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Background and purpose: Neuromodulation is a promising approach to increasing motor recovery in stroke; however, to date, there is a scarcity of evidence documenting the clinical potential of transcranial direct current stimulation (tDCS) administered in the acute phase of stroke. The present study aims to examine the clinical effects of a treatment involving the application of tDCS in the acute stage post‐stroke. Methods: This was a randomized, double‐blind, sham‐controlled trial. A cohort of 32 stroke patients with severe motor impairment underwent 5 days of treatment with real or sham bi‐hemispheric tDCS over the motor cortex. During the treatment, tDCS was applied twice per day (two daily applications each of 15 min), starting 48 to 72 h after stroke onset. Results: We found statistically significant improvements after both real and sham tDCS treatments in primary (hand grip strength, Motricity Index) and secondary (National Institutes of Health Stroke Scale score, Barthel Index) outcomes. Patients receiving real tDCS showed a larger improvement of upper‐limb muscle strength at the end of treatment phase; this advantage was no longer present after 6 months. Conclusions: Transcranial direct current stimulation may be used to accelerate the rate of upper‐limb motor recovery during the spontaneous recovery period. [ABSTRACT FROM AUTHOR]

One possible pathological mechanism underlying the rightward bisection error of right- brain-damaged patients with left spatial neglect is a leftward relaxation of the spatial representational medium. This view was originally based on the finding that patients with left neglect, required to extend horizontal segments, in order to double their original length, may exhibit a relative left overextension of the drawn lines (Bisiach et al., 1994). We investigated this putative distortion of representational space using a 16cm line segmentation' task (Experiment I). Were the representation of space relaxed contralesionally, a progressive increase from right to left of the size of the drawn segments would be expected. Right-brain-damaged patients with left unilateral neglect (N = 12) performed the segmentation task with no left versus right differences, as right-brain-damaged patients without neglect (N = 8), and neurologically unimpaired control subjects (N = 10), did. Experiments 2 and 3 explored the effects of sample length (1, 2, 4, and 8cm), by which the 16cm lines had to be segmented. Neglect patients produced longer left-sided segments only for the 8cm sample (i.e. half of the length of the segment). This set of experiments suggests an impairment in the segmentation task only with the larger (8cm) sample, when a more global level of processing may be involved. Experiment 4 assessed this hypothesis by a part/whole' bisection task, using 8cm lines, presented either embedded in a longer 16cm line or in isolation. Neglect patients made a larger rightward bisection error when the segment was not embedded. The suggestion is made that the lateral distortion of the representation of space in neglect patients (i.e. a leftward relaxation of the spatial medium) concerns tasks where a more 'global' representation of the visual stimulus has to be set up. The different demands of the segmentation and bisection tasks are discussed. [ABSTRACT FROM AUTHOR]

A quantitative assessment of a distortion involving the left side of space, both in two-dimensional (drawing), and three-dimensional (modeling), visuo-constructional tasks is reported in a patient with a right temporoparieto-occipital lesion, and left hemianopia, without visuospatial neglect. In drawing and clay modeling of objects the patient exhibited a disproportionate enlargement of the left-hand side of objects. Matching perceptually two rectangles, the patient underestimated the left side of the stimulus. In a visuomotor task requiring the reproduction of horizontal extent, the patient exhibited a leftward overextension. Observations in two right-brain-damaged patients by Rode, Michel, Rossetti, Boisson, and Vallar (2006, Neurology, 67, 1801) are confirmed and extended. The patient's impairment may involve a disordered representation of extrapersonal space, with a leftward disproportionate expansion of the spatial medium ('hyperschematia'). Accordingly, symmetrical productions are compensatorily expanded leftwards, and the left sides of objects are perceived as smaller in horizontal extent. The disorder is largely independent of left spatial neglect. [ABSTRACT FROM AUTHOR]

A new computerised test adopting touch-screen technology has been developed to assess the visuo-motor exploration of extra-personal space. The test was derived from well-known paper-and-pencil cancellation tasks used widely in the diagnosis and quantitative assessment of unilateral spatial neglect (USN), a neuropsychological syndrome that is more frequent and severe after damage to the right cerebral hemisphere. A main component deficit of USN is the defective visuo-motor exploration of the side of space contralateral to the side of the lesion (contralesional), namely, in right-sided brain-damaged patients it occurs on the left side and vice versa. The computer-based paradigm consisted of a visuo-motor spatial exploratory task: the subjects were instructed to touch, in any order they wished, all the targets they detected on a computer touch-screen. This measured the time of occurrence and the spatial co-ordinates of each touch event and forwarded the data to the computer for storage; the computer provided feedback to the subject by 'tagging' the touched target. The paradigm allowed the calculation of accuracy and latency indexes and recorded the exploratory pathway taken by each subject. A pilot study was performed in ten normal subjects and 15 brain-damaged patients, with and without psychometric evidence of USN; the results showed that the equipment was able to provide quantitative indexes related to the spatial-temporal aspects of exploratory ability, which are useful for diagnostic purposes, and revealed significant differences between the controls and patients with USN: the overall average values of latency and crossing indexes increased in patients with USN, compared with the controls (latency from 0.77 to 1.90s; path crossing index from 7.0% to 59.5%), and the significantly negative USN patient latency gradient (-2.79 against a null control value) evidenced a worsening of performance towards the left side. [ABSTRACT FROM AUTHOR]

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The anatomical correlates of tactile and visual extinction with double simultaneous stimulation were investigated in a series of 159 patients with right brain damage caused by stroke. Forty six patients showed extinction (22 tactile, 14 visual, 10 tactile and visual). Over 50% of the patients with extinction had deep lesions, which were found in about 25% of the patients with visuospatial neglect not associated with extinction. In the patients with extinction and cortico-subcortical damage the paraventricular occipital white matter and the dorsolateral frontal cortex were most often involved. By contrast, when neglect was also present, the lesions clustered in the inferior parietal lobule. These data suggest, from an anatomical perspective, that partly different neural mechanisms may underlie neglect and extinction. The comparatively high frequency of subcortical lesions involving the ascending pathways may be a neural correlate of a sensory component of extinction. [ABSTRACT FROM AUTHOR]

A patient with an ischaemic lesion involving the right frontal lobe and basal ganglia showed left spatial hemineglect in visuomotor exploratory tasks, requiring the use of the right unaffected hand. Her performance was, however, entirely preserved, with no evidence of neglect, when she was required to identify targets among distractors in both the left and right halves of space, and in the Wundt-Jastrow illusion test. The latter tasks do not require any arm movement in extrapersonal space. In this patient spatial hemineglect may be explained in terms of defective organisation of movements towards the left half-space (directional hypokinesia). The frontal lesion of the patient may be the neural correlate of this selective disorder. This pattern of impairment may be contrasted with the typical deficit found in patients with right brain damage with perceptual neglect. One case had a defective performance both in visuomotor and in purely perceptual tasks. [ABSTRACT FROM AUTHOR]

Cortical regional cerebral perfusion was assessed by N, N, N1-trimethyl-N1-(2)-hydroxy-3-methyl-5-(I-123) iodobenzyl-1, 3-propanediamine 2 HCl I-123 (HIPDM) and single photon emission computerised tomography (SPECT) in six aphasic and two neglect patients with unilateral subcortical vascular lesions. Assessments were carried out both in the acute phase and after a period ranging from 1 to 6 months after stroke onset. In all patients an almost complete spontaneous recovery occurred and was associated with a significant improvement of cortical perfusion. A relationship between severity of aphasia and degree of cortical hypoperfusion was found, in both the acute and the follow up assessments, in the aphasic subgroup. [ABSTRACT FROM AUTHOR]

Right brain-damaged patients with left visuospatial neglect were required to bisect a line placed in front of them in two different body positions (upright and supine) and two different light conditions (light and dark). The neglect patients, unlike right brain-damaged patients without neglect, strongly reduced their rightward directional error in the supine compared with the upright position. No systematic changes were produced by the light-dark manipulation. The present result cannot be explained with an attentional interpretation of hemispatial neglect. We suggest that the present data provide futher evidence that hemineglect is the consequence of a mismatch between different afferent information integrated into an egocentric space representation. According to this model, the presence of a lateralized brain lesion produces asymmetries in some intermediate spatial representations (eye-head, head-trunk, body-environment) but not in the retinotopic one. Any experimental manipulation that reduces the asymmetry of the intermediate representation such as the reduction of gravitational inputs may improve the dynamic integration of the egocentric coordinates. [ABSTRACT FROM AUTHOR]

Copyright of Italian Journal of Neurological Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Italian Journal of Neurological Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The incidence of somatosensory, visual half-field and motor deficits contralateral to a hemispheric lesion in a continuous series of 154 left brain damaged and 144 right brain damaged stroke patients were investigated. These contralateral disorders were more frequent after lesions of the right hemisphere. This difference cannot be attributed to a bias in patients' selection. It is suggested that left spatial neglect is the factor underlying this hemispheric difference. [ABSTRACT FROM AUTHOR]