Reduced prefrontal cortex activation using the Trail Making Test in schizophrenia

Abstract

Schizophrenia has been associated with a deficit of the prefrontal cortex, which is involved in attention, executive processes, and working memory. The Trail Making Test (TMT) is administered in two parts, TMT-A and TMT-B. It is suggested that the difference in performance between part A and part B reflects executive processes. In this study, we compared the characteristics of hemodynamic changes during TMT tasks between 14 outpatients with schizophrenia and 14 age- and gender-matched healthy control subjects. Using multichannel near-infrared spectroscopy, we measured relative changes in oxygenated hemoglobin concentration, which reflects brain activity of the prefrontal cortex during this task. In both tasks, patients showed significantly smaller activation than controls and, in an assessment of executive functions, a subtraction of oxygenated hemoglobin (oxy-Hb) changes during TMT-A from those of TMT-B showed a decrease in cerebral lateralization and hypoactivity in patients. There was a significant negative correlation between oxy-Hb changes and the severity of psychiatric symptoms. These findings may characterize disease-related features, suggesting the usefulness of oxy-Hb change measurement during TMT tasks for assessing functional outcomes in schizophrenic patients.

Comparison of changes in the oxygenated hemoglobin level during a ‘modified rock‐paper‐scissors task’ between healthy subjects and patients with schizophrenia

“…in which schizophrenic patients and healthy subjects were initially evaluated using a mirror‐drawing task and NIRS. The presence of frontal lobe dysfunction in schizophrenia was also reported by later studies using NIRS and various cognitive tasks, such as verbal fluency, Go/No Go, continuous performance tasks and the Trail‐Making Test . These also suggest the presence of impairments in inhibitory and attention‐related executive functions in schizophrenia patients, reflected in the impairment of WM.…”

“…The presence of frontal lobe dysfunction in schizophrenia was also reported by later studies using NIRS and various cognitive tasks, such as verbal fluency, 19 Go/No Go, 38 continuous performance tasks 39 and the Trail-Making Test. 40 These also suggest the presence of impairments in inhibitory and attention-related executive functions in schizophrenia patients, reflected in the impairment of WM. The decrease in the Δoxy-Hb during the condition to lose in the schizophrenia group may have been due to the difference in the difficulty of the task.…”

Bifrontale transkranielle Gleichstromstimulation zur Behandlung der Schizophrenie

“…Im hier geschilderten Fall wird über den Einsatz der tDCS bei paranoider Schizophrenie berichtet, wobei eine bifrontale Elektrodenplatzierung verwendet wurde, die bisher bei der Behandlung der Depression (21,22) (23). Während und zwischen den Behandlungen traten keine unerwünschten Nebenwirkungen auf.…”

Transcriptional regulation of GAD1 GABA synthesis gene in the prefrontal cortex of subjects with schizophrenia

“…Whether or not such types of activity-dependent mechanisms could have contributed to downregulated cortical GAD1 expression in some of the SCZ cases remains unclear given that the clinical studies are confined to postmortem brain. However, this is a plausible hypothesis given that there is ample evidence for functional hypoactivity affecting multiple cortical areas in SCZ (Cieslik et al, 2013; Diwadkar et al, 2011; Eack et al, 2013; Fujiki et al, 2013; Lee et al, 2014; Ota et al, 2014; Thoresen et al, 2014; Wolwer et al, 2012; Yoon et al, 2013)(and earlier references cited therein).…”