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At least 847 records · Page 47Linked to original sources
PubMed2004

Relevance of functional neuroimaging in the progression of mild cognitive impairment.

AIM: To assess whether combining neuropsychological tests and cerebral blood flow markers improves progression accuracy from mild cognitive impairment (MCI) to Alzheimer's disease (AD) than each of them on its own. METHODS: Forty-two patients were investigated prospectively, undergoing baseline and 3-year follow-up neuropsychological tests and neuroimaging with Tc-ECD-SPECT. Twenty-one patients had developed AD while 21 retained their initial diagnosis. The relative blood flow and cognitive differences were studied. Validity parameters, multivariant analysis and logistic regression model were calculated. RESULTS: Patients who deteriorated showed lower scoring than stable subjects in some neuropsychological tests (p = 0.03-0.001) and in relative blood flow in selected regions (8-10%). Low cognitive test scoring and low relative blood flow in some regions showed sensibilities and specificities from 70% to 86% for the diagnosis of early Alzheimer's disease. The relative risk of progression to AD was up to 4.7 times higher for these patients (p = 0.0001). The left frontal relative blood flow, the CAMCOG and orientation scoring were the best data to predict the risk of progression to AD. CONCLUSIONS: The combination of functional imaging and neuropsychological tests can diagnose with high sensitivity and specificity if a patient is suffering cognitive impairment in its early stages, and may aid in predicting the risk of developing dementia.

Brain↗
PubMed2003

Clinical and neuroimaging correlates of abnormal short-latency Somatosensory Evoked Potentials in elderly vascular dementia patients: A psychophysiological exploratory study.

BACKGROUND: Short Latency Somatosensory Evoked Potentials (SEPs) may serve to the testing of the somatosensory tract function, which is vulnerable and affected in vascular encephalopathy. The aim of the current study was to search for clinical and neuroimaging correlates of abnormal SEPs in vascular dementia (VD) patients. MATERIALS AND METHODS: The study included 14 VD patients, aged 72.93 PlusMinus; 4.73 years, and 10 controls aged 71.20 PlusMinus; 4.44 years. All subjects underwent a detailed clinical examination, blood and biochemical testing, brain MRI and were assessed with the MMSE. SEPs were recorded after stimulation from upper and lower limbs. The statistical Analysis included 1 and 2-way MANCOVAs and Factor analysis RESULTS: The N13 latency was significantly prolonged, the N19 amplitude was lower, the P27 amplitude was lower and the N11-P27 conduction time was prolonged in severely demented patients in comparison to controls. The N19 latency was prolonged in severely demented patients in comparison to both mildly demented and controls. The same was true for the N13-N19 conduction time, and for the P27 latency. Patients with subcortical lesions had all their latencies prolonged and lower P27 amplitude. DISCUSSION: The results of the current study suggest that there are significant differences between patients suffering from VD and healthy controls in SEPs, but these are detectable only when dementia is severe or there are lesions located in the subcortical regions. The results of the current study locate the abnormal SEPs in the white matter, and are in accord with the literature.

Journal Article↗
PubMed2004

Prognostic value of frontal functional neuroimaging in late-onset severe major depression.

BACKGROUND: There is growing evidence of a relationship between frontal neuroimaging and neuropsychological abnormalities and the physiopathology and course of late-onset major depression. AIMS: To assess acute antidepressant response in late-onset major depression in relation to baseline frontal perfusion ratios. METHOD: A 99mTc HMPAO single photon emission computed tomographic brain scan was performed in medication-free patients with late-onset major depression, who were then included in a 12-week antidepressant treatment regimen. Logistic regression was used to define a predictive model of non-remission. RESULTS: A total of 47 patients completed the study, 34 of whom were classed as remitters and 13 as non-remitters. The variable left anterior fronto-cerebellar perfusion ratio had a global predictive power of 87%. Analysing this variable together with the baseline variables age of onset and duration of index episode, the predictive power of the model rose to 94%. CONCLUSIONS: Our study suggests that a specific frontal functioning could predict the acute antidepressant response in late-onset severe major depression.

Age of Onset↗
PubMed2004

Neuroimaging of developmental psychopathologies: the importance of self-regulatory and neuroplastic processes in adolescence.

Normal brain maturational and developmental processes, together with plastic reorganization of the brain in response to experiential demands, contribute to the acquisition of improved capacities for self-regulation and impulse control during adolescence. The frontal lobe is a main focus for these developmental and plastic processes during the transition from adolescence into adulthood. Tourette syndrome (TS), defined as the chronic presence of motor and vocal tics, has been increasingly conceptualized as a disorder of impaired self-regulatory control. This disordered control is thought to give rise to semicompulsory urges to perform the movements that constitute simple tics, complex tics, or compulsions. Neuroimaging studies suggest that the expression of the genetic diathesis to TS is influenced by genetic and nongenetic factors affecting activity-dependent reorganization of neuroregulatory systems, thereby influencing the phenotype, illness severity, and adult outcome of tic disorders. Similar developmental processes during adolescence likely determine the phenotype and natural history of a broad range of other complex neuropsychiatric disorders of childhood onset, and they likely contribute to the acquisition of improved self-regulatory capacities that characterize normal adolescent development.

Adolescent↗
PubMed2005

Functional neuroimaging of semantic and episodic musical memory.

The distinction between episodic and semantic memory has become very popular since it was first proposed by Tulving in 1972. So far, very few neuropsychological, psychophysical, and imaging studies have related to the mnemonic aspects of music, notably on the long-term memory features, and practically nothing is known about the functional anatomy of long-term memory for music. Numerous functional imaging studies have shown that retrieval from semantic and episodic memory is subserved by distinct neural networks. For instance, the HERA model (hemispheric encoding/retrieval asymmetry) ascribes to the left prefrontal cortex a preferential role in the encoding process of episodic material and the recall of semantic information, while the right prefrontal cortex would preferentially operate in the recall of episodic information. However, these results were essentially obtained with verbal and visuo-spatial material. We have done a study to determine the neural substrates underlying the semantic and episodic components of music using familiar and nonfamiliar melodic tunes. Two distinct patterns of activations were found: bilateral activation of the middle and superior frontal areas and precuneus for episodic memory, and activation of the medial and orbital frontal cortex bilaterally, left angular gyrus, and the anterior part of the left middle and superior temporal gyri for semantic memory. We discuss these findings in light of the available neuropsychological data obtained in brain-damaged subjects and functional neuroimaging studies.

Auditory Pathways↗
PubMed2004

Reliability and validity of functional neuroimaging techniques for identifying language-critical areas in children and adults.

Advances in neuroimaging technologies over the last 15 years have prompted their relatively widespread use in the study of brain mechanisms supporting language function in children and adults. We reviewed reliability and external validity studies of 3 of the most common functional imaging methods, functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and positron emission tomography (PET). Although reliability and validity reports for fMRI are generally quite favorable, significant variability was found across studies with respect to methodology, preventing in some cases either the assessment of the reliability of individual datasets, or cross-study comparisons. Reliability and validity reports of MEG are strong, yet methodological questions regarding optimal modeling techniques remain. PET investigators report good concordance of language maps with data from more invasive brain mapping techniques, but its use of radioactive tracers and poorer spatial and temporal resolution make it the least optimal of the 3 methods for language mapping. Investigations of the cortical networks supporting language function during development and into adulthood should be viewed in the context of the validity and reliability of the methods used, with careful attention to details regarding the methodologies employed in the acquisition and analysis of statistical maps.

Aging↗
PubMed2004

Neuroimaging findings in scleroderma en coup de sabre.

OBJECTIVES: To describe the neuroimaging and clinical findings in patients with localized scleroderma en coup de sabre (LScs). METHODS: Patients with LScs were evaluated by high-resolution MRI and CT. The authors performed three-dimensional reconstructions of MRI and CT scans to evaluate brain and bone structures. RESULTS: Nine patients with LScs were evaluated (five women), with ages ranging from 6 to 53 years (mean, 30.7 years). Brain CT showed bone deformities with thinning of the skull under the skin lesions in six patients. MRI scans showed focal atrophy and blurring of the gray-white matter interface localized under the skin lesion in all patients. In three patients it was associated with hyperintense signal on fluid-attenuated inversion recovery (FLAIR) and T2-weighted images. Follow-up MRI showed extension of the brain lesion in one patient; in the remaining patients, the lesion did not progress. Four of the nine patients had partial epilepsy. One had surgery for management of refractory seizures, and pathologic findings indicated a focal inflammatory process. CONCLUSION: Localized scleroderma en coup de sabre is associated with focal, and in some progressive, brain lesions underlying the skin atrophy. Epilepsy, when present, is related to these brain lesions. Imaging findings and histopathology indicated that the process, most likely focal inflammatory, may be progressive.

Adolescent↗
PubMed2004

Progressive prosopagnosia: clinical and neuroimaging results.

The authors report the longitudinal case study of a patient with the right temporal variant of frontotemporal lobar degeneration. His deficit, initially limited to visuoperceptual disturbances, progressed 2 years later to a severe semantic breakdown. Neuroimaging data indicate that the underlying degenerative process, initially confined to unimodal visual associative cortices, progressed along the ventral pathways to multimodal areas in charge of integrating knowledge from various modalities (the anterior temporal lobes).

Aged↗
PubMed2002

Practice parameter: neuroimaging of the neonate: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society.

OBJECTIVE: The authors reviewed available evidence on neonatal neuroimaging strategies for evaluating both very low birth weight preterm infants and encephalopathic term neonates. IMAGING FOR THE PRETERM NEONATE: Routine screening cranial ultrasonography (US) should be performed on all infants of <30 weeks' gestation once between 7 and 14 days of age and should be optimally repeated between 36 and 40 weeks' postmenstrual age. This strategy detects lesions such as intraventricular hemorrhage, which influences clinical care, and those such as periventricular leukomalacia and low-pressure ventriculomegaly, which provide information about long-term neurodevelopmental outcome. There is insufficient evidence for routine MRI of all very low birth weight preterm infants with abnormal results of cranial US. IMAGING FOR THE TERM INFANT: Noncontrast CT should be performed to detect hemorrhagic lesions in the encephalopathic term infant with a history of birth trauma, low hematocrit, or coagulopathy. If CT findings are inconclusive, MRI should be performed between days 2 and 8 to assess the location and extent of injury. The pattern of injury identified with conventional MRI may provide diagnostic and prognostic information for term infants with evidence of encephalopathy. In particular, basal ganglia and thalamic lesions detected by conventional MRI are associated with poor neurodevelopmental outcome. Diffusion-weighted imaging may allow earlier detection of these cerebral injuries. RECOMMENDATIONS: US plays an established role in the management of preterm neonates of <30 weeks' gestation. US also provides valuable prognostic information when the infant reaches 40 weeks' postmenstrual age. For encephalopathic term infants, early CT should be used to exclude hemorrhage; MRI should be performed later in the first postnatal week to establish the pattern of injury and predict neurologic outcome.

Academies and Institutes↗
PubMed2002

Neuroimaging violence in the mentally ill: what can it tell us?

Incidents of aggression and violence in severe mental disorders like psychosis, personality disorders and substance misuse disorders are higher than in the general population. Recent advances in neuroimaging techniques may help to predict violent behaviour in mentally ill individuals and to identify anomalies in brain functioning that may be amenable to treatment.

Brain Diseases↗
PubMed2002

Neuroimaging in schizophrenia: from theory to practice.

Schizophrenia is a serious mental illness that affects 1% of the population. It is beset with problems of diagnosis and difficulties in assessing treatment. Neuroimaging has long contributed to our understanding of schizophrenia but recent developments suggest it may ultimately play a practical role in its early detection and management.

Humans↗
PubMed2002

Neuroimaging to predict preclinical Alzheimer's disease.

Alzheimer's disease is common in the elderly and causes tremendous distress to patients and their carers. With the advent of newer pharmacological treatments, significant improvement in the early diagnosis of Alzheimer's disease is required. This article examines the usefulness of neuroimaging techniques to predict Alzheimer's disease in prediagnosis individuals.

Alzheimer Disease↗
PubMed2003

Neuroimaging of sexual arousal: research and clinical utility.

The treatment of sexual dysfunction or deviancy requires an understanding of the underlying neural substrates. Neuroimaging techniques offer insight into brain regions involved in sexual arousal and inhibition. The development of robust paradigms has implications for the assessment and treatment of sexual disorder in men and women.

Adolescent↗
PubMed2005

Functional neuroimaging in motor recovery after stroke.

Neuroimaging techniques provide information on the neural substrates underlying functional recovery after stroke, the number one cause of long-term disability. Despite the methodological difficulties, they promise to offer insight into the mechanisms by which therapeutic interventions can modulate human cortical plasticity. This information should lead to the development of new, targeted interventions to maximize recovery.

Functional Laterality↗
PubMed2004

Mining for associations between text and brain activation in a functional neuroimaging database.

We describe a method for mining a neuroimaging database for associations between text and brain locations. The objective is to discover association rules between words indicative of cognitive function as described in abstracts of neuroscience papers and sets of reported stereotactic Talairach coordinates. We invoke a simple probabilistic framework in which kernel density estimates are used to model distributions of brain activation foci conditioned on words in a given abstract. The principal associations are found in the joint probability density between words and voxels. We show that the statistically motivated associations are well aligned with general neuroscientific knowledge.

Brain↗
PubMed1998

Neuroimaging, physical, and developmental findings after inflicted and noninflicted traumatic brain injury in young children.

OBJECTIVE: To characterize neuroimaging, physical, neurobehavioral, and developmental findings in children with inflicted and noninflicted traumatic brain injury (TBI) and to identify characteristic features of inflicted TBI. METHODS AND PATIENTS: Forty children, 0 to 6 years of age, hospitalized for TBI who had no documented history of previous brain injury were enrolled in a prospective longitudinal study. TBI was categorized as either inflicted (n = 20) or noninflicted (n = 20) based on the assessment of hospital and county protective services. Glasgow Coma Scale scores and neonatal history were comparable in both groups. OUTCOME MEASURES: Acute computed tomography/magnetic resonance imaging studies and physical findings were evaluated. Glasgow Outcome Scale scores, cognitive development, and motor functioning were assessed an average of 1.3 months after TBI. chi2 analyses assessed differences in the distribution of findings in the inflicted and noninflicted TBI groups. RESULTS: Signs of preexisting brain injury, including cerebral atrophy, subdural hygroma, and ex vacuo ventriculomegaly, were present in 45% of children with inflicted TBI and in none of the children with noninflicted TBI. Subdural hematomas and seizures occurred significantly more often in children with inflicted TBI. Intraparenchymal hemorrhage, edema, skull fractures, and cephalohematomas were similar in both groups. Retinal hemorrhage was only identified in the inflicted TBI group. Glasgow Outcome Scale scores indicated a significantly less favorable outcome after inflicted than noninflicted TBI. Mental deficiency was present in 45% of the inflicted and 5% of the noninflicted TBI groups. CONCLUSIONS: Characteristic features of inflicted TBI included acute computed tomography/magnetic resonance imaging findings of preexisting brain injury, extraaxial hemorrhages, seizures, retinal hemorrhages, and significantly impaired cognitive function without prolonged impairment of consciousness.

Brain Damage, Chronic↗
PubMed2003

Neuroimaging of intraparenchymal lesions predicts outcome in shaken baby syndrome.

OBJECTIVE: Studies of long-term outcome on nonaccidental head injury (NAHI) in young children have shown severe neurodevelopmental sequelae in most cases. For improving the knowledge of outcome and for identifying prognostic factors, additional clinical and cerebral imaging data are needed. The aim of this study was to describe clinical and imaging features over time and to consider their value for predicting neurodevelopmental outcome. METHODS: A retrospective medical record review was conducted of 23 children with confirmed NAHI, for whom an extended follow-up of 2.5 to 13 years (mean: 6 years) was contemplated. Glasgow Coma Scale scores, severity of retinal hemorrhages, presence of skull fractures, cranial growth deceleration, and sequential neuroimaging data (computed tomography and/or magnetic resonance imaging) were compared with patterns of clinical evolution assessed by the Glasgow Outcome Scale. RESULTS: Clinical outcome showed that 14 (61%) children had severe disabilities, 8 (35%) had moderate disabilities, and 1 (4%) was normal. A low initial Glasgow Coma Scale score, severe retinal hemorrhages, presence of skull fracture, and cranial growth deceleration were significantly associated with poor developmental outcome. Eighteen of the 23 patients had abnormal magnetic resonance imaging scans. This examination disclosed atrophy when performed beyond 15 days of injury. Atrophy seemingly resulted from various brain lesions, namely, contusions, infarcts, and other lesions within the white matter. Presence of intraparenchymal brain lesions within the first 3 months was significantly associated with neurodevelopmental impairment. Severity of motor and cognitive dysfunctions was related to the extent of intraparenchymal lesions. CONCLUSIONS: Early clinical and radiologic findings in NAHI are of prognostic value for neurodevelopmental outcome.

Atrophy↗
PubMed2005

Acute disseminated encephalomyelitis in children: discordant neurologic and neuroimaging abnormalities and response to plasmapheresis.

OBJECTIVES: To describe our experience with acute disseminated encephalomyelitis (ADEM), focusing on (1) the relationship between clinical course and MRI findings and (2) the response to plasmapheresis in a subgroup of patients. METHODS: A retrospective record review was conducted of 13 children who were admitted as inpatients with the diagnosis of ADEM during the period 1998-2003. RESULTS: Diagnosis was established by clinical signs and symptoms, cerebrospinal fluid changes and multifocal involvement of deep gray and white matter based on MRI. Initial therapy was high-dose methylprednisolone and intravenous immunoglobulin in 12 patients. One child improved spontaneously. Six of 12 children did not improve with corticosteroid treatment. All 6 had an acute progressive course neurologically, and 5 of them also showed a delay in the onset of neuroimaging changes, eventually developing lesions in the deep gray matter and brainstem. This latter group received 5 sessions of plasmapheresis and recovered over the course of several months with varying degrees of residual neurologic deficits. CONCLUSIONS: Presentation of ADEM with delayed development of MRI lesions in deep gray matter and brainstem may herald a prolonged clinical course and lack of response to glucocorticoid therapy. Plasmapheresis might be an effective therapeutic intervention in these patients. The role of plasmapheresis versus corticosteroids and intravenous immunoglobulin as a primary treatment of ADEM needs to be investigated further.

Adolescent↗