Social cognition in schizophrenia: Validation of an ecological fMRI task

Neuroimaging studies have revealed brain regions involved in social cognition, which reportedly show functional alterations in schizophrenia. However, the social neural network has not been investigated with regards to language perception and social interactions in daily life. Here we developed and validated an integrative fMRI task to explore the neural basis of social cognition with regards to language perception in schizophrenia. The task comprised listening to film extracts and inferring mental states to characters. We first identified the functional network activated during the task in 28 healthy controls (HC). Next, we evaluated the reproducibility of Blood-Oxygen-Level Dependent (BOLD) variations in 14 HC participants. Finally, we investigated network impairment in 20 patients with schizophrenia (SZ) compared to HC. The HC group exhibited bilateral activation in the superior and middle temporal gyri (including the poles and the temporo-parietal junction). Overall, our novel integrative task induced activation of a functional network with good reproducibility and involved in language conveying social information. Compared to the HC group, the SZ group showed decreased recruitment of the right temporo-parietal junction. These findings may be useful for testing the impact of remediation on the brain, particularly on the network of language conveying social information.

Impact of rTMS on functional connectivity within the language network in schizophrenia patients with auditory hallucinations

This exploratory study investigated the functional connectivity (FC) in the language network in schizophrenia patients (SZ) with auditory verbal hallucinations (AVHs), and the therapeutic efficacy of rTMS on it. Eleven SZ with AVHs and 10 healthy controls (HC) underwent two fMRI sessions using a speech listening paradigm. SZ received 20Hz rTMS following the first fMRI session. Compared to HC, SZ showed a reduced FC in the language network. While AVHs improved after 12days, no changes in FC were observed. This suggests the efficacy of high-frequency rTMS on AVH without any impact for rTMS on FC within the language network.

Familial sinistrality and handedness in patients with first episode schizophrenia: the EUFEST study

The population with schizophrenia is characterised by a leftward shift in handedness-sinistrality. However, findings are inconsistent in chronic patients, and familial sinistrality (FS), defined as the presence of left-handed close relatives, might contribute to the discrepancies. Therefore the aim of this study was to investigate the strength of manual lateralisation in patients with first episode schizophrenia, taking into account familial sinistrality. The Edinburgh Inventory (EI) allowed us to categorise 179 patients from the EUFEST study and 189 controls presenting "strong handedness" (SH: EI absolute value between ∣81∣ and ∣100∣) or "weak-handedness" (WH: EI value between -80 and +80). The nominal logistic regression did not show an FS effect, but a nearly significant interaction between illness and FS (p =.07). There were fewer participants without FS presenting SH among patients (99/151: 65.6%) than among controls (134/164: 81.7%, p =.001). In contrast, the number of participants with FS presenting SH was similar between controls (68%) and patients (75%, p =.57). The presence of left-handed relatives (FS + ) tended to reduce manual lateralisation, but only in controls. This supports the notion that reduced manual lateralisation in schizophrenia is related to the illness rather than to familial left-handedness.

Two-day treatment of auditory hallucinations by high frequency rTMS guided by cerebral imaging: a 6 month follow-up pilot study

BACKGROUND

Recently, repetitive Transcranial Magnetic Stimulation (rTMS) has been introduced as an alternative treatment for auditory hallucinations in schizophrenic patients that fail to respond to antipsychotics. Until now, application of rTMS has been at low frequency, and most commonly applied to the left temporoparietal cortex. This 6-month follow-up pilot study was performed to demonstrate the efficacy of high frequency rTMS guided by anatomical and functional Magnetic Resonance Imaging (MRI).

METHODS

Eleven patients with schizophrenia (DSM-IV) were treated with high frequency (20 Hz) rTMS delivered over 2 days; they were then followed for 6 months. The target area was identified by fMRI as the highest activation cluster along the posterior part of the left superior temporal sulcus from the BOLD signal of each subject during a language task.

RESULTS

A significant reduction in global severity and frequency of auditory hallucinations between baseline and post-treatment day 12 was observed. Auditory hallucinations were entirely relieved at 6-month follow-up in 2 patients. The treatment was well tolerated in all patients.

CONCLUSIONS

This is the first study reporting successful treatment of auditory hallucinations with 20 Hz rTMS. The efficacy at short term, the strength of the clinical response, the persistence of therapeutic effect over a 6-month follow-up, the safety profile, and the short duration of treatment present a considerable therapeutic gain compared to low frequency rTMS.