Biomedical subjects

B Leplow

Publications and source records attributed to B Leplow.

At least 19 recordsLinked to original sources

PubMed2006

Subtle cognitive dysfunction in adult onset myotonic dystrophy type 1 (DM1) and type 2 (DM2).

The authors performed neuropsychological testing in 21 patients with myotonic dystrophy type 1 (DM1) and 21 with type 2 (DM2) and healthy controls. They detected no general cognitive deficit in either DM1 or DM2, but compared to controls, both groups of patients were inferior in tests of prefrontal functioning. Patient groups did not differ in any measure. Mood status was not related to neuropsychological performance. This is consistent with findings of executive dysfunction in both DM1 and DM2.

Adult↗

PubMed2004

Conditional-associative learning in eating disorders: a comparison with OCD.

The acquisition of conditional associations using neutral and individually threatening verbal stimuli was assessed in 16 females with anorexia nervosa (AN), obsessive-compulsive disorder (OCD), bulimia nervosa and normal controls, respectively. Groups did not differ in terms of age, sex, intelligence, depression, verbal memory and verbal fluency measures. Patients and controls were widely comparable on tests assessing neuropsychological functioning. In the conditional-associative learning (CAL)-task only anorectic and OCD-patients displayed an impaired performance with neutral material but not with individually threatening material. Such a deficit was not evident in bulimics or in normal controls. These findings support the assumptions from functional neuroimaging investigations in AN and OCD and provide evidence that obsessive and compulsive behavior could have its origin within common neurobiological dysfunctions. The CAL possibly serves as a functional correlate of a neurophysiological dysfunction in obsessive-compulsive spectrum disorders.

Adolescent↗

PubMed2001

Spatial orientation in construction divers--are there associations with diving experience?

OBJECTIVE: The purpose of this work was to investigate whether or not navigation abilities are impaired in construction divers and if putative deficits can be related to MRT-verified brain lesions and/or to diving experience. METHODS: Nineteen construction divers and 19 controls matched for age, intelligence, and socioeconomic background were studied by use of a "locomotor search through" task which resembled working conditions at ground. The task incorporated a spatial working memory and a spatial reference memory component. Moreover, navigation parameters (i.e., rotational turns, distances traveled, speed of navigation) were derived from the participant's locomotor behavior, which was recorded automatically. Groups were compared by navigation performance, standard neuropsychological tests, and the number of brain lesions obtained by MRT-scans. RESULTS: Divers were widely comparable with respect to neuropsychological test scores, exploration behavior and speed of navigation during testing. Performance deficits in divers were seen in the three test trials with respect to the number of reference memory errors and navigation behavior. Only in controls were age and the number of MRI-verified lesions related to neuropsychological test performance and to maze variables, but in divers the number of lesions seemed to be related to hyperbaric exposure. CONCLUSION: Despite possible positive selection effects in long-term construction divers, these results may have implications for health care of middle-aged divers who are exposed to critical depths of more than 60 meter sea water (msw).

Adult↗

PubMed2001

Children's spatial behavior is differentially affected after traumatic brain injury.

Spatial behavior in 20 children with severe traumatic brain injury (TBI) and 20 healthy controls was investigated using the Kiel Locomotor Maze. Children had to remember defined locations in an experimental chamber with completely controlled intra- and extra-maze cues until learning criterion was reached. In a second experiment, spatial orientation strategies were assessed. Children with TBI were shown to be impaired in spatial learning and spatial memory. Spatial orientation was found to be deficient even in cases where spatial learning and memory proved to be unimpaired, especially in tasks that demanded the use of relational place strategies. Children who suffered a TBI at an early age proved to be more severely impaired in spatial learning and orientation than older children.

Brain Injuries↗

PubMed2000

[Recommendations for standarsized psychological diagnosis in Parkinson patients].

In addition to the motor symptoms of Morbus Parkinson, a number of cognitive and emotional changes take place. The diagnosis of these concomitant symptoms has received increasing attention in research and clinical practice. Global rating scales offer economical advantages but generally do not satisfy the requirements of psychometric criteria, and they do not suffice in light of the multidimensional symptoms of the disease. Based on recent research results, recommendations from the CAPSIT protocol (Core Assessment Program for Surgical Interventional Therapies) for diagnosis of neurosurgically treated Parkinson's patients, and the restraints of everyday clinical work, we propose a standardized neuropsychological diagnostic routine. It includes diagnostic methods that are in use internationally and so timesaving and easily accessible that they can be considered suitable for routine diagnostics. Data comparison among various treatment centers can thus take place more easily. We have included only methods that differentiate well and whose test criteria offer a basis for thorough consultation as well as planning and evaluation of multidimensional therapy.

Dementia↗

PubMed2000

Spatial information transfer from virtual to real versions of the Kiel locomotor maze.

The Kiel locomotor maze requires participants to choose five targets from among 20 locations marked by small red lights on the floor of a dimly lit circular environment having four wall-mounted extramaze cues and two intramaze cues at floor level. In the present study, acquisition of the real task was examined in 11-year-old children following prior accurate training in a virtual version, following misleading virtual training, or following no training. The virtual version was displayed on a desk-top computer monitor. Acquisition testing in the real maze was either locomotor or non-locomotor. Good transfer was achieved from virtual to real versions. Children's exploration of the real maze prior to real maze acquisition training revealed a clear transfer of spatial information previously learned in the virtual version. Children taught the correct target configuration in the simulation made fewer errors and more rapid, confident responses to targets in the real maze than children given no training. However, acquisition was also better following misleading training than no training, suggesting that a non-specific components of performance also transferred. Male superiority was only seen following misleading training, which was interpreted in terms of male superiority in mental rotation. After acquisition, a single probe trial was performed, in which proximal cues and participants' starting position were rotated, but this had equivalent effects on all groups' performance. It is clear that transfer of spatial information occurs from the simulated Kiel maze to the real version. This has implications for its use in diagnosis and training.

Child↗

PubMed1999

Magnetic resonance signal abnormalities and neuropsychological deficits in elderly compressed-air divers.

We investigated the association between MR signal abnormalities of the central nervous system, neuropsychologic performance and exposure indices in 20 experienced elderly compressed-air divers who had no history of neurological decompression illness (DCI). Results of MRI of the brain and psychometric testing were compared with 20 matched healthy commercial employees who never dived: 60% of the divers and 45% of the controls had hyperintense MR abnormalities. Among divers, both the number and the size of abnormalities correlated with hours diving in the deep air-diving range of 40-60 m (p < 0.05). Divers' mental flexibility and visual tracking performance were decreased in comparison with controls (p < 0.05 and p < 0.01). Divers thus are at risk of detrimental long-term effects of compressed-air diving on the central nervous system even in the absence of a history of neurological DCI.

Barotrauma↗

PubMed1999

Perception of dyspnea during histamine- and methacholine-induced bronchoconstriction.

BACKGROUND: Perception of dyspnea is poorly related to bronchoconstriction and may be influenced by distinct psychophysiologic stimuli. OBJECTIVE: This study compared the perceived psychophysiologic changes during histamine- and methacholine-induced bronchoconstriction using verbal as well as nonverbal assessment techniques. METHODS: Perception of dyspnea was studied during induced bronchoconstriction in 40 atopic subjects randomly ascribed to either histamine (n = 20) or methacholine (n = 20) bronchial challenge. A 100% increase in specific airway resistance (sR(aw)) indicated airway hyperresponsiveness (AHR). Dyspnea was verbally assessed by the Borg Scale (BS) and the Asthma Symptom Checklist (ASL). A hand dynamometer (HD) served for nonverbal assessment. Both challenge groups did not differ significantly with respect to age, anthropometric data, smoking and lung function before challenge. RESULTS: AHR did not differ between groups but groups differed significantly with respect to the number of symptoms and to symptom intensity reported after challenge. Subjects who underwent the histamine challenge scored significantly higher on both measures derived from the ASL. BS ratings and HD scores correlated significantly but were not significantly related to the degree of AHR. Accurate and poor perceivers could be discriminated by analysis of the relationship between BS and sR(aw). CONCLUSIONS: These findings suggest that perception of induced dyspnea differs between histamine and methacholine when assessed by a symptom report.

Adult↗

PubMed1998

Development of spatial memory and spatial orientation in preschoolers and primary school children.

The present study addresses the question of what kind of information children use when orientating in new environments, if given proximal and distal landmarks, and how spatial memory develops in the investigated age groups. Ten 5-year-old, ten 7-year-old and ten 10-year-old children were presented with the 'Kiel Locomotor Maze', containing features of the Radial Arm Maze and the Morris Water Maze, in order to assess spatial memory and orientation. Children had to learn to approach baited locations only. Task difficulty was equated with respect to the children's age. Training was given until the children reached criterion. During testing, the maze configuration and response requirements were systematically altered, including response rotation, cue rotation, cue deletion and response rotation with cue deletion in order to assess the spatial strategies used by the children. During training and testing, working-memory errors (WM), reference-memory errors (RM) and working-reference memory errors (WR) were recorded. As expected, no difference between age groups appeared during training, thus confirming comparable task difficulty across age groups. During testing, age groups differed significantly with regard to the orientation strategy used. The 5-year-olds were bound to a cue strategy, orientating towards local, proximal cues. The 10-year-olds mastered all tasks, thus displaying a place strategy, being able to use distal cues for orientation, and were even able to do so after being rotated 180 degrees. The 7-year-olds proved to be at an age of transition: five of them were bound to a cue strategy, five children were able to adopt a place strategy. The differences in the orientation strategies used by children of different age groups was reflected by the sum of errors they made, also by RM. WM were found to be rare, especially in older children. We conclude that preschoolers use a cue strategy, that the development of place strategies occurs during primary school age and seems to be complete by the age of 10 years.

Age Factors↗

PubMed1998

Memory deficits at 0.6 MPa ambient air pressure.

We investigated the effects of an elevated ambient air pressure of 0.6 MPa on verbal memory performance. Twenty-four experienced divers were compressed in a dry hyperbaric chamber to pressures equivalent to 0.5 meters of seawater (msw) (n = 12) and 50 msw (n = 12). Verbal memory was assessed by free recall and recognition of visually presented word lists. The testing procedure specified learning and testing at surface, learning at surface and testing at depth, learning and testing at depth, and learning at depth and testing at surface. Non-specific stress was assessed by measurement of salivary cortisol, heart rate, and subjective stress before, during, and after the dives. The 50-msw dive group showed a significant decrease of free recall performance when the material was learned at depth (P < 0.01). However, only postdive recall of material learned at depth remained significantly impaired (P < 0.05), whereas recognition performance was normal. For both groups no significant effects of depth on the investigated stress indices were obtained. These results are taken as evidence that inert gas narcosis may interfere with encoding and/or retrieval of verbal information, although the possibility that other stressors in the hyperbaric environment contributed to these deficits cannot be eliminated entirely.

Adult↗

PubMed1997

Remote memory in Parkinson's disease and senile dementia.

Remote memory for public events was investigated in 14 demented patients with Parkinson's disease (PD), 14 non-demented PD patients, and 14 controls. These groups were compared with 16 demented patients with dementia that was due to Alzheimer or was of vascular origin (SDAVT), and with a group of elderly controls. The two demented groups were of a different age but displayed a comparable degree of dementia. Remote memory was assessed using a 'famous events' questionnaire with items both of comparable salience and difficulty. Results showed severely impaired retrograde memory functions in the two demented groups for both recall and recognition with non-demented PD patients performing similar to the controls. Remote memory impairments extended 30-40 years without any temporal graded memory losses. Non-demented PD patients and controls showed an inferior free recall performance, especially for the remote past. The two PD groups benefited from recognition to the same extent as the controls, whereas the improvement for SDAVT patients was inferior when compared to their elderly controls. In contrast to SDAVT patients, anterograde memory was associated with remote memory for specific decades in demented PD patients. The results are interpreted with respect to an underlying retrieval deficit with a superimposed anterograde impairment common to both types of dementia and an additional loss of storage sites in SDAVT patients.

Aged↗

PubMed1997

Remote memory in patients with acute brain injuries.

Remote memory was investigated in an unselected sample of 26 patients with either unilateral tumours in the temporal lobes or traumatic brain injuries. Six patients underwent excisions within the left temporal lobe, and nine patients were operated on within the right temporal lobe. In both groups, patients with excisions including and sparing the hippocampal formation were studied. Their performance was compared to that of 11 patients with moderate to severe head trauma and to a normative sample of 214 healthy controls. Remote memory was assessed using a famous events test with items of extremely low salience that had been proven to be of low difficulty for those old enough at the time of the event's actuality. The results show severely disturbed retrograde memory functions in the left temporal tumour group. These patients achieved similar scores to patients with severe traumatic brain injury. Right hemispheric patients showed a pattern of results comparable to that of healthy controls. The strongest effects were in the free recall part of the test. In most of the patients, no graded memory loss was observable. No consistent association to recent memory function could be identified. Since most of the remote memory test items used denoted famous names which were cued by rich semantic information, the type of deficit seen may be best understood in terms of a specific dysfunction of the semantic stores containing information about famous proper names.

Adult↗

PubMed1997

Risk factors for pulmonary barotrauma in divers.

STUDY OBJECTIVES: Pulmonary barotrauma (PBT) of ascent is a feared complication in compressed air diving. Although certain respiratory conditions are thought to increase the risk of suffering PBT and thus should preclude diving, in most cases of PBT, risk factors are described as not being present. The purpose of our study was to evaluate factors that possibly cause PBT. DESIGN: We analyzed 15 consecutive cases of PBT with respect to dive factors, clinical and radiologic features, and lung function. They were compared with 15 cases of decompression sickness without PBT, which appeared in the same period. RESULTS: Clinical features of PBT were arterial gas embolism (n=13), mediastinal emphysema (n=1), and pneumothorax (n=1). CT of the chest (performed in 12 cases) revealed subpleural emphysematous blebs in 5 cases that were not detected in preinjury and postinjury chest radiographs. A comparison of predive lung function between groups showed significantly lower midexpiratory flow rates at 50% and 25% of vital capacity in PBT patients (p<0.05 and p<0.02, respectively). CONCLUSIONS: These results indicate that divers with preexisting small lung cysts and/or end-expiratory flow limitation may be at risk of PBT.

Adult↗

PubMed1996

Impairment of visuospatial function in idiopathic spasmodic torticollis.

We studied visuospatial function in 15 patients with idiopathic spasmodic torticollis (ST) and 15 age- and sex-matched controls. All subjects underwent a battery of visuospatial tests, assessing different functional components of spatial ability. The performance of ST patients on tasks of spatial perception did not significantly differ from that of normal subjects, but patients performed significantly worse on spatial tasks requiring mental manipulation of personal space. This distinct pattern of visuospatial impairment may result from basal ganglia dysfunction.

Adult↗

PubMed1994

Visuospatial functions in patients with spasmodic torticollis.

Visuospatial functions were studied in 18 patients with spasmodic torticollis and 18 matched controls. Subjects were examined with respect to their judgement of the subjective vertical, personal and extrapersonal orientation, the discrimination of left and right, the ability to judge angles and distances, and a drawing task. Patients showed marked deficits in extrapersonal orientation and atypical displacement errors to the right when requested to set the subjective vertical. Results were largely independent of the clinical characteristics of the disease. The pattern of results was attributed to a subtle attention deficit underlying complex measures of visuospatial functions. This may reflect a discrete dysfunction of the striatal-frontal circuits at least in a subgroup of patients.

Attention↗

PubMed1994

[Subjective stress factors and dyspnea in asthma patients over time].

The share of psychological factors involved in the disease pattern of asthma bronchiale is considered to be about one to two thirds, according to the literature. It is only rarely that a distinction is made between causative psychogenetic factors and such factors that exercise an influence on the course of the pattern of symptoms. The aim of the present study was to cover prospectively the possible--including the psychological--parameters influencing the pattern of symptoms of asthma in relation to time. To this end a symptom diary was kept for 35 asthma patients for an average time of 8 weeks. The entries were made daily. The points noted and counted were the concurrent occurrence of dyspnoea and various subjective influencing factors such as everyday stress, weather, etc. or their coincidence with a time lag of one day. There were surprisingly few links between dyspnoea and mental stress/stressors in relation to time. On the other hand, there was a high coincidence in relation to impairment of the quality of life and to a lesser extent also in relation to subjectively experienced weather and local conditions. The results show that stress factors--contrary to the aetiological beliefs held by laymen--are not represented by a simple relationship between psyche and asthma as time-concurrent or time-lagging coincidences to shortness of breath. However, clarification of complex socio-psychosomatic linkups in the psychogenesis of asthma bronchiale were not the subject of this study.

Adaptation, Psychological↗

PubMed1992

A new procedure for assessment of proprioception.

A new method for the assessment of proprioception was developed and tested with 40 healthy subjects on two facial muscles (i.e., masseter and zygomatic muscles). The experiment was repeated after 3 1/2 months. In our study, proprioception was studied with respect to sensations arising from the muscle spindles and tendon organs. Therefore, myesthesia was investigated, which was assessed by the correspondence between a voluntary muscle contraction and its immediate replication. Good perception was defined by a small integral of differences, standardized by duration and intensity of the contraction, and its replication. Results show that this measure is independent of the characteristics of muscle activation. In concordance with our hypothesis, myesthesia was superior in a muscle richly supplied with muscle spindles and afferent fibers (i.e., masseter muscle), to that for a muscle less prepared for afferent information processing (i.e., zygomatus major).

Adult↗

PubMed1991

A device for functional residual capacity controlled biofeedback of respiratory resistance.

A computer-aided procedure is presented providing subjects with analogous visual feedback of respiratory resistance, which is continuously measured using the forced oscillation method. Simultaneous pneumotachographical control of the breathing volume curve makes it possible to prevent reinforcement for decreases of respiratory resistance which are due to increases of functional residual capacity (FRC). Lung hyperinflation is an unsuitable way to reduce respiratory resistance; if it occurs, feedback is interrupted until the subject decreases his FRC to its initial level. Analysis of the data of 15 adult asthmatic subjects which underwent a 12-sessions feedback training showed that no substantial changes of FRC appeared within feedback trials. Advantages of this new biofeedback technique compared to other procedures are discussed with regard to volume control and feedback signal.

Airway Resistance↗