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At least 1,549 records · Page 86Linked to original sources
PubMed1999

Plasticity of language-related brain function during recovery from stroke.

BACKGROUND AND PURPOSE: This study was undertaken to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic, physiological, and functional changes as measured by MRI. METHODS: Blood oxygenation level-dependent contrast and echo-planar MRI were used to map language comprehension in 6 normal adults and in 2 adult patients during recovery from acute stroke presenting with aphasia. Perfusion, diffusion, sodium, and conventional anatomic MRI were used to follow physiological and structural changes. RESULTS: The normal activation pattern for language comprehension showed activation predominately in left-sided Wernicke's and Broca's areas, with laterality ratios of 0.8 and 0.3, respectively. Recovery of the patient confirmed as having a completed stroke affecting Broca's area occurred rapidly with a shift of activation to the homologous region in the right hemisphere within 3 days, with continued rightward lateralization over 6 months. In the second patient, in whom mapping was performed fortuitously before stroke, recovery of a Wernicke's aphasia showed a similar increasing rightward shift in activation recruitment over 9 months after the event. CONCLUSIONS: Recovery of aphasia in adults can occur rapidly and is concomitant with an activation pattern that changes from left to a homologous right hemispheric pattern. Such recovery occurs even when the stroke evolves to completion. Such plasticity must be considered when evaluating stroke interventions based on behavioral and neurological measurements.

Adult↗
PubMed2006

Pseudo current density maps of electrophysiological heart, nerve or brain function and their physical basis.

BACKGROUND: In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular. METHODS: The physical basis of these intuitive maps is clarified by means of analytically solvable problems. RESULTS: Examples in magnetocardiography, magnetoencephalography and magnetoneurography demonstrate the usefulness of this method. CONCLUSION: Hardware realizations of the HC-transformation and some similar transformations are discussed which could advantageously support cross-platform comparability of biomagnetic measurements.

Journal Article↗
PubMed1993

A single photon emission computerised tomography study of regional brain function underlying verbal memory in patients with Alzheimer-type dementia.

Ten patients with Alzheimer-type dementia and nine age-matched normal controls were examined with SPECT, using split-dose 99mTc-labelled exametazime. The baseline condition involved repetition of the word 'yes' or 'no'. The activation condition involved recognition (indicated by a 'yes' or 'no') of words from a previously learned list presented along with distractor words. Patients who performed this task successfully were selected, and efforts were made to match the patients with controls according to their performance on the task, although this was not fully achieved. Uptake of 99mTc-exametazime was estimated at baseline and during the word-recognition task for predetermined regions of interest drawn from a standard neuroanatomical atlas. The baseline task appeared to normalise tracer uptake for frontal, temporal and parietal cortex in the patient group. However, during the recognition task, controls but not patients showed activation effects. These were most prominent in dorsolateral frontal cortex and adjacent anterior cingulate cortex. Among patients, successful performance was correlated with activation of dorsolateral frontal and parietal cortex on the left side. The results confirm the central role of frontal mechanisms in a recognition memory task. The study highlights some of the difficulties of using cognitive challenge tests in clinical groups.

Acoustic Stimulation↗
PubMed2005

Autism: functional brain mapping of exceptional calendar capacity.

BACKGROUND: 'Autistic savants' are individuals with autism who have extraordinary skills. Brain mechanisms underlying such capacities are still unknown. AIMS: To map the exceptional calendar capacity of a man with primary autism. METHOD: Positron emission tomography was used to map brain activity in a man who is able to associate a day of the week with the corresponding calendar date. RESULTS: During the calendar task, the left hippocampus, the left frontal cortex and the left middle temporal lobe were activated. CONCLUSIONS: The cerebral circuit involved in this man's prodigious calendar skill is similar to that normally involved in memory retrieval tasks. These results suggest that the prodigious capacities may be sustained by memory processing.

Adult↗
PubMed1991

Effects of bifemelane hydrochloride, a brain function improver, on muscarinic receptors in the CNS of senescence-accelerated mouse.

Senescence-accelerated mouse (SAM-P/8) is known as a murine model of aging and memory dysfunction, compared with control mouse (SAM-R/1). In the hippocampus of 9-month-old SAM-P/8, the Bmax of [3H]QNB binding was decreased compared with that of SAM-R/1 at the same age. Single and repeated administrations of bifemelane to SAM-P/8 induced an increase in the Bmax of [3H]QNB binding in the hippocampus. From these results, bifemelane seems to exert pharmacological effects through possible activation of the cholinergic system in the hippocampus of SAM.

Aging↗
PubMed1997

A clinical study on the effect of reinforcement of kidney on senile brain functions.

In this study, Wu Zi Yan Zong ([symbol: see text] WZYZ) fluid was used as the main recipe for reinforcement of the kidney. Six weeks after the therapy, the abilities of instantaneous memory and the memory of the segments of logical story were elevated, the time of upright standing with one leg and closure of the eye was prolonged, and the hand tremor and degree of kidney deficiency were improved, but the memory width (memory in sequence and in reverse sequence of a figure) showed no significant difference in comparison with that before treatment.

Aged↗