SA79. Toxoplasma Gondii Affects Posterior Association Cortex and Related Functions in Healthy, but Not Schizophrenia, Individuals

Abstract

Posters (Saturday) S141 Background: Short-latency afferent inhibition (SAI) is the neurophysiological transcranial magnetic stimulation (TMS) paradigm that indexes central cholinergic activity from the motor cortex (M1). Recently, we established a method to index SAI from the dorsolateral prefrontal cortex (DLPFC), an area implicated in the pathophysiology of schizophrenia (SCZ). Here, we investigated SAI in both M1 and the DLPFC in SCZ patients compared to healthy controls (HC). We hypothesized that modulation of N100 on TMS-evoked potential (TEP) by SAI paradigm from the DLPFC would be attenuated in SCZ compared to HC. Further, the modulation of N100 would be correlated with cognitive performance. Methods: Age-matched 12 SCZ and 12 HC were examined with a combined TMS-electroencephalography (EEG). SAI from the left M1 (M1-SAI) and DLPFC (DLPFC-SAI) were indexed by conditioning a single suprathreshold TMS with right median nerve stimulation at interstimulus intervals of N20+2ms (M1-SAI) and N20+4ms (DLPFC-SAI), respectively. TEPs by M1-and DLPFC-SAI were analyzed using independent component analysis individually. Results: With M1-SAI paradigm, there was no significant change in TEP N100 (t11 = −2.30, P = .822) in the SCZ group or no significant difference in N100 modulation between the HC and SCZ groups (t22 = 1.917, P = 0.068). However, with DLPFC-SAI paradigm, we observed a significant N100 attenuation at the DLPFC (t11 = −4.926, P < .0001), and modulation of N100 was significantly different between the HC and SCZ groups (t22 = 5.456, P < .0001; SCZ < HC). Furthermore, the N100 modulation by DLPFC-SAI was significantly correlated with executive function as measured with the Trail Making Test (r = −0.740, P = .006, N = 12). Conclusion: The modulation of N100 by the DLPFC-SAI may reflect the prefrontal pathophysiology of SCZ and thus could be a potential biomarker for cholinergic and executive dysfunction in SCZ.

Association of Toxoplasma gondii Seropositivity With Cognitive Function in Healthy People

“…Two of those articles reported outcomes in which fewer than 4 studies were available and were therefore excluded. Thirteen studies met eligibility criteria and were included in the meta-analysis (Figure 1).…”

“…Partial data from the unpublished study were published as a conference abstract in a journal supplement . The authors provided additional (raw) data and written permission to use these data in the meta-analysis (D. Cobia, PhD, written communication, April 9, 2020).…”

“…requested additional (raw) data from the corresponding authors of selected studies when the available published results were not usable for meta-analysis. Data provided were used in the meta-analysis with written permission from the authors of the following studies: Cobia et al (D. Cobia, PhD, written communication, April 9, 2020), El-Hadidy et al (M. A. El-Hadidy, MD, written communication, May 11, 2020), Gajewski et al (P. D. Gajewski, PhD, written communication, April 3, 2020), Guenter et al (W. Guenter, PhD, written communication, April 30, 2020), Nimgaonkar et al (V. J. Nimgaonkar, MD, PhD, written communication, May 12, 2020), and Torniainen-Holm et al (M. Torniainen-Holm, PhD, written communication, May 8, 2020). Partial data from the Cobia et al study were published as a conference abstract in a journal supplement.…”

“…Data provided were used in the meta-analysis with written permission from the authors of the following studies: Cobia et al (D. Cobia, PhD, written communication, April 9, 2020), El-Hadidy et al (M. A. El-Hadidy, MD, written communication, May 11, 2020), Gajewski et al (P. D. Gajewski, PhD, written communication, April 3, 2020), Guenter et al (W. Guenter, PhD, written communication, April 30, 2020), Nimgaonkar et al (V. J. Nimgaonkar, MD, PhD, written communication, May 12, 2020), and Torniainen-Holm et al (M. Torniainen-Holm, PhD, written communication, May 8, 2020). Partial data from the Cobia et al study were published as a conference abstract in a journal supplement. Unpublished data from Cobia et al and other studies were used in the following calculations: mean age; male to female ratio; seropositivity to seronegativity ratio; overall SMD of processing speed, working memory, short-term verbal memory, and executive functioning; and corresponding sensitivity analyses, meta-regression analyses, and funnel plots.…”

“…Partial data from the Cobia et al study were published as a conference abstract in a journal supplement. Unpublished data from Cobia et al and other studies were used in the following calculations: mean age; male to female ratio; seropositivity to seronegativity ratio; overall SMD of processing speed, working memory, short-term verbal memory, and executive functioning; and corresponding sensitivity analyses, meta-regression analyses, and funnel plots.…”