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Superior Frontal Gyrus (superior + frontal_gyrus)
Selected AbstractsPalilalia, echolalia, and echopraxia,palipraxia as ictal manifestations in a patient with left frontal lobe epilepsyEPILEPSIA, Issue 6 2009Yang-Je Cho Summary Palilalia is a relatively rare pathologic speech behavior and has been reported in various neurologic and psychiatric disorders. We encountered a case of palilalia, echolalia, and echopraxia,palipraxia as ictal phenomena of left frontal lobe epilepsy. A 55-year-old, right-handed man was admitted because of frequent episodes of rapid reiteration of syllables. Video-electroencephalography monitoring revealed stereotypical episodes of palilalia accompanied by rhythmic head nodding and right-arm posturing with ictal discharges over the left frontocentral area. He also displayed echolalia or echopraxia,palipraxia, partially responding to an examiner's stimulus. Magnetic resonance imaging revealed encephalomalacia on the left superior frontal gyrus and ictal single photon emission computed tomography showed hyperperfusion just above the lesion, corresponding to the left supplementary motor area (SMA), and subcortical nuclei. This result suggests that the neuroanatomic substrate involved in the generation of these behaviors as ictal phenomena might exist in the SMA of the left frontal lobe. [source] The effects of the glutamate antagonist memantine on brain activation to an auditory perception taskHUMAN BRAIN MAPPING, Issue 11 2009Heidi van Wageningen Abstract Glutamate is critically involved in the regulation of cognitive functions in humans. There is, however, sparse evidence regarding how blocking glutamate action at the receptor site during a cognitive task affects brain activation. In the current study, the effects of the glutamate antagonist memantine were examined with functional magnetic resonance imaging (fMRI). Thirty-one healthy adults were scanned twice in a counter-balanced design, either in a no-drug session or after administration of memantine for 21 days. The subjects performed a simple auditory perception task with consonant-vowel stimuli. Group-level spatial independent component analysis (ICA) was used to decompose the data and to extract task-related activations. The focus was on four task-related ICA components with frontotemporal localization. The results showed that glutamate-blockage resulted in a significant enhancement in one component, with no significant effect in the other three components. The enhanced effect of memantine was in the middle temporal gyrus, superior frontal gyrus, and middle frontal gyrus. It is suggested that the results reflect effects of glutamatergic processes primarily through non- N -methyl- D -aspartate (NMDA) receptor pathways. Moreover, the results demonstrate that memantine can be used as a probe which allows for studying the effect of excitatory neurotransmission on neuronal activation. Hum Brain Mapp, 2009. © 2009 Wiley-Liss, Inc. [source] Functional magnetic resonance imaging response to increased verbal working memory demands among patients with multiple sclerosisHUMAN BRAIN MAPPING, Issue 1 2006Lawrence H. Sweet Abstract Multiple sclerosis (MS) patients frequently experience impaired verbal working memory (VWM). Functional magnetic resonance imaging (fMRI) may help identify neural mechanisms underlying these deficits. Neuroimaging studies of healthy adults have characterized responses associated with increased VWM demands during the n-Back task, suggesting that this experimental paradigm could help identify neural correlates of VWM deficits among MS patients. Fifteen MS patients and 15 matched control participants completed the n-Back during whole-brain fMRI. Mean signal during adjacent 0-Back blocks was subtracted, on a voxel-wise basis, from mean signal observed during n-Back blocks. Resulting difference scores for 1-, 2-, and 3-Back were compared across groups and difficulty levels. Signal intensity was positively related to difficulty level in anterior regions, including premotor, supplementary motor, and dorsolateral prefrontal cortices. MS patients exhibited significantly greater intensity in these areas compared to controls during the 1-Back, while portions of the left superior frontal gyrus, cingulate, and parahippocampal gyri were relatively less intense at more difficult levels. MS group responses were slower during the 1-Back and tended to be slower during the 3-Back; however, accuracy did not differ at any level. Lesion load was positively related to only 1-Back activity and unrelated to any performance measure. Results suggest that compensatory activity occurs among MS patients matched on performance accuracy. Furthermore, compensatory activity occurs predominantly in regions associated with VWM, and this may decline relative to controls as task demands increase. These findings may help to explain why MS patient performance decreases as a function of effort on neuropsychological tests. Hum Brain Mapp, 2005. © 2005 Wiley-Liss, Inc. [source] The functional neuroanatomy of geriatric depressionINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2009Gwenn S. Smith Abstract Objective Positron Emission Tomography (PET) studies of cerebral glucose metabolism have demonstrated sensitivity in evaluating the functional neuroanatomy of treatment response variability in depression, as well as in the early detection of functional changes associated with incipient cognitive decline. The evaluation of cerebral glucose metabolism in late life depression may have implications for understanding treatment response variability, as well as evaluating the neurobiological basis of depression in late life as a risk factor for dementia. Methods Sixteen patients with geriatric depression and 13 comparison subjects underwent resting PET studies of cerebral glucose metabolism, as well as magnetic resonance (MR) imaging scans to evaluate brain structure. Results Cerebral glucose metabolism was elevated in geriatric depressed patients relative to comparison subjects in anterior (right and left superior frontal gyrus) and posterior (precuneus, inferior parietal lobule) cortical regions. Cerebral atrophy (increased cerebrospinal fluid [CSF] and decreased grey and white matter volumes) were observed in some of these regions, as well. Regional cerebral metabolism was positively correlated with severity of depression and anxiety symptoms. Conclusions In contrast to decreased metabolism observed in normal aging and neurodegenerative conditions such as Alzheimer's disease, cortical glucose metabolism was increased in geriatric depressed patients relative to demographically matched controls, particularly in brain regions in which cerebral atrophy was observed, which may represent a compensatory response. Copyright © 2009 John Wiley & Sons, Ltd. [source] Imaging of Language-Related Brain Regions in Detoxified AlcoholicsALCOHOLISM, Issue 6 2009Sandra Chanraud-Guillermo Background:, Neuroimaging studies showed clear evidence of alcoholism-related damage to the frontal lobes and cerebellum. Although these regions have been involved in language processing, language skills are relatively spared in alcoholics. Here, we aimed at identifying neural substrates associated with the preserved mechanisms of language processing in alcoholics. We hypothesized that alcoholics would show a different pattern of neural activity compared with the controls. Methods:, Alcoholic and nonalcoholic subjects performed an auditory language task while receiving a functional magnetic resonance imaging (fMRI) scan in a 1.5 T magnet. This task has been previously shown to solicit the comprehension processing in healthy controls, with reliable fMRI response in the left frontal and temporal/parietal lobes. Results:, Behavioral results showed comparable performance (error rates, response time) between the alcoholics and the matched controls. However, analysis of the functional data revealed that the alcoholics exhibited greater fMRI response in the left middle frontal gyrus (pars triangularis), the right superior frontal gyrus, and the cerebellar vermis relative to the controls. Conclusions:, These findings suggest that frontocerebellar neural activity, supporting the comprehension processing of the auditory language task, may require compensatory mechanisms in alcoholics in order to maintain the same level of performance as the controls. [source] Parsing brain activity associated with acupuncture treatment in Parkinson's diseases,MOVEMENT DISORDERS, Issue 12 2009Younbyoung Chae KMD Abstract Acupuncture, a common treatment modality within complementary and alternative medicine, has been widely used for Parkinson's disease (PD). Using functional magnetic resonance imaging (fMRI), we explored the neural mechanisms underlying the effect of specific and genuine acupuncture treatment on the motor function in patients with PD. Three fMRI scans were performed in random order in a block design, one for verum acupuncture (VA) treatment, another one for a covert placebo (CP), and the third one for an overt placebo (OP) at the motor function implicated acupoint GB34 on the left foot of 10 patients with PD. We calculated the contrast that subtracts the blood-oxygen-level dependent (BOLD) response for the acupuncture effect (VA vs. CP) and the placebo effect (CP vs. OP). We found a significant improvement in the motor function of the affected hand after acupuncture treatment. The putamen and the primary motor cortex were activated when patients with PD received the acupuncture treatment (VA vs. CP) and these activations correlated with individual enhanced motor function. Expectation towards acupuncture modality (CP vs. OP) elicited activation over the anterior cingulate gyrus, the superior frontal gyrus, and the superior temporal gyrus. These findings suggest that acupuncture treatment might facilitate improvement in the motor functioning of patients with PD via the basal ganglia-thalamocortical circuit. © 2009 Movement Disorder Society [source] Trait impulsivity in female patients with borderline personality disorder and matched controlsACTA NEUROPSYCHIATRICA, Issue 3 2010Jørgen Assar Mortensen Mortensen JA, Rasmussen IA, Håberg A. Trait impulsivity in female patients with borderline personality disorder and matched controls. Objective: Impulsivity has been shown to load on two separate factors, rash impulsivity and sensitivity to reward (SR) in several factor analytic studies. The aims of the current study were to explore the nature of impulsivity in women with borderline personality disorder (BPD) and matched controls, and the underlying neuronal correlates for rash impulsivity and SR. Methods: Fifteen females diagnosed with BPD and 15 matched controls were recruited. All completed the impulsiveness-venturesomeness scale (I7), the sensitivity to punishment (SP) - sensitivity to reward (SR) questionnaire, and performed a Go-NoGo block-design functional magnetic resonance imaging (fMRI) paradigm at 3T. Correlation analyses were done with I7, SP and SR scores with the level of activation in different brain areas in the whole group. An independent group t -test was used to explore any differences between the BPD group and the matched controls. Results: I7 scores correlated negatively with activity in the left orbitofrontal cortex, amygdala and precuneus, and bilaterally in the cingulate cortices during response inhibition for the entire sample. SP yielded negative correlations in the right superior frontal gyrus and parahippocampal gyrus. No activity related to response inhibition correlated to SR. The Go-NoGo task gave similar brain activity in BPD and matched controls, but behaviourally the BPD group had significantly more commission errors in the NoGo blocks. The BPD group had increased I7 and SP scores indicating rash impulsiveness combined with heightened SP. Conclusion: These results imply that successful impulse inhibition involves interaction between the impulsive and the emotional systems. Furthermore, impulsivity in BPD is described as rash impulsivity, coexisting with increased SP. [source] | |||||||||||||||||||