Ideographic Alexia without Involvement of the Fusiform Gyrus in a Korean Stroke Patient: A Serial Functional Magnetic Resonance Imaging Study

BACKGROUND: Korean orthography is composed of Hanja (ideograms) and Hangul (phonograms). Based on previous studies, the fusiform gyrus has been associated with ideogram reading. We examine serial functional magnetic resonance imaging (fMRI) images in a patient exhibiting dissociation of Hanja and Hangul reading to identify brain areas associated with Hanja reading. CASE REPORT: fMRI were taken of a 63-year-old man showing profound Hanja alexia with normal Hangul reading after an acute stroke involving the left frontal and parietal lobes, who later spontaneously recovered his Hanja reading ability. Scans were taken while performing Hanja and Hangul reading tasks on three occasions. As a result, in spite of having profound Hanja alexia, partial activation of the fusiform gyrus was observed on the first fMRI. Serial fMRI scans showed activation of the bilateral middle frontal gyri that increased in parallel with the patient's recovery of Hanja reading. CONCLUSIONS: The frontal lobe, not only fusiform gyrus, may play role in reading Hanja, although more evidence is needed.

Deficit in Gender Discrimination Related Circuit in Nonaffected Siblings of Schizophrenia Patients : Preliminary Functional MRI Study / 신경정신의학

OBJECTIVES : A neural circuit including amygdala, the hippocampal complex and prefrontal cortex was associated with deficits in facial processing in schizophrenia. These deficits have a significant impact on social functioning in schizophrenia. Both neuropsychological deficits and brain structural abnormalities in first-degree relatives of schizophrenia patients suggest that they may also have the deficit in facial information processing as genetic factors. The purpose of this study was to explore the dysfunction of facial information processing in first-degree relatives of schizophrenia patients using functional magnetic neuroimaging (fMRI). METHODS : Ten non-affected siblings of schizophrenic patients and 10 normal comparison subjects having no schizophrenic siblings underwent fMRI during the d ynamic facial change procedure consisting of presentations of facial emotion and gender discrimination stimuli. The emotion discrimination condition consisted of the presentation of 12 happy faces and 12 disgust/fear faces. The gender discrimination condition consisted of the presentation of 12 male faces and 12 female faces. Condition-specific brain activations were compared between non-affected siblings and normal comparison subjects RESULTS : The facial information processing related brain regions including fusiform gyrus, several areas of frontal, temporal, occipital, and cerebellar regions exhibited more activation during gender discrimination than emotion discrimination tasks in each group. During gender discrimination task, siblings of schizophrenic patients showed less activation in right fusiform gyrus, both middle and superior frontal gyrus, left cuneus, and left inferior frontal gyrus, compared with normal comparison subjects. CONCLUSION : Dysfunctional facial information processing, such as a deficit in gender discrimination, might be an endophenotype of schizophrenia.

Working Memory Mapping Analysis using fMRI / 의학물리

Impaired processing of facial information is one of the broad ranges of cognitive deficits seen in patients with schizophrenia. The purpose of this study was to elucidate the differences in brain activities involved in the process of facial working memory between schizophrenic patients and healthy comparison subjects. Ten patients with schizophrenia were recruited along with matched healthy volunteers as a comparison group. Functional magnetic resonance imaging (fMRI) was used to assess cortical activities during the performance of a 1-back working memory paradigm using images of neutral faces as mnemonic content. The patient group performed the tasks with reduced accuracy. Group analysis revealed that left fusiform gyrus, right superior frontal gyrus, bilateral middle frontal gyri/insula, left middle temporal gyrus, precuneus and vermis of cerebellum and showed decreased cortical activities in the patient group. On the other hand, an increased level of activation in lateral prefrontal cortex and parietal lobule was observed from the patient group, all in the right hemisphere. A decreased level of activity in the left fusiform gyrus among the patient group implicates inefficient processing of facial information. An increased level of activation in prefrontal and parietal neural networks from the patient group confirms earlier findings on the impaired working memory of patients with schizophrenia.

Working Memory Deficits of Facial Images in Patients with Schizophrenia: fMRI Investigation / 신경정신의학

OBJECTIVES: Impaired processing of facial information is one of the broad ranges of cognitive deficits seen in patients with schizophrenia. We aimed to elucidate the differences in brain activities involved in the process of facial working memory between schizophrenic patients and healthy comparison subjects. METHODS: Twelve patients with schizophrenia were recruited along with twelve demographically matched healthy volunteers as a comparison group. Functional magnetic resonance imaging (fMRI) was used to assess cortical activities during the performance of a 2-back working memory paradigm using images of neutral faces as mnemonic content. RESULTS: The patient group performed the tasks with reduced accuracy. Group analysis revealed that the left fusiform gyrus, the right superior frontal gyrus, the bilateral middle frontal gyri/insula, the left middle temporal gyrus, the precuneus, the quadrangular lobules and the vermis of cerebellum showed decreased cortical activities in the patient group. On the other hand, an increased level of activation in the lateral prefrontal cortex and the parietal lobule was observed from the patient group, all in the right hemisphere. CONCLUSION: A decreased level of activity in the left fusiform gyrus among the patient group implicates inefficient processing of facial information. An increased level of activation in prefrontal and parietal neural networks from the patient group confirms earlier findings on the impaired working memory of patients with schizophrenia.

Cerebral Hemiachromatopsia

A 73-year-old woman developed visual disturbances in the right side of the visual fields along with headache. A neurological examination showed right upper quadrantanopsia and right hemiachromatopsia. She reported that she could only see in shades of gray in the right hemifield. She also had difficulties in recognizing and naming the colors of objects presented in the right hemifield. A color-sorting test revealed generalized impairments involving all color axes. A brain MRI showed acute infarction in the left fusiform and lingual gyri.