Variability in the functional connectivity of the bilateral inferior frontal gyrus with the whole brain in persons with Broca′s aphasia / 中华物理医学与康复杂志

Objective:To observe the temporal variability of functional connectivity between the bilateral inferior frontal gyrus and rest of the brain in persons with Broca′s aphasia (BA) and to compare the connectivity between Uygur and Chinese aphasics.Methods:Thirty Chinese and Uygur BA patients (the patient group) and 30 healthy people speaking Uygur and Chinese (the healthy group) were included. rs-fMRI images were acquired, and the patient group was divided then into a Uygur language patient group (9 cases) and a Chinese language patient group (12 cases). The healthy group was divided into a Uygur language healthy group (13 cases) and a Chinese language healthy group (15 cases). Dynamic functional connectivity (dFC) calculations were performed, and a two-factor analysis of covariance was used to obtain the brain regions in which there was an interaction between language and aphasia and to analyze the correlation between the brain regions with abnormal dFCs and linguistic behavior.Results:Interaction between the bilateral inferior frontal gyrus and the left medial and paracentral cingulate gyrus and the right postcentral gyrus dFC was observed to vary. Temporal variability among the Uygur patients was significantly less than among the Uygur healthy and Chinese patient groups. The temporal variability of Broca′s mirror area and the right postcentral gyrus in the Chinese patient group was significantly greater than in the Chinese healthy group or the Uygur patient group. Variability of Broca′s area and the left medial and paracingulate cingulate gyrus in the Uygur patients group correlated positively with oral fluency, reading comprehension and writing.Conclusion:There are differences in the temporal variability of the dFC in the bilateral inferior frontal gyrus between Uygur and Chinese BA patients. The lower variability of Broca′s area with the left medial and paracingulate and cingulate gyrus may help to identify impaired language function in BA patients. The enhanced variability of the Broca′s mirror image area with the right postcentral gyrus may be the result of reorganization of the linguistic network in Chinese BA patients.

Anatomical Correlates of Interlocking Pentagon Drawing

BACKGROUND: The interlocking pentagon drawing test, a part of the Mini-Mental State Examination (MMSE), is a widely used clinical practice to measure visuoconstructional ability of dementia patients. We investigated the anatomical structures of brain associated with pentagon drawing in subjects with mild to moderate Alzheimer's disease (AD) by using voxel-based morphometry (VBM). METHODS: Medical records of forty-four AD patients were reviewed and a 1.5 T SPGR 3D image data were used for VBM analysis. A voxel-based multiple regression analysis was used to investigate correlation between gray matter loss and pentagon drawing performance of AD patients. The correlations between pentagon drawing score and MMSE score were evaluated by Spearman correlation analysis. RESULTS: There was a positive correlation between the interlocking pentagon copying scores and the MMSE scores (r=0.448, p=0.002). The lower the scores of interlocking pentagon copying were, the more severe the atrophy of right inferior frontal gyrus became ([x, y, z]=[52, 39, 3], Broadmann area 45, and z score=3.86). CONCLUSIONS: The performance of interlocking pentagon drawing is associated with a general cognitive function in patients with mild-to-moderate Alzheimer's disease. It is also associated with the atrophy of the right inferior frontal gyrus.

Visual sexual stimuli induced asymmetrical activation on Broca's area on right hemisphere:an fMRI research / 中国心理卫生杂志

Objective:To investigate the brain activation patten associated with visual sexual stimuli.Method:Thirteen healthy right-handed women were enrolled through advertisements on campus.They were scanned under functional magnetic resonance imaging(fMRI) when they watched emotional neutral films excepts and erotic films excepts.Statistic on theses data reveals the difference of brain activation.Result:The results showed that,compared to emotional neutral films,sexual visual stimuli were associated with the activation of a set of bilateral brain areas including lateral occipital cortex,postcentral gyrus,superior parietal lobule,occipital fusiform gyrus, hippocampus,and so on.Most activated brain areas are bilateral.Only in inferior frontal gyrus pars opercularis(Z=3.64,P<0.0001) and pars triangular(Z=3.42,P=0.003) there were significant right hemispheric activation.Conclusion:fMRI results indicate that inferior frontal gyrus is related to the visual sexual stimuli of women subjects,and is specified on the right hemisphere rather than left one.This sphere-special area may play an important role on sexual message processing.

Compensatory Neural Correlates of Selective Attention Deficit in Schizophrenics Showing Normal Accuracy during Stroop / 신경정신의학

OBJECTIVES: This study investigated the compensatory neural correlate of selective attention deficit in schizophrenics showing near-normal performance. METHODS : A 'modified Stroop' was developed that can be used measure the response time during functional imaging. An event-related functional magnetic resonance imaging study was carried out in 10 clinically stabilized schizophrenics and 10 healthy controls during the performance of a 'modified Stroop'. In the 'modified Stroop', the subjects were required to respond with a two-button mouse to whether or not the color of a subsequent word corresponded to one of T-shirt. The significantly activated brain regions were investigated in a voxel-wise t-test of the Stroop load. RESULTS : Schizophrenics, compared with healthy controls, showed poorer response time, but had similar accuracy. Compensatory activation in the right inferior frontal gyrus (IFG) was observed in schizophrenics. The left paracingulate sulcus was less activated in the schizophrenics than in the healthy controls. CONCLUSION : These results suggest that, in schizophrenics showing a normal accuracy during the Stroop, selective attention deficits might be related to the left paracingulate sulcus as well as the anterior cingulate. In addition, their deficits may be compensated with the right IFG.

MRI-Based Lateralization of Anterior Speech Area

Speech lateralization by Wada is a necessary step in the presurgical evaluation of patients with intractable epilepsy. It, however, is invasive. We studied the usefulness of a noninvasive technique: MRI-based volumetric and anatomical analysis of the anterior speech area as compared to Wada test. Thirty nine patients with intractable epilepsy under presurgical evaluation includding Wada test for hemispheric lateralization for language, were studied: patients with left language dominance(n=20) and right language dominance (n=19). Sagittal and coronal T1-weighted turbo FLASH scans were acquired. Every image in each patient was reconstructed and inferior frontal gyrus was identified on the 3D-surface rendered brain. Then cortical gray matter of inferior frontal gyrus in each image was segmented and reconstructed using a 3D software(Allegro, ISG, Toronto, Canada). Sulcal and gyral patterns of the inferior frontal gyrus were evaluated and classified comparing with the normotive data of Steinmetz. Total volume of inferior frontal gyrus(ifg), regional volumes of pars triangularis(tr) and pars opercularis(op) were obtained. Asymmetry Quotient(AQ) of inferior frontal gyrus, (right-left)/0.5(right+left), between left and right were calculated in each patient. AQ from both groups of patients were compared and data was analysed. Complicated gyral pattern and presentation of a diagonal sulcus in the pars opercularis were prominent in the left side in patients with the left hemispheric dominance for language(p<0.006, p<0.02), and in the right side in patients with the right hemispheric dominance(p<0.002, p<0.03). In patients with language dominance in the left hemisphere, AQ of each portion of anterior speech area showed significant leftward asymmetry(M: Mean, SEM: Standard Error of Mean, Mifg=-.24; SEMifg=0.04, Mtr=-.19; SEMtr=0.09, Mop=-.26; SEMop=0.06). In patients with language dominance in the right hemisphere, AQ showed mild rightward asymmetry or no asymmetry(Masa=0.21; SEMifg=0.06, Mtr=0.15; SEMtr=0.08, Mop=0.24; SEMop=0.09). Fisher's Exact test demonstrated significant value of AQ in each portion of inferior frontal gyrus correlated with hemispheric dominance for language with confidence index(CI)in 95%. Interestingly, AQ of pars triangularis plus pars opercularis showed the highest value(p=0.00001) in predicting the language dominant hemisphere. MRI-based sulcal, gyral patterns and volumetric asymmetry of inferior frontal gyrus correlate with speech lateralization on Wada test. This is a promising noninvasive technique in hemispheric lateralization for language.