Judgment of spatial orientation in patients with focal brain damage

Abstract

Normal subjects reproduced the orientation of the rod on the horizontal plane with a constant error which was found to be dependent on the position of the model. Clockwise deviations were made when the model was on the left and counterclockwise deviations when the model was on the right. The constant error was present in left brain-damaged patients too, while it was not significantly different from zero in right brain-damaged patients. A systematic error was also found on the vertical plane and it consisted in the tendency to stop the rod below the level of the standard.Findings derived from clinical case study and experimental research support the view that there is both a regional and a hemispheric specialization of the cerebral cortex for spatial functions in the sense that impairment in these functions is associated more closely with damage to posterior than to anterior areas of the brain and of the right more than of the left hemisphere. The evidence, however, is not entirely consistent.

Perception of Verticality After Recent Cerebral Hemispheric Stroke

“…12 However, the number of patients with such a defect was too small to allow separate analyses for right and left hemiplegic patients. The existence of such a relationship is in fact questionable, in the light of the work of Kerkhoff and Zoelch, 17 who were the first to report impairment of spatial orientation in the frontal plane in patients who had visual neglect but no visual field defect, after a lesion of the parietal lobe, irrespective of the side of the lesion.…”

“…A central lesion of the sensory pathways also leads to SVV disturbances, but previous results are sometimes inconsistent, and the mechanisms underlying the observed perturbations of the SVV remain unclear. Contralateral tilt of the SVV after hemispheric lesions was reported long ago, 10 -13 especially after right hemispheric lesions, 12,13 before precise localization of the lesion became possible. Since then, brain stem lesions have been demon-strated to induce an SVV deviation toward the side of the lesion 7 or, more precisely, contralateral to the lesion when it is rostral to the upper pons and ipsilateral when it is caudal.…”

“…16 Sensory perturbation can also induce tilt of the SVV after thalamic infarction 3 or after a lesion involving the sensory cortex. 4 The presence of a visual field defect after right cerebral lesions would at least lead to a tilt of the SVV, 12 but, according to Kerkhoff and Zoelch,17 this tilt is strongly correlated to visuospatial neglect and not to a visual field defect, whichever the side of the lesion.…”

“…However, opinions in this regard are still somewhat unclear because lesions could not be precisely located before the advent of the CT scanner and also because of the heterogeneous nature of the populations studied. Most authors have included stroke victims 10,14,16,17 and a few examined patients with brain injury, 12 brain injury and tumor, 13 or associated lesions. 7 The time elapsing since the lesion is probably an important factor to take into account because of the spontaneous symptom regression shown after thalamic infarction.…”

Effects of Feedback-Based Visual Line-Orientation Discrimination Training for Visuospatial Disorders After Stroke

“…4 Typically, righthemispheric lesions cause more frequent and more severe deficits compared with left-hemispheric lesions. 5,6 Deficits following such lesions include impairments in lineorientation discrimination 7,8 ; the subjective vertical 9 ; line bisection and subjective straight ahead 10 ; size, distance, and position estimation 11 ; clock reading/drawing 12 ; and block-design performance. 13 Deficits in visual orientation discrimination most frequently occur after lesions affecting the parietal cortex and/ or the basal ganglia.…”