栗田 幸平

BACKGROUND: Generalized anxiety disorder (GAD) and social anxiety disorder (SAD) are distinguished by whether anxiety is limited to social situations. However, reports on the differences in brain functional networks between GAD and SAD are few. Our objective is to understand the pathogenesis of GAD and SAD by examining the differences in resting brain function between patients with GAD and SAD and healthy controls (HCs). METHODS: This study included 21 patients with SAD, 17 patients with GAD, and 30 HCs. Participants underwent psychological assessments and resting-state functional magnetic resonance imaging (rsfMRI). Whole-brain analyses were performed to compare resting-state functional connectivity (rsFC) among the groups. Additionally, logistic regression analysis was conducted on the rsFC to identify significant differences between GAD and SAD. RESULTS: Patients with SAD and GAD had significantly higher rsFC between the bilateral postcentral gyri and bilateral amygdalae/thalami than HCs. Compared with patients with SAD, those with GAD had significantly higher rsFC between the right nucleus accumbens and bilateral thalami and between the left nucleus accumbens and right thalamus. RsFC between the left nucleus accumbens and right thalamus positively correlated with state anxiety in patients with SAD and GAD, respectively. In addition, logistic regression analysis revealed that the right nucleus accumbens and the right thalamus connectivity could distinguish SAD from GAD. CONCLUSIONS: GAD and SAD were distinguished by the right nucleus accumbens and the right thalamus connectivity. Our findings offer insights into the disease-specific neural basis of SAD and GAD.

BACKGROUND: Studies comparing the brain functions of major depressive disorder (MDD) and social anxiety disorder (SAD) at the regional and network levels remain scarce. This study aimed to elucidate their pathogenesis using neuroimaging techniques and explore biomarkers that can differentiate these disorders. METHODS: Resting-state fMRI data were collected from 48 patients with MDD, 41 patients with SAD, and 82 healthy controls. Differences in the amplitude of low-frequency fluctuations (ALFF) among the three groups were examined to identify regions showing abnormal regional spontaneous activity. A seed-based functional connectivity (FC) analysis was conducted using ALFF results as seeds and different connections were identified between regions showing abnormal local spontaneous activity and other regions. The correlation between abnormal brain function and clinical symptoms was analyzed. RESULTS: Patients with MDD and SAD exhibited similar abnormal ALFF and FC in several brain regions; notably, FC between the right superior frontal gyrus (SFG) and the right posterior supramarginal gyrus (pSMG) in patients with SAD was negatively correlated with depressive symptoms. Furthermore, patients with MDD showed higher ALFF in the right SFG than HCs and those with SAD. LIMITATION: Potential effects of medications, comorbidities, and data type could not be ignored. CONCLUSION: MDD and SAD showed common and distinct aberrant brain function patterns at the regional and network levels. At the regional level, we found that the ALFF in the right SFG was different between patients with MDD and those with SAD. At the network level, we did not find any differences between these disorders.

Developmental prosopagnosia (DP) is a condition that indicates the inability to recognize individuals by their faces from birth, without any history of brain damage. The assessment of face recognition ability and diagnosis of DP involve the use of face tests such as the Cambridge Face Memory Test (CFMT) and the Cambridge Face Perception Test, along with self-reported measures like the 20-Item Prosopagnosia Index (PI20). Face recognition accuracy is affected by anxiety. However, previous studies on the relationship between face recognition ability and anxiety have not used the PI20 measure. This study aimed to investigate the relationship between self-reported measures of face recognition ability and anxiety tendencies among healthy young individuals for DP diagnosis and its implications. We used a face recognition test, involving the PI20, CFMT, Visual Perception Test for Agnosia-Famous Face Test (VPTA-FFT), and State-Trait Anxiety Inventory (STAI). We assessed the performance of 116 Japanese young adults (75 females, median age of 20.7 years, with a standard deviation of 1.2). Subsequently, we conducted a statistical analysis to examine the relationship between the outcomes of the face recognition tests and STAI scores using Pearson correlation analysis and single correlation coefficients. The results showed a positive correlation between state anxiety and PI20 (r = 0.308, p = 0.007), and a weak positive correlation was also observed between trait anxiety and PI20 (r = 0.268, p = 0.04). In contrast, there was no correlation between CFMT and VPTA-FFT with respect to STAI. The results of the hierarchical multiple regression analysis also suggested that the correlation between the performance on the PI20 (self-report) and objective measures of face recognition performance (the CFMT and the VPTA-FFT) are driven by differences in anxiety. This study is the first to explore the relationship between face recognition abilities and anxiety using the PI20 self-report measure. There are implications for future research on the diagnosis of DP and the relationship between anxiety and face recognition.

INTRODUCTION: Previous neuroimaging studies in social anxiety disorders (SAD) have reported potential neural predictors of cognitive behavioral therapy (CBT)-related brain changes. However, several meta-analyses have demonstrated that cognitive therapy (CT) was superior to traditional exposure-based CBT for SAD. OBJECTIVE: To explore resting-state functional connectivity (rsFC) to evaluate the response to individual CT for SAD patients. METHODS: Twenty SAD patients who attended 16-week individual CT were scanned pre- and post-therapy along with twenty healthy controls (HCs). The severity of social anxiety was assessed with the Liebowitz Social Anxiety Scale (LSAS). Multi-voxel pattern analysis (MVPA) was performed on the pre-CT data to extract regions associated with a change in LSAS (∆LSAS). Group comparisons of the seed-based rsFC analysis were performed between the HCs and pre-CT patients and between the pre-and post-CT patients. RESULTS: MVPA-based regression analysis revealed that rsFC between the left thalamus and the frontal pole/inferior frontal gyrus was significantly correlated with ∆LSAS (adjusted R2 = 0.65; p = 0.00002). Compared with HCs, the pre-CT patients had higher rsFCs between the thalamus and temporal pole and between the thalamus and superior/middle temporal gyrus/planum temporale (p < 0.05). The rsFC between the thalamus and the frontal pole decreased post-CT (p < 0.05). CONCLUSION: SAD patients had significant rsFC between the thalamus and temporal pole, superior/middle temporal gyrus, and planum temporale, which may be indicators of extreme anxiety in social situations. In addition, rsFC between the thalamus and the frontal pole may be a neuromarker for the effectiveness of individual CT.

若年健常者121名を対象に日常生活上における主観的な相貌認識を測るThe 20-item prosopagnosia index（PI20），客観的相貌認知検査である標準高次視知覚検査熟知相貌検査第二版（VPTA-FFT）およびCambridge face memory test（CFMT）を実施し，各検査間の関連について検討した．その結果，3者で相互に有意な相関が認められた．一方，発達性相貌失認疑い例は3検査すべてで異常と判断されたわけではなく，基準値設定に影響されることが示唆された．発達性相貌失認の評価にはPI20，VPTA，CFMTを組み合わせて用いることでより精度の高い判断につながると考えられた．

Prosopagnosia is a deficit in the ability to recognize familiar faces, it can be acquired or developmental with fewer cases of the latter. In developmental prosopagnosia, both the heading disorientation and landmark agnosia constituting the disorder are extremely poor. The presented case is of a woman in her late twenties. Her main complaint is “It’s hard for me to learn the faces from my childhood” and “I often forget where in the shopping mall parking lot I parked my car.” An MRI scan of her brain showed no abnormalities. She was screened for autism spectrum disorder, general cognition and memory, visuoperception, and human identification from an auditory cue and the results are good. However, she showed a deficit in the Cambridge Face Memory Test. These results fulfill the diagnostic criteria for developmental prosopagnosia. In the results of a topographical test, while she showed good results for the test of heading disorientation such as “map drawing task for around her home” and “direction localization task for buildings around the home,” she showed poor results in the “scene and object identification test” as a test of landmark agnosia. We revealed for the first time that our case has landmark agnosia but not heading disorientation in developmental prosopagnosia with the topographical disorder heading disorientation.

社交不安症（Social anxiety disorder; SAD）は，社交場面において他者からの評価を恐れる特徴があり，自然には治癒しにくく慢性的な経過をたどりやすい精神疾患である．小児期・青年期では，行動抑制気質がSADの発症リスクとして挙げられており，SADでは扁桃体の体積が小さいことに加えて，恐怖を予測する場面において内側前頭前皮質の賦活の程度が小さいことが報告されている．さらに，幼少期に行動抑制気質があることにより，成人期において背側帯状皮質の体積が小さくなるという長期的な影響についても検討されている．成人期では，扁桃体などの辺縁系と前頭前皮質との情動処理領域に関して研究されてきた．しかし，近年は視覚領域など広範囲にわたる関連性について報告されている．SADの治療では認知行動療法が推奨されているが，病態生理機序について十分な理解があるとはいえない．本稿では，小児・青年期と成人におけるSADの脳画像研究について概説した．

Mirror writing refers to writing as if the script was reflected in a mirror. This study describes the case of a patient who exhibited mirror writing with her left hand after suffering thalamic hemorrhage. Before the stroke, she was right-handed, but became unable to write with her right hand due to severe paralysis. Afterwards, she began writing with her left hand and mirror writing emerged. Interestingly, her mirror writing occurred frequently, even six months after the stroke. In addition, these features influenced the writing direction. There are more frequently emerged leftward and vertical directions. The reason why the feature of the phenomenon is characteristics of the movement to write a letter with left hand, and the role of the right hemisphere for writing.