Biomedical subjects

C W Wallesch

Publications and source records attributed to C W Wallesch.

At least 55 records · Page 3Linked to original sources

PubMed1997

Neuropsychological disorders after coronary bypass surgery.

OBJECTIVES: A prospective assessment of neuropsychological impairment in the early postoperative stage after coronary bypass surgery. METHODS: Seventy patients undergoing elective coronary bypass surgery (CABG) were investigated preoperatively, two to three and five to nine days postoperatively with a comprehensive neuropsychological assessment including orientation, word fluency, naming, arithmetic, memory, and visuoconstructive tasks. RESULTS: Patients exhibited significant early postoperative impairment affecting all tasks but naming. Except for the orientation measurement, most patients recovered by the fifth to ninth postoperative day. Only six patients had delirium according to DSM III-R criteria on the second or third postoperative day. Cluster analysis of neuropsychological data obtained on the second to third postoperative day identified 10 patients who were cognitively compromised. As a group, these patients had required a greater number of defibrillations and exhibited lower cardiac indices postoperatively. Preoperatively, patients at risk for postoperative dysfunction were characterised by lower verbal memory, word fluency, and clock orientation scores. CONCLUSIONS: Simple preoperative neuropsychological assessment may be helpful and clinically applicable in identifying patients at risk for postoperative cognitive dysfunction and may contribute to improve postoperative management aiming at the prevention of delirium or other transient neuropsychological disorders.

Aged↗

PubMed1997

Coping with chronic neurological impairment: a contrastive analysis of Parkinson's disease and stroke.

This study aimed at a contrastive analysis of coping strategies and psychosocial alterations in patients with Parkinson's disease (PD) and stroke (CVA) and their relatives. Fifty-four PD and 50 CVA patients were investigated with a standardized semistructured interview to assess the severity of psychosocial changes following illness, the Freiburg Questionnaire on Coping with Illness, the Cornell Depression Scale and instruments to assess motor impairment. Psychosocial alterations were most prominent in the professional and emotional-cognitive domains. Degree of depression correlated with familial and emotional-cognitive alterations in both patient groups. Active problem-oriented coping and distraction predominated as coping styles. Religious relief and quest for sense were significantly more important for the PD patients. Coping styles did not correlate with degrees of depression, motor impairment or psychosocial alterations.

Adaptation, Psychological↗

PubMed1997

Detection of mitochondrial defects by laser fluorimetry.

The mitochondrial function in skeletal muscle biopsies of three patients with chronic progressive external ophthalmoplegia, having deletions of the mitochondrial DNA, was studied by laser-excited fluorescence measurements of NAD(P)H and flavoproteins in saponin-skinned fibers. We detected substantially elevated steady state redox states of the mitochondrial NAD-system in the muscle fibers of these patients. Moreover, the respiratory chain-linked autofluorescence changes in the muscle fibers of these patients were larger in comparison to controls indicating substantial alterations of the mitochondrial content. These results are in line with the presence of elevated numbers of partially respiratory chain inhibited mitochondria in the skeletal muscle of chronic progressive external ophthalmoplegia patients.

Aged↗

PubMed1996

Freud's impact on aphasiology--aphasiology's impact on Freud.

In 1891, Sigmund Freud published a book on aphasia. Although Freud's contribution to aphasiology could have been important in retrospect, it was hardly acknowledged for three quarters of a century. It may have had an impact on psychoanalytic theory, but this was not acknowledged by Freud. If there are neurological roots in psychoanalysis, they are buried by paradigmatic shifts in Freud's theory.

Aphasia↗

PubMed1995

Oxygraphic evaluation of mitochondrial function in digitonin-permeabilized mononuclear cells and cultured skin fibroblasts of patients with chronic progressive external ophthalmoplegia.

For quantitative elucidation of maximal mitochondrial oxidation capacities in human mononuclear cells, cultured human skin fibroblasts and human thrombocytes the optimal amount of digitonin for plasma membrane permeabilization was determined to be 5, 10, and 0.1 micrograms/10(6) cells, respectively. Using these concentrations the rate of respiration of permeabilized cells with the mitochondrial substrates succinate (+ rotenone) or glutamate + malate can be stimulated between two- and fourfold by ADP and inhibited by carboxyatractyloside. The maximal respiratory activities of well-characterized preparations of permeabilized mononuclear cells of five patients with chronic progressive external ophthalmoplegia were compared to healthy controls and a 30 to 50% decrease of the ADP-stimulated respiration rates with glutamate + malate and succinate + rotenone was detected. This is an indication for the presence of the mitochondrial defect in respiratory active blood cells. Additionally, for two of these patients the mitochondrial defects were proven to be detectable by the determination of maximal oxygen consumption rates of digitonin-permeabilized cultured skin fibroblasts. Therefore, the determination of maximal oxidation capacities of a well-defined cell population using strictly standardized conditions of digitonin permeabilization is judged as a useful and sensitive method for the elucidation of mitochondrial function in extramuscular tissue.

Adolescent↗

PubMed1995

Poststroke depression. Is there a pathoanatomic correlate for depression in the postacute stage of stroke?

BACKGROUND AND PURPOSE: This study is aimed at the pathoanatomic correlates of depression in the postacute stage of patients with stroke. METHODS: Of a consecutive series of 104 stroke patients, a subgroup of 47 patients with single demarcated unilateral lesions was selected. Clinical examination, neuroradiological CT scan examination, and psychiatric assessment were performed within a 2-month period after the acute stroke. Depression was assessed with the Cornell Depression Scale, the Montgomery-Asberg Depression Rating Scale, and according to modified DSM-III-R criteria. The neuroradiological examination of all patients was performed on the same scanner, and lesion location, lesion volume, and ventricle-to-brain ratio were analyzed. RESULTS: We found no significant differences in depression scores between patients with left and right hemisphere lesions and no correlation between the severity of depression and the anteriority and the volume of lesion or brain atrophy. Major depressive disorders were only found in nine patients with left hemisphere lesions, all involving the basal ganglia, whereas none of the patients with right hemisphere stroke exhibited major depression. CONCLUSIONS: Lesions in the vicinity of the left hemisphere basal ganglia tend to play a crucial role in the development of major depression after the acute stage of stroke. The pathophysiological implications of this finding are discussed.

Brain↗

PubMed1995

[Determining patient staff with regard to needs and requirement profile for neuropsychologists, speech therapists and occupational therapists of acute care neurologic clinics in Germany].

The directors of neurological emergency-care departments were asked about the number and work profile of psychologists, occupational and speech therapists in their institutions. A majority of departments in West Germany employed their own speech and occupational therapists. In East Germany, a majority had their own psychology service. Work profiles and demands for personnel did not differ between the East and West. On the basis of the results, recommendations are made for the number of therapists required in neurological emergency-care departments.

Acute Disease↗

PubMed1994

Incomplete split-brain syndrome in a patient with chronic Marchiafava-Bignami disease.

A 40-year-old male patient is presented who survived Marchiafava-Bignami disease and recovered sufficiently to be assessed neurologically and neuropsychologically in some detail. Besides dementia, lack of initiative, and psychomotor retardation here ascribed to extracallosal damage, he showed a number of symptoms of hemispheric disconnection such as left-sided apraxia, poor bimanual coordination in specific laboratory tests, and deficits in the interhemispheric transfer of somaesthetic information. Other commissural functions, such as interhemispheric transfer of tactile, visual and auditory information as well as bilateral coordination in previously overlearned tasks, were nearly intact. The observed dysarthria could be meaningfully discussed in relationship to postcallosotomy mutism. It is concluded, that the partial interhemispheric disconnection syndrome in Marchiafava-Bignami disease lacks functional compensation which is different from the usual course in partial commissural section.

Adult↗

PubMed1994

Different mechanisms underly shifting set on external and internal cues in Parkinson's disease.

A set shifting task consisting of the comparison of two digits according to their numerical value or their form guided by an explicit (external cue) or implicit (internal cue) rule was performed by 8 untreated and 19 treated patients suffering from Parkinson's disease (PD) and 15 control subjects. The subjects could not predict the number of trials for a given target. The treated PD patient group exhibited increased post-shift error rates under the internal cue condition. In the external cue condition, only the untreated patients produced more errors when shifting to a new response criterion. Reaction times were prolonged in treated PD patients, irrespective of type of cue. Large interindividual variability within the patient groups is considered as meaningful and indicates individual differences in the neuropsychological impairment and/or the neurotransmission deficit. Pathophysiological and neuropsychological impairments underlying these findings are discussed on the basis of the models of Penney and Young (1983/1986) and Norman and Shallice (1980/1986).

Aged↗

PubMed1994

Language function in delirium: a comparison of single word processing in acute confusional states and probable Alzheimer's disease.

Thirteen patients suffering from transient acute confusional states (ACS) and 11 patients with probable Alzheimer's disease (AD) who were comparable for age and Mini-Mental State score were investigated with a naming and a comprehension task. The latter included both words that were previously included in the naming task and unfamiliar items. With five patients of each group, the assessment was repeated 1 to 3 days later. The number of misnamings was comparable for both groups. An effect of word frequency upon naming success was found only with the AD group. Unrelated misnamings were significantly more frequent in the ACS group. Closer analysis suggested that part of the unrelated misnamings in the ACS patients were caused by visual misperceptions. Behavioral strategies aiming at the target were more frequently exhibited by Ad patients. Perseverations, especially of the intrusion type, were characteristic for ACS patients and only occasionally found with AD. There was an item consistency over time with naming failure in the AD, but not in the ACS group. Cross-modal performance consistency seemed greater in the ACS than in the AD group.

Aged↗

PubMed1993

Depression in acute and chronic aphasia: symptoms, pathoanatomical-clinical correlations and functional implications.

Depressive alterations were investigated in 21 acute and 21 chronic aphasic patients with single left sided strokes. The assessment of depression was based on a psychometrically evaluated German version of the Cornell Scale for Depression (CDS) and the Research Diagnostic Criteria (RDC). No significant difference was found concerning depression sum-scores between the two aphasic groups. The acute group, however, exhibited significantly higher ratings in items related to physical signs of depression and disturbances of cyclic functions. Patients corresponding to the RDC-syndrome of major depression were only found in the acute group. Neither age, sex nor degree of hemiparesis discriminated the patients on the severity of depressive symptoms. In the acute patient group, nonfluency of aphasia was the only parameter that could be identified which had an effect on the mood symptom scores. A CT scan analysis in the acute patient group showed an association between the severity of depression and anterior lesions. A significant correlation was found between CDS sum-scores and the proximity of the anterior border of the lesion to the frontal pole of the hemisphere whereas the volume of lesions seemed to have no effect on depressive alterations in acute aphasic patients. Superimposition of the lesions of the aphasic patients with major depressive disorders showed a common subcortical lesion area involving putaminal and external pallidal structures.

Acute Disease↗

PubMed1992

Inflexibility of mental planning: a characteristic disorder with prefrontal lobe lesions?

Inflexibility of mental planning processes has repeatedly been discussed to represent a specific disorder resulting from human frontal lobe lesions. Patient groups suffering from acute or chronic unilateral frontal (medial, lateral) or retrorolandic (temporal, parietal) lesions and nonbrain-damaged controls were requested to mirror and to reverse mentally a maze structure that had been learned by the covered maze presentation technique (KARNATH et al., Neuropsychologia 29, 271-290, 1991). The patients with acute frontal lesions were impaired to adapt the acquired mental plan to the new (but related) problem and made more errors than those with acute temporal or parietal lesions and controls. However, no impaired plan modification was detected in patients with chronic frontal brain lesions. The difference of task performance in the acute and chronic (recovered) stage of frontal brain damage is discussed.

Attention↗

PubMed1992

Cognitive slowing in decision tasks in early and advanced Parkinson's disease.

Ten untreated patients with recently diagnosed Parkinson's disease (PD), 9 treated patients with more advanced pathology, and 17 matched normal controls were investigated with three reaction tasks with increasing cognitive load but identical motor requirements: simple reaction, choice reaction with indicative stimuli, and choice reaction with ambiguous stimuli. Times required until a home key was released (= reaction time) and from then until a response key was pressed (= movement time) were recorded. Estimates of pure decision time (overall response time minus movement time in a simple reaction time task) revealed a difference between advanced and early PD patients. Advanced PD patients showed an overall slowing of decision time in the reaction time tasks, but the effect of the cognitive load of the tasks on the decision time was comparable to a control group. The untreated early PD patients performed quite normally in the more simple decision tasks but showed a disproportionate slowing of decision time in tasks with higher cognitive load.

Adult↗

PubMed1991

Mental planning and anticipatory processes with acute and chronic frontal lobe lesions: a comparison of maze performance in routine and non-routine situations.

A series of computerized mazes were masked during presentation allowing only partial view of their structure. Patients suffering from acute or chronic unilateral frontal (medial, lateral) or retrorolandic (temporal, parietal) lesions and non-brain-damaged controls were required to pass through the mazes repeatedly, until they solved them without reaching a dead end. Because the mazes could not be viewed in their entirety at any one time, the subjects were forced to mentally generate and apply a plan of the maze. The first ("non-routine" situation), the second and the last ("routine" situation) trials of the mazes were analysed separately. The prefrontal cortex is supposed to subserve important functions in the planning of behaviour in unfamiliar, non-routine situations. Shallice (Phil. Trans. R. Soc. Lond. B298, 199-209, 1982; From Neuropsychology to Mental Structure, Cambridge University Press, Cambridge, 1988) therefore postulated that the behaviour of patients with frontal lobe lesions should not be disturbed in routine situations, but rather these patients should exhibit difficulties in dealing with new and unfamiliar situations. In the present investigation, patients with acute and chronic frontomedial lesions exhibited deficits in generating mental plans. Patients with acute frontomedial lesions made a larger number of errors in their second trials and subsequently required more trials to reach task criterium. Patients with chronic frontomedial lesions showed more frequent rule-breaking behaviour in their second trials. The analysis of maze performance in the first trial and that trial in which task criterion was achieved, showed that frontal lobe patients were impaired in neither routine nor non-routine situations. The observed results suggest a modification concerning Shallice's assumptions. Patients with frontomedial lesions are not generally incapable of dealing with non-routine situations. But they seem to be slower than patients with retrorolandic lesions and controls in profiting from experiences made in an unfamiliar, non-routine situation represented by the first explorations of new maze problems. This deficit can possibly be explained by the observation that anticipatory processes or the formation of expectations about possibly correct decisions in non-routine situations were altered in acute and chronic frontomedial patients. When these patients reached a maze intersection for the first time and therefore had no information about the continuation of the correct path, they showed significantly different intuitive directional decisions when compared to controls.

Adult↗

PubMed1991

Limitations of interhemispheric extracallosal transfer of visual information in callosal agenesis.

A 57-year-old patient with callosal but not anterior commissure agenesis was investigated with a visual interfield comparison and a naming task. Stimuli were presented tachistoscopically either bilateral-simultaneously or unilaterally in the LVF and/or RVF. The stimuli presented bilaterally differed with respect to their degree of similarity. Whereas the patient was able to detect gross differences between stimuli presented in the left and right half-field, he was impaired at discriminating similar and identical stimuli across the half-fields. Identification by naming was correct on unilateral presentation of a stimulus, while with bilateral presentation of two stimuli, errors increased considerably with the stimulus named second. The data are thought to indicate a limited capacity of the extracallosal commissures, probably the anterior, for the transfer of visual information.

Agenesis of Corpus Callosum↗

PubMed1990

Patterns of task-related slow brain potentials in dyslexia.

Six dyslexic youths who met the Hughes and Denckla criteria of "dyslexia pure" and 10 normal control subjects were investigated with DC recordings of task-related cortical negativity using 10 leads over the right and left hemispheres. Potentials were recorded during the following tasks: reading, orthographic error detection, letter series, word assembly, word fluency, finding of antonyms, and viewing of Necker cubes. Both groups exhibited greater right hemisphere negativity during the Necker cube task. Whereas controls revealed greater left hemisphere negativity during linguistic tasks, the reverse was found with dyslexics. The right shift was pronounced with the reading, orthographic error detection, and antonym conditions. Differences between the two groups were also found for the pattern of cortical distribution. We conclude that dyslexia is associated with changes in the lateral distribution of cortical activity during certain types of language processing.

Adolescent↗

PubMed1990

Parkinson's disease patient's behaviour in a covered maze learning task.

A computerized maze task was constructed that allowed only partial vision of the maze structure and produced measurements for separate analysis of cognitive processes described as impaired in Parkinson's disease. Eighteen patients suffering from mild Parkinson's disease and 18 individually matched normal controls were investigated. Baseline task response times were found to be identical for both groups. Differences between patients' and controls' performance could be related to (a) a response bias in Parkinson patients that favoured repetition of the previous action and slowed down shifting and (b) an impairment of multistep plan generation. It is speculated that the response bias reflects the disinhibition of cortico-thalamo-cortical reverberation loops which results from striatal dopamine depletion.

Aged↗

PubMed1990

Long-term effects of cerebellar pathology on cognitive functions.

Twelve patients with circumscribed chronic neocerebellar lesions but without CT-evidence of forebrain damage (other than the effects of shunting) were investigated for deficits of cognitive functions. Two different mechanisms were considered as possible causes of cognitive impairment: (1) Damage to the dentato-thalamo-cortical projection leading to impairments of cortical functions, and (2) prolonged intracranial pressure resulting in diffuse forebrain damage and subcortical dementia. Patients with lesions in the left neocerebellum showed deficits in cognitive operations in three dimensional space, consistent with the right forebrain dominance for spatial functions. Prolonged intracranial pressure, on the other hand, resulted in a mild overall cognitive impairment.

Brain Damage, Chronic↗