Functional magnetic resonance imaging to word generation task in a patient with Broca’s aphasia

We describe the findings of functional magnetic resonance imaging (fMRI) in a patient with Broca’s aphasia. The patient was a 45-year-old, right-handed woman who developed Broca’s aphasia after infarction in the left frontal lobe. The first fMRI showed no signals in the left frontal lobe during verbal tasks, 2 weeks after the onset of infarction. Four weeks later, when the patient’s symptom had improved, the second fMRI showed some increase in the fMRI signals in the left frontal lobe. Seven months later, she had completely recovered the ability to speak. The last fMRI then showed that the increment in signal activity in the left frontal lobe during verbal tasks had recovered to the level seen in normal subjects. There was a good correlation between the increase in task-related signals in Broca’s area and the recovery of language function. Our findings show that fMRI has can be important in assessing cognitive functions in patients with Broca’s aphasia. Received: 27 November 1998 Received in revised form: 30 March 1999 Accepted: 26 April 1999     

Distribution of cerebral cortical lesions in corticobasal degeneration: a clinicopathological study of five autopsy cases in Japan

We investigated five Japanese patients with autopsy-proven corticobasal degeneration (CBD) both clinically and pathologically, and examined the distribution of their cerebral cortical lesions in hemisphere specimens. The lesions were classified into three categories (slight, moderate and severe). Only two of our patients had clinical features considered to be typical of CBD. Severe lesions were present in the posterior portions of the frontal lobe, anterior to the precentral gyrus in two patients with the clinical diagnosis of CBD. By comparison, in two patients with clinically diagnosed frontal Pick’s disease, and one with the clinical diagnosis of progressive supranuclear palsy (PSP), severe lesions were seen in the anterior portions of the frontal lobe. The primary motor area of all five had mostly slight to moderate lesions. We postulate that the clinical features of CBD have a much wider spectrum than previously believed. Our data also indicate that the lesion responsible for limb-kinetic apraxia in CBD is in the premotor cortex. We suggest that when the anterior portions of the frontal lobe are damaged, the clinical picture mimics those of Pick’s disease and PSP. In addition, we consider that focal cerebral atrophy of CBD is multicentric. Received: 3 February 1997 / Revised: 14 April 1997 / Accepted: 2 May 1997     

A Chance SPECT Study of Ictal Aphasia During Simple Partial Seizures

Summary: We report obtaining an ictal single photon emission computed tomographic (SPECT) scan in a right-handed 51-year-old man who had an astrocytoma in the left cerebral hemisphere and simple partial seizures characterized by aphasia. An epileptic seizure producing loss of speech and right-sided facial twitching occurred by chance during a SPECT scan. During the attack, he was unable to speak, but auditory comprehension and writing were intact. Ictal SPECT showed an area of increased perfusion in the left frontal cortex, with the area of highest perfusion involving the left frontal operculum to the inferior part of the left precentral gyrus. Interictal SPECT showed hypoperfusion in the same area. These SPECT findings suggest that the frontal operculum of the dominant hemisphere is one of the regions that can give rise to epileptic aphasia.     

弥散张量成像在继发全面性发作癫痫患者中的应用研究

目的 评价弥散张量成像(DTI)对于常规MRI未发现病灶的部分性继发全面性发作癫痫患者的病灶检出能力.方法 使用Siemens 3.0T磁共振成像系统对30例成年继发全面性发作癫痫患者和30例正常对照者进行扫描,得到弥散加权成像,采用基于体素的分析方法对癫痫患者和正常对照组的数据进行分析.结果 癫痫组右侧梭状回和楔前叶、右侧额内侧回和钩回、左侧扣带回、左侧颞下回、左侧小脑扁桃体和左侧中央前回的脑区FA值较正常对照组降低,差异有统计学意义(P＜0.001);癫痫组右侧海马旁回、右侧颞下回、右侧胼胝体、右侧额内侧回、右侧额下回、扣带回、右侧前扣带回、右侧舌回、右侧梭状回和枕中回,左侧颞中回、左侧钩回和左侧中央前回的脑区ADC值较正常对照组升高,差异具有统计学意义(P＜0.001);左侧直回的脑区ADC值较正常对照组降低,差异具有统计学意义(P＜0.001).结论 DTI检查可发现常规MRI检查为阴性的部分性继发全面性发作癫痫患者存在的广泛脑白质微结构异常.     

Speech disturbances due to left precentral cortical lesions

We encountered two patients with lesions predominantly localized to the left precentral cortex who presented with speech disorders. Patient 1 had a lesion localized to the anterior part of the left precentral cortex along the precentral sulcus, in the middle part of the convexity. Patient 1 predominantly exhibited disturbance of prosody. Patient 2 had a lesion localized to the left precentral cortex, located slightly more posterior and more inferior in the convexity. Patient 2 predominantly exhibited disturbance of articulation, with distortion of sounds without apparent inconsistency. Even lesions localized to the left precentral cortex present with various types of speech disturbance.     

Upper motor neuron predominant degeneration with frontal and temporal lobe atrophy

The autopsy findings of a 78-year-old man mimicking primary lateral sclerosis (PLS) are reported. He showed slowly progressive spasticity, pseudobulbar palsy and character change, and died 32 months after the onset of symptoms. Autopsy revealed severe atrophy of the frontal and temporal lobes, remarkable neuronal loss and gliosis in the precentral gyrus, left temporal lobe pole and amygdala, mild degeneration of the Ammon’s horn, degeneration of the corticospinal tract, and very mild involvement of the lower motor neurons. The anterior horn cells only occasionally demonstrated Bunina body by cystatin-C staining, and skein-like inclusions by ubiquitin staining. This is a peculiar case with concomitant involvement in the motor cortex and temporal lobe in motor neuron disease predominantly affecting the upper motor neuron. Received: 18 November 1997 / Revised, accepted: 2 April 1998     

Brain functional changes in facial expression recognition in patients with major depressive disorder before and after antidepressant treatment A functional magnetic resonance imaging study

Functional magnetic resonance imaging was used during emotion recognition to identify changes in functional brain activation in 21 first-episode, treatment-naive major depressive disorder patients before and after antidepressant treatment. Following escitalopram oxalate treatment, patients exhibited decreased activation in bilateral precentral gyrus, bilateral middle frontal gyrus, left middle temporal gyrus, bilateral postcentral gyrus, left cingulate and right parahippocampal gyrus, and increased activation in right superior frontal gyrus, bilateral superior parietal lobule and left occipital gyrus during sad facial expression recognition. After antidepressant treatment, patients also exhibited decreased activation in the bilateral middle frontal gyrus, bilateral cingulate and right parahippocampal gyrus, and increased activation in the right inferior frontal gyrus, left fusiform gyrus and right precuneus during happy facial expression recognition. Our experimental findings indicate that the limbic-cortical network might be a key target region for antidepressant treatment in major depressive disorder.     

Anterior cingulate, gyrus rectus, and orbitofrontal abnormalities in elderly depressed patients: an MRI-based parcellation of the prefrontal cortex

OBJECTIVE: To examine structural abnormalities in subregions of the prefrontal cortex in elderly patients with depression, the authors explored differences in gray matter, white matter, and CSF volumes by applying a parcellation method based on magnetic resonance imaging (MRI). METHOD: Twenty-four elderly patients with major depression and 19 group-matched comparison subjects were studied with high-resolution MRI. Cortical surface extraction, tissue segmentation, and cortical parcellation methods were applied to obtain volume measures of gray matter, white matter, and CSF in seven prefrontal subregions: the anterior cingulate, gyrus rectus, orbitofrontal cortex, precentral gyrus, superior frontal cortex, middle frontal cortex, and inferior frontal cortex. RESULTS: Highly significant bilateral volume reductions in gray matter were observed in the anterior cingulate, the gyrus rectus, and the orbitofrontal cortex. Depressed patients also exhibited significant bilateral white matter volume reductions and significant CSF volume increases in the anterior cingulate and the gyrus rectus. Finally, the depressed group showed significant CSF volume reductions in the orbitofrontal cortex relative to the comparison subjects. None of the other regions examined revealed significant structural abnormalities. CONCLUSIONS: The prominent bilateral gray matter deficits in the anterior cingulate and the gyrus rectus as well as the orbitofrontal cortex may reflect disease-specific modifications of elderly depression. The differential pattern of abnormalities detected in the white matter and CSF compartments imply that distinct etiopathological mechanisms might underlie the structural cortical changes in these regions.     

Altered structure and functional connection in patients with classical trigeminal neuralgia

Classical trigeminal neuralgia (TN) is a specific type of neuropathic orofacial pain of which the plasticity of brain structure and connectivity have remained largely unknown. A total of 62 TN patients were included and referred to MRI scans. Voxel‐based morphometry was used to analyze the change of gray matter volume. Resting‐state functional imaging was used to analyze the connectivity between brain regions. The results showed gray matter volume reduction in components of the prefrontal cortex, precentral gyrus, cerebellar tonsil, thalamus, hypothalamus, and nucleus accumbens among right TN patient and in the inferior frontal gyrus, precentral gyrus, cerebellum, thalamus, ventral striatum, and putamen among left TN patients. The connections between the right superior frontal gyrus and right middle frontal gyrus were lower in right TN patients. The connection between the left precentral gyrus and the left superior frontal gyrus was lower while the connection between bilateral thalamus was higher in left TN patients. The changes of volume in bilateral thalamus of right TN patients and left ventral striatum of left TN patients, and the connectivity between bilateral thalamus of left TN patients were moderately correlated with pain duration. These findings suggest that brain regions such as the thalamus may not only be involved in processing of pain stimuli but also be important for the development of TN. The left hemisphere may be dominant in processing and modulation of TN pain signal. Chronification of TN induces volume changes in brain regions which are associated with emotional or cognitive modulation of pain. Hum Brain Mapp 39:609–621, 2018. © 2017 Wiley Periodicals, Inc.     

Regional brain structural abnormality in ischemic stroke patients：a voxel-based morphometry study

Our previous study used regional homogeneity analysis and found that activity in some brain areas of patients with ischemic stroke changed significantly.In the current study,we examined structural changes in these brain regions by taking structural magnetic resonance imaging scans of 11 ischemic stroke patients and 15 healthy participants,and analyzing the data using voxel-based morphometry.Compared with healthy participants,patients exhibited higher gray matter density in the left inferior occipital gyrus and right anterior white matter tract.In contrast,gray matter density in the right cerebellum,left precentral gyrus,right middle frontal gyrus,and left middle temporal gyrus was less in ischemic stroke patients.The changes of gray matter density in the middle frontal gyrus were negatively associated with the clinical rating scales of the Fugl-Meyer Motor Assessment(r=–0.609,P=0.047) and the left middle temporal gyrus was negatively correlated with the clinical rating scales of the nervous functional deficiency scale(r=–0.737,P=0.010).Our findings can objectively identify the functional abnormality in some brain regions of ischemic stroke patients.     

原发性进行性失语的临床、影像及语言特征

目的 探讨原发性进行性失语（PPA）的临床、影像及语言特征.方法 PPA患者7例,其中语义性痴呆（SD）6例,进行性非流利性失语（PNFA）1例,收集患者的人口学资料、病史,进行头MRI检查,采用汉语失语成套测验进行语言评估.结果 患者平均发病年龄56岁,均缓慢起病,以语言表达、命名障碍为首发症状.MRI示左侧颞极萎缩为主,病程长的患者左侧额叶和顶叶、右侧颞叶也明显萎缩.语言评估发现所有患者的自发语言、复述、命名、听理解、阅读和书写均不同程度损害.SD患者言语流利,复述、朗读能力下降相对较轻,命名、复杂语句的理解能力损害突出.PNFA言语顿挫吃力,患者列名能力明显下降,但命名相对保存完好.结论 PPA多为老年前期发病,语言障碍为最早、最突出的症状.MRI特征性的改变为额叶和颞极萎缩,左侧为著.其中SD表现为命名性失语和经皮质感觉性失语,PNFA表现为经皮质运动性失语的特征.     

Lesion localization of global aphasia without hemiparesis by overlapping of the brain magnetic resonance images

Global aphasia without hemiparesis is a striking stroke syndrome involving language impairment without the typically manifested contralateral hemiparesis, which is usually seen in patients with global aphasia following large left perisylvian lesions. The objective of this study is to elucidate the specific areas for lesion localization of global aphasia without hemiparesis by retrospectively studying the brain magnetic resonance images of six patients with global aphasia without hemiparesis to define global aphasia without hemiparesis-related stroke lesions before overlapping the images to visualize the most overlapped area. Talairach coordinates for the most overlapped areas were converted to corresponding anatomical regions. Lesions where the images of more than three patients overlapped were considered significant. The overlapped global aphasia without hemiparesis related stroke lesions of six patients revealed that the significantly involved anatomi- cal lesions were as follows： frontal lobe, sub-gyral, sub-lobar, extra-nuclear, corpus callosum, and inferior frontal gyrus, while caudate, claustrum, middle frontal gyrus, limbic lobe, temporal lobe, superior temporal gyrus, uncus, anterior cingulate, parahippocampal, amygdala, and subcallosal gyrus were seen less significantly involved. This study is the first to demonstrate the heterogeneous anatomical involvement in global aphasia without hemiparesis by overlapping of the brain magnetic resonance images.     

Abnormal functional connectivity in patients with vascular cognitive impairment, no dementia: a resting-state functional magnetic resonance imaging study

The functional connectivity (FC) method was used to investigate the changes in the resting state of patients with vascular cognitive impairment, no dementia (VCIND). Resting-state functional magnetic resonance images (fMRIs) were acquired from 16 patients with subcortical ischemic vascular disease (SIVD) who fulfilled the criteria for VCIND, as well as 18 age- and sex-matched subjects with SIVD with no cognitive impairment (control group). Posterior cingulate cortex connectivity was gathered by investigating synchronic low-frequency fMRI signal fluctuations with a temporal correlation method. Compared with the control group, the patients showed FC decrease in the left middle temporal gyrus, the left anterior cingulate/left middle frontal gyrus, the right caudate, the right middle frontal gyrus, and the left medial frontal gyrus/paracentral lobule. There were also some regions that showed increased connectivity. These regions included the right inferior temporal gyrus, the left middle temporal gyrus, the left precentral gyrus, and the left superior parietal lobule. Our findings revealed the change in resting-state patterns of neuronal activity in patients with VCIND. This change may be caused by subcortical white matter lesions that destroyed direct and indirect fiber tract connectivity across the cerebral white matter and influenced the cortical FC and hypoperfusion resulted from small vascular disease. The results of the increased connectivity may be evoked by the compensatory recruitment and plasticity mechanism. Our findings suggest that the simplicity and noninvasiveness of this method makes it a potential tool to help thoroughly understand the pathogenesis of VCIND.     

Symptomatology and Neuropathology of patients presenting with focal cortical signs

Here, we describe two patients who presented with focal cortical signs and underwent neuropathological examination. Case 1 was a 73-year-old woman with progressive speech disorder and abnormal behavior. She showed agraphia of the frontal lobe type, featured by the omission of kana letters when writing, other than pyramidal tract signs, pseudobulbar palsy, and frontal lobe dementia. Neuropathological examination, including TAR DNA-binding protein 43 (TDP-43) immunohistochemistry, revealed bilateral frontal and anterior temporal lobe lesions accentuated in the precentral gyrus and posterior part of the middle frontal gyrus. Both upper and lower motor neurons showed pathological changes compatible with amyotrophic lateral sclerosis. Case 2 was a 62-year-old man with progressive speech disorder and hand clumsiness. He had a motor speech disorder, compatible with apraxia of speech, and limb apraxia of the limb-kinetic and ideomotor type. Neuropathological examination revealed degeneration in the left frontal lobe, including the precentral gyrus, anterior temporal, and parietal lobe cortices. Moreover, numerous argyrophilic neuronal intracytoplasmic inclusions (Pick body) and ballooned neurons were observed in these lesions and the limbic system. The pathological diagnosis was Pick disease involving the peri-Rolandic area and parietal lobe. In these two cases, the distribution of neuropathological changes in the cerebral cortices correlated with the clinical symptoms observed.     

fMRI auditory language differences between dyslexic and able reading children

During fMRI, dyslexic and control boys completed auditory language tasks (judging whether pairs of real and/or pseudo words rhymed or were real words) in 30 s 'on' conditions alternating with a 30 s 'off' condition (judging whether tone pairs were same). During phonological judgment, dyslexics had more activity than controls in right than left inferior temporal gyrus and in left precentral gyrus. During lexical judgment, dyslexics were less active than controls in bilateral middle frontal gyrus and more active than controls in left orbital frontal cortex. Individual dyslexics were reliably less active than controls in left insula and left inferior temporal gyrus. Dyslexic and control children differ in brain activation during auditory language processing skills that do not require reading.     

Depressive mood in pre-dialytic chronic kidney disease: Statistical parametric mapping analysis of Tc-99m ECD brain SPECT

The purpose of this study was to investigate depression-related regions in pre-dialytic patients with chronic kidney disease (CKD) patients. Participants comprised 33 patients with stage 4 and 5 CKD (age, 55 [42–63]) and 32 healthy volunteers (age, 53.5 [49.5–57]). Depressed mood was assessed in the patients, and both groups underwent Tc-99m-labeled ethylcysteinate dimer (Tc-99m ECD) single photon emission computed tomograpy (SPECT). Statistical parametric mapping identified 18 areas of hypoperfusion in the patients in comparison with the normal controls. The largest clusters were areas including left precentral gyrus, right superior and middle temporal gyrus, both cerebellar posterior lobes, both inferior frontal gyrus, right superior and middle frontal gyrus, right cuneus, right inferior parietal lobule, and right putamen. However, there were no specific hypoperfusion areas in CKD patients with depression compared with CKD patients without depression. Interestingly, several hypoperfusion areas in CKD patients (inferior frontal gyrus [BA46], superior temporal gyrus [BA42], anterior cingulate gyrus [BA24]) were concordant with hypoperfusion areas found in patients with major depression who were free of kidney disease. In conclusion, this study did not demonstrate specific depression-related cerebral hypoperfusion areas. However, the cerebral blood flow pattern in CKD patients was similar to that of patients with major depression in some areas. Although further investigations are needed in the future, we suggest that the causes of the higher prevalence of depression in CKD might be associated with this finding.     

Altered patterns of cortical activation in ALS patients during attention and cognitive response inhibition tasks

Since amyotrophic lateral sclerosis (ALS) can be accompanied by executive dysfunction, it is hypothesised that ALS patients will have impaired performance on tests of cognitive inhibition. We predicted that ALS patients would show patterns of abnormal activation in extramotor regions when performing tests requiring the inhibition of prepotent responses (the Stroop effect) and the inhibition of prior negatively primed responses (the negative priming effect) when compared to healthy controls. Functional magnetic resonance imaging was used to measure activation during a sparse sequence block design paradigm investigating the Stroop and negative priming effects in 14 ALS patients and 8 healthy age- and IQ-matched controls. Behavioural measures of performance were collected. Both groups’ reaction times (RTs) reflected the Stroop effect during scanning. The ALS and control groups did not differ significantly for any of the behavioural measures but did show significant differences in cerebral activation during both tasks. The ALS group showed increased activation predominantly in the left middle temporal gyrus (BA 20/21), left superior temporal gyrus (BA 22) and left anterior cingulate gyrus (BA 32). Neither group’s RT data showed clear evidence of a negative priming effect. However the ALS group showed decreased activation, relative to controls, particularly in the left cingulate gyrus (BA 23/24), left precentral gyrus (BA 4/6) and left medial frontal gyrus (BA 6). Greater cerebral activation in the ALS group accompanying the performance of the Stroop effect and areas of decreased activation during the negative priming comparison suggest altered inhibitory processing in ALS, consistent with other evidence of executive dysfunction in ALS. The current findings require further exploration in a larger study.     

Neural plasticity and treatment-induced recovery of sentence processing in agrammatism

This study examined patterns of neural activation associated with treatment-induced improvement of complex sentence production (and comprehension) in six individuals with stroke-induced agrammatic aphasia, taking into account possible alterations in blood flow often associated with stroke, including delayed time-to-peak of the hemodynamic response function (HRF) and hypoperfused tissue. Aphasic participants performed an auditory verification fMRI task, processing object cleft, subject cleft, and simple active sentences, prior to and following a course of Treatment of Underlying Forms (TUF; Thompson et al., 2003), a linguistically based approach for treating aphasic sentence deficits, which targeted object relative clause constructions. The patients also were scanned in a long-trials task to examine HRFs, to account for any local deviations resulting from stroke, and perfusion images were obtained to evaluate regions of hypoperfused tissue. Region-of-interest (ROI) analyses were conducted (bilaterally), modeling participant-specific local HRFs in left hemisphere areas activated by 12 healthy age-matched volunteers performing the same task, including the middle and inferior frontal gyri, precentral gyrus, middle and superior temporal gyri, and insula, and additional regions associated with complex syntactic processing, including the posterior perisylvian and superior parietal cortices. Results showed that, despite individual variation in activation differences from pre- to post-treatment scans in the aphasic participants, main-effects analyses revealed a general shift from left superior temporal activation to more posterior temporoparietal areas, bilaterally. Time-to-peak of these responses correlated negatively with blood flow, as measured with perfusion imaging.     

Co‐speech gestures influence neural activity in brain regions associated with processing semantic information

Everyday communication is accompanied by visual information from several sources, including co‐speech gestures, which provide semantic information listeners use to help disambiguate the speaker's message. Using fMRI, we examined how gestures influence neural activity in brain regions associated with processing semantic information. The BOLD response was recorded while participants listened to stories under three audiovisual conditions and one auditory‐only (speech alone) condition. In the first audiovisual condition, the storyteller produced gestures that naturally accompany speech. In the second, the storyteller made semantically unrelated hand movements. In the third, the storyteller kept her hands still. In addition to inferior parietal and posterior superior and middle temporal regions, bilateral posterior superior temporal sulcus and left anterior inferior frontal gyrus responded more strongly to speech when it was further accompanied by gesture, regardless of the semantic relation to speech. However, the right inferior frontal gyrus was sensitive to the semantic import of the hand movements, demonstrating more activity when hand movements were semantically unrelated to the accompanying speech. These findings show that perceiving hand movements during speech modulates the distributed pattern of neural activation involved in both biological motion perception and discourse comprehension, suggesting listeners attempt to find meaning, not only in the words speakers produce, but also in the hand movements that accompany speech. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.     

Paralysis of saccades and pursuit: clinicopathologic study

We report a 73-year-old patient with an eye movement disorder characterized by paralysis of saccades and pursuit. At autopsy, there were small cortical lesions in the middle frontal gyrus immediately anterior to the precentral gyrus and in the inferior parietal lobule on both sides.