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Brain Imaging (brain + imaging)
Kinds of Brain Imaging Terms modified by Brain Imaging Selected AbstractsBrain Imaging in Migraine ResearchHEADACHE, Issue 9 2010David Borsook MD Understanding the pathophysiology and pharmacology of migraine has been driven by astute clinical observations, elegant experimental medicine studies, and importantly by studying highly effective anti-migraine agents in the laboratory and the clinic. Significant progress has been made in the use of functional brain imaging to compliment observational studies of migraine phenotypes by highlighting pathways within the brain that may be involved in predisposition to migraine, modulating migraine pain or that could be sensitive to pharmacological or behavioral therapeutic intervention (Fig. 1). In drug discovery, molecular imaging approaches compliment functional neuroimaging by visualizing migraine drug targets within the brain. Molecular imaging enables the selection and evaluation of drug candidates by confirming that they engage their targets sufficiently at well tolerated doses to test our therapeutic hypotheses. Figure 1.,. Imaging and defining the migraine brain disease state: from anatomy to chemical entities (targets) to functional systems (function and pathways) (from Borsook et al31 with permission, Nature Publishing Group). Migraine is a progressive disorder. Developing our knowledge of where drugs act in the brain and of how the brain is altered in both episodic migraine (interictal state and ictal state) and chronic migraine are important steps to understanding why there is such differential responsiveness to therapeutics among migraine patients and to improving how they are evaluated and treated. [source] Brain imaging in psychiatry: from a technique of exclusion to a technique for diagnosisACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2006E. Osuch No abstract is available for this article. [source] Psychiatric epidemiology of old age: the H70 study , the NAPE Lecture 2003ACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2004I. Skoog Objective: To describe methodological issues and possibilities in the epidemiology of old age psychiatry using data from the H70 study in Göteborg, Sweden. Method: A representative sample born during 1901,02 was examined at 70, 75, 79, 81, 83, 85, 87, 90, 92, 95, 97, 99 and 100 years of age, another during 1906,07 was examined at 70 and 79 years of age, and samples born between 1922 and 1930 were examined at 70 years of age. The study includes psychiatric examinations and key informant interviews performed by psychiatrists, physical examinations performed by geriatricians, psychometric testings, blood sampling, computerized tomographies of the brain, cerebrospinal fluid analyses, anthropometric measurements, and psychosocial background factors. Results: Mental disorders are found in approximately 30% of the elderly, but is seldom detected or properly treated. Incidence of depression and dementia increases with age. The relationship between blood pressure and Alzheimer's disease is an example of how cross-sectional and longitudinal studies yield completely different results. Brain imaging is an important tool in epidemiologic studies of the elderly to detect silent cerebrovascular disease and other structural brain changes. The high prevalence of psychotic symptoms is an example of the importance to use several sources of information to detect these symptoms. Dementia should be diagnosed in all types of studies in the elderly, as it influences several outcomes such as mortality, blood pressure, and rates of depression. Suicidal feelings are rare in the elderly and are strongly related to mental disorders. Conclusion: Modern epidemiologic studies in population samples should be longitudinal and include assessments of psychosocial risk factors as well as comprehensive sets of biologic markers, such as brain imaging, neurochemical analyses, and genetic information to maximize the contribution that epidemiology can provide to increase our knowledge about the etiology of mental disorders. [source] A systematic review on the diagnosis and treatment of primary (idiopathic) dystonia and dystonia plus syndromes: report of an EFNS/MDS-ES Task ForceEUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2006A. Albanese chairman To review the literature on primary dystonia and dystonia plus and to provide evidence-based recommendations. Primary dystonia and dystonia plus are chronic and often disabling conditions with a widespread spectrum mainly in young people. Computerized MEDLINE and EMBASE literature reviews (1966,1967 February 2005) were conducted. The Cochrane Library was searched for relevant citations. Diagnosis and classification of dystonia are highly relevant for providing appropriate management and prognostic information, and genetic counselling. Expert observation is suggested. DYT-1 gene testing in conjunction with genetic counselling is recommended for patients with primary dystonia with onset before age 30 years and in those with an affected relative with early onset. Positive genetic testing for dystonia (e.g. DYT-1) is not sufficient to make diagnosis of dystonia. Individuals with myoclonus should be tested for the epsilon-sarcoglycan gene (DYT-11). A levodopa trial is warranted in every patient with early onset dystonia without an alternative diagnosis. Brain imaging is not routinely required when there is a confident diagnosis of primary dystonia in adult patients, whereas it is necessary in the paediatric population. Botulinum toxin (BoNT) type A (or type B if there is resistance to type A) can be regarded as first line treatment for primary cranial (excluding oromandibular) or cervical dystonia and can be effective in writing dystonia. Actual evidence is lacking on direct comparison of the clinical efficacy and safety of BoNT-A vs. BoNT-B. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for generalized or cervical dystonia, after medication or BoNT have failed to provide adequate improvement. Selective peripheral denervation is a safe procedure that is indicated exclusively in cervical dystonia. Intrathecal baclofen can be indicated in patients where secondary dystonia is combined with spasticity. The absolute and comparative efficacy and tolerability of drugs in dystonia, including anticholinergic and antidopaminergic drugs, is poorly documented and no evidence-based recommendations can be made to guide prescribing. [source] Reading, complexity and the brainLITERACY, Issue 2 2008Usha Goswami Abstract Brain imaging offers a new technology for understanding the acquisition of reading by children. It can contribute novel evidence concerning the key mechanisms supporting reading, and the brain systems that are involved. The extensive neural architecture that develops to support efficient reading testifies to the complex developmental processes that underpin the acquisition of literacy. Here, I provide a brief overview of recent studies, analysed within a cognitive framework of reading development. [source] Perfusion computed tomography in the acute phase of mild head injury: Regional dysfunction and prognostic value,ANNALS OF NEUROLOGY, Issue 6 2009Zwany Metting MD Objective Traumatic brain injury is a major cause of disability and death. Most patients sustain a mild head injury with a subgroup that experiences disabling symptoms interfering with return to work. Brain imaging in the acute phase is not predictive of outcome, as 20% of noncontrast computed tomographic (CT) scans on admission is normal in patients with a suboptimal outcome. The aim of this study was to perform perfusion CT imaging in the acute phase of mild head injury in patients without intracranial abnormalities on the noncontrast CT, to assess whether these patients had cerebral perfusion abnormalities. Furthermore, the relation between perfusion CT parameters and severity of head injury and outcome was evaluated. Methods In patients with mild head injury and normal noncontrast CT, perfusion CT was performed directly after admission. The perfusion data were compared with data of 25 healthy control subjects. Outcome was determined 6 months after injury with the extended Glasgow Coma Outcome Scale score and return to work. Results Seventy-six patients were included. In patients with a decreased Glasgow Coma Scale score, a significant decrease of cerebral blood flow and cerebral blood volume was detected in the frontal and occipital gray matter. In logistic regression analyses, decreased cerebral blood flow and cerebral blood volume in the frontal lobes predicted worse outcome according to the extended Glasgow Coma Outcome Scale score. CT perfusion parameters did not predict return to work. Interpretation In the acute phase of mild head injury, disturbed cerebral perfusion is seen in patients with normal noncontrast CT correlating with severity of injury and outcome. Ann Neurol 2009;66:809,816 [source] Physical foundations, models, and methods of diffusion magnetic resonance imaging of the brain: A reviewCONCEPTS IN MAGNETIC RESONANCE, Issue 5 2007Ludovico Minati Abstract The foundations and characteristics of models and methods used in diffusion magnetic resonance imaging, with particular reference to in vivo brain imaging, are reviewed. The first section introduces Fick's laws, propagators, and the relationship between tissue microstructure and the statistical properties of diffusion of water molecules. The second section introduces the diffusion-weighted signal in terms of diffusion of magnetization (Bloch,Torrey equation) and of spin-bearing particles (cumulant expansion). The third section is dedicated to the rank-2 tensor model, the bb -matrix, and the derivation of indexes of anisotropy and shape. The fourth section introduces diffusion in multiple compartments: Gaussian mixture models, relationship between fiber layout, displacement probability and diffusivity, and effect of the b -value. The fifth section is devoted to higher-order generalizations of the tensor model: singular value decompositions (SVD), representation of angular diffusivity patterns and derivation of generalized anisotropy (GA) and scaled entropy (SE), and modeling of non-Gaussian diffusion by means of series expansion of Fick's laws. The sixth section covers spherical harmonic decomposition (SHD) and determination of fiber orientation by means of spherical deconvolution. The seventh section presents the Fourier relationship between signal and displacement probability (Q -space imaging, QSI, or diffusion-spectrum imaging, DSI), and reconstruction of orientation-distribution functions (ODF) by means of the Funk,Radon transform (Q -ball imaging, QBI). © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 278,307, 2007. [source] Perfusion MR imaging with pulsed arterial spin-labeling: Basic principles and applications in functional brain imagingCONCEPTS IN MAGNETIC RESONANCE, Issue 5 2002Yihong Yang Abstract Basic principles of the arterial spin-labeling perfusion MRI are described, with focus on a brain perfusion model with pulsed labeling. A multislice perfusion imaging sequence with adiabatic inversion and spiral scanning is illustrated as an example. The mechanism of the perfusion measurement, the quantification of cerebral blood flow, and the suppression of potential artifacts are discussed. Applications of the perfusion imaging in brain activation studies, including simultaneous detection of blood flow and blood oxygenation, are demonstrated. Important issues associated with the applications such as sensitivity, quantification, and temporal resolution are discussed. © 2002 Wiley Periodicals, Inc. Concepts Magn Reson 14: 347,357, 2002 [source] The neuroanatomy and neuroendocrinology of fragile X syndromeDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2004David Hessl Abstract Fragile X syndrome (FXS), caused by a single gene mutation on the X chromosome, offers a unique opportunity for investigation of gene,brain,behavior relationships. Recent advances in molecular genetics, human brain imaging, and behavioral studies have started to unravel the complex pathways leading to the cognitive, psychiatric, and physical features that are unique to this syndrome. In this article, we summarize studies focused on the neuroanatomy and neuroendocrinology of FXS. A review of structural imaging studies of individuals with the full mutation shows that several brain regions are enlarged, including the hippocampus, amygdala, caudate nucleus, and thalamus, even after controlling for overall brain volume. These regions mediate several cognitive and behavioral functions known to be aberrant in FXS such as memory and learning, information and sensory processing, and social and emotional behavior. Two regions, the cerebellar vermis, important for a variety of cognitive tasks and regulation of motor behavior, and the superior temporal gyrus, involved in processing complex auditory stimuli, are reported to be reduced in size relative to controls. Functional imaging, typically limited to females, has emphasized that individuals with FXS do not adequately recruit brain regions that are normally utilized by unaffected individuals to carry out various cognitive tasks, such as arithmetic processing or visual memory tasks. Finally, we review a number of neuroendocrine studies implicating hypothalamic dysfunction in FXS, including abnormal activation of the hypothalamic,pituitary,adrenal (HPA) axis. These studies may help to explain the abnormal stress responses, sleep abnormalities, and physical growth patterns commonly seen in affected individuals. In the future, innovative longitudinal studies to investigate development of neurobiologic and behavioral features over time, and ultimately empirical testing of pharmacological, behavioral, and even molecular genetic interventions using MRI are likely to yield significant positive changes in the lives of persons with FXS, as well as increase our understanding of the development of psychiatric and learning problems in the general population. MRDD Research Reviews 2004;10:17,24. © 2004 Wiley-Liss, Inc. [source] Magnetic resonance imaging findings in a population-based cohort of children with cerebral palsyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2009MARNIE N ROBINSON MBBS The purpose of this study was to investigate the frequency and spectrum of magnetic resonance imaging (MRI) abnormalities in a population of children with cerebral palsy (CP) who were born in the years 2000 and 2001 in Victoria, Australia. In 2000 and 2001, 221 children (126 males, 95 females; mean age 6y [SD 7mo], range 5,7y) with CP, excluding those with CP due to postneonatal causes (6% of all cases), were identified through the Victorian Cerebral Palsy Register. All medical records were systematically reviewed and all available brain imaging was comprehensively evaluated by a single senior MRI radiologist. MRI was available for 154 (70%) individuals and abnormalities were identified in 129 (84%). The study group comprised 88% with a spastic motor type CP; the distribution was hemiplegia in 33.5%, diplegia in 28.5%, and quadriplegia in 37.6% of children. Overall, pathological findings were most likely to be identified in children with spastic hemiplegia (92%) and spastic quadriplegia (84%). Abnormalities were less likely to be identified in non-spastic motor types (72%) and spastic diplegia (52%). The most common abnormalities identified on MRI were periventricular white matter injury (31%), focal ischaemic/haemorrhagic lesions (16%), diffuse encephalopathy (14%), and brain malformations (12%). Dual findings were seen in 3% of patients. This is the first study to document comprehensively the neuroimaging findings of all children identified with CP born over a consecutive 24-month period in a large geographical area. [source] A case of hydrocephalus occlusus presenting as bipolar disorderACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2005T. Reisch Objective:, This case highlights the fact that manic and depressive symptoms can be related to hydrocephalus occlusus even in the absence of neurological symptoms. Method:, Single case report. Results:, A 22-year-old male patient presented with a 2-year history of manic and depressive symptoms. He was admitted to psychiatric in-patient care fulfilling sufficient criteria of bipolar disorder presenting with a hypomanic state. No neurological symptoms could be detected. Three months later, a MRI of the brain showed a hydrocephalus occlusus because of a space-occupying lesion of 5 mm in the lamina tecti obstructing the aqueduct of Silvius. The MRI also showed parahippocampal changes, which were probably related to the hydrocephalus. After the implantation of a ventriculo-peritoneal shunt, manic symptoms resolved, but the patient continued to suffer from adynamic symptoms. Follow-up MRIs over 3 years showed no progression of the lesion of unknown etiology. Conclusions:, In this case, early routine neuroimaging might have reduced long-term brain damage. The case underlines that even in the absence of neurological symptoms, brain imaging in bipolar disorder might be crucial. The feasibility of routine brain imaging in bipolar patients is discussed. [source] Cognitive dysfunction in patients with type 2 diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 7 2010Yael D. Reijmer Abstract People with diabetes mellitus are at increased risk of cognitive dysfunction and dementia. This review explores the nature and severity of cognitive changes in patients with type 2 diabetes. Possible risk factors such as hypo- and hyperglycemia, vascular risk factors, micro- and macrovascular complications, depression and genetic factors will be examined, as well as findings from brain imaging and autopsy studies. We will show that type 2 diabetes is associated with modest cognitive decrements in non-demented patients that evolve only slowly over time, but also with an increased risk of more severe cognitive deficits and dementia. There is a dissociation between these two ,types' of cognitive dysfunction with regard to affected age groups and course of development. Therefore, we hypothesize that the mild and severe cognitive deficits observed in patients with type 2 diabetes reflect separate processes, possibly with different risk factors and aetiologies. Copyright © 2010 John Wiley & Sons, Ltd. [source] Psychiatric epidemiology of old age: the H70 study , the NAPE Lecture 2003ACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2004I. Skoog Objective: To describe methodological issues and possibilities in the epidemiology of old age psychiatry using data from the H70 study in Göteborg, Sweden. Method: A representative sample born during 1901,02 was examined at 70, 75, 79, 81, 83, 85, 87, 90, 92, 95, 97, 99 and 100 years of age, another during 1906,07 was examined at 70 and 79 years of age, and samples born between 1922 and 1930 were examined at 70 years of age. The study includes psychiatric examinations and key informant interviews performed by psychiatrists, physical examinations performed by geriatricians, psychometric testings, blood sampling, computerized tomographies of the brain, cerebrospinal fluid analyses, anthropometric measurements, and psychosocial background factors. Results: Mental disorders are found in approximately 30% of the elderly, but is seldom detected or properly treated. Incidence of depression and dementia increases with age. The relationship between blood pressure and Alzheimer's disease is an example of how cross-sectional and longitudinal studies yield completely different results. Brain imaging is an important tool in epidemiologic studies of the elderly to detect silent cerebrovascular disease and other structural brain changes. The high prevalence of psychotic symptoms is an example of the importance to use several sources of information to detect these symptoms. Dementia should be diagnosed in all types of studies in the elderly, as it influences several outcomes such as mortality, blood pressure, and rates of depression. Suicidal feelings are rare in the elderly and are strongly related to mental disorders. Conclusion: Modern epidemiologic studies in population samples should be longitudinal and include assessments of psychosocial risk factors as well as comprehensive sets of biologic markers, such as brain imaging, neurochemical analyses, and genetic information to maximize the contribution that epidemiology can provide to increase our knowledge about the etiology of mental disorders. [source] Migrating Partial Seizures in Infancy: Expanding the Phenotype of a Rare Seizure SyndromeEPILEPSIA, Issue 4 2005Eric Marsh Summary:,Purpose: The constellation of early-onset, unprovoked, alternating electroclinical seizures and neurodevelopmental devastation was first described by Coppola et al. We report six new patients and the prospect of a more optimistic developmental outcome. Methods: Retrospective chart reviews were performed on six infants evaluated at the Children's Hospital of Philadelphia (five patients) and at Hershey Medical Center (one patient) who had electroclinically alternating seizures before age 6 months of age. Electroclinical characteristics and long-term follow-up were recorded. Results: All had unprovoked, early-onset (range, 1 day to 3 months; mean, 25 days) intractable electroclinical seizures that alternated between the two hemispheres. Each patient underwent comprehensive brain imaging and neurometabolic workups, which were unrevealing. In all patients, subsequently intractable partial seizures developed and often a progressive decline of head circumference percentile occurred with age. Three demonstrated severe developmental delay and hypotonia. All survived, and 7-year follow-up on one patient was quite favorable. Conclusions: Our patients satisfied the seven major diagnostic criteria first described by Coppola et al. The prognosis of this rare neonatal-onset epilepsy syndrome from the original description and subsequent case reports was very poor, with 28% mortality, and the majority of survivors were profoundly retarded and nonambulatory. Our patient data validate the diagnostic criteria of this syndrome and further quantify a previously described observation of progressive decline of head circumference percentiles with age. Our data also suggest that the prognosis of this syndrome, although poor, is not as uniformly grim as the cases reported previously in the literature. [source] The clinical utility of MRI in patients with neurodevelopmental disorders of unknown originEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2010H. M. Engbers Introduction:, Neuroimaging of the brain in the diagnostic work-up of patients with neurodevelopmental disorders is a matter of continuing debate. Recommendations range from performing brain imaging in all patients with neurodevelopmental disorders to performing an MRI only in those with indication on clinical examinations. Important indications for neuroimaging are head size abnormalities and focal neurological findings. Methods:, Patients with neurodevelopmental disorders of unknown origin (n = 410), referred to a specialized tertiary diagnostic center for neurodevelopmental disorders were included in a retrospective analysis. A 1-day work-up, including an MRI of the brain was performed. Studied were the: (i) yield of MRI scans of the brain and (ii) associations of specific clinical symptoms/signs with abnormal and diagnostic MRI scans. Results:, (i) In 30.7% of the 410 patients with neurodevelopmental disorders (n = 126), abnormal MRI scans were observed, leading to an etiological diagnosis in 5.4% of the patients (n = 22). (ii) Pyramidal disorders (P = 0.001), epilepsy (P = 0.04) and an abnormal head circumference (P = 0.02) were associated with an abnormal MRI scan. The presence of one of the following neurological symptoms/signs: movement disorders, pyramidal disorders, epilepsy, or an abnormal head circumference was associated with a diagnostic MRI scan (P < 0.001) (diagnostic MRI % in neurological versus no neurological symptoms/signs, 13.0% versus 1.9%). Conclusion:, Neuroimaging of the brain in a tertiary care center for patients with neurodevelopmental disorders of unknown origin is useful, especially in case of neurological symptoms/signs. [source] Variant Creutzfeldt,Jakob disease: first two indigenous cases in Republic of Ireland.EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2007Case report, perspective The first two cases of indigenous variant Creutzfeldt,Jakob disease (vCJD) in the Republic of Ireland are reported in two men, neither of whom had lived outside Ireland. Both diagnoses were made ante-mortem based on clinical presentation, brain imaging, positive 14-3-3 protein in one case, and tonsillar biopsy. We discuss some of the clinical aspects of vCJD and the significance of these cases in the Irish context. [source] Extra temporal involvement in herpes simplex encephalitisEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2005M. Wasay Temporal lobe abnormalities on brain imaging have been described as strong evidence for herpes simplex encephalitis (HSE) in appropriate clinical settings. Extra temporal abnormalities are less well described in these patients. We retrospectively reviewed 20 patients of HSE and found extra temporal involvement in 11 (55%) patients. Three patients (15 %) had pure extra temporal abnormalities. Twelve patients (60%) had temporal lobe involvement, four patients (20%) had pure temporal lobe involvement and five patients (25%) had normal CT/MRI scans. Our study suggests that extra temporal involvement on brain imaging is common in HSE and in a significant minority of the patients this can even be the sole abnormality. [source] No change in the structure of the brain in migraine: a voxel-based morphometric studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2003M. S. Matharu Migraine is a common, disabling form of primary neurovascular headache. For most of the twentieth century it was regarded as a vascular headache whose primary pathophysiology lay in the cranial vasculature. Functional brain imaging using positron emission tomography has demonstrated activation of the rostral brain stem in acute migraine. Voxel-based morphometry is a new fully automated whole brain technique that is sensitive to subtle macroscopic and mesoscopic structural differences between groups of subjects. In this study 11 patients suffering from migraine with aura (10 females, one male: 23,52 years, mean 31); 11 controls (10 females, one male: 23,52, mean 31); 17 patients with migraine without aura (16 females, one male: 24,57, mean 34); 17 controls (16 females, one male: 24,57, mean 34) were imaged with high resolution volumetric magnetic resonance imaging. There was no significant difference in global grey or white matter volumes between either patients with migraine and controls, or patients with aura and without aura. This study did not show any global or regional macroscopic structural difference between patients with migraine and controls, with migraine sufferers taken as homogenous groups. If structural changes are to be found, other methods of phenotyping migraine, such as by genotype or perhaps treatment response, may be required to resolve completely whether there is some subtle structural change in the brain of patients with migraine. [source] Subjective neuronal coding of reward: temporal value discounting and riskEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2010Wolfram Schultz Abstract A key question in the neurobiology of reward relates to the nature of coding. Rewards are objects that are advantageous or necessary for the survival of individuals in a variety of environmental situations. Thus reward appears to depend on the individual and its environment. The question arises whether neuronal systems in humans and monkeys code reward in subjective terms, objective terms or both. The present review addresses this issue by dealing with two important reward processes, namely the individual discounting of reward value across temporal delays, and the processing of information about risky rewards that depends on individual risk attitudes. The subjective value of rewards decreases with the temporal distance to the reward. In experiments using neurophysiology and brain imaging, dopamine neurons and striatal systems discount reward value across temporal delays of a few seconds, despite unchanged objective reward value, suggesting subjective value coding. The subjective values of risky outcomes depend on the risk attitude of individual decision makers; these values decrease for risk-avoiders and increase for risk-seekers. The signal for risk and the signal for the value of risky reward covary with individual risk attitudes in regions of the human prefrontal cortex, suggesting subjective rather than objective coding of risk and risky value. These data demonstrate that important parameters of reward are coded in a subjective manner in key reward structures of the brain. However, these data do not rule out that other neurons or brain structures may code reward according to its objective value and risk. [source] Short-term plasticity visualized with flavoprotein autofluorescence in the somatosensory cortex of anaesthetized ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2004Hiroatsu Murakami Abstract In the present study, short-term plasticity of somatosensory neural responses was investigated using flavoprotein autofluorescence imaging in rats anaesthetized with urethane (1.5 g/kg, i.p.) Somatosensory neural activity was elicited by vibratory skin stimulation (50 Hz for 1 s) applied on the surface of the left plantar hindpaw. Changes in green autofluorescence (, = 500,550 nm) in blue light (, = 450,490 nm) were elicited in the right somatosensory cortex. The normalised maximal fluorescence responses (,F/F) was 2.0 ± 0.1% (n = 40). After tetanic cortical stimulation (TS), applied at a depth of 1.5,2.0 mm from the cortical surface, the responses elicited by peripheral stimulation were significantly potentiated in both peak amplitude and size of the responsive area (both P < 0.02; Wilcoxon signed rank test). This potentiation was clearly observed in the recording session started 5 min after the cessation of TS, and returned to the control level within 30 min. However, depression of the responses was observed after TS applied at a depth of 0.5 mm. TS-induced changes in supragranular field potentials in cortical slices showed a similar dependence on the depth of the stimulated sites. When TS was applied on the ipsilateral somatosensory cortex, marked potentiation of the ipsilateral responses and slight potentiation of the contralateral responses to peripheral stimulation were observed after TS, suggesting the involvement of commissural fibers in the changes in the somatosensory brain maps. The present study clearly demonstrates that functional brain imaging using flavoprotein autofluorescence is a useful technique for investigating neural plasticity in vivo. [source] Comprehensive studies of cognitive impairment of the elderly with type 2 diabetesGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2006Takashi Sakurai Type 2 diabetes mellitus is associated with cognitive dysfunction and increases the risk of dementia for the elderly. The aim of the study presented here was to provide a brief review of how disturbance of glucose and metabolic homeostasis may be implicated in the cognitive decline of patients with type 2 diabetes. Several risk factors such as nutrition, cerebrovascular disorders and the neurotoxic effects of hyperglycemia may combine for the formation of mechanisms of cognitive decline in the diabetic elderly. It should be noted that cognitive deficits of diabetes are accompanied by neuroradiological changes in the brain, so that cognitive dysfunction both with and without brain structural changes may overlap during cognitive decline of the diabetic elderly. Recently, we conducted two studies to explore, by means of brain imaging, hierarchical relationships among clinical profiles of diabetes, cognitive function, white matter hyperintensity and brain atrophy. The results suggested that subcortical brain atrophy and hyperintensity constitute predictors of the rate of progression of cognitive dysfunction in the diabetic elderly, while cortical atrophy is associated with high diastolic blood pressure and lower HbA1c. These hypotheses may explain in part the underlying mechanisms of cognitive impairment in the diabetic elderly. Prospective intervention studies are needed, however, to clarify the mechanism of cognitive dysfunction of the diabetic elderly and what the targets are for preventive measures. [source] Brain Imaging in Migraine ResearchHEADACHE, Issue 9 2010David Borsook MD Understanding the pathophysiology and pharmacology of migraine has been driven by astute clinical observations, elegant experimental medicine studies, and importantly by studying highly effective anti-migraine agents in the laboratory and the clinic. Significant progress has been made in the use of functional brain imaging to compliment observational studies of migraine phenotypes by highlighting pathways within the brain that may be involved in predisposition to migraine, modulating migraine pain or that could be sensitive to pharmacological or behavioral therapeutic intervention (Fig. 1). In drug discovery, molecular imaging approaches compliment functional neuroimaging by visualizing migraine drug targets within the brain. Molecular imaging enables the selection and evaluation of drug candidates by confirming that they engage their targets sufficiently at well tolerated doses to test our therapeutic hypotheses. Figure 1.,. Imaging and defining the migraine brain disease state: from anatomy to chemical entities (targets) to functional systems (function and pathways) (from Borsook et al31 with permission, Nature Publishing Group). Migraine is a progressive disorder. Developing our knowledge of where drugs act in the brain and of how the brain is altered in both episodic migraine (interictal state and ictal state) and chronic migraine are important steps to understanding why there is such differential responsiveness to therapeutics among migraine patients and to improving how they are evaluated and treated. [source] Imaging genetics and development: Challenges and promisesHUMAN BRAIN MAPPING, Issue 6 2010B.J. Casey Abstract Excitement with the publication of the human genome has served as catalyst for scientists to uncover the functions of specific genes. The main avenues for understanding gene function have been in behavioral genetics on one end and on the other end, molecular mouse models. Attempts to bridge these approaches have used brain imaging to conveniently link anatomical abnormalities seen in knockout/transgenic mouse models and abnormal patterns of brain activity seen in humans. Although a convenient approach, this article provides examples of challenges for imaging genetics, its application to developmental questions, and promises for future directions. Attempts to link genes, brain, and behavior using behavioral genetics, imaging genetics, and mouse models of behavior are described. Each of these approaches alone, provide limited information on gene function in complex human behavior, but together, they are forming bridges between animal models and human psychiatric disorders. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source] fMRI evidence for multisensory recruitment associated with rapid eye movements during sleepHUMAN BRAIN MAPPING, Issue 5 2009Charles Chong-Hwa Hong Abstract We studied the neural correlates of rapid eye movement during sleep (REM) by timing REMs from video recording and using rapid event-related functional MRI. Consistent with the hypothesis that REMs share the brain systems and mechanisms with waking eye movements and are visually-targeted saccades, we found REM-locked activation in the primary visual cortex, thalamic reticular nucleus (TRN), ,visual claustrum', retrosplenial cortex (RSC, only on the right hemisphere), fusiform gyrus, anterior cingulate cortex, and the oculomotor circuit that controls awake saccadic eye movements (and subserves awake visuospatial attention). Unexpectedly, robust activation also occurred in non-visual sensory cortices, motor cortex, language areas, and the ascending reticular activating system, including basal forebrain, the major source of cholinergic input to the entire cortex. REM-associated activation of these areas, especially non-visual primary sensory cortices, TRN and claustrum, parallels findings from waking studies on the interactions between multiple sensory data, and their ,binding' into a unified percept, suggesting that these mechanisms are also shared in waking and dreaming and that the sharing goes beyond the expected visual scanning mechanisms. Surprisingly, REMs were associated with a decrease in signal in specific periventricular subregions, matching the distribution of the serotonergic supraependymal plexus. REMs might serve as a useful task-free probe into major brain systems for functional brain imaging. Hum Brain Mapp 2009. © 2008 Wiley-Liss, Inc. [source] Investigating the potential neurotoxicity of Ecstasy (MDMA): an imaging approachHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 8 2001Liesbeth Reneman Abstract Human users of 3,4-methylenedioxymethamphetamine (MDMA, ,Ecstasy') users may be at risk of developing MDMA-induced neuronal injury. Previously, no methods were available for directly evaluating the neurotoxic effects of MDMA in the living human brain. However, development of in vivo neuroimaging tools has begun to provide insights into the effects of MDMA in the human brain. In this review, contributions of brain imaging studies on the potential neurotoxic effects of MDMA and functional consequences are highlighted. An overview is given of PET, SPECT and MR spectroscopy studies, most of which show evidence of neuronal injury in MDMA users. Different neuroimaging tools are discussed that have investigated potential functional consequences of MDMA-induced 5-HT neurotoxic lesions. Finally, the contribution of brain imaging in future studies is discussed, emphasising the crucial role it will play in our understanding of MDMA's short- and long-term effects in the human brain. Copyright © 2001 John Wiley & Sons, Ltd. [source] Antidepressants in clinical practice: limitations of assessment methods and drug responseHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 1 2001Sidney H Kennedy Abstract There is a recognized gap between knowledge derived from ,efficacy' data , based on usually brief randomized controlled trials and findings in natural practice ,effectiveness' studies. In considering the limitations of current antidepressants in clinical practice, we have selected three clinically important issues to examine in a natural practice data base that has been in existence for several years. These relate to: (1) Diagnostic heterogeneity and potential advances using functional brain imaging; (2) Variability of outcome measures during treatment and (3) Time to response and prediction of outcome. Copyright © 2001 John Wiley & Sons, Ltd. [source] Decreasing myelin density reflected increasing white matter pathology in Alzheimer's disease,a neuropathological studyINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 10 2005Martin Sjöbeck Abstract Background White matter disease (WMD) is frequently seen in Alzheimer's disease (AD) at neuropathological examination. It is defined as a subtotal tissue loss with a reduction of myelin, axons and oligodendrocytes as well as astrocytosis. Studies quantitatively defining the myelin loss in AD are scarce. The aim was to develop a method that could provide numerical values of myelin density in AD. The purpose was to compare the myelin contents in increasing grades of pathology of WMD, with age and cortical AD pathology as well as in different regions of the brain in AD. Material and methods Sixteen cases with AD and concomitant WMD were investigated with an in-house developed image analysis technique to determine the myelin attenuation with optical density (OD) in frontoparietal, parietal, temporal and occipital white matter on whole brain coronal sections stained for myelin with Luxol Fast Blue (LFB). The OD values in LFB were compared grouped according to Haematoxylin/Eosin (HE) evaluated mild, moderate and severe WMD or normal tissue. The OD values were also correlated with age and cortical AD pathology and compared between the different studied white matter regions. Results Increasing severity of WMD was associated with a statistically significant OD reduction. No correlation was seen between age and OD or overall cortical AD pathology. The OD values were significantly lower in frontoparietal-compared to occipital white matter. Conclusions Myelin loss in AD with WMD is a marked morphologic component of the disease and it is possible to determine the reduction objectively in neuropathological specimens with quantitative measures. This may be of use for clinical diagnostics including brain imaging. Copyright © 2005 John Wiley & Sons, Ltd. [source] Maximizing Clinical Research Participation in Vulnerable Older Persons: Identification of Barriers and MotivatorsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2008Edward R. Marcantonio MD OBJECTIVES: To identify barriers and motivators to participation in long-term clinical research by high-risk elderly people and to develop procedures to maximize recruitment and retention. DESIGN: Quantitative and qualitative survey. SETTING: Academic primary care medicine and pre-anesthesia testing clinics. PARTICIPANTS: Fifty patients aged 70 and older, including 25 medical patients at high risk of hospitalization and 25 patients with planned major surgery. MEASUREMENTS: Fifteen- to 20-minute interviews involved open- and closed-ended questions guided by an in-depth script. Two planned study protocols were presented to each participant. Both involved serial neuropsychological assessments, blood testing, and magnetic resonance brain imaging (MRI); one added lumbar puncture (LP). Participants were asked whether they would be willing to participate in these protocols, rated barriers and incentives to participation, and were probed with open-ended questions. RESULTS: Of 50 participants (average age 78, 44% male, 40% nonwhite), 32 (64%) expressed willingness to participate in the LP-containing protocol, with LP cited as the strongest disincentive. Thirty-eight (76%) expressed willingness to participate in the protocol without LP, with phlebotomy and long interviews cited as the strongest disincentives. Altruism was a strong motivator for participation, whereas transportation was a major barrier. Study visits at home, flexible appointment times, assessments shorter than 75 minutes, and providing transportation and free parking were strategies developed to maximize study participation. CONCLUSION: Vulnerable elderly people expressed a high rate of willingness to participate in an 18-month prospective study. Participants identified incentives and barriers that enabled investigators to develop procedures to maximize recruitment and retention. [source] Mild Cognitive Impairment Subtypes and Vascular Dementia in Community-Dwelling Elderly People: A 3-Year Follow-Up StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2006Mariella Zanetti MD OBJECTIVES: To investigate whether mild cognitive impairment (MCI) with multiple impaired cognitive domains (mcd-MCI) is a prodromal manifestation of vascular dementia (VaD). DESIGN: Prospective cohort study. SETTING: Geriatric unit of the Ospedale Maggiore Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy. PARTICIPANTS: Four hundred community-dwelling subjects aged 65 and older who came freely to the geriatric unit as part of a comprehensive geriatric assessment program were evaluated for memory impairment or other cognitive disorders. Subjects with MCI were kept under observation for 3 years. MEASUREMENTS: Subjects with MCI were studied by applying a standardized clinical evaluation and a conducting a computed tomography brain scan. Cognitive performance was assessed using the Mini-Mental State Examination, the Clock Drawing Test, and a comprehensive battery of neuropsychological tests. Cardiovascular comorbidity was assessed on the basis of medical history and using electrocardiography, echocardiography, and carotid color Doppler ultrasound. RESULTS: MCI was found in 65 of the 400 community-dwelling subjects; 31 were classified with amnestic MCI (a-MCI) and 34 with mcd-MCI. A dysexecutive syndrome characterized people with mcd-MCI, who had significantly more vascular comorbidity and signs of vascular disease on brain imaging as well as a higher prevalence of extra pyramidal features, mood disorders, and behavioral symptoms than people with a-MCI. Twenty of the 65 subjects with MCI (31%) progressed to dementia within 3 years of follow-up: 11 subjects with Alzheimer's disease (AD) and nine with VaD. All patients who evolved to AD had been classified with a-MCI at baseline, whereas all patients who evolved to subcortical VaD had been classified with mcd-MCI at baseline. CONCLUSION: All subjects who converted to subcortical VaD had been classified with mcd-MCI, suggesting that mcd-MCI might be an early stage of subcortical VaD. [source] Functional and Cognitive Consequences of Silent Stroke Discovered Using Brain Magnetic Resonance Imaging in an Elderly PopulationJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2004Wolf-Peter Schmidt MD Objectives: To evaluate the prevalence of silent stroke and its associated consequences on physical, cognitive, and emotional functioning in an elderly population. Design: Population-based cross-sectional survey. Setting: The Memory and Morbidity in Augsburg Elderly project in the Augsburg region of southern Germany. Participants: Two hundred sixty-seven community-dwelling persons aged 65 to 83. Measurements: The presence of silent stroke was determined using magnetic resonance imaging brain scan and a single question asking for physician-diagnosed stroke in each participant. The health effect of silent stroke was assessed using rating scales for self-perceived health status (36-item short-form health survey), activities of daily living (ADLs) and instrumental ADLs, cognitive function, and depression (Center for Epidemiologic Studies Depression scale). Results: Just fewer than 13% (12.7%) of participants were affected by silent stroke. Silent stroke was associated with a history of hypertension, heart surgery, and elevated C-reactive protein. Individuals with silent stroke showed impairments on the Mini-Mental State Examination test and in the cognitive domains of memory, procedural speed, and motor performance. Conclusion: The presence of silent stroke has a considerable effect on cognitive performance in those affected. Determining the presence of silent stroke using brain imaging may contribute to identifying individuals at risk for developing gradual neurological deficits. [source] | ||||||||||||||||||||||||||||||||||||||||