PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Brain Mapping”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources

Imaging: window on the brain.

Given the rapid advances in neuroimaging and brain mapping, it is no surprise that a whole host of new and burgeoning techniques are on the horizon as we enter the 21st century. This brief review focuses on methods that are just entering the clinical experience or are now being explored in a research setting but have the imminent potential for clinical use. A number of brain mapping techniques now allow the clinician to monitor disease progression and therapeutic effects in either the routine clinical setting or experimental clinical trials. A battery of methods are now available for the preoperative and intraoperative evaluation of patients with lesions in or near critical cortical areas or for targeting purposes when deep nuclei of the brain are potential sites of therapeutic ablation or electrophysiologic stimulation. The development of probabilistic atlases will soon provide a means of understanding normal variants of human brain structure and function and studying brain disorders and their treatment in an objective and quantifiable fashion. Techniques that are now on the horizon for imaging gene expression, neuronal excitivity, and connectivity are presented in their current stage of development. It is clear that brain mapping and neuroimaging will continue to be ever more important parts of clinical neuroscience and may ultimately serve as the bridge between the molecular and clinical domains of this field. Arch Neurol. 2000;57:1413-1421

Brain↗

Towards multimodal atlases of the human brain.

Atlases of the human brain have an important impact on neuroscience. The emergence of ever more sophisticated imaging techniques, brain mapping methods and analytical strategies has the potential to revolutionize the concept of the brain atlas. Atlases can now combine data describing multiple aspects of brain structure or function at different scales from different subjects, yielding a truly integrative and comprehensive description of this organ. These integrative approaches have provided significant impetus for the human brain mapping initiatives, and have important applications in health and disease.

Anatomy, Artistic↗

[Functional recuperation after resection of gliomas infiltrating primary somatosensory fields. Study of perioperative electric stimulation].

BACKGROUND: With the aim to achieve the most complete resection in cases of parietal low-grade glioma involving the primary somatosensory area (S I), the authors describe a series with resection of S I using an intraoperative brain mapping. The immediate and delayed postoperative functional results are analyzed. PATIENTS AND METHODS: Six patients were operated on for a low-grade glioma involving S I, revealed by seizures with a normal clinical examination. All patients underwent awake surgery under local anesthesia, to allow realization of an intraoperative sensorimotor brain mapping using direct electrical stimulations. RESULTS: The primary motor area (M I) and S I were detected in all procedures. A part of infiltrated S I was removed in spite of a sensitive response of this area during stimulations (sensory face in 2 cases, upper limb area in 5 cases, and lower limb area in 2 cases). All patients presented an immediate postoperative sensory deficit, with recovery in the 6 cases within 3 months. Five resections were total and one subtotal. CONCLUSIONS: In our experience, the primary somatosensory area could be resected in case of tumoral infiltration, without inducing a permanent neurological deficit. This may be due to brain plasticity mechanisms, with recruitment of loco-regional and controlateral eloquent regions, and also the learning of new compensatory strategies. Such a phenomenon can lead to perform more extensive resections in cases of infiltrative gliomas in the somatosensory region.

Adult↗

[Brain potential mapping by a new method of polynomial interpolation].

The mapping of evoked cerebral activity is largely determined by the choice of the interpolation system used. When the number of electrodes is very large, practically any interpolation system is valid, but the geometrical and anatomical limitations imposed by the animals normally chosen for these experiments impede the use of a large number of electrodes; hence the overriding importance of a workable interpolation system. The polynomic interpolation method on the monomial structure is presented as valid, and compared with the pseudolineal interpolation method, which is more commonly used.

Algorithms↗

Mapping of brain areas containing RNA homologous to cDNAs encoding the alpha and beta subunits of the rat GABAA gamma-aminobutyrate receptor.

An in situ hybridization technique was used to determine the distribution in rat brain of RNA homologous to cDNA clones encoding the alpha and beta subunits of the rat brain GABAA gamma-aminobutyrate receptor. The subunit proteins were mapped in adjacent sections autoradiographically and immunohistochemically. Many brain areas containing high densities of GABAA receptors showed strong hybridization signals with both the alpha- and the beta-subunit antisense RNA probe--e.g., cerebral cortex, hippocampus, and cerebellum. On a cellular level, a dense dendritic localization of GABAA receptors was correlated with a strong hybridization in the corresponding somata--e.g., in mitral cells of the olfactory bulb, pyramidal cells of hippocampus, granule cells of the dentate gyrus, and Purkinje and granule cells of the cerebellum. In some brain areas--e.g., substantia nigra--the intensity of the hybridization signal with the beta-subunit probe was much weaker than that with the alpha-subunit probe, whereas the inverse ratio of hybridization intensity was found in others--e.g., in bed nucleus. This regional heterogeneity in the hybridization pattern may reflect regional differences in RNA stability, transcription rate, or subunit composition. The results open the way for studies on the regulation of GABAA-receptor gene expression in normal and pathological brain in situ.

Animals↗

Positron emission tomography using [18F] fluorodeoxyglucose and [11C] l-methionine to metabolically characterize dysembryoplastic neuroepithelial tumors.

Dysembryoplastic neuroepithelial tumors are unique and benign congenital tumors occurring frequently in children and adolescents. Differentiation from other low-grade tumors is important for management. Five patients with confirmed dysembryoplastic neuroepithelial tumors were studied with positron emission tomography using glucose and protein metabolic uptake in an attempt to categorize these tumors metabolically. Functional brain mapping also was obtained to aid in operative management. Results of the study conclude that dysembryoplastic neuroepithelial tumors, although having similar neuroimgaing characteristics to other low-grade tumors, are distinguished by a unique metabolic profile. They are inactive tumors with no significant glucose or protein metabolic activity. The combination of preoperative positron emission tomographic metabolic studies with functional brain mapping allowed for prediction of tumor type, defined eloquent areas of cortical function, and improved approach and resection of the tumors with minimal risk of neurologic impairment.

Adolescent↗

Restored speech comprehension linked to activity in left inferior prefrontal and right temporal cortices in postlingual deafness.

The left inferior prefrontal cortex (LIPC) is involved in speech comprehension by people who hear normally. In contrast, functional brain mapping has not revealed incremental activity in this region when users of cochlear implants comprehend speech without silent repetition. Functional brain maps identify significant changes of activity by comparing an active brain state with a presumed baseline condition. It is possible that cochlear implant users recruited alternative neuronal resources to the task in previous studies, but, in principle, it is also possible that an aberrant baseline condition masked the functional increase. To distinguish between the two possibilities, we tested the hypothesis that activity in the LIPC characterizes high speech comprehension in postlingually deaf CI users. We measured cerebral blood flow changes with positron emission tomography (PET) in CI users who listened passively to a range of speech and non-speech stimuli. The pattern of activation varied with the stimulus in users with high speech comprehension, unlike users with low speech comprehension. The high-comprehension group increased the activity in prefrontal and temporal regions of the cerebral cortex and in the right cerebellum. In these subjects, single words and speech raised activity in the LIPC, as well as in left and right temporal regions, both anterior and posterior, known to be activated in speech recognition and complex phoneme analysis in normal hearing. In subjects with low speech comprehension, sites of increased activity were observed only in the temporal lobes. We conclude that increased activity in areas of the LIPC and right temporal lobe is involved in speech comprehension after cochlear implantation.

Adult↗

Rapid termination of intraoperative stimulation-evoked seizures with application of cold Ringer's lactate to the cortex. Technical note.

One major risk of intraoperative stimulation mapping is the production of stimulation-evoked seizures. Cold Ringer's lactate solution was applied directly to the irritated cortex in 22 patients with stimulation-induced seizures that occurred during intraoperative brain mapping procedures. The irrigation rapidly and reliably terminated these simple partial seizures and eliminated the need for intravenously administered short-acting barbiturates with antiepileptic properties. The authors describe a practical and simple method for controlling stimulation-induced seizure activity during brain mapping procedures.

Administration, Topical↗

Network operations revealed by brain metabolic mapping in a genetic model of hyperactivity and attention deficit: the naples high- and low-excitability rats.

Genetic rat models are important for research on the neural networks of attention and emotionality. Naples-High Excitability (NHE) rats and Naples Low-Excitability (NLE) rats were investigated with random-bred (NRB) rats as controls. These rat lines were named for their respective behavior on spatial novelty tasks. Quantitative cytochrome oxidase (CO) histochemistry has been demonstrated to reflect long-lasting changes in tissue metabolic capacity. CO metabolic differences between the NLE and NHE were found in the granular cell layer of the outer blade of the dentate gyrus. In addition, NLE showed greater CO activity than NRB in medial frontal cortex, and lower activity in perirhinal cortex (dorsal region). NHE showed greater CO activity than NRB in entorhinal cortex (superficial layers) and lower activities in perirhinal cortex and cortical amygdala. These data support the hypothesis that NLE/NHE rats may be an appropriate model for studying genetically altered limbic regions related to impaired emotional processing. The results support the involvement of limbic circuits in attentive processes and impulsiveness, and support the use of the NLE and NHE strains as animal models of Attention Deficit Hyperactivity Disorder (ADHD) in children.

Animals↗

[Brain biopotential mapping in emotional and cognitive pathology].

The EEG rhythms spectral power and intracortical connections were studied in depressive and schizophrenic patients in four schematically outlined main cortical quadrants. In depressive patients two cortical quadrants--right anterior and left posterior ones appeared to be predominantly involved in negative emotions regulation. Alpha-rhythm spectral power and cortical connections in these areas were decreased, pointing to their relative hyperactivation and functional disturbances. Schizophrenics patients were divided into two groups--with the predominance of "positive" and "negative" symptoms. In the first group there was revealed the decrease of the most EEG rhythms spectral power only in parietal areas, on the second one--in all cortical areas. There was also the significant alpha-rhythm spectral power asymmetry, different in the two groups of schizophrenic patients. In "positive" schizophrenics the decrease of alpha-rhythm spectral power was revealed in parietal and occipital areas of the right hemisphere, and in "negative" ones--vice versa, these results pointing of the relatively higher activation of the right posterior quadrant in the former group and of the left posterior quadrant in the latter one. In the anterior cortical quadrants the intracortical connections were however higher in the left hemisphere in "positive" and in the right one--in "negative" schizophrenics. Thus, there are some contradictory results obtained by different methods in anterior and posterior cortical quadrants in each hemisphere, these results being of opposite directions in patients with "positive" and "negative" manifestations. "Region of interest" (ROI) in schizophrenics appeared to be predominantly the frontal and temporal ones, while the "Rhythm of interest"--beta2.

Adjustment Disorders↗

Statistical parametric mapping in brain single photon computed emission tomography after carbon monoxide intoxication.

The purpose of this retrospective study was to assess regional cerebral blood flow in patients after carbon monoxide intoxication by using brain single photon emission computed tomography and statistical parametric mapping. Eight patients with delayed neuropsychiatric sequelae and ten patients with no neuropsychiatric symptoms after carbon monoxide intoxication were studied with brain single photon emission tomography imaging with 99mTc-hexamethyl-propyleneamine oxime. Forty-four control subjects were also studied. We used the adjusted regional cerebral blood flow images in relative flow distribution (normalization of global cerebral blood flow for each subject to 50 ml x 100 g(-1) x min(-1) with proportional scaling) to compare these groups with statistical parametric mapping. Using this technique, significantly decreased regional cerebral blood flow was noted extensively in the bilateral frontal lobes as well as the bilateral insula and a part of the right temporal lobe in the patients with delayed neuropsychiatric sequelae as compared with normal volunteers (P< 0.005). In the patients with no neuropsychiatric symptoms, significantly decreased regional blood flow in the bilateral frontal lobes particularly on the left side was detected. There was a significantly decreased regional cerebral blood flow in the right frontal lobe and insula in the patients with delayed neuropsychiatric sequelae as compared to those with no neuropsychiatric sequelae. It is concluded that statistical parametric mapping is a useful technique for highlighting differences in regional cerebral blood flow in patients following carbon monoxide intoxication as compared with normal volunteers. The selectively reduced blood flow noted in this investigation supports the contention that the decrease following carbon monoxide intoxication may be prolonged and further worsen in the frontal lobe. In addition, the present study may help to clarify the characteristics of the pathophysiological alteration underlying delayed neuropsychiatric sequelae.

Adult↗

Microtubule-associated proteins of HeLa cells: heat stability of the 200,000 mol wt HeLa MAPs and detection of the presence of MAP-2 in HeLa cell extracts and cycled microtubules.

One of the major groups of microtubule-associated proteins (MAPs) found associated with the microtubules isolated from HeLa cells has a molecular weight of just over 200,000. Previous work has demonstrated that these heLa MAPs are similar in several properties to MAP-2, one of the major MAPs of mammalian neural microtubules, although the two types of proteins are immunologically distinct. The 200,000 mol wt HeLa MAPs have now been found to remain soluble after incubation in a boiling water bath and to retain the ability to promote tubulin polymerization after this treatment, two unusual properties also shown by neural MAP-2. This property of heat stability has allowed the development of a simplified procedure for purification of the 200,000 HeLa MAPs and has provided a means for detection of these proteins, even in crude cell extracts. These studies have also led to the detection of a protein in crude extracts of HeLa cells and in cycled HeLa microtubules which has been identified as MAP-2 on the basis of (a) comigration with calf brain MAP-2 on SDS PAGE, (b) presence in purified microtubules, (c) heat stability, and (d) reaction with two types of antibodies prepared against neural high molecular weight-MAPs, one of these a monoclonal antibody against hog brain MAP-2, although present in HeLa cells, is at all stages of microtubule purification a relatively minor component in comparison to the 200,000 HeLa MAP's.

Cross Reactions↗

Isolation of novel human fetal brain cDNAs mapped to human chromosome bands, 1q25 and 8q24.1.

We isolated chromosome band-specific human fetal brain cDNAs by the microdissection mediated cDNA capture method, and localized these cDNA using in situ hybridization histochemistry with developing rat brain sections. Uni-Amp cDNAs were prepared from an 18-week old human fetal brain, and hybridized to human metaphase chromosomes. Eight Uni-Amp cDNAs, hybridized to chromosome band 1q25 or 8q24.1, were recovered by microdissection and PCR amplification with Uni-Amp primers. Among these cDNAs, two novel genes (FB113 of 8q24.1 and FB134 of 1q25) showed a temporospatially interesting expression pattern in the developing rat brains. The expression of FB113 was under dynamic regulation in the developing granule cells of cerebellum and dentate gyrus. FB134 showed a nervous tissue specific expression pattern and an exclusively prominent expression in the developing presubiculum and parasubiculum. By the fluorescence in situ hybridization using human genomic DNAs, FB113 and FB134 were mapped back to the human chromosome bands 8q24.1 and 1q25, respectively. These results indicate that combined application of the microdissection mediated cDNA capture method and in situ hybridization histochemistry can be used for the isolation of chromosomal band-specific genes related to brain development or human genetic diseases.

Animals↗

Pain imaging: future applications to integrative clinical and basic neurobiology.

We have entered a new era in understanding CNS circuitry involved in acute and chronic pain. The ability to objectively measure a pain or analgesic state of the brain using non-invasive methods that define neural activation provides the possibility for top-down approaches to drug discovery. These brain maps represent the specific brain state. In the future, correlations with such states and behavioral, genetic, epigenetic or other chemical markers may help define specific diagnostic tools and novel approaches to drug discovery.

Animals↗

Association of a cytoplasmic dynein-like protein recognizable by anti-MAP 1C with the mammalian mitotic spindle.

A rabbit antibody to bovine brain MAP 1C was prepared. The antibody stained the mitotic spindle of PtK2 cells by immunofluorescence. On immunoblots of PtK2 cell extract the antibody reacted with polypeptides of molecular weights greater than 350 and 80 KD that resemble the subunit proteins of bovine brain MAP 1C. An additional 135 KD polypeptide in the extract was also stained. These results indicate that a cytoplasmic dynein recognizable by the anti-MAP 1C antibody is localized in the mitotic spindle.

Adenosine Triphosphatases↗

Neuronavigation in surgery of intracranial and spinal tumors.

PURPOSE: To demonstrate the new possibilities and advantages of neuronavigation in the surgery of intracranial and spinal tumors, based on patient populations treated in our hospital. MATERIALS AND METHODS: An infrared navigation system with integrated microscope guidance was used for frameless intracranial neuronavigation. The biopsies of intracranial tumors were carried out using a frame-based stereotactic technique. Intracranial navigation was, in part, combined with the use of an intraoperative CT scanner and a three-dimensional ultrasound system for data acquisition, correction of brain shifts, and intraoperative quality control. The navigation was also supported by presurgical brain mapping with magnetic source imaging. Navigation in spinal surgery was exclusively performed using an infrared navigation system in combination with an intraoperative CT scanner. RESULTS: The stereotactic tumor biopsies (n = 57) were carried out with an accuracy of 91.4% as compared with the histological diagnosis. The work flow of stereotactic procedures could be increased by using the intraoperative CT scanner. Fifty-seven patients with intracranial tumors were treated with the aid of neuronavigation between July 1997 and December 1999. These patients showed an improvement from 80% to 86% on the Karnofsky index 8 weeks postoperatively. The majority of intracranial cases were primary brain tumors (n = 30) and metastases (n = 13) in functionally important areas of the brain. In four patients, a significant brain shift was observed during neuronavigation, and could be corrected by an image update using either the intraoperative CT scanner (n = 2) or the three-dimensional ultrasound system (n = 2). The presurgical brain mapping with magnetoencephalography was shown to be reliable in the sensory cortex (n = 25). Eleven patients with a thoracic or lumbar tumor were treated by open surgery or stabilization, using a combination of spinal neuronavigation and the intraoperative CT scanner. Two patients with spinal tumors underwent navigated biopsies. Neither of them showed a reduction in the clinical stage, but the Karnofsky index improved from 63% up to 72% 8 weeks postoperatively. CONCLUSION: Neuronavigation allows very precise intracranial and spinal surgery. The problem of brain shift during the navigation procedures has been solved by intraoperative image acquisition. The use of neuronavigation was shown to improve the postoperative quality of life of patients suffering from brain and spinal tumors.

Adult↗

Functional imaging of the brain in psychiatry--mapping of EEG and evoked potentials.

Topographic brain mapping of EEG and evoked potentials permits the display of spontaneous and event-related activity of the brain. This new method is superior to conventional polygraphy because of the topographic approach which delineates structural and functional brain lesions. Data from 16 to 20 scalp electrodes were evaluated. Not only spontaneous EEG but also EEG during various testing conditions which activated particular brain regions was measured. For EEG fast Fourier transformation (FFT) was used for mapping. For late evoked potentials (VEP, AEP, SEP and P300) a single value representing the amplitude of EP at each 2-ms poststimulus latency point was used. Statistical techniques (Students'-test, correlation coefficient) were used to render the regions where a clinical population differs from normal subjects. The results show abnormalities of EGG and EP in patients with psychiatric and neurological diseases.

Arousal↗