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At least 523 records · Page 29Linked to original sources
PubMed1998

[Electroclinical and neuroimaging studies in epilepsy].

INTRODUCTION AND MATERIAL: During 54 months, we have studied the electro-clinical and neuroimaging features in outpatients with active epilepsy. Each patient was interviewed for one of us. Then, we have reviewed the medical records about both the clinical featuring. EEG and neuroimaging (NI) studies and seizures frequency (SF) outcome. Differences in crude proportions were assessed by chi 2 test for independence by 2 x 2 tables. RESULTS AND CONCLUSIONS: It has been 207 patients with 49 +/- 19.6 years of mean age at review. Partial seizures was significantly related with both a higher SF at onset and politherapy. Also, with a focal EEG distribution but only in case of complex partial seizures. Abnormal NI was significantly more frequent in oldest patients. A greater proportion of patients were in politherapy in four situation: SF at onset > 1 by day, a focal EEG distribution, duration of epilepsy longer than 20 years and age of onset lesser than 60 years. A 37.2% was seizures-free in the last year and in 34% the SF was improved a 50% or more from the beginning. A significantly greater proportion of patients was following with seizures in four cases: when the SF at onset has been > or = 1 by day, being partial seizures, women and having politherapy.

Adult↗
PubMedDate not supplied

Volumetric neuroimaging in children with neurodevelopmental disorders--mapping the brain and behavior.

The recent volumetric neuroimaging studies in children with fragile X syndrome, Down syndrome (DS), Rett syndrome (RS), and Tourette syndrome (TS) were reviewed. Neuroimaging studies and cognitive and behavioral phenotypes pertinent to each disorder were reviewed within the context of current knowledge of their neurobiological mechanisms. The mainly involved brain regions in fragile X syndrome are the cerebellar vermis, temporal areas, and the caudate nucleus which may be related to autistic tendency, problems of memory and language and deficits in executive function, respectively. The preferential involvement of frontal lobe, cerebellum and mesial temporal areas may correspond to the selective language and speech deficits in DS children. There was significantly generalized cerebral volume reduction with greater loss of gray matter in comparison to white matter, consistent with the extensive clinical features of RS. Right side predominance of basal ganglia supported the suggestion that the basal ganglia is related to pathogenesis of TS, which may also be related to the impaired executive function and the absence of functional asymmetry. Further prospectives for integrating neuroanatomic findings and neurobehavioral studies also were discussed.

Brain↗
PubMed2026

Neuroimaging in cerebral folate deficiencies.

Cerebral folate deficiency refers to neurological disorders associated with a reduced cerebrospinal fluid (CSF) concentration of 5-methyltetrahydrofolate (5-MTHF), arising from primary defects in folate transport or metabolism, or secondarily from acquired or other inherited conditions. Clinical presentation ranges from infancy to adulthood, with manifestations including developmental delay, seizures, cognitive impairment, and neuropsychiatric symptoms. Folate plays a central role in one-carbon metabolism, requiring interaction with other B-vitamins, most notably vitamin B12, to support nucleotide synthesis, methylation reactions, and myelin production. Disruption of folate-dependent pathways contributes to the imaging findings of cerebral folate deficiencies, which include abnormal white matter, calcifications, cerebral or cerebellar atrophy, and in some cases, stroke, or stroke-like lesions. This review outlines folate biochemistry, transport mechanisms into the central nervous system, and associated genetic defects, followed by a discussion of imaging features in primary and secondary cerebral folate deficiencies. Relevant differential diagnoses, particularly cobalamin-related disorders, are also examined. Importantly, many cerebral folate deficiencies are potentially reversible with timely recognition and therapy, underscoring the important role of neuroimaging in diagnosis and follow-up of these disorders.

Humans↗
PubMed2026

Complement component C4 and neuroimaging in psychiatry: A systematic review.

INTRODUCTION: Genomic, transcriptomic, and proteomic studies suggest that the complement system contributes to the pathophysiology of various psychiatric disorders partly through neurodevelopmental effects linked to C4A protein levels variations. We conducted a systematic review to characterize how brain micro- and macrostructure and connectivity vary with proxies of in vivo brain C4A protein levels in both psychiatric and general-population cohorts. METHODS: We used Medline, Web of Science, and Embase, and included all studies published before April 14, 2025. Inclusion criteria were: (1) inclusion of healthy controls and/or individuals with psychiatric disorders assessed according to recognized diagnostic manuals (DSM or ICD); (2) use of MRI-based neuroimaging; and (3) use of genomic, transcriptomic and/or proteomic approaches as proxies of in vivo brain C4A proteins levels. RESULTS: From 317 identified articles, 11 were included. Associations between C4A levels and brain structure were heterogeneous across regions. Only the mOFC, dlPFC, and entorhinal cortex were implicated in more than one study. Findings for the mOFC and dlPFC varied by the type of metrics and clinical status, whereas higher C4A levels were more consistently associated with smaller entorhinal cortex surface area and cortical thickness in pediatric, middle-aged, and older general-population cohorts. In addition, one study found higher genetically predicted C4A expression to be associated with higher TSPO levels. CONCLUSION: The limited number of available studies and their methodological heterogeneity make synthesis challenging. However, biological hypotheses such as excessive synaptic pruning or broader inflammatory effects on the brain may provide plausible explanatory frameworks for the reported associations.

Humans↗
PubMed2026

Neuroimaging anxious children and adolescents before and after cognitive behavioral therapy: a systematic review.

OBJECTIVE: This systematic review investigates brain changes in youths with anxiety disorders following cognitive behavioral therapy (CBT) and neural markers that predict CBT responses. METHODS: We conducted a systematic search using the electronic databases PubMed, Web of Science, and ProQuest. The inclusion deadline was set to October 27, 2025. We included fifteen peer-reviewed neuroimaging studies that examined the effects of CBT in youths under 19 years old with a primary clinical diagnosis of an anxiety disorder based on DSM-5 criteria. RESULTS: Although the existing literature is marked by substantial diversity in methods and outcomes, task-related neural response in the anterior cingulate cortex (ACC, 2/8, 25.0%), insula (1/8, 12.5%) increased from pre to post CBT and these changes were further correlated with clinical symptom improvements. Moreover, CBT outcomes were predicted by pre-treatment activity or connectivity in the ACC and amygdala (3/13, 23.0%). A smaller proportion of studies (2/13, 15.3%) found that activity or connectivity in the insula, precuneus/cuneus, postcentral gyrus, and activity or structure in the nucleus accumbens (NAcc) predicted response to CBT. The low consistency of these findings was driven by methodological variability, low reliability of the neural markers, and relatively small sample sizes. CONCLUSIONS: This review highlights promises of neural predictors and outcomes to enhance anxiety disorder treatments in children and adolescents, facilitating future personalized and effective CBT. Beyond this initial promise, the field is hindered by methodological inconsistencies and limited replications. While longitudinal and personalized approaches are important next steps, the central challenge remains: identifying neural markers that are both reliable and robust.

Adolescent↗
PubMedDate not supplied

Stroke outcome and neuroimaging of intracranial atherosclerosis (SONIA): design of a prospective, multicenter trial of diagnostic tests.

UNLABELLED: BACKGROUND AND RELEVANCE: Intracranial atherosclerosis is responsible for 70,000 ischemic strokes each year in the USA. Noninvasive testing such as transcranial Doppler ultrasound (TCD) and magnetic resonance angiography (MRA) to identify intracranial atherosclerosis is in widespread use, but has not been rigorously validated against the gold standard, catheter angiography. The recently NIH-funded Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial will compare warfarin with aspirin for stroke prevention in patients with intracranial atherosclerosis. WASID requires performance of angiography along with TCD and MRA, providing an opportunity to critically evaluate these noninvasive tests. MAIN OBJECTIVE: The purpose of the Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) study is to develop the noninvasive diagnosis of intracranial atherosclerosis. The primary aim of SONIA is to define velocity values on TCD and anatomic abnormalities on MRA that identify severe (50-99%) intracranial stenosis of large, proximal arteries seen on catheter angiography. SONIA will define the criteria, or 'cutpoints', for an abnormal TCD or MRA and show that they perform with a reliable positive predictive value (PPV). STUDY DESIGN: SONIA will be conducted in collaboration with WASID. Study-wide cutpoints defining positive TCD and MRA have been developed and reviewed by the site investigators of WASID. Hard copy angiography, TCD and MRA generated in WASID will be centrally read in SONIA. TCD and MRA cutpoints seek to achieve a target PPV of 80% for the identification of severe intracranial stenosis on angiography. CONCLUSIONS: Central readings will be used to validate the cutpoints and to develop measures of negative predictive value, and inter- and intra-observer variability. Sensitivity and specificity will be determined after adjustment for verification bias and employed in receiver-operator characteristic analyses. SONIA will use these techniques to develop TCD and MRA cutpoints that minimize the clinical consequences of test errors occurring in the noninvasive evaluation of patients with suspected intracranial atherosclerosis.

Humans↗
PubMed1993

Clinical, neuroimaging, and environmental risk differences in monozygotic female twins appearing discordant for dementia of the Alzheimer type.

OBJECTIVE: The study of monozygotic twins can elucidate possible environmental causes for a disease in genetically identical subjects. To this end, we studied a pair of monozygotic female twins appearing discordant for dementia of the Alzheimer type (DAT). DESIGN: Clinical and neuroimaging findings were compared in terms of potential environmental risk factors. SETTING: University referral center. PARTICIPANTS: An 81-year-old female monozygotic twin pair. OUTCOME MEASURES: Clinical assessments, standardized rating scales, and brain imaging studies, including magnetic resonance imaging, positron emission tomography, and electroencephalography, were performed. Neuropsychological tests were performed initially and after 1 year. RESULTS: Although DAT was confirmed clinically in only one twin, neuropsychological and brain imaging studies suggested that the unaffected twin may be developing the prodrome of DAT. The twins' varied life histories suggest that environmental risk factors may contribute to apparent discordance for DAT and possible delay in disease onset for the currently nondemented twin. CONCLUSIONS: These results suggest that both genetic and nongenetic factors influence disease onset and expression. Moreover, review of previous reports of monozygotic twin pairs concordant or discordant for Alzheimer's disease, with adequate family history data, suggest a pattern indicating interactions among age at dementia onset, sex, and familiarity. Such patterns point to hypotheses regarding neurobiologically meaningful Alzheimer's disease subgroups.

Aged↗
PubMed2003

West nile virus encephalitis involving the substantia nigra: neuroimaging and pathologic findings with literature review.

West Nile virus has become a medically important arbovirus in the continental United States with its debut in 1999 in the New York City area. We present neuroimaging features and pathologic findings in 2 patients who were severely affected out of the more that 100 documented cases at our institution. Both patients showed striking involvement of the substantia nigra, a finding not previously reported for West Nile virus.

Aged↗
PubMed2004

Correlation of in vivo neuroimaging abnormalities with postmortem human immunodeficiency virus encephalitis and dendritic loss.

BACKGROUND: In the absence of significant opportunistic infection, the most common alterations on neuroimaging in the brains of patients with AIDS include enlarged cerebrospinal fluid spaces, white-matter loss, volume loss in striatal structures, and white-matter signal abnormalities. Although previous studies have linked brain viral levels to these alterations, other neuropathological mechanisms might also contribute to them. OBJECTIVE: To examine the relationship between findings on premortem magnetic resonance images and postmortem neuropathologic evidence of human immunodeficiency virus (HIV) encephalitis and neurodegeneration. DESIGN: Morphometric analysis of magnetic resonance imaging in seropositive cases with matched seronegative controls, and the correlation of these volumes to neuropathological measures in autopsied seropositive cases. SETTING: University of California, San Diego, HIV Neurobehavioral Research Center. SUBJECTS: Twenty-one seropositive subjects studied at autopsy and 19 seronegative cases. MAIN OUTCOME MEASURES: In vivo structural magnetic resonance imaging data analyzed by quantitative methods, with comparison of volumes from magnetic resonance imaging and neuropathological data from autopsies. RESULTS: The HIV-seropositive subjects demonstrated cerebrospinal fluid increases relative to seronegative controls. These increases were associated with a significant decrease in the volumes of cerebral and cerebellar white matter, caudate nucleus, hippocampus, and, to a lesser extent, cerebral cortex. The volume of cerebral white-matter tissue with elevated signal was also increased. This signal elevation in white matter predicted the autopsy diagnosis of HIV encephalitis, as well as the extent of dendritic loss as assessed by analysis of microtubule-associated protein 2 immunoreactivity. CONCLUSIONS: White-matter and cortical damage resulting from HIV disease are closely related. In vivo magnetic resonance imaging may be a valuable adjunct in the assessment of patients at risk for developing HIV encephalitis.

Adult↗
PubMed1998

Brain activations in schizophrenia during a graded memory task studied with functional neuroimaging.

BACKGROUND: Functional neuroimaging experiments have implicated prefrontal cortex (PFC) in memory processes. Several studies of schizophrenic patients have shown failure of activation in the dorsolateral region of PFC (DLPFC). We used a graded memory challenge to characterize functional neuroanatomical differences between schizophrenic and control subjects. The graded manipulation of task demands enabled us to assess group differences in the context of normal and abnormal psychological task performance. METHODS: Memory-related activity was assessed using positron emission tomography in schizophrenic patients and age-matched controls during performance of a graded memory task. Subjects underwent scanning while learning and recalling word lists of variable length. RESULTS: We used a model that assessed linear and nonlinear effects of memory load. Nonlinear group differences in DLPFC activation were observed. Controls showed a steepening slope of DLPFC increase as task demands increased. By contrast, schizophrenic subjects showed initial DLPFC increases that fell away with increasing memory load. The DLPFC response in schizophrenic subjects was closely related to measured task performance. In addition, schizophrenic subjects failed to show task-related decreases in activity in the left superior temporal and inferior parietal gyrus. CONCLUSIONS: Patients with schizophrenia showed a failure in DLPFC activation only in the face of diminished performance measures, suggesting that a full characterization of task-related changes in DLPFC activation must consider performance levels. However, striking failures of deactivation in superior temporal and inferior parietal regions were independent of task performance, possibly reflecting a core abnormality of the condition.

Adult↗
PubMedDate not supplied

Statistical thinking in functional and structural magnetic resonance neuroimaging.

Burning issues abound in the emerging field of biostatistics for imaging studies of the living human brain. This paper employs two examples to discuss the roles of informed empirical models and modern statistical methods in the analysis of functional and structural magnetic resonance neuroimages. The first example derives from an analysis of a functional baseline study in which simulated signals are embedded in actual brain 'noise' generated by a resting subject lying passively in the imaging device. The second example is taken from a structural volumetric analysis of human brain structure size differences in a sample of healthy adults.

Analysis of Variance↗
PubMed1999

Hippocampal system and declarative (relational) memory: summarizing the data from functional neuroimaging studies.

In the last several years there have been impressive strides in the ability to explore the nature of hippocampal system functioning in humans by employing functional neuroimaging methods, permitting such methods to be used in conjunction with neuropsychological methods to better understand the role of the hippocampal system in memory. In this paper, we review the literature on functional imaging studies of the hippocampal system, summarizing the data and testing these data against a number of theories or explanatory accounts of hippocampal function. We consider five alternative explanatory accounts of, or ideas about, hippocampal function- some from already existing work, for which the functional imaging data can provide a new test, and others that have emerged directly from the functional imaging work, and that have yet to be tested for their fit of data from neuropsychological methods. We conclude that the relational (declarative) memory account, in which it is proposed that the hippocampal system plays a critical role in binding together multiple inputs to permit representations of the relations among the constituent elements of scenes or events, can better accommodate the full range of imaging (and other existing) data than any other explanatory account of hippocampal function.

Brain Mapping↗
PubMed1995

Adaptation of personal projection television to a head-mounted display for intra-operative viewing of neuroimaging.

We describe an adaptation of a personal projection television for intra-operative viewing of conventional neuroimaging and frameless stereotaxy displays. In addition to image display, the device provides surgical magnification and eye protection from body fluids. Image data is first processed by a scan converter to provide a National Standards Television Committee (NTSC) television signal. The adjustable optics of the system display are permanently secured to avoid displacement during surgery. A virtual image of the data is projected to an apparent size of four feet in the inferior visual field of the surgeon's dominant eye. Magnification is provided by the surgical telescopes mounted in the visor. Resolution of the device is consistent with that obtained in a slice of computed tomography or magnetic resonance imaging data. Optimal display of multiplanar data awaits improvement in density of the light emitting diode device used for image generation.

Humans↗
PubMed2000

Locating and fractionating working memory using functional neuroimaging: storage, maintenance, and executive functions.

Working memory encompasses the short-term store of information and operations on that information. We review functional neuroimaging studies that have attempted to determine cortical areas involved in working memory functions. Current research suggests distinct systems for verbal information, visual objects, and spatial locations. Passive storage buffers appear to be located in posterior brain areas, whereas active maintenance of the information involves ventrolateral prefrontal areas. More complex, executive operations appear to recruit dorsolateral prefrontal cortex and anterior cingulate cortex. The possible involvement of reciprocal circuits including frontal cortex, basal ganglia, and thalamus is also discussed.

Brain↗
PubMed2000

Multiple trace theory of human memory: computational, neuroimaging, and neuropsychological results.

Hippocampal-neocortical interactions in memory have typically been characterized within the "standard model" of memory consolidation. In this view, memory storage initially requires hippocampal linking of dispersed neocortical storage sites, but over time this need dissipates, and the hippocampal component is rendered unnecessary. This change in function over time is held to account for the retrograde amnesia (RA) gradients often seen in patients with hippocampal damage. Recent evidence, however, calls this standard model into question, and we have recently proposed a new approach, the "multiple memory trace" (MMT) theory. In this view, hippocampal ensembles are always involved in storage and retrieval of episodic information, but semantic (gist) information can be established in neocortex, and will survive damage to the hippocampal system if enough time has elapsed. This approach accounts more readily for the very long RA gradients often observed in amnesia. We report the results of analytic and connectionist simulations that demonstrate the feasibility of MMT. We also report a neuroimaging study showing that retrieval of very remote (25-year-old) memories elicits as much activation in hippocampus as retrieval of quite recent memories. Finally, we report new data from the study of patients with temporal lobe damage, using more sensitive measures than previously the case, showing that deficits in both episodic and spatial detail can be observed even for very remote memories. Overall, these findings indicate that the standard model of memory consolidation, which views the hippocampus as having only a temporary role in memory, is wrong. Instead, the data support the view that for episodic and spatial detail the hippocampal system is always necessary.

Epilepsy, Temporal Lobe↗
PubMed2000

Methodological issues in pediatric neuroimaging.

The emergence of new technologies to study brain function in vivo has resulted in an explosion of interest in cognitive neuroscience within the last ten years. While most research in functional neuroimaging has been geared toward adult normal volunteers, the development of functional magnetic resonance imaging (fMRI) has made it possible to study neural development in normal children, as well as those with developmental disorders. This technology provides an unprecedented opportunity to expand our knowledge of brain function throughout childhood. A variety of technological, experimental, and practical difficulties are amplified when imaging children. This paper reviews some of the more challenging theoretical and practical concerns and provides suggestions for their management.

Child↗
PubMed2000

Functional neuroimaging of autistic disorders.

Functional neuroimaging methods hold promise for elucidating the neurobiology of autistic disorders, yet they present difficult practical and scientific challenges when applied to these complex and heterogeneous syndromes. Single-state studies of brain metabolism and blood flow thus far have failed to yield consistent findings, but suggest considerable variability in regional patterns of cerebral synaptic activity. Patients with idiopathic autism are less likely to show abnormalities than are patients with comorbid illness or epilepsy. Activation studies have begun to suggest alterations in brain organization for language and cognition. Neurotransmitter studies using positron emission tomography (PET) suggest abnormalities of serotonergic and dopaminergic function. Studies using magnetic resonance spectroscopy (MRS) have begun to document metabolic deficits in the frontal cortex and cerebellum. A single study using magnetoencephalography suggests a high incidence of epileptiform activity in children with autistic regression. Research needs include well-controlled developmental studies, particularly of young subjects and relatively homogeneous subgroups, which balance scientific rigor with ethical constraints. Investigations of the serotonergic and dopaminergic systems, limbic-based memory and emotional systems, and the role of epileptiform activity in autism represent priorities for future research.

Autistic Disorder↗
PubMed2000

Functional neuroimaging studies of reading and reading disability (developmental dyslexia).

Converging evidence from a number of neuroimaging studies, including our own, suggest that fluent word identification in reading is related to the functional integrity of two consolidated left hemisphere (LH) posterior systems: a dorsal (temporo-parietal) circuit and a ventral (occipito-temporal) circuit. This posterior system is functionally disrupted in developmental dyslexia. Reading disabled readers, relative to nonimpaired readers, demonstrate heightened reliance on both inferior frontal and right hemisphere posterior regions, presumably in compensation for the LH posterior difficulties. We propose a neurobiological account suggesting that for normally developing readers the dorsal circuit predominates at first, and is associated with analytic processing necessary for learning to integrate orthographic features with phonological and lexical-semantic features of printed words. The ventral circuit constitutes a fast, late-developing, word identification system which underlies fluent word recognition in skilled readers.

Cerebral Cortex↗