Praxis performance with left versus right hemisphere lesions

51 children with localized cerebral lesions were investigated with the British Ability Scales, Wechsler test, Porteus Mazes, Conners Teacher Rating Scale, and computerized tomography. The extent of the lesions was quantitatively determined. The IQ was 10 points lower in the left hemispheric lesions, although the right hemispheric lesions were larger. When corrected for size of lesions, the IQ is 17 points higher (p less than 0.05) in children with right than with left hemispheric early lesions. The children with left hemispheric lesions had also significantly more behavioural problems (Conners Scale). Children with bilateral lesions had 15 points lower IQ than those with unilateral lesions, although from the slightly larger extent one could expect only 3 points difference. There was no influence of hemiparesis or of epilepsy of the IQ independent of the extent of lesion. There was more plasticity of the hemisphere than of the lobes as shown by Wisconsin Card Sorting data. The higher density of mental capacities in the left cerebral hemisphere of man is explained by more efficient programs, and more dense packing of functions due to more training of the left cerebral hemisphere.

There are a number of studies concerning difference of postural control following left or right hemisphere lesions. Few studies, however, compare the role of the right and left hemisphere in learning new postural tasks. This study aimed to address this question. Twenty patients with hemiparesis after ischemic stroke in the middle cerebral artery territory (11 with a right and 9 with a left hemispheric lesion) were investigated. All subjects were trained using two different tasks during ten training sessions. In both tasks, the subjects stood on a force platform and were taught to change the position of the center of pressure (COP) presented as a cursor on a monitor screen in front of the patient. The subjects were instructed to align the COP with the target and then move the target by shifting the COP in the indicated direction. In the "Balls" task, the position of the target (a ball) varied randomly, so the subject had to learn a general strategy of voluntary COP control. In "Bricks", the subject always had to move the target in a single direction (downward) from the top to the bottom of the screen, so that a precise postural coordination had to be learned. The number of correctly performed trials for a session was scored. The task performance and its rate were analyzed and compared with respect to the lesion lateralization between two patient groups. The voluntary control of the COP position and learning course were initially impaired in all groups of patients in both tasks. In "Balls", there were no differences between the two groups of patients. In contrast, in "Bricks", there was a greater initial deficit in patients with right hemisphere lesions, while the rate of postural learning and the final performance level did not differ between the groups. With a lower initial deficit and similar rate of learning, the maximal level of the task performance was reached earlier (on the 5th day of training) in patients with left hemisphere lesions. This group stopped improving its performance during follow-up training. The results suggest that the motor structures of the right hemisphere are more involved in the precise control of COP trajectory, but not in learning. There is no difference between hemispheres in the initial performance and learning of the general strategy of voluntary COP control. Possibly, the control of specific COP trajectory needs more sensory feedback that is associated with greater involvement of the right hemisphere. This might be a reason for the greater initial impairment of this task after lesions in the right hemisphere.

Unilateral left and right hemisphere lesions produce numerous well documented neuropsychological consequences (DeRenzi, 1982). Some of these sequelae are attentional, involving anatomical systems related to the selection of information for conscious detection (Nissen, 1986; Posner & Rafal, 1986). Such attentional deficits can often be demonstrated in tasks involving conflicts between stimuli (Posner & Presti, 1987). For example, patients with left hemisphere lesions have difficulty selecting a verbal input when it conflicts with a simultaneous spatial command. Patients with right hemisphere damage show the reverse pattern (Walker, Friedrich, & Posner, 1983). Similarly, patients with parietal lobe lesions often have great difficulty when an event in the contralesional visual field is in conflict with one in the ipsilesional field. In severe cases these patients may be completely unaware of contralesional targets while in milder cases the target may be detected but with longer latency (DeRenzi, 1982; Posner, Walker, Friedrich & Rafal, 1984).

Crossed Apraxia: Implications for Handedness

Language and cognitive outcomes after childhood stroke: Theoretical implications for hemispheric specialization

Temporal Sequencing of Verbal and Nonverbal Materials: The Effect of Laterality of Lesion

We investigated how changes in the writing of 14 Korean stroke patients reflect the unique features of the Korean writing system. The Korean writing system, Han-geul, has both linguistic and visuospatial/constructive characteristics. In the visuospatial construction of a syllable, the component consonant(s) and vowel(s) must be arranged from top-to-bottom and/or left-to-right within the form of a square. This syllabic organization, unique to Korean writing, may distinguish dysgraphia in Korean patients from the disorder in other languages, and reveal the effects of stroke on visuospatial/constructive abilities. We compared 2 groups of patients affected by stroke, 1 group with left hemisphere (LH) lesions and the other with right hemisphere (RH) lesions. We instructed them to write from a dictation of 90 monosyllabic stimuli, each presented with a real word cue. Patients had to repeat a target syllable and a word cue, and then to write the target syllable only. Patients with LH and RH lesions produced qualitatively different error patterns. While the LH lesion group produced primarily linguistic errors, visuospatial/constructive errors predominated in the group with RH lesions. With regard to language-specific features, these Korean patients with RH lesions produced diverse visuospatial/constructive errors not commonly observed in dysgraphia of the English language. Language-specific writing errors by Korean stroke patients reflect the unique characteristics of Korean writing, which include the arrangement of strokes and graphemes within a square syllabic form by dimensional and spatial rules. These findings support the notion that the Korean writing system possesses a language-specific nature with both linguistic and visuospatial/constructive processes. Distinctive patterns of dysgraphia in the Korean language also suggest interactivity between linguistic and visuospatial/constructive levels of processing. This study is noteworthy for its systematic description of Korean dysgraphia in the largest group of patients studied to date.

Emotional and Physiological Responses to False Feedback

Acquired aphasia in children has been generally characterized as nonfluent, transient, and frequently due to right hemisphere lesions. We studied 65 children with unilateral hemispheric brain lesions occurring after speech acquisition any time from the second through the fourteenth year. Of 34 patients with a left hemisphere lesion, 25 had an initial aphasic speech disturbance, while of 31 patients with a right hemisphere lesion, only 4 (including 2 left-handers) showed any initial aphasia. All those who became aphasic before the age of 8 years eventually regained speech, but recovery time required ranged from less than a month to more than two years. One 5-year-old boy who recovered had initial jargon aphasia. Our review of the literature indicated that the conflict between our results and the traditional claim of frequent aphasia with right hemisphere lesions only apparent; the great majority of crossed aphasias are concentrated in reports written before antibiotics were used, and many cases were assoicated with systemic bacterial infections.

Cerebral lateralization and cognitive deficits after congenital hemiparesis

The Role of the Left Hemisphere in Verbal and Spatial Reasoning Tasks

The effect of unilateral brain lesions on perception of visual illusions

Concomitant with the right hemispheric restitution of language functions after early left hemisphere lesions, suppression effects on originally right hemispheric visuospatial/constructional functions have repeatedly been reported. The present study evaluated this issue in 10 right hemisphere language-dominant patients with temporal lobe epilepsy. Left hemisphere language-dominant patients with left (n = 10) or right (n = 10) temporal lobe epilepsy served as controls. The following results were obtained: in all but one of the right dominant patients, left hemisphere lesions, left hemisphere foci and histories of early left brain damage indicated that secondary language transfer rather than a genetically determination is the more likely cause of the right hemisphere dominance. Despite this transfer, the language functions (comprehension, fluency, reasoning) of the right dominant patients remained significantly impaired. Language generally appeared to be better preserved in patients with an onset of epilepsy before the third year of life or a circumscribed left hemisphere lesion. No suppression effects could be detected on the level of complex cortical language and non-language functions. In contrast, on the level of temporo-limbic memory functions, verbal learning and recognition were left largely intact, albeit mostly at the expense of visuo-spatial learning and memory. The findings of the study thus indicate that the cerebral plasticity of the right hemisphere differs according to the extent of the left-hemisphere lesion, the onset of structural/functional damage and the complexity of the functions requiring restitution. Assuming that language and memory represent neocortical and palaeocortical functions, respectively, the restitution process is seemingly governed by their status in a phylogenetically determined hierarchy of functional importance.

Event Abstract Back to Event The role of lateralization in the functional outcome of patients after middle cerebral artery stroke Sanja Draca1*, Aleksandra Stefanovic1, Aleksandra Dragin1, Biljana Ljesevic1 and Dalibor Paspalj1 1 Clinic "Dr M.Zotovic", Russia Objective: To test the influence of lateralization (right vs. left hemisphere lesion) to the motor and behavioral sequels in patients after middle cerebral artery (MCA) territory infarct. Materials and methods: This study included a total of 31 patients with chronic stroke (1 year post stroke) of MCA origin, aged 54-78 years. The study included the patients with right MCA infarction (14 patients), or left MCA infarction (17 patients). All patients were treated with conventional physical and occupational therapy during 2 months following stroke. Measures: Upper extremity (UE) spasticity was assessed by the Modified Ascworth Scale (MAS), UE motor functions by the Fugl-Meyer Motor Impairment Scale (FMA)-upper extremity portion, and the performance of the paretic arm in the of activities of daily living by the Chedoke Arm and Hand Activity Inventory (CAHAI). The Beck Depression Inventory (BDI)-II was used as a screening instrument for depression. Results: No significant difference was found for MAS score (2, 3 vs. 2, 1), FM score (20, 9 vs. 27, 8), as well as the CAHAI score (43, 3 vs. 49, 6) between patients with right vs. left MCA infarction. Nevertheless, the patients with left hemisphere lesion had a significantly increased BDI-II scores compared to patients with right hemisphere lesion (8, 7 vs. 16, 2, p < 0, 05). Conclusion: These results indicate that UE motor recovery did not differ between patients with right or left MAC infarction. However, an increased rate of PSD in patients with left hemisphere lesion (both cortical and subcortical) compared to patients with right hemisphere lesion, indicates a need for depressive symptoms screening in stroke patients. Conference: 41st European Brain and Behaviour Society Meeting, Rhodes Island, Greece, 13 Sep - 18 Sep, 2009. Presentation Type: Poster Presentation Topic: Poster presentations Citation: Draca S, Stefanovic A, Dragin A, Ljesevic B and Paspalj D (2009). The role of lateralization in the functional outcome of patients after middle cerebral artery stroke. Conference Abstract: 41st European Brain and Behaviour Society Meeting. doi: 10.3389/conf.neuro.08.2009.09.137 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 09 Jun 2009; Published Online: 09 Jun 2009. * Correspondence: Sanja Draca, Clinic "Dr M.Zotovic", Belgrade, Russia, odracha@EUnet.rs Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sanja Draca Aleksandra Stefanovic Aleksandra Dragin Biljana Ljesevic Dalibor Paspalj Google Sanja Draca Aleksandra Stefanovic Aleksandra Dragin Biljana Ljesevic Dalibor Paspalj Google Scholar Sanja Draca Aleksandra Stefanovic Aleksandra Dragin Biljana Ljesevic Dalibor Paspalj PubMed Sanja Draca Aleksandra Stefanovic Aleksandra Dragin Biljana Ljesevic Dalibor Paspalj Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Reorganization of the cerebro-cerebellar network of language production in patients with congenital left-hemispheric brain lesions