Background:Visual-spatial neglect (VSN) is a neuropsychological syndrome,and right-hemisphere stroke is the most common cause.The pathogenetic mechanism of VSN remains unclear.This study aimed to investigate the behav...Background:Visual-spatial neglect (VSN) is a neuropsychological syndrome,and right-hemisphere stroke is the most common cause.The pathogenetic mechanism of VSN remains unclear.This study aimed to investigate the behavioral and event-related potential (ERP) changes in patients with or without VSN after right-hemisphere stroke.Methods:Eleven patients with VSN with right-hemisphere stroke (VSN group) and 11 patients with non-VSN with righthemisphere stroke (non-VSN group) were recruited along with one control group of 11 age- and gender-matched healthy participants.The visual-spatial function was evaluated using behavioral tests,and ERP examinations were performed.Results:The response times in the VSN and non-VSN groups were both prolonged compared with those of normal controls (P<0.001).In response to either valid or invalid cues in the left side,the accuracy in the VSN group was lower than that in the non-VSN group (P<0.001),and the accuracy in the non-VSN group was lower than that in controls (P<0.05).The P1 latency in the VSN group was significantly longer than that in the control group (F[2,30]= 5.494,P = 0.009),and the N1 amplitude in the VSN group was significantly lower than that in the control group (F[2,30]= 4.343,P = 0.022).When responding to right targets,the lefthemisphere P300 amplitude in the VSN group was significantly lower than that in the control group (F[2,30]= 4.255,P = 0.025).With either left or right stimuli,the bilateral-hemisphere P300 latencies in the VSN and non-VSN groups were both significantly prolonged (all P<0.05),while the P300 latency did not differ significantly between the VSN and non-VSN groups (all P > 0.05).Conclusions:Visual-spatial attention function is impaired after right-hemisphere stroke,and clinicians should be aware of the subclinical VSN.Our findings provide neuroelectrophysiological evidence for the lateralization of VSN.展开更多
A 61 year-old right handed man, who suffered from right cerebral infarction with evidences of visual-spatial neglect and constructive disorder, was reported. When copying simple geometric designs, he omitted to copy f...A 61 year-old right handed man, who suffered from right cerebral infarction with evidences of visual-spatial neglect and constructive disorder, was reported. When copying simple geometric designs, he omitted to copy figures on the left side of the page; he tended to bisect the line to the right of the line's real center; after memorizing the familiar pictures he mainly mentioned the pictures on the right side of the page; when copying the 'Rey Complex' he also ignored the structures on the left side. The relations of the neglect and construction disorder are discussed.展开更多
Cognitive disturbances with neglect-like features have been reported occasionally in patients with chiasmal disorders, so far however with no obvious substrate by conventional brain imaging. Thus, there were no right ...Cognitive disturbances with neglect-like features have been reported occasionally in patients with chiasmal disorders, so far however with no obvious substrate by conventional brain imaging. Thus, there were no right hemisphere lesions that could explain the lateralised visual inattention as observed in particular during monocular visual acuity testing. On this background, we further examined four adult patients who consented to functional 18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) scan. In three there were no significant findings. The fourth patient, a 26-year-old male with cognitive defects after surgery for craniopharyngioma, will be discussed in more detail. His PET scan demonstrated a widespread reduction of regional metabolic activity in left hemisphere primary visual cortex and higher order visual areas, despite absence of explanatory pathological signal changes on MRI. As present in only one out of four patients, however, the findings do not allow specific pathogenetic mechanisms to be suggested, nor generally to substantiate involvement of higher cerebral circuits. Obviously, even developed imaging has its limits, and in the very theory the visual dysfunctions observed might still depend on higher brain centres’ faulty adaptation to loss of pre-geniculate visual information.展开更多
Spatial neglect syndrome with cerebral lesions is characterized by the ina-bility to orient, report, or respond to relevant visual stimuli contralateral to the lesions. In this study, we investigated the pattern of ho...Spatial neglect syndrome with cerebral lesions is characterized by the ina-bility to orient, report, or respond to relevant visual stimuli contralateral to the lesions. In this study, we investigated the pattern of horizontal visual search in a large space;this search was performed by patients with right hemisphere damage caused by cerebrovascular disease. The neck rotation angle and search time in each increment were continuously recorded during the task, and quantitative data of the measurements were collected. Head position during the visual search task in a large space (%) was then calculated. We set angular bands in increments of 5 degrees from the midline on the left and right sides, and calculated the total search time in each angular band. In patients with unilateral spatial neglect (USN), the search time in the angular band of 5 - 9 on the right side was significantly longer (with USN 16.7%, without USN 4.5%, t = 2.52, df = 16, p < 0.05). Furthermore, in patients with neglect in the leftmost end area in a large space, the search time was significantly shorter in the angular band of 1 - 4 degrees to the left (with neglect 13.1%, without neglect 23.7%, t = 2.13, df = 16, p < 0.05), and tended to be long in the angular band of 5 - 9 to the right. The neck rotation angle and pattern during the search task in a large field deviated slightly to the right, and the search time slightly to the left was short. We believe that these results support the rightward deviation of the search pattern and frame of USN patients.展开更多
Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal ...Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal side of the chart. Often it is combined with impairment of reading and other cognitive impairments. Methods: Eighteen patients with lesions to the chiasm and some degree of temporal blocking aged 24 - 76 years underwent: 1) tests for visual neglect (Gothenburg test;behavioural inattention tests: star cancellation;line bisection);2) visuo-perceptual tests;and 3) a test involving reading a crowded ten-letter and cipher bar. Results: The temporal blocking in two patients recovered after emergency neurosurgery and their results were normal when subsequently tested. Of the 16 patients with deficiencies, 14 had a poorer left eye (p Conclusions: The best neuropsychologic tests appeared to be those for visual neglect and the crowded bar test. In most cases, the right cerebral hemisphere’s lack of some crossed information from the left eye, usually needed for normative saccades and adjustment to visual space, may be a factor underlying the specific visual behaviour.展开更多
文摘Background:Visual-spatial neglect (VSN) is a neuropsychological syndrome,and right-hemisphere stroke is the most common cause.The pathogenetic mechanism of VSN remains unclear.This study aimed to investigate the behavioral and event-related potential (ERP) changes in patients with or without VSN after right-hemisphere stroke.Methods:Eleven patients with VSN with right-hemisphere stroke (VSN group) and 11 patients with non-VSN with righthemisphere stroke (non-VSN group) were recruited along with one control group of 11 age- and gender-matched healthy participants.The visual-spatial function was evaluated using behavioral tests,and ERP examinations were performed.Results:The response times in the VSN and non-VSN groups were both prolonged compared with those of normal controls (P<0.001).In response to either valid or invalid cues in the left side,the accuracy in the VSN group was lower than that in the non-VSN group (P<0.001),and the accuracy in the non-VSN group was lower than that in controls (P<0.05).The P1 latency in the VSN group was significantly longer than that in the control group (F[2,30]= 5.494,P = 0.009),and the N1 amplitude in the VSN group was significantly lower than that in the control group (F[2,30]= 4.343,P = 0.022).When responding to right targets,the lefthemisphere P300 amplitude in the VSN group was significantly lower than that in the control group (F[2,30]= 4.255,P = 0.025).With either left or right stimuli,the bilateral-hemisphere P300 latencies in the VSN and non-VSN groups were both significantly prolonged (all P<0.05),while the P300 latency did not differ significantly between the VSN and non-VSN groups (all P > 0.05).Conclusions:Visual-spatial attention function is impaired after right-hemisphere stroke,and clinicians should be aware of the subclinical VSN.Our findings provide neuroelectrophysiological evidence for the lateralization of VSN.
文摘A 61 year-old right handed man, who suffered from right cerebral infarction with evidences of visual-spatial neglect and constructive disorder, was reported. When copying simple geometric designs, he omitted to copy figures on the left side of the page; he tended to bisect the line to the right of the line's real center; after memorizing the familiar pictures he mainly mentioned the pictures on the right side of the page; when copying the 'Rey Complex' he also ignored the structures on the left side. The relations of the neglect and construction disorder are discussed.
文摘Cognitive disturbances with neglect-like features have been reported occasionally in patients with chiasmal disorders, so far however with no obvious substrate by conventional brain imaging. Thus, there were no right hemisphere lesions that could explain the lateralised visual inattention as observed in particular during monocular visual acuity testing. On this background, we further examined four adult patients who consented to functional 18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) scan. In three there were no significant findings. The fourth patient, a 26-year-old male with cognitive defects after surgery for craniopharyngioma, will be discussed in more detail. His PET scan demonstrated a widespread reduction of regional metabolic activity in left hemisphere primary visual cortex and higher order visual areas, despite absence of explanatory pathological signal changes on MRI. As present in only one out of four patients, however, the findings do not allow specific pathogenetic mechanisms to be suggested, nor generally to substantiate involvement of higher cerebral circuits. Obviously, even developed imaging has its limits, and in the very theory the visual dysfunctions observed might still depend on higher brain centres’ faulty adaptation to loss of pre-geniculate visual information.
文摘Spatial neglect syndrome with cerebral lesions is characterized by the ina-bility to orient, report, or respond to relevant visual stimuli contralateral to the lesions. In this study, we investigated the pattern of horizontal visual search in a large space;this search was performed by patients with right hemisphere damage caused by cerebrovascular disease. The neck rotation angle and search time in each increment were continuously recorded during the task, and quantitative data of the measurements were collected. Head position during the visual search task in a large space (%) was then calculated. We set angular bands in increments of 5 degrees from the midline on the left and right sides, and calculated the total search time in each angular band. In patients with unilateral spatial neglect (USN), the search time in the angular band of 5 - 9 on the right side was significantly longer (with USN 16.7%, without USN 4.5%, t = 2.52, df = 16, p < 0.05). Furthermore, in patients with neglect in the leftmost end area in a large space, the search time was significantly shorter in the angular band of 1 - 4 degrees to the left (with neglect 13.1%, without neglect 23.7%, t = 2.13, df = 16, p < 0.05), and tended to be long in the angular band of 5 - 9 to the right. The neck rotation angle and pattern during the search task in a large field deviated slightly to the right, and the search time slightly to the left was short. We believe that these results support the rightward deviation of the search pattern and frame of USN patients.
文摘Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal side of the chart. Often it is combined with impairment of reading and other cognitive impairments. Methods: Eighteen patients with lesions to the chiasm and some degree of temporal blocking aged 24 - 76 years underwent: 1) tests for visual neglect (Gothenburg test;behavioural inattention tests: star cancellation;line bisection);2) visuo-perceptual tests;and 3) a test involving reading a crowded ten-letter and cipher bar. Results: The temporal blocking in two patients recovered after emergency neurosurgery and their results were normal when subsequently tested. Of the 16 patients with deficiencies, 14 had a poorer left eye (p Conclusions: The best neuropsychologic tests appeared to be those for visual neglect and the crowded bar test. In most cases, the right cerebral hemisphere’s lack of some crossed information from the left eye, usually needed for normative saccades and adjustment to visual space, may be a factor underlying the specific visual behaviour.
