Right hemispatial ipsilesional neglect with chronic right hemisphere strokes

Background: Patients who present with spatial neglect after stroke often perform normally on tests for neglect after a few weeks. Whereas tests for neglect are often performed directly in front of a patient, in their actual environments many important stimuli may be present within their left or right hemispace. The presence and severity of neglect often depends on the hemisphere injured. It is possible, in chronic stroke, for spatial judgments to be influenced by an interaction of stroke laterality and the spatial location of stimuli. The objective of this study was to learn if unilateral hemispheric chronic strokes contribute to a spatial bias with laterally presented stimuli.

Method: There were 70 participants, 62 with unilateral chronic strokes (>6 months post onset) including 35 with left hemisphere damage (LHD), 27 with right hemisphere damage (RHD), and 8 demographically similar people without history of stroke. Participants were asked to bisect 300 lines presented with distractors on the left, right, or both sides of the line, or no distractor, on a touch-screen monitor in right, center or left hemispace.

Results: There was a significant interaction between the side of the hemispheric lesion and the side of the body where these lines were presented. Specifically, in right space, patients with RHD deviated leftward in comparison to the other groups. Furthermore, there was an interaction between group and distractor induced bias. All three groups approached the left distractor, and the patients with LHD also approached the right distractor.

Conclusions: Although spatial neglect is more severe in contralesional than ipsilesional hemispace in the period immediately following a stroke, over time patients with RHD may develop ipsilesional neglect that is more severe in ipsilesional than contralesional space. The mechanism underlying this bias is not known and may be related to attempted compensation or the development of a contralateral attentional/intentional grasp.     

Is one hand always better than two? A replication study

Abstract

Recently, it has been shown that the active movement of the left hand in the left hemispace reduces left neglect in visual exploratory tasks. Despite the important theoretical and practlcal implications, there exists no direct confirmation of these findings in the literature. To verify the presence of the beneficial effect of left hand movement in left space, we replicated three of the nine experiments devised by Robertson and North (Neuropsychologia 1992; 30: 553-63, Neuropsychologia 1994; 32: 1-11). To this end, we tested 10 consecutive patients with right brain damage and left neglect. We found the expected pattern of performance in only one patient: on reading and cancellation the total number of omissions significantly decreased when irrelevant movements were performed with the left hand in the left space. This finding underlines the importance of replication studies in cognitive neuropsychology.     

The multiplicity of neglect phenomena

Abstract

Neglect for the extrapersonal space is not a disorder of seeing, hearing, or moving but one of looking, detecting, listening, and exploring. It is said to be present when the impact of sensory events upon conscious (explicit) behaviours displays a spatially-addressed bias that cannot be attributed entirely to elementary sensory-motor deficits such as weakness, clumsiness, or poor acuity. In clinical practice. the more dramatic manifestations of neglect occur within the left side of the extrapersonal space in patients with right hemisphere damage. The distribution of left neglect can display retinocentric, cephalocentric, or somatocentric coordinates and can shift from one coordinate to another in the same individual, usually gravitating towards the coordinates that maximise the extent of neglect. On occasion, an allocentric, object-centred component can also emerge, so that the patient neglects not only the left hemispace but also the left side of sensory events in the right hemispace. Neglect can be multimodal or unimodal. It can encompass the extrapersonal, peripersonal, or personal spaces. It can be elicited by a large number of tasks, including lime bisection, target detection, bilateral simultaneous stimulation, clock drawing, and reading. The severity of deficits may vary considerably from one task to another. Neglected sensory events do not influence overt, declarative responses but may exert an implicit influence on behaviour even when the patient denies conscious awareness of the stimulus.     

Transcranial electric stimulation optimizes the balance of visual attention across space

ObjectiveTranscranial direct current stimulation (tDCS) provides a way to modulate spatial attention by enhancing the ratio of neural activity between the left and right hemispheres, with a potential benefit for the rehabilitation of visual neglect.MethodsWe tested the effect of bilateral tDCS in healthy individuals performing a visual detection task. This protocol consists in the positioning of the anode and cathode on mirror positions over the left and right parietal areas. The stimulation was repeated over three days to maximize the chance to observe a bias to the hemispace controlateral to the anode.ResultsCompared to a sham treatment, left anodal – right cathodal stimulation enhanced attention across the full range of space, since the first day with no build-up effect on the next days, and modified the balance of left-right omissions when stimuli appeared at the same time.ConclusionBilateral tDCS improved detection in both visual fields, with no privileged processing of one side, except when concurrent stimuli were presented. The results provide partial support to the hemispheric rivalry hypothesis.SignificanceThe technique has the potential to boost attention in neglect patients but should be used as an adjuvant rather than as an alternative to functional rehabilitation.     

Leg Orthosis Treatment for a Patient with Left Parietal Foot Amputation and Right Hemiplegia

Abstract

In developing a training program from standing to walking for a patient with a left parietal foot amputation and right hemiplegia, we found that the leg orthosis was effective in allowing the patient to regain the balancing ability when standing. The leg orthosis had practical effects on increasing walking distance.     

Differential Effects of Unilateral Temporal Lobectomy on Visuospatial Memory and Attention

Abstract

We investigated free recall of visuospatial arrays in a free-field format in epileptic patients following unilateral temporal lobectomy (TL) (left = 15, right = 17). TL patients exhibited leftward deviation in right hemispace, but more variable response in left hemispace, a pattern that has been observed in healthy adults. This finding is postulated to result from combined preferential right cerebral activation and a tendency to err toward peri-personal space. Temporal lobectomy affected overall leftward deviation by initially shifting deviation more toward the side of lesion. The initial directional shift in immediate memory dissipated over time suggesting that these subtle attentional shifts may be compensated by learning. Consistent with differential cerebral hemispheric mechanisms, absolute vertical errors were greater in right than left TL patients, and absolute horizontal errors were worse in right hemispace.     

Leftward movement in severe neglect

Abstract

The difficulty that patients with unilateral spatial neglect (USN) have in exploring into the contralesional space may be explained by motor or attentional disorder. We experienced a patient with severe USN following cerebral infarction in the right postrolandic region, who showed a strong resistance to leftward movement. We devised two sets of tasks using a whiteboard. In the first experiment, the patient showed great difficulty in tracing a line from the right endpoint to the left endpoint. The examiner barely made him start further tracing even by pushing the hand leftward. By contrast, he quickly erased a whole line leftward with an eraser pen. In the second experiment, he was required to erase a line with or without an attention-attracting stimulus at the right endpoint. Not only the leftward extent, but also the velocity of erasing, were decreased when there was a stimulus at the right endpoint. The results of the two experiments suggest that the ability of leftward movement itself was preserved and overattention to the right-sided stimuli impaired his leftward movement. We consider that use of the line-tracing and line-erasing tasks may contribute to a better understanding of interaction of attentional andmotor and motor factors in severe USN.     

A novel technique to perform cerebral angiography via the left radial approach: An 80 patients series

PurposeTo demonstrate that left radial access for diagnostic cerebral angiography with Extra backup and 4F vertebral catheters is feasible and safe.Materials and methodsThis study is a retrospective review of our prospective database on left radial access for cerebral angiography procedures, using an extra backup catheter associated with a 4Fr vertebral catheter, performed between March and September 2019. Patient demographics, procedural and radiographic metrics as well as clinical data were recorded.ResultsSeventy five patients with mean age of 51...years (range 21...73) underwent 80 cerebral angiographies. An average of four vessels were catheterized and mean fluoroscopy times per subject and vessel were was of 13.9 and 3.3...min, respectively. One patient required crossover to transfemoral access because of radial artery spasm. There were one asymptomatic distal radial artery occlusion and one patient presenting with asymptomatic skin blanching area on the forearm, just proximal to the tip of the sheath, that spontaneously resolved within an hour.ConclusionDiagnostic cerebral angiography via left radial access is feasible and safe and allows to preserve the right radial access for future neurointerventions while providing more comfort to the right handed patient.     

Contrecoup injury in the misdiagnosis of crossed aphasis

Abstract

Crossed aphasia is reported to be more frequent in traumatic series than in series of patients with other pathologies. A right-handed young man suffered a closedhead trauma and became aphasic and hemiparetic on the left. CT scan revealed a right frontal-lobe hematoma. Neuropsychological examination revealed a fluent aphasia and a Gerstmann syndrome. These signs were compatible with left supramarginal gyrus syndrome. However, the presence of a right frontal-lobe lesion suggested that this patient could be a crossed aphasic. Subsequent EEG study showed a left occipitotemporal focus and a right frontal one. Aphasic signs could thus be due to the left lesion, which was the result of a contrecoup mechanism. Fluent aphasias have been reported in closed-head trauma with right frontal impact. Attention is called for the possible bias of including cases like this in series of traumatic crossed aphasia.     

Serial MRI findings in patient with chronic cryptococcus meningo-encephalitis

Abstract

We describe the serial changes of magnetic resonance imaging (MRI) in a patient with chronic cryptococcus meningo-encephalitis. In the subacute phase, MRI revealed a focal lesion with hyperintensity on T2-weighted image (WI) in the left thalamus. At 11 months after the onset, MRI showed a focal lesion with hyperintensity on T2-WI in the right pons that was enhanced with gadolinium (Gd). At 13 months after the onset, the lesion in the left thalamus became rim enhanced with Gd. After antifungal therapy (amphotericin B and 5-flucytosine), the rim enhancement in the left thalamus and the high signal intensity area in the right pons decreased. Cryptococcoma should be in the differential from other ring enhancing lesions. [Neurol Res 2001; 23: 810-812]     

Lasting mutism associated with buccofacial apraxia

Abstract

A right-handed 56-year-old male patient suddenly presented with mutism, and right hemiparesis. Hemiparesis quickly evolved and disappeared, and language slightly improved. However, 7 months later a total mutism and a very severe buccofacial apraxia associated with a mild aphasia were observed. A CT scan disclosed two almost homologous infarction areas: a left frontal opercular and a right orbitofrontal gyms infarction area. Several months later the patient passed away without any further change in his speech disorder. It is asserted that transient mutism can be associated with unilateral left damage, but lasting mutism associated with buccofacial apraxia requires bilateral lesions.     

Lateralized alpha-motoneuron excitabilities during lying and standing of healthy individuals in relation to Parkinsonian rigidity

Abstract

Objectives: To elucidate mechanisms of Parkinsonian rigidity by assessing excitability of alpha-motoneurons innervating right and left soleus muscles in healthy controls and Parkinson’s disease (PD) patients with rigidities in the right, left and both legs.

Methods: One group of 45 controls was recruited and 60 PD patients in three groups: rigidities, predominantly in the right, left and both legs. H-reflex (H) and muscle response (M) were recorded from right and left soleus muscles during stimulations of the posterior tibial nerve at the popliteal fossa while lying and standing. The H/M ratio was taken as an index for motoneuron excitability.

Results: Mean H/M ratios were significantly different on the right and left sides, modified by postural changes in controls and PD patients. Analysis of variance showed that in healthy subjects the H/M ratio was: standing>lying (right), lying>standing (left). In right leg rigidity patients, the H/M ratio was greatest during standing, and smallest during lying. In left leg rigidity patients, the H/M ratios on the right and left sides were equally independent of posture. In controls, left H/M>right while lying, <right while standing. In right leg rigidity patients, right H/M>left, but <right in left leg rigidity patients, independent of posture. There was no side difference in patients with rigidity in both legs.

Conclusions: (i) motoneuron excitability may show side and postural differences in healthy individuals and PD patients; (ii) posture may be associated with lateralized motoneuron excitability in these subjects; and (iii) Parkinsonian rigidity may have spinal motor origins.     

Left hemispatial neglect with a splenial lesion

ABSTRACT

With injury of the anterior two-thirds of the corpus callosum, each hemisphere’s attentional bias to contralateral hemispace becomes manifest with each hand deviating ipsilaterally during line bisection tasks. Patients with infarctions in the right posterior cerebral artery distribution with occipital and splenial damage can also exhibit spatial neglect. The goal of this report is to learn the role of the splenium of the corpus callosum in mediating visuospatial attention. A right-handed woman with Marchiafava-Bignami disease and damage to the splenium of her corpus callosum without evidence of a mesial frontal, parietal, or occipital injury was assessed for spatial neglect with line bisections. When bisecting lines in her left hemispace with her right hand, she deviated to the right, but revealed no major deviations when the line was place in the midline, in right hemispace, or when bisecting lines with her left hand. This patient provides evidence that damage to the splenium can induce a special form of asymmetrical spatial neglect. This asymmetry might be related to the disconnected right hemisphere’s ability to allocate attention to both right and left hemispaces with the disconnected left hemisphere’s ability to allocate attention to the right but not left hemispace.     

Deep dyslexia and right hemisphere reading-a regional cerebral blood flow study

Abstract

Deep dyslexia is an acquired reading disorder that is characterized by the production of semantic reading errors, greater success when reading aloud concrete and highly imageable words, frequent visual and visual-semantic errors, morphological errors and very poor reading of nonwords. The right hemisphere hypothesis proposes that in deep dylsexia the patient is not reading with an impaired version of the normal left hemisphere reading system, and cannot use that system for reading at all. Instead, a different reading system, located in the right hemisphere is used. The right hemisphere hypothesis was examined in this study by investigating the amount of cortical activation in the left and right cerebral hemispheres of a deep dyslexic patient (L.H.) during visual word recognition. Three experimental tasks were devised to isolate a Visual Word Recognition process and a Spoken Word Production process and these tasks were administered to the deep dyslexic patient as well as another patient with left-hemisphere-damage but a different form of acquired dyslexia (surface dyslexia) and two matched control subjects. Regional cerebral blood flow (rCBF) was monitored during performance on each of the tasks. For L.H., but not the other three subjects, rCBF in the right hemisphere was greater than in the left hemisphere during Visual Word Recognition. By contrast, there was greater activation of the left hemisphere than the right hemisphere for L.H. during Spoken Word Production: this was also true of the other three subjects, but the effect was statistically significant only for L.H. These results support the right-hemisphere hypothesis of deep dyslexia.     

The impact of hippocampal impairment on task-positive and task-negative language networks in temporal lobe epilepsy

ObjectiveTo study hippocampal integration within task-positive and task-negative language networks and the impact of a diseased left and right hippocampus on the language connectome in temporal lobe epilepsy (TLE).MethodsWe used functional magnetic resonance imaging (fMRI) to study a homogenous group of 32 patients with TLE (17 left) and 14 healthy controls during a verb-generation task. We performed functional connectivity analysis and quantified alterations within the language connectome and evaluated disruptions of the functional dissociation along the anterior-posterior axis of the hippocampi.ResultsConnectivity analysis revealed significant differences between left and right TLE compared to healthy controls. Left TLE showed widespread impairment of task-positive language networks, while right TLE showed less pronounced alterations. Particularly right TLE showed altered connectivity for cortical regions that were part of the default mode network (DMN). Left TLE showed a disturbed functional dissociation pattern along the left hippocampus to left and right inferior frontal language regions, while left and right TLE revealed an altered dissociation pattern along the right hippocampus to regions associated with the DMN.ConclusionsOur results showed an impaired hippocampal integration into active language and the default mode networks, which both may contribute to language impairment in TLE.SignificanceOur results emphasize the direct role of the left hippocampus in language processing, and the potential role of the right hippocampus as a modulator between DMN and task-positive networks.     

Verifying the hypothesis of disconnection syndrome in patients with conduction aphasia using diffusion tensor imaging

BACKGROUND: It is thought in disconnection theory that connection of anterior and posterior language function areas, i.e. the lesion of arcuate fasciculus causes conduction aphasia. OBJECTIVE: To verify the theory of disconnection elicited by repetition disorder in patients with conduction aphasia by comparing the characteristics of diffusion tensor imaging between healthy persons and patients with conduction aphasia. DESIGN: Case-control observation. SETTING: Department of Neurology, Hongqi Hospital Affiliated to Mudanjiang Medical College. PARTICIPANTS: Five male patients with cerebral infarction-involved arcuate fasciculus conduction aphasia, averaged （43±2）years, who hospitalized in the Department of Neurology, Hongqi Hospital Affiliated to Mudanjiang Medical College from February 2004 to February 2005 were involved in this experiment. The involved patients were all confirmed as cerebral infarction by skull CT and MRI, and met the diagnosis criteria revised in 1995 4th Cerebrovascular Conference. They were examined by the method of Aphasia Battery of Chinese (ABC) edited by Surong Gao. The results were poorer than auditory comprehension disproportionately, and consistented with the mode of conduction aphasia. Another 5 male healthy persons, averaged （43±1）years, who were physicians receiving further training in the Department of Neurology, Beijing Tiantan Hospital were also involved in this experiment. Informed consents of detected items were obtained from all the subjects. METHODS: All the subjects were performed handedness assessment with assessment criteria of handedness formulated by Department of Neurology, First Hospital Affiliated to Beijing Medical University. Arcuate fasciculus of involved patients and health controls were analyzed with diffusion tensor imaging (DTI) and divided into 3 parts (anterior, middle and posterior segments) for determining FA value (mean value was obtained after three times of measurements), and a comparison of FA value was made between two sides. MAIN OUTCOME MEASURES: Analysis results of arcuate fasciculus DTI of healthy controls and patients with conduction aphasia. RESULTS: Five patients with conduction aphasia and 5 healthy controls participated in the final analysis. ①All the subjects were right-handedness. ② The left FA value of anterior, middle and posterior segments of arcuate fasciculus was larger than the right one in most normal volunteers, i.e. arcuate fasciculus with normal function on the left side was more than that on the right side. Because the amount of healthy controls was small, so positive conclusion has not been obtained, and only above-mentioned tendency was demonstrated. Healthy controls had good bilateral arcuate fasciculus; Three patients with conduction aphasia presented left FA value of anterior segment of arcuate fasciculus smaller than the right one, and two patients presented the left FA value larger than the right one. Four patients presented the left FA value of middle segment of arcuate fasciculus smaller than the right one, and one patient presented the left FA value larger than the right one, i.e. middle segment of arcuate fasciculus of 5 patients with conduction aphasia was all involved in at different degrees. Four patients with conduction aphasia presented the left FA value of posterior segment of arcuate fasciculus smaller than the right one, and one patient presented the left FA value larger than the right one, i.e. posterior segment of arcuate fasciculus of 5 patients was all injured at different degrees. CONCLUSION: Arcuate fasciculus of patients with conduction aphasia all is involved in at different degrees, which verifies the theory of disconnection of repetition disorder in patients with conduction aphasia.     

The influence of stimulus proximity on judgments of spatial relationships in patients with chronic unilateral right or left hemisphere stroke

Objective: This was to learn how chronic right hemispheric damage (RHD) versus left hemispheric damage (LHD) may influence attentional biases in proximal and distal space. Background: Prior research has suggested that the left hemisphere primarily attends to proximal space and the right hemisphere to distal space. The purpose of this study was to contrast line bisection performed in proximal versus distal space in patients with chronic LHD versus RHD. Design/method: Participants were 32 LHD and 26 RHD patients who sustained a stroke a mean of 3.4 years prior to testing, along with 9 healthy controls. Subjects attempted to bisect 30 lines in proximal space and 30 lines in distal space. Results: Patients with both RHD and LHD had a greater contralesional bias in proximal than distal space (rightward bias for patients with LHD and leftward bias for patients with RHD). Compared to controls, patients with LHD were most different in proximal space, and patients with RHD were most different in distal space. Conclusions: Proximity appears to influence spatial judgments of patients with RHD and LHD in an opposing manner. Relatively, both patient groups bisect lines contralesionally in proximal space and ipsilesionally (relative to proximal) in distal space. Patients with RHD have the biggest difference between their proximal and distal judgments. The reason for these differences is unknown. However, these biases may be related to an attentional or action-intentional grasp or a learned compensation strategy, and proximity may increase the allocation of attention or intention and thereby enhance this grasp or use of this compensation strategy. Another contributing factor may be dominance of the left and right hemisphere for information presented in proximal and distal space, respectively.     

Application of diffusion tensor imaging for detecting structural changes in the brain of schizophrenic patients

Abstract

Objective. Schizophrenia is a severe psychiatric illness. Although magnetic resonance imaging has been widely used for detecting brain structural and functional abnormalities in patients with schizophrenia, the findings are highly inconsistent between reports. This study investigates structural changes in the brains of schizophrenic patients. Methods. The brains of fifty male adults with schizophrenia and fifty age- and gender-matched healthy controls were scanned by diffusion tensor imaging. The differences in fractional anisotropy （FA） values between schizophrenic patients and healthy controls were analyzed. Results. Schizophrenic patients exhibited significantly decreased FA values in the right middle frontal gyrus, right inferior frontal gyrus, right superior temporal gyrus, left sub-temporal gyrus, left middle temporal gyrus, left cingulate gyrus, and left precentral gyrus compared with the control group. We did not find any brain regions with higher FA values in the patient group than in the control group. Conclusion. This study suggested that structural abnormalities in the frontal region of gray matter and white matter are present at the same time in patients with schizophrenia.     

Different localizations underlying cortical gelastic epilepsy: Case series and review of literature

BackgroundGelastic seizures (GS) are classically observed with hypothalamic hamartomas but they can also be associated with cortical epileptogenic foci.ObjectiveTo study the different cortical localizations associated with GS.MethodsWe reviewed the data from all patients with cortical GS investigated in our epilepsy unit from 1974 to 2012 and in the literature from 1956 to 2013.ResultsSixteen cases were identified in our database and 77 in the literature. Investigations provided confident focus localization in 9 and 18, respectively. In our series, the identified foci were located in the mesial temporal structures (2 left, 1 right), lateral temporal cortex (1 right), superior frontal gyrus (1 left), and operculoinsular region [3 right (orbitofrontal or frontal operculum extending into the anterior insula) and 1 left (frontal operculum extending into the anterior insula)]. In the literature, the identified foci (13 right/5 left) were located in the temporal lobe of 4 (1 right inferior, 1 right medial and inferior, 1 right posterior middle, inferior extending posteriorly to the lingual gyrus, and 1 left middle, inferior, and medial), in the frontal lobe of 12 [10 (6 right/4 left) medial (i.e., superior, medial frontal, and/or anterior cingulate gyri), 1 lateral (right anterior inferior frontal gyrus), and 1 right medioposterior orbitofrontal cortex] and in the parietal lobe of 2 (1 left superior parietal lobule and 1 right parietal operculum) patients.ConclusionIctal laughter is a poorly lateralizing and localizing feature as it may be encountered in patients with a focus in the left or right frontal, temporal, parietal, or insular lobe.     

Cervical syringohydromyelia secondary to chronic supratentorial subdural hematoma

Introduction: Syringohydromyelia associated with supratentorial space-occupying lesion has rarely been reported. We present a 28-year-old woman was admitted to the hospital with head and neck pain. Upon examination, there was only left central facial paralisia, with no evidence of papilledema. Methods and Results: Cranial magnetic resonance imaging (MRI) revealed a left parietal and temporal chronic subdural hematoma (CSH) with a 1-cm shift to the right from midline. Also, cervical MRI revealed a syringohydromyelic cavity at the level of C6/7. The patient was operated on for supratentorial CSH. A follow-up cervical MRI revealed no syringohydromyelic cavity after 2 months. No neurological deficit was reported, and overall outcome was excellent. Conclusion: Syringohydromyelia was secondary to a space-occupying lesion in our case of supratentorial chronic subdural hematoma.