Functional Connectivity of the Caudate in Schizophrenia Evaluated with Simultaneous Resting-State Functional MRI and Electroencephalography Recordings.

BACKGROUND: Aberrant functional connectivity (FC) is increasingly implicated in the clinical phenomenology of schizophrenia. This study focused on the FC of the cortico-striatal network, which is thought to be disrupted in schizophrenia and to contribute to its clinical manifestations. METHODS: We used simultaneous resting-state functional magnetic resonance imaging (rsfMRI) and electroencephalography (EEG) recordings to investigate FC in patients with schizophrenia. The study included 20 patients with schizophrenia and 20 healthy controls (HCs). Simultaneously recorded rsfMRI and EEG data were collected with an MR-compatible amplifier, and rsfMRI data were analyzed with the CONN toolbox to calculate FC. The study focused on the caudate, which was defined as the seed. We also performed between-group comparisons of standardized low-resolution electromagnetic tomography intracortical lagged coherence for each EEG frequency band. RESULTS: Compared to HCs, patients with schizophrenia showed enhanced FC between the caudate nucleus and the posterior cingulate cortex, temporal, and occipital regions on rsfMRI. It is thus possible that HCs have negative FC between these regions, whereas patients with schizophrenia have non-negative FC. The EEG results showed no significant differences in oscillations or in FC between the groups in any frequency band in any region. CONCLUSIONS: Increased FC in the caudate may represent aberrant between-network FC resulting from the disruption of segregation between networks.

Simultaneous resting-state functional MRI and electroencephalography recordings of functional connectivity in patients with schizophrenia.

AIM: It remains unclear how functional connectivity (FC) may be related to specific cognitive domains in neuropsychiatric disorders. Here we used simultaneous resting-state functional magnetic resonance imaging (rsfMRI) and electroencephalography (EEG) recording in patients with schizophrenia, to evaluate FC within and outside the default mode network (DMN). METHODS: Our study population included 14 patients with schizophrenia and 15 healthy control participants. From all participants, we acquired rsfMRI data, and simultaneously recorded EEG data using an MR-compatible amplifier. We analyzed the rsfMRI-EEG data, and used the CONN toolbox to calculate the FC between regions of interest. We also performed between-group comparisons of standardized low-resolution electromagnetic tomography-based intracortical lagged coherence for each EEG frequency band. RESULTS: FC within the DMN, as measured by rsfMRI and EEG, did not significantly differ between groups. Analysis of rsfMRI data showed that FC between the right posterior inferior temporal gyrus and medial prefrontal cortex was stronger among patients with schizophrenia compared to control participants. CONCLUSION: Analysis of FC within the DMN using rsfMRI and EEG data revealed no significant differences between patients with schizophrenia and control participants. However, rsfMRI data revealed over-modulated FC between the medial prefrontal cortex and right posterior inferior temporal gyrus in patients with schizophrenia compared to control participants, suggesting that the patients had altered FC, with higher correlations across nodes within and outside of the DMN. Further studies using simultaneous rsfMRI and EEG are required to determine whether altered FC within the DMN is associated with schizophrenia.

Response of schizophrenic patients to dynamic facial expressions: an event-related potentials study.

OBJECTIVE: Patients with schizophrenia have an impaired ability to respond to faces and may specifically show an impaired response to dynamic facial expressions. Here we investigated the responses of schizophrenic patients and healthy controls to dynamic facial images using event-related potentials (ERPs). METHODS: We showed 13 schizophrenic patients and 13 healthy controls visual stimuli comprising facial expressions that continually changed from neutral to emotional. RESULTS: N200 latencies and P100-N200 peak-to-peak amplitudes in controls were prolonged or greater for dynamic emotions in comparison with those for static stimuli, but the group with schizophrenia showed no significant differences in responses to dynamic and static emotions. A significant negative correlation was observed between N200 latencies for dynamic negative emotion and PANSS (positive and negative syndrome scale) general psychopathology scale scores. CONCLUSIONS: A combination of hypersensitivity to static emotions and hyposensitivity to dynamic emotions in people with schizophrenia might underlie the absence of differences in response to these stimuli. A tendency in the schizophrenic group to hypersensitivity to static emotions might arise from the enhanced fear and arousal characteristics of this group; their hyposensitivity to dynamic emotions might result from controlled attentional bias away from facial expressions to reduce fear and anxiety.

Case reports and literature review: the association between reactivation of human herpes virus-6 and peripheral white blood cell count in patients with carbamazepine-induced hypersensitivity syndrome.

Eruptions induced by anticonvulsants can often be experienced clinically, and the clinical diagnosis of "drug induced hypersensitivity syndrome (HS)" was proposed to characterize these drug eruptions. Reactivation of human herpes virus-6 seems to be an integral component of HS. Previously, we experienced two cases of carbamazepine (an anticonvulsant) induced HS and both cases did not show a reactivation of human herpes virus-6 infection (no elevation of anti-human herpes virus-6 IgG titres). The features of these two cases were compared with other reported cases that presented HS with the reactivation of human herpes virus-6. In the early phase of HS, a change in peripheral white blood cell count seems to be important and could be used as an indicator to predict whether late phase HS with reactivation of human herpes virus-6 will occur, since the increase in white blood cell count is seen before the increase in anti-human herpes virus-6 titres. Reactivation of human herpes virus-6 may cause severe clinical symptoms such as encephalitis. When an increase in white blood cells are observed in HS cases at onset, immediate discontinuation of cause drug and intensive care are necessary to avoid the more severe symptoms of HS.