The prevalence of anti-Toxoplasma gondii antibodies in stutterers is higher than in the control group

Abstract

The purpose of this study was to investigate the possible relationship between Toxoplasma gondii (Nicolle et Manceaux, 1908) and stuttering. We investigated the seropositivity rate for anti-T. gondii IgG and antibodies by enzyme-linked immunosorbent assay (ELISA) in stuttering children to ascertain a possible relationship between T. gondii infection and stuttering. We selected 65 stuttering children and 65 control children (non-stutterers) to investigate the seropositivity rate of anti-T. gondii antibodies by ELISA. Cranial magnetic resonance imaging (MRI) and scalp electroencephalography (EEG) were also performed in stuttering children. The seropositivity rate of anti-T. gondii IgG antibodies among stuttering children (28%) was significantly higher than in control group (5%; p = 0.001). No abnormality was detected in cranial MRI's of stutttering children and their EEG recordings were also normal. There was no significant difference in seropositivity rate regarding age, genders and residence area. The association between seroprevalence of infection with T. gondii and stuttering may be due to hyperdopaminergic state in brains of patients who are T. gondii-seropositive. Thus, there might be a causal relationship between toxoplasmosis and stuttering.

Systematic Review on the Relationship between Toxoplasmosis and Mental Disorders

“…All these processes also occur during toxoplasma infection [17]. Furthermore, there is evidence that infection with T. gondii has a greater impact on the hippocampus and amygdala [15]. A relationship has been observed with the synthesis of neurotransmitters such as dopamine and serotonin, also related to the other pathologies cited in this work (dopamine in Tourette, autism, hyperactivity, and serotonin in depression), combined impairment of dopaminergic regulation and presynaptic serotonergic with dopaminergic transmission dysfunction [17,19].…”

“…Only a study showed a significant association between hyperactivity disorder and gender, being more prevalent in men [19]. No significant differences related to area of residence [15] or socioeconomic status [13,18] were identified. However, significant differences were found in the assessments of the scales measuring the severity of Tourette [16], autism [17], hyperactivity [19], and anxiety and OCD [14], observing more severe symptoms in seropositive patients.…”

“…In 4 of these 7 studies, a statistically significant association was observed, with T. gondii infection being related to de- pression [13], OCD and generalized anxiety [14]. A statistically significant association was also found with disorders that began in infancy, childhood or adolescence: stuttering [15] and Tourette syndrome and vocal and motor tics [16].…”

“…Table 1 (Ref. [7,8,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]) summarizes the characteristics of these 20 articles. Of these, 7 studies were carried out on children and adolescents (Table 2, Ref.…”

“…Of these, 7 studies were carried out on children and adolescents (Table 2, Ref. [13][14][15][16][17][18][19]). In 4 of these 7 studies, a statistically significant association was observed, with T. gondii infection being related to de- pression [13], OCD and generalized anxiety [14].…”