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Biomedical subjects

A B Rubens

Publications and source records attributed to A B Rubens.

At least 37 records · Page 2Linked to original sources
PubMed1985

The critical role of Wernicke's area in sentence repetition.

The anatomical correlates of persistent deficits in sentence repetition were studied in a group of 32 right-handed patients with fluent aphasia caused by left hemisphere ischemic stroke. Patients whose ability to repeat remained impaired by 6 months after onset almost without exception had damage to Wernicke's area. Furthermore, all patients with damage to Wernicke's area had impaired repetition 6 months after onset. The most consistent lesion correlating with chronic impairment of repetition, therefore, was one destroying parts or all of Wernicke's area. Lesions outside of this area typically resulted in milder impairment of repetition that resolved within a few months. Only 5 patients had no repetition impairment when tested early (1 month after onset). These patients all had lesions anterior to the rolandic fissure, some including Broca's area.

Adult↗
PubMed1985

Left ear suppression on verbal dichotic tests in patients with multiple sclerosis.

Verbal dichotic listening tests employing nonsense consonant-vowel stimulus pairs were administered to 11 right-handed patients with chronic multiple sclerosis and to 10 right-handed normal controls. A highly significant reduction of left-ear scores was found in the multiple sclerosis group. We propose that the basis for this finding is a disconnection of the auditory callosal pathway and that dichotic listening tests may be of value in detecting the presence of lesions of the deep white matter of the cerebral hemispheres in multiple sclerosis.

Adult↗
PubMed1985

Caloric stimulation and unilateral visual neglect.

We studied performance on tests of visual neglect and left lateral gaze after caloric stimulation in 18 patients with left-sided visual neglect after strokes. Except for one patient with absent vestibulo-ocular responses, all improved during caloric stimulation on the left by cold (LC) or on the right by warm water (RW). Improvement seemed to depend on the facilitation of left lateral gaze and on past-pointing to the left. During LC and RW caloric stimulation, patients worked from left to right instead of their usual right to left. Caloric stimulation may be of use in training patients with hemispatial neglect to orient toward the affected hemispatial field.

Adult↗
PubMed1984

Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies.

In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery.

Adult↗
PubMed1984

Recovery of single word comprehension: CT-scan correlates.

9tory comprehension for single words, as measured by the BDAE Word Discrimination subtest, was studied longitudinally in a group of 37 aphasic patients. The majority of the patients had impaired performance at 1 month postonset, but recovery by Month 6 postonset was quite striking. Damage to Wernicke's area did not preclude recovery of single word comprehension to within the normal range. Only patients with very extensive left hemisphere lesions had incomplete recovery of single word comprehension.

Adult↗
PubMed1984

Disturbances of long-term memory in aphasic patients. A comparison of anterior and posterior lesions.

The performance of 20 aphasic patients on a verbal list-learning task was examined in relation to site of lesion, as documented by CT scan. Patients with lesions of the inferior frontal lobe and/or the basal ganglia were severely impaired in both acquisition and long-term retention of the list, while the performance of patients with posterior temporoparietal involvement was nearly normal. These results contrasted sharply with scores on short-term memory tests by the same patient groups which showed an opposite trend. The findings support a functional and neuroanatomical dissociation of short and long-term memory systems and suggest that neural connections of the inferior frontal lobe and the basal ganglia may be crucial for initiating the retrieval process.

Adult↗
PubMed1984

Recovery of naming in aphasia: relationship to fluency, comprehension and CT findings.

We assessed oral naming skill after left hemisphere ischemic stroke in 54 right-handed aphasics. Initially, almost all had moderate to severe disability in oral naming. After 6 months, normal scores were achieved by one-third of the patients, all with lesions less than 60 cm3 in volume. Only 2 of 18 patients who were nonfluent at 6 months had normal naming then. Among patients with lesions less than 60 cm3 and persistently poor naming, there were two discrete lesion sites: posterior superior temporal-inferior parietal (semantic paraphasic errors) and insula-putamen (phonologic paraphasic errors). Individual variability was notable, with several patients regaining normal naming ability despite posterior temporal or insula-putamen lesions.

Adult↗
PubMed1983

Computed tomographic scan correlates of auditory comprehension deficits in aphasia: a prospective recovery study.

Lesion localization and volume as assessed on computed tomography were analyzed to determine their relationships to auditory comprehension deficits following left hemisphere ischemic stroke in 39 patients. Auditory comprehension was initially tested approximately four weeks after onset, and then monthly for five months, using the Token Test, a series of commands of increasing complexity. Computed tomographic scans obtained five months after onset were used for lesion localization and volume determination. Lesions in the posterior superior temporal and infrasylvian supramarginal regions were strongly associated with poor outcome. Patients with initially preserved auditory comprehension tended to have lesions that spared these regions, whereas patients with persistent deficits had lesions that included these regions. Six of 8 patients who initially had severe deficits in auditory comprehension but recovered completely lacked lesions in these regions. Lesion volume except when very large or very small was not closely associated with outcome.

Adult↗
PubMed1983

Reversal of ear advantage in recovery from aphasia: a case report.

A reversal from a left ear advantage to a right ear advantage on a digit dichotic listening test was observed during the first 3 months post-onset of aphasia in a 52-yr-old male patient. Explanations for this pattern of recovery were discussed under both a "lesion effect" and a "dominance effect" interpretation.

Aphasia↗
PubMed1983

Dichotic listening performance, language impairment, and lesion location in aphasic listeners.

This investigation sought to identify relations between dichotic listening performance and both specific language functions and CT scan evidence of lesion location in order to determine whether the nature of these relations would support either "dominance effect" or "lesion effect" interpretations of the dichotic scores. Twenty-five aphasic patients completed our digit dichotic listening test, the Boston Diagnostic Aphasia Examination (BDAE), an experimental sentence comprehension test, and a digit immediate memory span test. Right ear scores (and the ear advantage) accurately reflected the integrity of the central auditory structures for all but one of the patients, and thus were interpreted as "lesion effects." These same right ear scores also were related more strongly to performance on phrase repetition subtests of the BDAE and to scores obtained on our sentence comprehension test than to the other language measures analyzed. These relations were maintained even when general measures of auditory comprehension and immediate memory were held constant through the use of partial correlations. Both "dominance" and "lesion" effect interpretations were discussed, but the "lesion effect" interpretation more adequately characterized the data. That is, the integrity of the posterior, superior temporal area seemed to be essential for perception of right ear stimuli on the digit dichotic test and for accurate performance on specific language tests.

Adult↗
PubMed1983

A longitudinal study of speech fluency in aphasia: CT correlates of recovery and persistent nonfluency.

The anatomic correlates of speech fluency were studied in 54 right-handed patients with aphasia due to stroke. Speech fluency was assessed at 1 month postonset and then monthly for 5 months. CTs obtained at 5 months postonset were used for lesion localization and volume determination. Persistent nonfluency was associated with lesions in the rolandic cortical region and underlying white matter. Recovery from nonfluency occurred in 6 of 27 patients. Lesions in these six patients were less extensive than lesions in patients with persistent nonfluency. Patients who were fluent by 1 month lacked extensive rolandic lesions.

Adult↗
PubMed1982

Regional cerebral blood flow correlates of auditory processing.

To study the regional cerebral blood flow (rCBF) correlates of auditory processing, we performed rCBF measurements in young, normal right-handed volunteers engaged in listening tasks. Using the xenon Xe 133 inhalation technique, rCBF was measured in 11 regions in each hemisphere. Compared with a baseline condition, significant rCBF increases in the left posterior Sylvian regions were associated with both verbal phonologic processing and nonverbal acoustic processing. Verbal semantic processing was associated with unilateral increased rCBF in the posterior Sylvian region contralateral to the hand used for response signaling. Comparison of rCBF from homologous regions of the two hemispheres also confirmed a clear difference between the rhyme detection and meaning detection tasks, with the former strongly lateralized to the left hemisphere. Thus, changes in rCBF were related to the nature of the listening task.

Acoustic Stimulation↗
PubMed1981

Effects of stimulus material on the dichotic listening performance of aphasic patients.

Sixteen aphasic patients were given five different verbal dichotic listening tests. The differences among results obtained on a digit test, a high-contrast word test (perception of either vocalic or consonantal information was sufficient for accurate responses), and a vowel-word test (perception of vocalic information was required for accurate responses) were not significant. However, a consonant-word test resulted in significant decreases in both left- and right-ear scores and an increase in the performance levels, and the magnitude of difference scores between ears was limited by low levels of performance for the majority of patients. Attempts to identify relations between patterns of performance on dichotic listening tests and radiographic evidence of lesion location were most profitable when they involved the right-ear (RE) scores on the digit test. The discontinuity in the distribution of these scores corresponded to the presence of absence of damage to the geniculo-temporal system. That is, when the geniculo-temporal system was spared, the RE scores exceeded 75% correct, whereas damage to the geniculo-temporal system was associated with RE scores of less than 50% correct.

Adult↗