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Biomedical subjects

F Boller

Publications and source records attributed to F Boller.

At least 109 records · Page 6Linked to original sources
PubMed1986

Computerized EEG spectral analysis in elderly normal, demented and depressed subjects.

Computerized spectral analysis of the EEG was performed in 35 patients with Alzheimer's disease and compared to patients with major depression (23) and healthy elderly controls (61). Compared to controls, demented patients had a significant increase in the theta and alpha 1 bandwidths as well as an increased theta-beta difference. The parasagittal mean frequency, beta 1 and beta 2 activity were significantly decreased. Depressed patients differed from demented patients, particularly at the lower end of the spectrum, having significantly less delta and theta activity. Like the demented group, depressed patients also had a decreased parasagittal mean frequency, beta 1 and beta 2 when compared to controls. In demented patients, there was a high correlation between several spectral parameters (parasagittal mean frequency, delta and theta activity, and the theta-beta difference) and the Folstein score, EEG measures used for discriminant analysis were more accurate in identifying demented patients who had lower Folstein scores.

Aged↗
PubMed1986

Use of semantic context by patients with Alzheimer's disease.

In this study we used semantic-priming procedures to examine limitations in the use of semantic context by patients with Alzheimer's disease. We also tried to determine whether any such contextual effects were mediated solely through automatic processes or whether attentional processes were also involved. Three tasks were applied to examine the effect of semantic context on the performance of 18 normal elderly and 18 normal young subjects, and on 18 patients with Alzheimer's disease. When normal and demented subjects were asked to decide whether a given item was a member of a certain category, results showed that their response times were equally affected by the item's dominance in the category. The time that demented patients took to recognize a word was actually affected more by the semantic context provided by a priming sentence than was that of normal subjects. When asked to generate the final word of an incomplete sentence, demented subjects performed very poorly unless potential responses were highly constrained by sentence context.

Adult↗
PubMed1984

Visuospatial impairment in Parkinson's disease. Role of perceptual and motor factors.

We investigated the role of perceptual and motor factors in visuospatial impairment in 30 patients with Parkinson's disease (PD) and 30 matched controls. All subjects were administered visuospatial tests, which included "visuoperceptual" tasks, requiring minimal motor responses, and "visuomotor" tasks. The performance of patients with PD was considerably impaired on several tasks from both groups, and this impairment was not related to depression or intellectual impairment. Patients in stage 3 of the disease tended to show the greatest impairment. Those in stage 1 (unilateral symptoms), however, tended to show more impairment than those in stage 2.

Aged↗
PubMed1984

Visuoperceptual and visuomotor abilities and locus of lesion.

Possible differential effects of laterality and caudality of cerebral lesions on simple visuoperceptual and visuomotor skills were examined. As expected, the right hemisphere lesion group was significantly more impaired than the left hemisphere lesion group. The effects of the caudality of lesion, however, yielded interesting results. While the right posterior group was worse than the right anterior lesion group, as expected, the left posterior lesion group was better than the left anterior lesion group. Our findings points to a possibility that the left hemisphere, especially the anterior region, might not be as silent in processing simple visual stimuli as has been accepted.

Brain Diseases↗
PubMed1983

Acalculia: historical development and current significance.

Acalculia is a loss of calculating abilities occurring as a result of cerebral damage. This paper reviews the development of the notion of acalculia from an expected concomitant of aphasia or dementia to that of a sometimes autonomous disorder. Current evidence indicates that acalculia tends to occur particularly in lesions of the left posterior hemispheric areas.

Aphasia↗
PubMed1982

Calculation disturbances in adults with focal hemispheric damage.

It has been suggested that hemisphere-damaged patients with calculation disorders can be subdivided into 3 groups: agraphia or alexia for numbers, spatial dyscalculia and anarithmetia. The purpose of the present study was to evaluate the role played by visuospatial disorders and by anarithmetia in subjects with impaired calculation abilities. Seventy-six patients with focal hemispheric lesions and 26 normal controls with demonstrated ability to read and write numbers were given a written calculation task, the Token Test, the Crosses Test, a test of Constructional Apraxia and Raven's Progressive Matrices. In the calculation task, a quantitative score represented the number of digits that were correct numerically and put in correct position. A qualitative score with emphasis on visuospatial factors was obtained by scoring each problem with the criteria used in Benton's Visual Retention Test. Analysis of the results showed that both left and right hemisphere-damaged patients performed significantly worse than controls and that patients with left posterior lesions were particularly impaired even after correction of the acalculia scores by the results of the other neuropsychological tests. These results suggest that even though different factors may contribute to calculation disorders (impairment of intelligence, visuoconstructive difficulties and above all aphasia), left posterior lesions are particularly prone to produce an impairment in calculating abilities which is partially independent from the above disorders.

Aphasia↗
PubMed1982

Auditory dysfunction following a gunshot wound of the pons.

A patient with a gunshot wound penetrating the right side of the brainstem at the level of the pons was given a test battery to evaluate peripheral hearing function and central auditory processing abilities. A month later, the left ear had a loss of sensitivity for high frequency tones, decreased speech discrimination, and excess tone decay. Two years later these deficits had resolved. However, a central auditory impairment remained, affecting the right ear score on Binaural Fusion and left ear scores on dichotic tasks and tonal pattern sequences.

Adolescent↗
PubMed1982

Visual hallucinations in blindness: the Charles Bonnet syndrome.

A 64-year-old woman developed complex visual hallucinations consisting of snakes crawling out of people's head and on her body. She had become blind 14 years before the onset of the hallucinations. Neurosurgical removal of a large suprasellar meningioma was followed by disappearance of her hallucinations. This case suggests that the complex hallucinations often encountered in blind subjects ("release hallucinations"), a phenomenon originally described by Charles Bonnet in 1769, are related to both sensory deprivation and an impairment in CNS functioning.

Blindness↗
PubMed1980

Unilateral gunshot wound of the pons: clinical, electrophysiologic, and neuroradiologic correlates.

Following a gunshot wound to the face, a 17-year-old male patient experienced a right trigeminal and abducens paralysis, dysarthria, right-sided ataxia, left-sided weakness of the lower part of the face and limbs, and left-sided sensory loss from his neck down. Brainstem auditory evoked potentials showed a decreased P5/P1 amplitude ratio for left ear presentation, and inconsistent replication of P2 and P3 on the right and, to a lesser extent, on left ear click presentations. A computerized tomography scan showed right pontine atrophy. These findings point to a unilateral lesion of the right pons.

Adolescent↗
PubMed1980

Parkinson disease, dementia, and Alzheimer disease: clinicopathological correlations.

Clinical records and neuropathological specimens from 36 patients with autopsy-demonstrated idiopathic Parkinson disease (PD) were reviewed independently and the results compared. Nine (31%) of the 29 patients with adequate clinical data had severe dementia and 7 (24%) had mild dementia. The cerebral cortex showed senile plaques and fibrillary tangles in 15 of the 36 patients (42%). These changes were found in all 9 patients with severe dementia, in 3 of the 7 with mild dementia, and in 3 of the 13 patients with normal mental status. The prevalence of pathologically established Alzheimer changes and dementia among the patients with PD (33%) was over six times that found in an age-matched population (5.1%). Survival after the onset of PD with Alzheimer disease was shorter than in PD without Alzheimer disease.

Age Factors↗
PubMed1980

Temporal sequencing of verbal and nonverbal materials: the effect of laterality of lesion.

The effect of laterality of cerebral lesion on sequencing ability, which is an ability to process two or more stimulus events with respect to the order in which they occur, was examined. Patients with either left or right hemisphere lesions performed on verbal and nonverbal sequencing tasks. Left hemisphere lesioned patients were inferior to the right hemisphere lesioned patients on verbal sequencing tasks, while the right hemisphere lesioned patients were inferior to the left hemisphere lesioned patients on nonverbal sequencing tasks. Impaired performance of the right hemisphere lesioned patients on sequencing tasks raises questions with respect to the notion that sequencing per se is processed in the left hemisphere. Our results demonstrate that sequencing ability, as many other abilities, follows the rule of material-specific laterality of hemispheric asymmetry: the left hemisphere associated with verbal sequencing ability and the right hemisphere associated with nonverbal sequencing ability.

Aphasia↗
PubMed1979

Evaluation of delayed auditory feedback (DAF) effect: comparison between subjective judgments and objective measures.

The effect of Delayed Auditory Feedback (DAF) on speech duration was evaluated subjectively and measured objectively in 30 subjects (10 normals, 10 nonfluent aphasics and 10 fluent aphasia). The average correlation coefficient between the subjective and objective data was .52 for 180 msec. delay and .46 for 360 msec. delay. Analysis of variance of data derived from the two methods showed the same highly significant differences among groups, delay and tasks. We conclude from these results that both objective and subjective procedures are equally useful in evaluating DAF effect on speech duration, and that both may also be valuable in assessing other types of behavior.

Aphasia↗