Search PubMed⌕ Search

Biomedical subjects

T Mulder

Publications and source records attributed to T Mulder.

At least 37 records · Page 2Linked to original sources
PubMed1998

Cognitive decline following stroke: a comprehensive study of cognitive decline following stroke.

General insight into the frequency and gravity of cognitive dysfunctions following stroke and its influencing factors is still lacking. With an extensive neuropsychological battery 229 patients who had suffered a stroke were assessed. More than 70% of the patients showed a marked slowness of information processing, whereas at least 40% of all patients had difficulty with memory, visuospatial and constructive tasks, language skills, and arithmetic. A significant effect was found for side and type of stroke, gender, and the presence of aphasia. No significant effect was found for cortical versus subcortical lesions, having one versus multiple strokes, having lowered consciousness on admission, the presence of risk factors, a paresis of the hand, or the interval between the stroke and the neuropsychological assessment.

Aphasia↗
PubMed1998

Clinical gait analysis in a rehabilitation context: some controversial issues.

OBJECTIVE: To determine the focus of clinical gait analysis in order to explain the observed mismatch between the available technology for movement analysis and the aims of clinical rehabilitation medicine. DESIGN: Literature search using two different interactive computerized search systems. OUTCOME MEASURES: The selected studies on clinical gait analysis were screened on the type of tasks they employed in the assessment of gait. The tasks were divided into impairment-orientated and disability-orientated. RESULTS: The results indicated a dominance of simple motor tasks focusing at the level of impairments. In only 15 out of the 96 reviewed articles were tasks used that were aimed at the level of disabilities. CONCLUSIONS: A gap exists between the conceptual frameworks used in clinical rehabilitation medicine and those used in clinical movement analysis.

Activities of Daily Living↗
PubMed1998

Cognitive deficits following stroke in the basal ganglia.

OBJECTIVE: To examine the effect of a stroke in the basal ganglia on cognitive functioning. DESIGN: As part of a larger prospective study on the neuropsychological and psychosocial consequences of stroke, 12 patients with a stroke confined to the basal ganglia were examined. SETTING: The patients were assessed in one of the three participating hospitals. SUBJECTS: The results of 12 patients with a stroke in the basal ganglia (mean age 55 years), were compared to 24 controls (mean age 54.3 years). MAIN OUTCOME MEASURES: Different aspects of memory, attention and concentration, visuospatial and visuoconstructive functions, language and arithmetic were assessed using neuropsychological tests. RESULTS: The data show a significant abnormality in cognitive functioning on all cognitive domains. CONCLUSIONS: The results stress the notion that subcortical damage may lead to substantial neuropsychological disorders and have clear implications for neurological rehabilitation.

Basal Ganglia↗
PubMed1997

Changes in mean chorioallantoic artery blood flow and heart rate produced by hypoxia in the developing chick embryo.

Hypoxia in the mammalian fetus produces cardiovascular changes, such as bradycardia, systemic hypertension, and changes in heart rate variability. This response was studied in 140 chick embryos ranging from stage 34 to stage 42 (d 9-16 of the 21-d incubation), by measuring the changes in mean chorioallantoic artery blood flow (CABF) and heart rate for 5 min in two levels of hypoxia (group 1; n = 90; 100% N2) or (group 2; n = 50; 5% O2). Eggs were opened at the air cell and placed in a small plexiglass holder, which had a continuous gas flow of an O2/N2 mixture (5 L/min), at 38 degrees C and 60% humidity. The chorioallantoic artery was placed in the lumen of a flow probe to measure mean CABF, heart rate, peak flow, and blood flow acceleration. After baseline measurements, the gas mixture was changed to 100% N2 or 5% O2 in N2 for 5 min. Mean CABF and heart rate decreased significantly in both groups (Wilcoxon paired sample test, p < 0.05). This response was more pronounced with the development of the chick embryo. Chorioallantoic artery peak flow (mL/min) and CABF acceleration (mL/s2) increased with incubation time and decreased during periods of hypoxia. During recovery, heart rate returned to baseline levels, whereas mean CABF showed an overshoot. The initial decrease in mean CABF and heart rate was similar in both groups. The cardiovascular response to hypoxia in the chick embryo is similar to the response in the mammalian fetus. The more pronounced response in the more developed chick embryo may represent a maturation of cardiovascular control.

Allantois↗
PubMed1996

[Many chronic problems in CVA patients at home].

OBJECTIVE: To find out what the late implications of a stroke were for patients and relatives and whether specific requests for help existed. DESIGN: Cross sectional study. SETTING: Academic Hospital Nijmegen, department of Neurology and Sint Maartenskliniek (rehabilitation centre), The Netherlands. METHOD: Patients who had sustained a cerebrovascular accident (CVA) in the last five years were asked, using the sickness impact profile (SIP), about their subjective functioning and the effect of the CVA on daily life. They were also asked about the degree to which they experienced their complaints as a problem, and whether they needed help. RESULTS: In this study 165 patients and their close relatives filled out the SIP. Stroke had a very high impact on everyday functioning as indicated by a total SIP score of 20. The results further showed that psychosocial problems arise independently of the degree of physical problems, that these problems were chronic, and that psychosocial problems hindered 52% of the patients often to always. The physical problems hindered 60% of them often to always. A third of the patients wanted help for their physical problems, a quarter for their psychosocial problems. CONCLUSION: The impact of stroke on both patients and their relatives was extensive and appeared chronic. There was need for physical and psychosocial help in a third or quarter of the cases.

Activities of Daily Living↗
PubMed1996

[Poor prognosis in children with ultrasonographically diagnosed abnormalities of the central nervous system].

OBJECTIVE: Long-term follow-up of children with a prenatally diagnosed malformation of the central nervous system. DESIGN: Descriptive study. SETTING: Department of prenatal diagnosis, Academic Medical Center, Amsterdam, the Netherlands. METHODS: Evaluation of all documented ultrasound examinations between 1985 and 1990 (6 years). These ultrasound examinations were performed in women with an increased risk for a foetal malformation, because of obstetrical complications or when a foetal malformation was suspected on ultrasound examination performed elsewhere. Paediatricians and general practitioners were asked to provide follow-up data on the children who were still alive. RESULTS: Seven out of 67 foetuses with a prenatally diagnosed malformation of the central nervous system lived longer than one month. Two out of these 7 children developed normally, one child died after several years and four children were severely retarded. The two children who developed normally both had mild hydrocephaly. CONCLUSION: Prognosis of children with a prenatally diagnosed malformation of the central nervous system is poor. Children with mild hydrocephaly may have a better prognosis.

Adult↗
PubMed1996

The chorioallantoic artery blood flow of the chick embryo from stage 34 to 43.

Chorioallantoic artery blood flow and heart rate were studied in the chick embryo from stage 34 until stage 43 (d 9-16 of 21-d incubation). Baseline blood flow profiles of the chorioallantoic artery were measured with a flow probe (Transonic) in 100 chick embryos. The eggs were opened at the air cell and placed in a small plexiglass box with a continuous gas flow of a N2/O2 mixture (5 L/min), at 38 degrees C and 60% humidity. The chorioallantoic artery was localized near the fetal abdomen and placed in the lumen of the Transonic flow probe. The heart rate was derived from the blood flow signal. The mean chorioallantoic artery blood flow rose from 0.35 +/- 0.14 mL/min (mean +/- SD) at stage 34 to 3.13 +/- 1.49 mL/min at stage 43 (R2 = 0.69, p < 0.0001), which correlated with an increase in body weight (1.51 +/- 0.18 g to 15.08 +/- 0.76 g). Heart rate increased from 195 +/- 38 beats/min at stage 34 to 289 +/- 13 beats/min at stage 43 (R2 = 0.38, p < 0.0001). The chorioallantoic artery blood flow, which in avian species correlates with umbilical blood flow in mammals, increased with incubation time as reported in the mammalian fetus. This study shows that the chick embryo could be useful as a preparation for further perinatal cardiovascular research.

Allantois↗
PubMed1996

Towards a disability-oriented epidemiology of traumatic brain injury.

The aim of this study was to investigate the value of using a disability-oriented approach to the epidemiology of traumatic brain injury (TBI) in order to improve health administration by preventing long-term sequelae. The epidemiology of disease was established by registration system of inpatients which covers more than 99% of all hospital admissions in The Netherlands. Some international differences and national trends are discussed. The disability-related epidemiology was investigated by means of structured interviews, 3-7 years after the injury, in a clustered sample of 51 patients with major TBI according to the ICD-9-CM. The survey included evaluation scales such as the Sickness Impact Profile, the Barthel Index, and a Disability Rating Questionnaire. Concerning the disease-related epidemiological data, the overwhelming majority of all TBI patients went home, which suggests good recovery. Nevertheless, the disability-oriented research revealed long-term situational, cognitive and behavioral disabilities in at least 67% of the major-TBI population, whereas only 10% received any rehabilitation services at all after the acute-care period. It is concluded that preventive measures and a comprehensive service for brain injury survivors should be based both on disease and disability-oriented data.

Adult↗
PubMed1993

Recovery of motor skill following nervous system disorders: a behavioural emphasis.

Recovery of motor behaviour is, for a large part, the complex reintegration of sensory processes and motor output against the background of a decreasing cognitive involvement. Therefore, the measurement of motor output under simple and unperturbed conditions, isolated from these processes, reflects only a minor part of the recovery of skill. It is argued that there is an urgent need for procedures aimed at the objective study of behavioural recovery across time. Until now, these procedures have been lacking. This chapter provides a modest contribution to the development of these procedures.

Attention↗
PubMed1991

Slowness of information processing after traumatic head injury.

One of the main aftereffects of traumatic head injury is slowness of information processing. In the present study, it was hypothesized that an important causal mechanism is a problem in the activation of information stored in memory; this is thought to be due to a reduced redundancy of these representations. An experimental drawing task was employed in which the degree of familiarity and motor complexity of the items was varied. It was expected that increasing the novelty of a task would be more detrimental for the patients than increasing motor complexity. Ten head-injured patients and 10 matched control subjects participated. Task execution was recorded on-line on a graphic digitizer. The results were in accordance with the hypothesis: That is, novelty but not motor complexity had a crucial influence on the speed of information processing. The implications of the results for therapy are discussed.

Adolescent↗
PubMed1991

A process-oriented model of human motor behavior: toward a theory-based rehabilitation approach.

The purpose of this article is to present a behavioral model of human motor acts that may have relevance for therapeutic procedures aimed at the restoration of motor function after neurological or orthopedic problems. A key point of this model is that motor behavior is the result of an integrated and adaptive biological system. Cognitive, perceptual, and motor mechanisms are not independent elements, but are viewed as inseparable parts of this functional system. Implications for therapy are discussed. [Mulder T. A process-oriented model of human motor behavior: toward a theory-based rehabilitation approach.

Biomechanical Phenomena↗
PubMed1989

The phantom phenomenon: a critical review.

Although phantom sensations and phantom pain are quite common sequelae of amputation and other related surgical procedures, these phenomena are not well understood. There are many, often conflicting theories which attempt to explain their nature and causes, and to provide a foundation for more effective treatment. This paper reviews recent literature on this topic. The review encompasses information about the prevalence and nature of phantom phenomena; evidence from empirical studies concerned with identification of possible predictors; and various psychological and neurophysiological theories that have been proposed in an attempt to explain why phantom sensations and pain are experienced. It is concluded that the fragmented approach adopted in the past has resulted in pockets of knowledge that are not too well integrated. There is therefore an outstanding need for a general theory to synthesise the knowledge gained to date about the multiplicity of factors associated with phantom phenomena. In this context, Melzack and Loeser's (1978) concept of "pattern generating mechanisms" may offer the most useful model for future research.

Humans↗
PubMed1986

EMG feedback and the restoration of motor control. A controlled group study of 12 hemiparetic patients.

A controlled group study involving 12 patients was performed with the purpose of comparing the effects of EMG feedback in the (re-)learning of motor control to the effects of a conventional physical therapy procedure (NDT). The therapy was focussed on the improvement of the dorsiflexion function of the foot. Special attention was given to the measurement and evaluation of functional parameters (range of motion and gait). The results indicated no significant differences between the two methods. The implications of the results for the employment of EMG feedback and other therapeutic procedures in motor rehabilitation are discussed.

Adult↗
PubMed1985

Sensory feedback in the learning of a novel motor task.

The role of different forms of feedback is examined in learning a novel motor task. Five groups of ten subjects had to learn the voluntary control of the abduction of the big toe, each under a different feedback condition (proprioceptive feedback, visual feedback, EMG feedback, tactile feedback, force feedback). The task was selected for two reasons. First, in most motor learning studies subjects have to perform simple movements which present hardly any learning problem. Second, studying the learning of a new movement an provide useful information for neuromuscular reeducation, where patients often also have to learn movements for which no control strategy exists. The results show that artificial sensory feedback (EMG feedback, force feedback) is more powerful than "natural" (proprioceptive, visual, and tactile) feedback. The implications of these results for neuromuscular reeducation are discussed.

Journal Article↗