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PubMed2006

Beta2-microglobulin concentrations in cerebrospinal fluid correlate with neuroimaging findings in newborns with symptomatic congenital cytomegalovirus infection.

OVERVIEW: In newborns with symptomatic congenital cytomegalovirus (CMV) infection, neuroimaging is the best available predictor of neurodevelopmental outcome. Cerebrospinal fluid (CSF) findings in congenital CMV infection have seldom been described. Neonates with central nervous system infections present high CSF Beta(2)-microglobulin (beta(2)-m) levels. OBJECTIVES: The objectives of this study were: (1) to determine whether CSF beta(2)-m is increased in newborns with symptomatic congenital CMV infection, and (2) to examine its correlation with neuroimaging findings. MATERIALS AND METHODS: Fourteen newborns with symptomatic congenital CMV infection admitted to La Paz Hospital from 1990 through 2004 underwent determination of CSF beta(2)-m. Ninety-three newborns, constituting the comparison group, underwent CSF beta(2)-m determination as part of a sepsis or meningo/encephalitis work-up, and at discharge had sterile cultures and normal neurological status. Neuroimaging findings were scored according to a semiquantitative system: (0) no abnormalities; (1) single punctate periventricular (PV) calcification and/or hyperechogenic areas in the thalamus and basal ganglia; (2) multiple discrete PV calcifications and/or ventriculomegaly; and (3) extensive PV calcifications and/or brain atrophy. DISCUSSION AND CONCLUSION: CSF beta(2)-m was increased in newborns with CMV infection (median 6.21 mg/L) compared with controls (1.68 mg/L) (P<.001). beta(2)-m showed a correlation with neuroimaging scores (r (s)=0.753, P=.002). beta(2)-m was higher in patients who scored 2-3 (12.83 mg/L) than in patients who scored 0-1 (5.52 mg/L) (P=.028). CSF beta(2)-m is increased in newborns with symptomatic congenital CMV infection and correlates with neuroimaging abnormalities. beta(2)-m appears to be an indicator of the severity of brain involvement in congenital CMV infection.

Apgar Score↗

PubMed2005

Plasma DNA as a prognostic marker for stroke patients with negative neuroimaging within the first 24 h of symptom onset.

Modern neuroimaging safely and reliably diagnoses stroke and provides information for outcome prediction. However, some patients with clinical stroke have no detectable abnormality on neuroimaging and other patients are not fit for such investigations. Therefore, we evaluated the potential of plasma DNA and serum S100 protein concentrations to predict post-stroke mortality and morbidity in patients with negative neuroimaging results. Patients with stroke-like symptoms but negative neuroimaging results were recruited. Both plasma and serum were collected from each patient for plasma DNA and serum S100 analysis. The primary outcome measures were 6-month mortality and morbidity using the post-stroke modified Rankin score (mRS). Forty-four patients were recruited to the study. Seventeen (39%) patients were classified as post-stroke mRS grades 3-6. The median plasma DNA concentration of this group of patients was significantly higher than that of patients with post-stroke mRS grades 0-2. Median serum S100 protein concentrations did not show significant differences between the two groups. Plasma DNA concentrations > 800 kilogenome-equivalent/l have a sensitivity of 42% and a specificity of 100% for predicting 6-month post-stroke mRS (grades 0-2), with an area under the receiver operator characteristic (ROC) curve of 0.742. By comparison, serum S100 protein concentrations > 0.09 microg/l have a sensitivity of 48% and specificity of 75% for predicting 6-month post-stroke mRS (grades 0-2), and the area under the curve is 0.542. Plasma DNA concentration predicts post-stroke morbidity and mortality in patients with negative neuroimaging, and may be more effective than S100 protein measurement.

Aged↗

PubMed2003

Audit of a policy of magnetic resonance imaging with diffusion-weighted imaging as first-line neuroimaging for in-patients with clinically suspected acute stroke.

AIM: To audit the feasibility and use of diffusion-weighted (DW) magnetic resonance imaging (MRI) as initial neuroimaging for in-patients with clinically suspected acute stroke. MATERIALS AND METHODS: In April 2000, MRI with DW and T2-weighted sequence was locally instituted as initial neuroimaging for patients with clinically suspected acute stroke. This retrospective study reviewed imaging performed for in-patients with suspected acute stroke over a 9-month period. Data were collected on image type, result and need for repeat imaging. RESULTS: During the study period, 124 patients had neuroimaging for suspected cerebrovascular accident, and 119 were MRI safe. Eighty-eight (73.9%) patients underwent DW MRI as first-line investigation. Five patients were not MRI safe and 31 had computed tomography (CT) as first-line imaging due to lack of available MRI capacity. Repeat neuroimaging was performed in 16 (12.9%) patients. Study times were comparable for both types of neuroimaging: a mean of 13 min for MRI and 11 min for CT. CONCLUSION: The audit standard was achieved in 88 (73.9%) patients. The use of DW MRI as a first-line investigation for patients with a clinical diagnosis of acute stroke is achievable in a district general hospital setting.

Decision Making↗

PubMed2006

Neuroimaging methods in affective neuroscience: selected methodological issues.

A current goal of affective neuroscience is to reveal the relationship between emotion and dynamic brain activity in specific neural circuits. In humans, noninvasive neuroimaging measures are of primary interest in this endeavor. However, methodological issues, unique to each neuroimaging method, have important implications for the design of studies, interpretation of findings, and comparison across studies. With regard to event-related brain potentials, we discuss the need for dense sensor arrays to achieve reference-independent characterization of field potentials and improved estimate of cortical brain sources. Furthermore, limitations and caveats regarding sparse sensor sampling are discussed. With regard to event-related magnetic field (ERF) recordings, we outline a method to achieve magnetoencephalography (MEG) sensor standardization, which improves effects' sizes in typical neuroscientific investigations, avoids the finding of ghost effects, and facilitates comparison of MEG waveforms across studies. Focusing on functional magnetic resonance imaging (fMRI), we question the unjustified application of proportional global signal scaling in emotion research, which can greatly distort statistical findings in key structures implicated in emotional processing and possibly contributing to conflicting results in affective neuroscience fMRI studies, in particular with respect to limbic and paralimbic structures. Finally, a distributed EEG/MEG source analysis with statistical parametric mapping is outlined providing a common software platform for hemodynamic and electromagnetic neuroimaging measures. Taken together, to achieve consistent and replicable patterns of the relationship between emotion and neuroimaging measures, methodological aspects associated with the various neuroimaging techniques may be of similar importance as the definition of emotional cues and task context used to study emotion.

Brain↗

PubMed2001

Exploring the neural bases of episodic and semantic memory: the role of structural and functional neuroimaging.

Exploration of the neural bases of episodic and semantic memory is best pursued through the combined examination of the effects of identified lesions on memory and functional neuroimaging of both normal people and patients when they engage in memory processing of various kinds. Both structural and functional neuroimaging acquisition and analysis techniques have developed rapidly and will continue to do so. This review briefly outlines the history of neuroimaging as it impacts on memory research. Next, what has been learned so far from lesion-based research is outlined with emphasis on areas of disagreement as well as agreement. What has been learned from functional neuroimaging, particularly emission tomography and functional magnetic resonance imaging, is then discussed, and some stress is placed on topics where the interpretation of imaging studies has so far been unclear. Finally, how functional and structural imaging techniques can be optimally used to help resolve three areas of disagreement in the lesion literature will be discussed. These disagreements concern what the hippocampus and perirhinal cortex contribute to memory; whether any form of priming depends on the medial temporal lobes; and whether remote episodic as well as semantic memories cease to depend on the medial temporal lobes. Although the discussion will show the value of imaging techniques, it will also emphasize some of the limitations of current neuroimaging studies.

Brain↗

PubMed2004

Can ophthalmic requests for neuroimaging be improved?

AIM: To review and set guidelines for all neuroradiological referrals from the ophthalmic service in a typical UK district general hospital. METHOD: Patients referred for diagnostic neuroimaging were identified from the radiology database over a 1-year period. A case note review was undertaken. The clinical indication for and results of neuroimaging performed were ascertained. The justification for neuroimaging was determined. RESULTS: Of the total 31,411 patients that were seen in the eye department, 103 (0.32%) had diagnostic neuroradiological imaging performed. The indications for imaging were: suspected compressive lesion of the anterior visual pathway in 57 patients (55.3%), acquired ocular motility disturbance in 20 patients (19.4%), suspected orbital pathology in 11 patients (10.6%), cerebrovascular accident in nine patients (8.7%), and six patients (5.8%) were imaged for either headache or sinusitis. Radiological lesion detection rate was highest for cerebrovascular accident (88.8%) and lowest acquired for ocular motility disturbance (4.9%). CONCLUSION: Ophthalmic requests for diagnostic neuroimaging were found to be unnecessary in only 9% of patients. Guidelines for the referral of ophthalmic patients for neuroimaging are discussed.

Eye Diseases↗

PubMed2001

A survey of neuroimaging research in European neurological departments.

In the international neurological literature, neuroimaging research plays an important role. Neuroimaging techniques are also of steadily increasing importance for clinical diagnosis and treatment monitoring. Therefore, neuroimaging research activities were surveyed by a questionnaire, which was completed by 100 neurological centres across Europe. It showed that most groups use magnetic resonance imaging (MRI), fMRI, computerized tomography (CT) and single photon emission computerized tomography (SPECT). Positron emission tomography (PET) and ultrasound are also employed by nearly half of the centres. Neuroimaging research involves co-operation amongst typically five to 10 disciplines. Cerebrovascular disease, dementia, cognitive disorders, epilepsy, movement disorders, brain tumours and multiple sclerosis are frequently being studied. Many groups rely on small budgets, have few full-time scientists and limited access to expensive resources. There is little exchange of scientists amongst laboratories. It was felt that funding and co-operation needed improvement in order to maintain a high standard in neuroimaging research.

Data Collection↗

PubMed2000

The utility of neuroimaging in the evaluation of children with migraine or chronic daily headache who have normal neurological examinations.

OBJECTIVES: To assess the utility of neuroimaging in the evaluation of children presenting with two of the most common forms of headache, migraine and chronic daily headache, and to determine the utility and pathological yield of neuroimaging in specific headache syndromes in children whose neurological examinations are normal. METHODS: We retrospectively reviewed the medical records of patients coded for headache (ICD 784) in the Pediatric Neurology Clinic at Children's Hospital of the King's Daughters between 1997 and 1999. The age range considered was between 6 and 18 years. The study focused on the two most common types of headache, uncomplicated migraine and chronic daily headache. Only patients with normal physical and neurological examinations were considered in this analysis. RESULTS: Three hundred two patients were coded for headache within the defined age group. One hundred seven (35.4%) patients fulfilled IHS-R criteria as having uncomplicated migraine with a normal examination, and 30 (9.9%) patients fulfilled criteria for chronic daily headache. Twenty-nine (9.6%) patients presented with migrainelike symptoms, and 6 (2.0%) presented with chronic daily symptoms, but had neurological abnormalities present on examination. The remainder of the patients with headache had the following etiologies: 50 (16.6%) with secondary headache, 22 (7.3%) with complicated migraine, 20 (6.6%) with posttraumatic headache, 13 (4.3%) with seizure-related headache, 11 (3.6%) with brain tumors, 10 (3.3%) with tension-type headache, and 4 (1.3%) with pseudotumor cerebri. Of the 107 patients with migraine, 42 (39.3%) received CT scans; 2 (4.8%) of which were considered "abnormal." One of the abnormalities was an arachnoid cyst and the other was a dilated Virchow-Robin space. Twelve (11.2%) patients with migraine received an MRI, 2 (16.7%) of which were considered abnormal. Both of the abnormal findings were Chiari type I malformations. Of the 30 patients with chronic daily headache, 17 (56.7%) received CT scans, 3 (17.6%) of which were considered abnormal. The abnormalities consisted of a maxillary opacification, a mucous retention cyst, and an occult vascular malformation. Eight (26.7%) of the patients with chronic daily headache had an MRI, 2 (25.0%) of which were abnormal. One of the abnormalities was a Chiari I malformation, and the other was an occult vascular malformation. CONCLUSION: The yield of neuroimaging in children with uncomplicated migraine and normal neurological examination was 3.7%. The yield in children with chronic daily headache and normal neurological examination was higher at 16.6%. The abnormalities discovered included arachnoid cysts, Chiari I malformations, sinus disease, occult vascular malformations and "dilated Virchow-Robin spaces." While none of the neuroimaging findings were apparent clinically, their discovery did not influence the diagnosis, management, or outcome of the patients. None of the abnormalities necessitated surgical intervention or were associated with the headache presentation. Therefore, neuroimaging is not warranted in children and adolescents with defined clinical headache syndrome diagnoses whose neurological examinations are normal.

Adolescent↗

PubMedDate not supplied

The neuroimaging of long-term memory encoding processes.

There needs to be more crosstalk between the lesion and functional neuroimaging memory literatures. This is illustrated by a discussion of episode and fact encoding. The lesion literature suggests several hypotheses about which brain regions underlie the storage of episode and fact information, which can be explored by functional neuroimaging. These hypotheses have been underexplored because neuroimaging studies of encoding have been insufficiently hypothesis-driven and have not controlled encoding-related processes sufficiently well to allow clear interpretations of results to be made. Nevertheless, there is good evidence that certain kinds of associative encoding and/or consolidation are sufficient to activate the medial temporal lobes, and preliminary evidence that some kinds of associative priming may reduce activation of this region. It remains to be proved that attentional orienting to certain kinds of novel information activates the medial temporal lobes. Evidence is growing that the HERA model, developed from neuroimaging rather than lesion data, requires modification and that frontal cortex encoding activations are probably caused by executive processes that are important in effortful memory processing. Neuroimaging studies allow the detection of encoding-related activations in previously unexpected brain regions (e.g. parietal lobes) and, in turn, these findings can be explored with lesion studies.

Brain↗

PubMedDate not supplied

Using neuroimaging to predict treatment response in mood and anxiety disorders.

BACKGROUND: Functional neuroimaging has begun to show promise as a clinical tool in the prediction of treatment response in mood and anxiety disorders. Given the variance in patient responses to psychiatric treatments, the use of such predictive tools could be tremendously valuable, especially in situations where treatments carry substantial risks or costs. METHODS: A literature search was conducted in December 2004 to identify published neuroimaging treatment prediction papers. "Neuroimaging," "treatment," and "depression or anxiety" were used as keywords. Studies of treatment prediction were complemented by studies of treatment effects to provide context. RESULTS: Fifteen original published papers were identified as investigations of treatment prediction in mood and anxiety disorders. These studies have predominantly been conducted in patients with major depression (MDD) and obsessive-compulsive disorder (OCD). We review this literature and provide a discussion of design considerations in psychiatric neuroimaging studies of treatment response prediction. CONCLUSIONS: The neuroimaging literature pertaining to treatment response prediction is largely limited to studies of MDD and OCD. While these initial reports are preliminary, the findings reviewed suggest that treatment outcome may be predicted by patterns of pre-treatment brain activity in psychiatric patients. However, the actual clinical utility of such tests remains to be shown.

Affect↗

PubMed2005

Neuroimaging as a guide to predict outcomes for patients with coccidioidal meningitis.

Sixty-two patients with coccidioidal meningitis underwent neuroimaging. Magnetic resonance imaging detected neuroimaging abnormalities in 76% of patients, and computed tomography scanning detected neuroimaging abnormalities in 41.6%. The most common abnormal neuroimaging findings were hydrocephalus (51.6%), basilar meningitis (46.8%), and cerebral infarction (38.7%). Significantly elevated mortality rates were associated with hydrocephalus and hydrocephalus coexisting with infarction. Basilar meningitis did not influence outcome. Patients without neuroimaging abnormalities had a mortality rate of 7.7%.

Adolescent↗

PubMed1996

Neuroimaging of focal malformations of cortical development.

Neuroimaging is playing an increasingly important role in the evaluation of patients with malformations of cerebral cortical development. In this review, the authors address optimal neuroimaging of cortical malformations using x-ray computed tomography, single-photon-emission computed tomography, positron emission tomography, magnetic resonance imaging, and magnetic resonance spectroscopy. Initially, the authors discuss the strengths and weaknesses of the various imaging techniques. This is followed by a discussion of the clinical and neuroimaging characteristics of several different imaging manifestations of focal malformations of cortical development, including polymicrogyria, focal subcortical heterotopia, schizencephaly, focally thickened gyri, focally irregular gyri, hemimegalencephaly, and transmural dysplasia. The authors intend that, after reading this review, the reader will have a better understanding of the optimal neuroimaging techniques for evaluating these malformations and their many neuroimaging appearances.

Cerebral Cortex↗

PubMed2005

Functional neuroimaging and cognitive rehabilitation for people with traumatic brain injury.

Cognitive deficits are a common consequence of traumatic brain injury. Although such deficits are amenable to rehabilitation, methods for individualizing cognitive interventions are still unrefined. Functional neuroimaging methods such as positron emission tomography and functional magnetic resonance imaging are emerging as possible technologies for measuring and monitoring the cerebral consequences of plasticity associated with brain injury and for evaluating the effectiveness of rehabilitation interventions. Functional neuroimaging may even enable more customized and efficient selection, design, or adaptation of individual cognitive rehabilitation programs. We review the current literature on functional neuroimaging after traumatic brain injury, relating these findings to cognitive rehabilitation. Overall, functional neuroimaging after traumatic brain injury has shown reliable differences in brain activity within several regions of frontal cortex, partly but not uniformly consistent with neuropsychological and structural findings in traumatic brain injury. We also outline a number of promising research opportunities for applying functional neuroimaging in traumatic brain injury settings, along with associated challenges.

Brain Injuries↗

PubMed2002

The role of neuroimaging in headache.

Headaches are a universal experience and one of the most common causes for physician consultation. The physician must determine whether a neuroimaging study is warranted to aid in the diagnosis of primary or secondary headaches. Guidelines on neuroimaging of headache patients have been developed based on review of the literature; however, their applicability must be adapted to specific clinical situations. In general, neuroimaging is most likely to be useful if the history is not typical of a primary headache type (e.g., tension type, migraine, cluster headaches) or the neurological examination is abnormal. Neuroimaging has been crucial in the investigation of the pathogenesis of migraine and cluster headaches. Secondary headaches, which may be diagnosed by neuroimaging studies, include subarachnoid hemorrhage, cerebral venous thrombosis, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, aqueductal stenosis, and arterial dissection.

Diagnosis, Differential↗

PubMed2001

Neuroimaging databases.

These are comments written by the Governing Council of the Organization for Human Brain Mapping (OHBM), the primary international organization dedicated to neuroimaging research. The purpose of these comments is to identify and frame issues concerning data sharing within the neuroimaging community. Data sharing has become an important issue in most fields of science. The neuroimaging community is no exception, and it clearly perceives potential benefits in such efforts, as have been realized in other fields such as genomics. At the same time, such efforts can be costly (both in time and expense), and there are important factors that differentiate brain imaging from other fields and that pose specific challenges to the generation of useful neuroimaging databases. These include the rapid pace of change in brain imaging technologies; the complexity of the variables that must be specified to meaningfully interpret the results (such as the method of image acquisition, behavioral design, and subject characteristics); and concerns about participant confidentiality. These issues are outlined with the goal of framing and promoting a public discussion of the benefits and risks of data sharing, which can inform the field of neuroimaging as well as others that face similar challenges.

Brain↗

PubMed1995

The CERAD experience, Part VIII: Neuroimaging-neuropathology correlates of temporal lobe changes in Alzheimer's disease.

We compared premortem neuroimaging findings with neuropathologic evidence of temporal lobe atrophy in 20 patients with Alzheimer's disease (AD) confirmed by autopsy. There were significant correlations between temporal horn enlargement observed by neuroimaging and hippocampal atrophy at autopsy, and between the overall cerebral atrophy severity on neuroimaging and scores on the Mini-Mental State Examination. This report confirms previous studies correlating temporal lobe atrophy on neuroimaging with a clinical diagnosis of AD, although more precise neuroimaging techniques are needed for use in multicenter studies of AD.

Alzheimer Disease↗

PubMed2005

[Brain effects of cannabis--neuroimaging findings].

Cannabis is the most widely used illicit drug. Despite this, only a small number of studies have investigated the long-term neurotoxic consequences of cannabis use. Structural and functional neuroimaging techniques are powerful research tools to investigate possible cannabis-induced pathophysiological changes. A computer literature review was conducted in the MEDLINE and PsycLIT databases between 1966 and November of 2004 with the search terms 'cannabis', 'marijuana', 'neuroimaging', 'magnetic resonance', 'computed tomography', 'positron emission tomography', 'single photon emission computed tomography", 'SPET', 'MRI' and 'CT'. Structural neuroimaging studies have yielded conflicting results. Most studies report no evidence of cerebral atrophy or regional changes in tissue volumes, and one study suggested that long-term users who started regular use on early adolescence have cerebral atrophy as well as reduction in gray matter. However, several methodological shortcomings limit the interpretation of these results. Functional neuroimaging studies have reported increases in neural activity in regions that may be related with cannabis intoxication or mood-change effects (orbital and mesial frontal lobes, insula, and anterior cingulate) and decreases in activity of regions related with cognitive functions impaired during acute intoxication. The important question whether residual neurotoxic effects occur after prolonged and regular use of cannabis remains unclear, with no study addressing this question directly. Better designed neuroimaging studies, combined with cognitive evaluation, may be elucidative on this issue.

Atrophy↗

PubMed2006

The value of morphological neuroimaging after acute exposure to toxic substances.

Many toxic agents induce brain dysfunction and/or lesions. Modern neuroimaging techniques, such as CT and more recently magnetic resonance imaging (MRI), are able to demonstrate toxic brain lesions at both early and delayed phases of disease progression. In the early phase, neuroimaging enables the detection of acutely injured brain areas responsible for sudden onset of neurological dysfunction, but the severity and the extension of brain lesions on neuroimages do not necessarily parallel the severity of the clinical status. In the chronic phase, when neurological dysfunction has become permanent, neuroimaging allows precise identification of neuroanatomical sequelae that do not necessarily match the severity of the chronic neurological impairment. Papers in the medical imaging literature have dealt mainly with the brain changes induced by 'chronic exposure' to toxic substances such as solvents or heavy metals. This article selectively reviews the main radiological changes observed on CT/magnetic resonance (MR) neuroimages after 'acute exposure' to industrial products (methanol [methyl alcohol], ethylene glycol), environmental agents (cyanide, carbon monoxide), pharmaceuticals (insulin, valproic acid) and illicit substances (heroin, cocaine). Different kinds of lesions, which lack specificity for toxic injury, can be observed on radiological images, but deep grey matter lesions with symmetrical distribution throughout basal ganglia are most often seen. However, such findings have also been reported after anoxic-ischaemic insults or during severe metabolic disturbances. Lesions in the white matter may also be present in the case of acute exposure to toxic agents. The true prognostic value of toxic-induced brain changes in the acute phase in CT or MR studies is unclear, although serial MRI may add new information as may quantitative or molecular imaging techniques such as the MR diffusion-weighted imaging or MR spectroscopy.

Acute Disease↗