摘要:

Objective:To delineate regions involved in visual word recognition.Background:The processes and regions involved in visual word recognition have been somewhat controversial for over 100 years.Methods:This study used regional cerebral blood flow as assessed by functional magnetic resonance imaging to study normal subjects (N = 9) on an individual within‐subject basis while they were actively engaged on‐line in a visual lexical decision task. Standard analysis techniques were used for identifying regions of activation.Results:Across subjects, the task activated a number of regions, including the occipital pole, lateral and basal occipitotemporal (including lingual and fusiform) regions, superior and middle temporal gyri, and supramarginal and angular gyri. Typically, these regions were activated bilaterally; when activation was unilateral, it was on the left. Some of the areas activated (e.g., inferior parietal regions) have not been previously reported to be involved in such types of processing by activation studies but have been implicated in lesion studies.Conclusions:These results broaden the areas known to be involved in visual word recognition. The bilateral activation associated with visual word recognition is in some respects analogous to the “what” system in visual recognition described in subhuman primates. In addition, the study raises several methodologic issues. The within‐subject analysis showed variability in the specific regions activated when subsequently comparing across individuals, raising implications for future functional imaging studies.(NNBN 2000;13:1‐7)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:The relation of perinatal complications to metabolism of orbitofrontal cortex was studied in 12 normal adolescents aged 13 to 17 years.Background:Perinatal complications are associated with both (a) behavioral signs of frontal lobe dysfunction and (b) increased risk for mood disorders and schizophrenia. Perinatal complications are not usually sufficient to produce these disorders, however, suggesting an etiologic model in which perinatal complications interact with a second, familial, liability factor. The present study tested a key prediction of this “two‐factor” model, namely, that perinatal complications will be associated with physiologic signs of frontal dysfunction, even in persons who have no personal or family history of these psychiatric disorders.Methods:Subjects were screened by structured interviews with the Kiddie Schedule for Affective Disorders and Schizophrenia and had no personal or family history of psychiatric disorder. Ratios of choline andN‐acetyl aspartate to creatine in orbitofrontal cortex were measured using proton magnetic resonance spectroscopy. Perinatal complications were scored with the examiners blinded to magnetic resonance spectroscopy data, applying published scales to hospital records on subjects' gestations and births.Results:Perinatal complications were significantly correlated with reduced concentrations of choline andN‐acetyl aspartate.Conclusions:Our results complement earlier findings of significant relations between perinatal complications and signs of frontal lobe dysfunction, as well as elevated rates of these two types of variables in mood disorders and schizophrenia.(NNBN 2000;13:8‐12)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:The goal of this study was to assess the types of auras and their associations with the focus of seizures in 144 consecutive adult patients with partial epilepsy refractory to medical treatment. The association of frequency and type of aura with a psychiatric disorder was also studied.Background:The nature of the aura, its association with the seizure focus, and its relation with emotions and behavioral dysfunction have received relatively little attention, and remain controversial.Methods:Patients were admitted to an epilepsy investigation unit for detailed observation of their seizures and type of aura. Patients underwent standard electroen‐cephalographic telemetry, including implanted subdural electrodes, if necessary, to delineate the seizure focus. The auras were classified into nine categories. All patients had an independent clinical psychiatric interview for aDiagnostic and Statistical Manual, Third Edition‐Revised(DSM‐III‐R)‐based diagnosis.Results:Of the 144 patients studied, 111 (77.1%) had one or more symptoms during the aura and 33 (22.9%) had no aura. The most frequent aura types were viscerosensory (47 cases [32.6%]), experiential (44 cases [30.6%]), and cephalic (21 cases [14.6%]). A temporal lobe focus was present in 116 (80.5%) patients. Only experiential auras were significantly associated with a temporal lobe seizure focus (33 of 44 cases). A DSM‐III‐R psychiatric diagnosis was present in 74 (51.4%) patients. Of the 116 patients with a temporal lobe focus, 60 (50.2%) had a DSM‐III‐R psychiatric diagnosis. Patients with two or more auras were significantly more likely to have a psychiatric diagnosis (70.2%) compared with those with one aura (39.1%) or no aura (48.5%). A significant association between experiential auras and psychiatric morbidity was seen.Conclusions:Auras occurred in a majority of patients with a treatment‐refractory partial epilepsy who were hospitalized for assessment of their seizure focus for possible surgical candidacy. Two or more auras were associated with a psychiatric diagnosis as was the presence of an experiential aura. Experiential auras were most common in temporal lobe epilepsy. Approximately half the patients, irrespective of seizure focus, had an associated psychiatric morbidity.(NNBN 2000;13:13‐19)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:To investigate the relation between neuropsychological dysfunction and volumetric measures of neuroanatomic structures in patients with bipolar disorder.Background:Previous research suggests that neuropsychological deficits are associated with neuroanatomic changes in patients with bipolar disorder.Method:Twenty‐six outpatients who metDiagnostic and Statistical Manual, Third Edition‐Revisedcriteria for bipolar disorder were administered a battery of neuropsychological tests that assessed memory, abstracting ability, psychomotor performance, sustained attention, and intelligence. Patients also received a magnetic resonance imaging scan, from which volumes of the temporal lobes, hippocampus, third ventricle, and areas of the lateral ventricles were calculated. Using multiple regression analyses, neuroanatomic structures were compared with neuropsychological test variables.Results:Data suggest that a larger right hippocampal volume is associated with poorer neuropsychological functioning.Conclusions:Further studies are needed to both replicate and examine the relation between potential mechanisms of neuroanatomic alterations and neuropsychological dysfunction in patients with bipolar disorder.(NNBN 2000;13:20‐28)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:The objectives of this study were to examine common patterns in the lives and artwork of five artistic savants previously described and to report on the clinical, neuropsychological, and neuroimaging findings from one newly diagnosed artistic savant.Background:The artistic savant syndrome has been recognized for centuries, although its neuroanatomic basis remains a mystery.Methods:The cardinal features, strengths, and weaknesses of the work of these six savants were analyzed and compared with those of children with autism in whom artistic talent was absent. An anatomic substrate for these behaviors was considered in the context of newly emerging theories related to paradoxical functional facilitation, visual thinking, and multiple intelligences.Results:The artists had features of “pervasive developmental disorder,” including impairment in social interaction and communication as well as restricted repetitive and stereotyped patterns of behavior, interest, and activities. All six demonstrated a strong preference for a single art medium and showed a restricted variation in artistic themes. None understood art theory. Some autistic features contributed to their success, including attention to visual detail, a tendency toward ritualistic compulsive repetition, the ability to focus on one topic at the expense of other interests, and intact memory and visuospatial skills.Conclusions:The artistic savant syndrome remains rare and mysterious in origin. Savants exhibit extraordinary visual talents along with profound linguistic and social impairment. The intense focus on and ability to remember visual detail contributes to the artistic product of the savant. The anatomic substrate for the savant syndrome may involve loss of function in the left temporal lobe with enhanced function of the posterior neocortex.(NNBN 2000;13:29‐38)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:The goal of this study was to examine the convergent validity of informant‐rated changes in depressive and related personality traits with clinician‐assessed depression in memory‐disordered patients.Background:Depressive symptoms are frequent complications in persons with dementias such as Alzheimer disease, and caregiver informants consistently report changes in depression and related neurotic traits on the NEO Personality Inventory (NEO‐PI) in dementia patients.Methods:In 78 patients undergoing evaluation of memory complaints at an Alzheimer disease clinic, depression was characterized by clinical diagnosis, a clinician‐rated scale, and informant ratings of premorbid versus current depression, anxiety, vulnerability, and neuroticism on the NEO‐PI.Results:The diagnostic groups differed in meaningful patterns on the NEO‐PI measures. Those with a diagnosis of major depression differed from never‐depressed patients in all personality areas, although those with depressed mood differed only on NEO‐PI depression. The clinician‐rated depression scale correlated modestly with current personality and change from baseline personality.Conclusions:The NEO‐PI provides a useful measure of informants' perspectives on depressive personality changes in patients with memory disorders but does not correspond fully with a clinical syndrome of depression.(NNBN 2000;13:39‐47)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:To examine the relation between dopamine (DA) D2receptor‐specific binding and personality, we assessed the relation between DA D2binding and the NEO Personality Inventory‐Revised (NEO PI‐R).Background:Previous studies have demonstrated a relation between DA D2receptor‐specific binding and a personality trait involving personal detachment as defined by the Karolinska Scales of Personality. A subsequent study using a different measure of personal detachment failed to replicate this finding, suggesting that metric properties of the personality scale may be important. To further examine this issue, we assessed the relation between DA D2binding and a third personality measure, the NEO PI‐R.Methods:Eighteen adult subjects completed the NEO PI‐R and participated in an11C‐raclopride positron emission tomography study to quantify striatal DA D2receptor binding.Results:We did not find a significant relation between binding and detachment‐like traits on the NEO PI‐R; however, we found a significant relation between DA D2receptor binding and the NEO PI‐R personality facet of Depression (r= 0.75,p<0.0001).Conclusions:The results fail to replicate the findings of previous studies reporting an association between DA D2receptor density and personal detachment, suggesting that the relation is relatively specific to the trait defined by the Karolinska Scales of Personality. The relation between a nonclinical personality trait of depression and DA D2binding, if replicated, may help to elucidate the role of dopamine in depression.(NNBN 2000;13:48‐52)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:The purpose of the current study was to examine the relation between regional cerebral blood flow (rCBF) and negative symptoms (NS) in patients with dementia of Alzheimer type (DAT).Background:Negative symptoms in neuropsychiatric disorders were associated with altered rCBF in frontal cortex.Methods:Twenty‐five subjects with a diagnosis of DAT were administered the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative Symptom Scale, the Hamilton Rating Scale for Depression, and the Mini‐Mental State Examination. The subjects were divided into two groups by means of a median split with regard to NS severity (high NS group, N = 12; low NS group, N = 13). Each patient underwent a single photon emission tomography scan using99mTc‐HMPAO at rest. Cortical and subcortical regions of interest were symmetrically defined in each hemisphere. Cortical‐to‐cerebellar perfusion ratios were established quantitatively using ADAC software.Results:High NS group subjects had a significantly lower rCBF than low NS group subjects in the frontal cortex and cingulate gyrus (MANOVA:p= 0.022) as a result of differences in the dorsolateral prefrontal cortex bilaterally (right:F= 12.12,p= 0.002; left:F= 6.55,p= 0.02) and in the frontal cortex, mainly in the right hemisphere (right:F= 6.33,p= 0.02; left:F= 3.26,p= 0.08). For all the subjects (N = 25), there were negative correlations between the SANS total score and rCBF, most prominently in the dorsolateral prefrontal cortex bilaterally (right:r= ‐0.48,p<0.01; left:r= ‐0.49,p= 0.01). No significant correlation was found between rCBF in any of the regions of interest and either the Mini‐Mental State Examination or the Hamilton Rating Scale for Depression scores.Conclusions:This study indicates that decreased perfusion in the frontal cortex is associated with NS severity but not with measures of cognitive impairment or depressive symptoms in DAT patients. These results support the hypothesis that the frontal lobes may be involved in the cause of NS in DAT, and they underscore the importance of NS evaluation in neuroimaging studies.(NNBN 2000;13:53‐59)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:We conducted a follow‐up study on a patient with enduring psychic shock‐induced cognitive impairment to study by neuropsychological and functional imaging methods the degree of his recovery process on the brain and cognitive levels.Background:Based on the assumption that trauma and stress conditions can alter the functions of the nervous systems, we report on a patient whom we studied 2 and 12 months after he suffered “mnestic block syndrome” and additional cognitive deterioration symptoms.Methods:We report on a patient studied 2 and 12 months after he suffered “mnestic block syndrome” and additional cognitive deterioration symptoms. Magnetic resonance imaging and fluorodeoxyglucose positron emission tomography were used for neural and detailed neuropsychological testing for cognitive deficits.Results:The patient initially manifested severe intellectual decline, including severe anterograde and retrograde amnesia. His symptoms were correlated with major, although selective, reductions in his brain metabolism (2‐3 SD below those of controls). Presently, he shows a normal brain metabolism and has regained parts of his memory and many of his other intellectual capabilities. Nevertheless, he still has long‐term memory impairments.Conclusions:This case demonstrates a close relation between brain metabolism and cognitive performance, with major deficits of both at 2 months and major recovery of both at 12 months after a shocking event. It can serve as an example for possible stress‐related deteriorations in certain brain regions, which can be partly corrected by psychotherapeutic interventions, passing time, and favorable environmental conditions.(NNBN 2000;13:60‐66)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Objective:We postulated that disruption of callosal pathways as occurs in Marchiafava‐Bignami disease (MBD) is associated with marked impairment in brain functioning as measured by cognitive assessment and neuroimaging.Background:MBD is considered to be a rare and severe complication of chronic alcoholism. It is characterized by necrosis and subsequent atrophy of the corpus callosum, which is the major brain structure connecting corresponding areas of both hemispheres.Methods:We review the existing literature on MBD with respect to conceptualization, theories of pathogenesis, forms of the disease, and neuroimaging and neuropsychological findings. We then present the case of a middle‐aged man with MBD who underwent extensive clinical, neuropsychological, and neuroimaging studies.Results:Neuropsychological evaluation revealed a pattern of severe global dementia. Magnetic resonance imaging showed moderate atrophy of anterior callosal regions and severe atrophy of posterior callosal regions in the setting of cortical and subcortical atrophy. Resting metabolism positron emission tomography revealed decreased glucose metabolism most pronounced in subcortical and mesial frontal regions. The differential diagnosis, function of the corpus callosum, and potential limitations of our case study are discussed.Conclusions:On account of the history, clinical presentation, and results of magnetic resonance imaging of the brain, we diagnosed our patient with chronic MBD.(NNBN 2000;13:67‐76)

ISSN:0894-878X    

出版商:OVID    

年代:2000

数据来源: OVID