Neurological asymmetries immediately after unilateral ECT.

Twenty-nine right handed patients were examined neurologically before and immediately after each of 62 unilateral ECTs to the dominant and non-dominant hemispheres. Most convulsions were followed by signs of transitory neurological dysfunction referable to the treated hemisphere. These signs included deep tendon reflex asymmetry, hemiparesis, tactile and visual inattention, and homonymous hemianopia. After treatment to the right hemisphere some patients had left visuospatial neglect, while all patients who had dominant hemisphere ECT were transiently dysphasic. All neurological abnormalities tested resolved within 20 minutes of treatment.     

"Crossed homonymous hemianopia" and "crossed left hemispatial neglect" in a case of Marchiafava-Bignami disease.

"Crossed homonymous hemianopia" and "crossed left hemispatial neglect" were observed in a woman with Marchiafava-Bignami disease. Two forms of "crossed homonymous hemianopia" were observed. Initially, Goldmann perimeter testing showed a left homonymous hemianopia with the right hand and vice versa. Later, confrontation tests showed a left homonymous hemianopia, whereas visual field testing using the Goldmann perimeter (kinetic quantitative perimeter) and the OCTOPUS (Interzeag AG, static automated perimeter) showed a right homonymous hemianopia with either hand. "Crossed left hemispatial neglect" was not seen with the left hand, but neglect of the left hemifield was seen with the right hand. CT and MRI showed a lesion occupying almost the entire corpus callosum. PET showed no significant differences between comparable areas of the left and right cerebral hemispheres. These findings indicate that both signs of interhemispheric disconnection were due to the callosal lesion. Moreover, the "crossed left hemispatial neglect" can be explained as being a consequence of the dominance of the right cerebral hemisphere for visuospatial recognition.     

Laterality of motor response in visuo-spatial neglect: a case study

We report a case of severe visuo-spatial neglect consequent upon right hemisphere stroke. At time of testing, the patient had a left visual field deficit and a very mild left hemiparesis. Star cancellation and line bisection performed with the right hand revealed profound left neglect; tested with the left hand, performance was only slightly impaired. The results are compatible with recent accounts of differential hemispheric activation provoked by lateralized pre-motor programming.     

Jargonagraphia in a left-handed aphasia due to a left hemisphere lesion]

We report a case who developed jargonagraphia, severe aphasia and unilateral spatial neglect due to cerebral infarction in the left hemisphere. The patient was a 57 year-old left-handed woman. She suddenly developed hemiplegia on the right side and aphasia, and was admitted to our hospital. Neuropsychological examination showed non-fluent spontaneous speech. Repetition, reading and auditory comprehension were impaired. Writing was severely impaired and she showed paragraphia without meaning (jargonagraphia). Right unilateral spatial neglect and buccofacial apraxia were noted, but neither ideomotor nor ideational apraxia was observed. The mechanisms of jargonagraphia remain unknown. The localization of language function in this patient is not a mirror image of same function in dextral aphasia. Her condition was considered that free-running on motor engrams of characters stored in the right hemisphere caused jargonagraphia.     

Hemianopia and neglect influence on straight-ahead perception

In spatial neglect, the pathological ipsilesional deviation of the subjective straight ahead (SSA) received both 'translational' and 'rotational' interpretations. Furthermore, hemianopia per se could also influence straight-ahead (SA) perception. Here, we aimed at disentangling the relative effects of neglect and hemianopia on the SSA by using a method analyzing translation and rotation in parallel. We included patients with a right hemisphere stroke. Ten had neglect and hemianopia, 6 neglect only, 3 hemianopia only, and 12 neither one nor the other. 15 were controls. Participants had to adjust a bar, movable in translation and rotation, SA of the navel, in darkness. Patients with spatial neglect showed systematic rightward translation, greater when hemianoptic. The rotation component appeared more variable and was influenced by the presence of a visual field defect, as most of the patients with hemianopia showed an anticlockwise rotation and most of the patients without hemianopia a clockwise rotation. Non-neglect patients and control subjects demonstrated a fair performance level. In conclusion, both neglect and hemianopia resulted in a translation error of the SSA to the ipsilesional side. In neglect patients, additional hemianopia resulted in a counterclockwise rotation. Furthermore, rotation and translation errors appeared dissociated, suggesting a different coding of these dimensions by the right posterior hemisphere.     

Neglected attention in apparent spatial compression

Halligan and Marshall [Cortex 27 (1991) 623] devised a new test to evaluate the hypothesis that in visual neglect, left space is systematically compressed rightwards. In the critical condition of the original study, rows of horizontally arranged numbers with a target arrow pointing to one of them from the opposite margin of the display were presented. When asked to verbally identify the number indicated by the arrow, a right brain-damaged patient with left neglect and hemianopia often indicated a number to the right of the target. The more the target was located on the left, the greater the response shift rightward, as if rightward compression were linearly proportional to the co-ordinates of Euclidian space. However, a possible alternative account could be that the patient's attention was attracted by the numbers located to the right of the target digit, thus biasing her responses toward numbers on the right. To explore this hypothesis, we asked normal participants and patients with right hemisphere lesions, with and without neglect or hemianopia, to mark on the margin of a sheet the approximate location indicated by an arrow situated on the opposite margin. In three different conditions, the arrow indicated either one of several numbers or lines in a row, or a blank location on the sheet margin. Only patients with left neglect, and especially those with associated hemianopia, deviated rightward, and then crucially only on those conditions where visible targets were present, consistent with the attentional bias account.     

Jargonagraphia with severe aphasia due to a right hemisphere lesion: case report.

The authors report a case of a patient who developed jargonagraphia, severe aphasia, unilateral spatial neglect and apraxia due to a right hemisphere lesion. Jargonagraphia with severe aphasia, unilateral spatial neglect and apraxia is quite rare. The mechanisms of jargonagraphia remain unknown. A possible mechanism underlying this case of jargonagraphia is discussed.     

Crossed aphasia: a PET follow up study of two cases.

Two cases of aphasia after right hemispheric stroke in right handed patients are described. The first patient had a severe mixed transcortical aphasia, apraxia and neglect after a lesion involving the right lenticular nucleus and periventricular white matter; aphasia was still present after three months. The second patient had a mild, transient fluent aphasia after a small right hemispheric periventricular lesion. Studies with [18F]FDG and positron emission tomography (PET) showed functional depression extending to the structurally unaffected left hemisphere in both patients in the acute stage. After three months, in the patient with persistent aphasia, metabolism was still reduced in the right hemisphere, with some recovery of hypometabolism on the left, while metabolic values had returned to normal in the patient with full language recovery. A close parallelism between glucose metabolism and clinical course in crossed aphasia is shown, as well as the presence of a functional involvement of the structurally unaffected left hemisphere in the acute stage.     

Right-sided neglect following a left subcortical lesion

Unilateral spatial neglect is, in humans, typically consequent to lesions of the right hemisphere and pertains to the left hemispace. Although neglect is maximally frequent after right cortical lesions, it may also ensue from lesions confined to right subcortical structures. By contrast, hemispatial neglect consequent to left hemispheric lesions occurs less frequently. Reports of neglect following lesions to left subcortical structures are even more rare and largely anecdotal. Here we report on a right-handed man who had two successive left-sided brain lesions at an interval of 10 years from one another. The first lesion, centered upon the occipital lobe, induced a contralateral hemianopia, but no signs of hemispatial neglect; by contrast, the second lesion, a capsulo-thalamic hemorrhage, did induce a florid and persistent right-sided neglect. This finding would suggest that left subcortical structures may be important nodes in the network subserving spatial representations.     

Visual neglect as a predictor of functional outcome one year after stroke

OBJECTIVE: The aim was to study the role of visual neglect in acute right hemisphere brain infarct as a predictor of poor functional outcome during the first year after stroke. In particular, we were interested in the additional value of neglect measures besides hemiparesis, hemianopia, cognitive deficits and age. PATIENTS AND METHODS: A consecutive series of 57 patients with a neuroradiologically verified right hemisphere infarct was examined within 10 days of the stroke. Fifty patients were followed up for 1 year. Neglect was measured with the Conventional and the Behavioural subtests of the Behavioural Inattention Test (BITC and BITB, respectively). The predictors were determined at the 10-day examination. Functional outcome was assessed 3, 6 and 12 months after the onset with the Frenchay Activities Index. RESULTS: Neglect in BITB was the best single predictor, which together with high age formed the best combination of predictors for poor functional outcome at each follow-up. Hemiparesis was also included in this prediction model at the 3-month follow-up, but hemianopia, BITC, or visuoconstructional and memory deficits showed no additional predictive value. However, neglect usually recovered soon. When neurological and cognitive deficits were assessed at the same time as the outcome, hemiparesis rather than neglect was the strongest correlate of poor outcome. CONCLUSION: Neglect in acute stroke is an important predictor of poor functional recovery. Residual neglect, which could be compensated in the follow-up tests, may nevertheless restrict patients' real-life activities and hobbies.     

Dissociation Between Personal and Extrapersonal Neglect in a Crossed Aphasia Study

Several reports document crossed aphasia following a right cerebral infarct. However, few of them provide a detailed investigation of associated neuropsychological disorders. A personal neglect disorder with no difficulty in orienting attention in the contralesional space has not been frequently reported independently of lesion side for the language deficit. In most cases, the deficit is described in the acute period. We report the case of a patient who showed severe crossed aphasia several months after cerebral damage. In addition to his language deficit, he suffered from finger agnosia, acalculia, and right/left confusion. Although he was able to orient attention in the contralesional space, he had a persistent personal neglect disorder with severe difficulty in attending to his own body. Results suggest that right hemisphere language dominance does not preclude ipsilateral specialisation for other functions. Furthermore, the dissociation between the two spatial functions provides further confirmation that they are subserved by two independent systems.     

Crossed Aphasia: One Or More Syndromes?

Seven strongly right-handed patients developed aphasia following a right hemisphere vascular lesion documented by computerized tomography. One patient had a severe unilateral neglect, indication of its presence were evident in three and absent in three patients. The Token Test scores were significantly higher than in matched controls. Two patients had Broca aphasia, four had Wernicke aphasia and one had agraphia. The correlation between type of aphasia and locus of lesion was not much different from that normally found in standard left hemisphere brain damaged aphasics.     

Dissociation between personal and extrapersonal neglect in a crossed aphasia study

Abstract Several reports document crossed aphasia following a right cerebral infarct. However, few of them provide a detailed investigation of associated neuropsychological disorders. A personal neglect disorder with no difficulty in orienting attention in the contralesional space has not been frequently reported independently of lesion side for the language deficit. In most cases, the deficit is described in the acute period. We report the case of a patient who showed severe crossed aphasia several months after cerebral damage. In addition to his language deficit, he suffered from finger agnosia, acalculia, and right/left confusion. Although he was able to orient attention in the contralesional space, he had a persistent personal neglect disorder with severe difficulty in attending to his own body. Results suggest that right hemisphere language dominance does not preclude ipsilateral specialisation for other functions. Furthermore, the dissociation between the two spatial functions provides further confirmation that they are subserved by two independent systems.     

A case of cerebral thrombosis presenting global aphasia without hemiparesis]

We reported a 62-year-old male with cerebral thrombosis presenting global aphasia without hemiparesis. The patient had an episode of aphasia 15 years ago, but recovered within 6 months. This time he had transient right sided mild hemiparesis, then he became aphasia next morning. When we examined at day 10 and day 15, his consciousness was clear, nothing he could speech, he could not understand or repeat. We diagnosed him global aphasia, but he had no hemiparesis except for right facial mild paresis and was able to walk. CT scan showed low density area in left and right posterior, left anterior watershed and left terminal zone. Cerebral angiography disclosed thrombotic occlusion of main trunk of left middle cerebral artery, and ambient segment of right posterior cerebral artery. Global aphasia without hemiparesis has been said a sign of embolic encephalopathy. This case was considered a very rare case, because he revealed global aphasia without hemiparesis by thrombotic occlusion.     

Crossed aphasia: description of a case

We describe a new case of crossed aphasia in a right-handed patient with a right hemispheric lesion. A right-handed man, 76 year-old, developed a sudden left hemiparesis with sensitive impairment and mutism. He has neither family history of left handeness or ambidexterity or vascular risk factors. CT cerebral scan showed a large infarct of the middle cerebral artery on the right side, with haemorrhagic suffusion. Cerebral MRI and EEG-cartography confirmed the indemnity of the left hemisphere. Aphasia studies confirmed a mutism with spared verbal comprehension, but alexia was present. A year later, left hemiparesis was recovered but aphasia remained. Crossed aphasia is rarely seen. It is caused by a right hemispheric lesion in right-handed subjects. Fluency is most commonly impaired. At onset, mutism is the common symptom, which evolves to expressive aphasia. Several hypothesis have been raised about the possible mechanisms involved. The few number of PET or SPECT studies performed in these patients have disclosed extensive areas of hypometabolism in the right hemisphere, that exceed the size of the image observed with CT scan or MRI.     

Sequential changes of brain CT and MRI after febrile status epilepticus in a 6-year-old girl

Brain CT or MRI occasionally shows transient or permanent changes in the brain after status epilepticus (SE). The mechanism for these changes has not been well elucidated. We performed repeated imaging studies on a patient with febrile SE characterized by right hemiconvulsion. CT showed transient mild edema on both hemispheres immediately after the cessation of SE. The edema improved the next day. But aphasia and right hemiparesis were observed. On day 17, CT revealed edema on left hemisphere and MRI showed a high signal intensity in cortex and subcortical white matter of the left hemisphere on T2-weighted images. Although right hemiparesis and aphasia were improved, severe atrophy of the left hemisphere was noted on CT and MRI. The results suggest that brain edema observed in several days after SE but not edema observed immediately after the cessation of SE is more pathological for the permanent brain damage. Possible mechanisms of the initial brain edema and the second edema preceded severe atrophy in left hemisphere were discussed.     

Dissociated crossed aphasia: a challenging language representation disorder

A monolingual strongly right-handed woman developed a left hemiparesis and severe motor aphasia following a right middle cerebral artery infraction, whereas comprehension was entirely intact. She had a history of a transient cerebrovascular event characterized by right hemiparesis and fluent sensory aphasia. This case suggests a transhemispheric pattern of language organization in which the Broca area resides in the right hemisphere, whereas the Wernicke area is in the left.     

Transcortical motor aphasia due to a right hemisphere lesion in a right-handed man

Abstract

A 67-year-old, right-handed male became aphasic following a right hemispheric infarction involving the frontal and parietal regions. The patient was evaluated by means of neurological, behavioural, and neuroradiological examinations. Behavioural investigations included Ianguage and nonverbal visuospatial and constructive evaluations. Language evaluation demonstrated transcortical motor aphasia and nonverbal tests showed left-sided visual neglect, left hemiakinesia, and constructional apraxia. Besides the information concerning crossed aphasia in a right-handed person, this case also supports the hypothesis that right-sided language representation does not affect right hemisphere dominance for visuospatial abilities.     

Visual Search and Visual Target Detection in Patients with Infarctions of the Left or Right Posterior or the Right Middle Brain Artery

We compared visual target detection and search performance of patient groups with infarctions of (1) the right middle brain artery (R-MBA) and with neglect; (2) the left posterior artery (L-PBA), (3) the right posterior artery (R-PBA), the latter two groups had contralesional hemianopias, or (4) with right hemisphere lesions without hemianopia or neglect. We found that: (1) The first three groups differed from the fourth (control) group in omissions. (2) The first three groups differed only in horizontal search but not in target detection. (3) No vertical search deficit was present for either group. (4) R-MBA patients found increasingly more targets in visual search from left to right, R-PBA patients had problems with the outermost contralesional column, L-PBA patients showed a generally slowed and more variable search pattern. Infarctions of left and R-PBA therefore resulted in different visual search patterns. The behavior of the patients with R-MBA is consistent with Kinsbourne's (1992) interactive inhibition theory of neglect.     

Acceleration perception and spatial distortion in a left unilateral neglect patient

To explain relative leftward overextension in a line extension task by left unilateral neglect subjects, Bisiach et al. (1998) suggested that the representation of space is distorted--i.e., dilated towards the left side. If perception of the velocity of a moving stimulus is due to a calculation of the distance covered per unit time in representational space, then a stimulus with uniform linear motion should be perceived as decelerating when moving leftwards in the visual field of a subject with left unilateral neglect. We investigated the perception of acceleration in a patient with left unilateral neglect and spatial distortion (revealed as relative left overextension in a line extension task) using a task in which the stimuli were right and left moving targets with variable acceleration. The patient's ability to perceive acceleration was much lower (higher acceleration threshold) for leftward movements than rightward movements. Fourteen months later unilateral neglect had improved, and the relative left overextension and decreasing acceleration threshold for leftward movements were reduced. By contrast, alterations in the perception of acceleration for leftward movements were not found in a patient with left unilateral neglect and left underextension and in a patient with right brain damage and left hemianopia. These findings in one patient with left spatial unilateral neglect and a relative left overextension in a line extension task are consistent with the hypothesis that representational space is distorted, with a disproportionate leftward expansion, that affects perception of movement.