper diagnosis and education (involving the affected child and his or her parents, teachers, and peers) are essential prerequisites to the successful management of children with TS. When necessary, modestly effective antitic medications are available, although intervening to treat the comorbid attention-deficit/hyperactivity disorder and/or obsessive-compulsive disorder is usually the place to start.

CONCLUSIONS

Prospective longitudinal studies and randomized clinical trials have led to the refinement of several models of pathogenesis and advanced our evidence base regarding treatment options. However, fully explanatory models are needed that would allow for more accurate prognosis and the development of targeted and efficacious treatments.

Mycoplasma pneumoniae central nervous system infections

PURPOSE OF REVIEW

Mycoplasma pneumoniae is associated with a wide range of central nervous system diseases, most importantly with childhood encephalitis. This review summarizes and discusses recent findings in the field of M. pneumoniae central nervous system infections in context with previously published findings, with reference to clinical spectrum, pathogenesis, diagnosis, and treatment.

RECENT FINDINGS

Further insight into the pathogenesis has been provided by studies on cytokine production and autoantibody formation. Some new manifestations have been described (e.g. Kluver-Bucy syndrome, intracranial hypertension). Anecdotal descriptions on the association of M. pneumoniae with uncommon neurologic diseases remain to be confirmed by additional reports, however, especially when aetiologic diagnosis relied exclusively on serology. New knowledge on treatment options targeting the immune system has been provided by isolated reports. Recent diagnostic advances refer to general methods (polymerase chain reaction, serology), without specific reference to neurologic disease.

SUMMARY

M. pneumoniae must be considered as causative agent of various neurologic diseases. The recent literature shows, however, that the clinical spectrum of M. pneumoniae central nervous system disease is still not well defined. In addition, the main future challenges are the investigation of the pathogenesis of M. pneumoniae central nervous system disease and the establishment of therapeutic approaches.

Tic disorders: from pathophysiology to treatment

Tic disorders are stereotypic behaviours,more frequent than once believed, and therefore likely to be encountered by primary care physicians. Tics usually begin in childhood and are the clinical hallmark of Tourette Syndrome (TS), the most common cause of tics. TS is a relatively common neurobehavioural disorder with a spectrum of manifestations that wax and wane during its natural course. The pathophysiology of tics, at molecular and cellular level, is still unknown,whereas structural and functional neuroimaging studies have shown the involvement of the basal ganglia and related cortico-striato-thalamo-cortical circuits, and the dopaminergic neuronal system. Moreover, TS has a strong genetic background. The management of TS is often complicated by the presence of attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, and other behaviour disorders. The correct diagnosis is a fundamental step for a proper management of these disorders, and a multimodal treatment is usually indicated. This approach includes educational and supportive interventions, as well as pharmacological treatments when tics are at their worst.

Tic disorders and obsessive-compulsive disorder: is autoimmunity involved?

The precise cause of tic disorders and paediatric obsessive-compulsive disorder (OCD) is unknown. In addition to genetic factors, autoimmunity may play a role, possibly as a sequela of preceding streptococcal throat infections in susceptible children. Here we review the most recent findings, from July 2003 onwards, with regard to a possible relationship between tics/OCD and autoimmunity. Evidence about an intriguing correlation between streptococcal infections and tic disorders and OCD is accumulating. Specific criteria have been outlined for paediatric autoimmune disorders associated with streptococcal infections (PANDAS), but autoimmunity may also be involved in tic disorders and/or OCD in general. Anti-basal ganglia auto-antibodies are an important potential indicator of autoimmunity. Although the lack of a standardized methodology makes comparisons of findings difficult, new data has emerged pointing to the possible involvement of specific auto-antigens. Earlier findings of increased D8/17 B cell expression as a putative susceptibility marker could not be replicated, possibly due to instability of the D8/17-binding antibody. Although PANDAS patients have been reported to improve after therapeutic plasma exchange, and antibiotics may prevent symptom exacerbations, immune-based treatments should not be routinely given. In future studies, demonstrating the pathogenetic significance of anti-basal ganglia antibodies in animals is a major challenge to draw any firm conclusions about a role for autoimmunity. Future longitudinal studies should be aimed at assessing the precise relationship between symptom exacerbations, infections, and immune parameters, possibly along with gene expression profiles.

High risk of schizophrenia and other mental disorders associated with chlamydial infections: hypothesis to combine drug treatment and adoptive immunotherapy

Many microbial factors have been implicated as pathogenic factors in mental disorders. Occurrence of such microbial factors also in the mentally unaffected population raised skepticism against such findings, although each microbial factor may cause mental problems only in some individuals, depending on the individual's immunogenetic disposition. Skepticism against the role of infection in schizophrenia was also fostered by the low impact of antiinfections treatment on the course of disease progression in schizophrenia. We discovered previously that neurotrophins like neurotrophin3 (NT-3) and brain-derived neurotrophic factor (BDNF), involved in processes of neuroplasticity, are also secreted by immune cells, but only by subpopulations of immune cells. Therefore, infection of the immune cell subpopulation, specialized in secreting BDNF, or of another subpopulation, specialized in secreting NT-3, could distort communication of immune cells with the central nervous system (CNS). Chlamydiaceae could cause disbalancement of immune cell sub-populations and, in some individuals with a vulnerable disposition, symptoms of mental illness. Based on previous observations of persisting IgA titers in some patients with mental illness we hypothesize that the intracellular parasites Chlamydiaceae are main pathogenic factors in schizophrenia. We hypothesize furthermore that antiinfectious treatment has to be accompanied by adoptive immunotherapy because antibiotics alone will not restore the balance of immune subpopulations. Our hypothesis is supported by examination of patients with schizophrenia and other mental disorders. Using nested PCR we found a significant prevalence of the intracellular parasites Chlamydophila psittaci, C. pneumoniae and Chlamydia trachomatis (9/18, 50%), as compared to controls (8/115, 6.97%) (chi(2)=25.86, Fisher's exact p two-tailed=5x10(-5)). Treatment with in vitro-activated immune cells together with antibiotic modalities showed sustained mental improvements in patients that did not depend on treatment with antipsychotic drugs. Future controlled studies including sham treatment of patients have to be carried out to prove our hypotheses.