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At least 1,099 records · Page 61Linked to original sources
PubMed1988

Noradrenaline response to edrophonium in primary autonomic failure: distinction between central and peripheral damage.

The effects of intravenous edrophonium on plasma noradrenaline were studied in 12 subjects with primary autonomic failure. 5 had clinical features of central autonomic damage, 4 with parkinsonism (PD) and 1 with multiple system atrophy (MSA); the other 7 had clinical features of progressive autonomic failure without detectable central neurological damage (PAF). After edrophonium all but 1 subject showed falls in heart rate of about 6 beats/min; there were no consistent blood pressure changes. The 5 PD/MSA patients all had normal plasma noradrenaline responses to edrophonium, with rises of 35-66% within 2-8 min of injection. 6 of the 7 PAF patients had no response or very small responses (-6 to +11%), while the other subject had a normal response (70% rise). The noradrenaline response to edrophonium may provide a simple way to differentiate between central and peripheral autonomic damage.

Aged↗
PubMed1998

Neuronal plasticity: adaptation and readaptation to the environment of space.

While there have been few documented permanent neurological changes resulting from space travel, there is a growing literature which suggests that neural plasticity sometimes occurs within peripheral and central vestibular pathways during and following spaceflight. This plasticity probably has adaptive value within the context of the space environment, but it can be maladaptive upon return to the terrestrial environment. Fortunately, the maladaptive responses resulting from neuronal plasticity diminish following return to earth. However, the literature suggests that the longer the space travel, the more difficult the readaptation. With the possibility of extended space voyages and extended stays on board the international space station, it seems worthwhile to review examples of plastic vestibular responses and changes in the underlying neural substrates. Studies and facilities needed for space station investigation of plastic changes in the neural substrates are suggested.

Adaptation, Physiological↗
PubMed2002

Dynamic posturography using a new movable multidirectional platform driven by gravity.

Human upright balance control can be quantified using movable platforms driven by servo-controlled torque motors (dynamic posturography). We introduce a new movable platform driven by the force of gravity acting upon the platform and the subject standing on it. The platform consists of a 1 m2 metal plate, supported at each of its four corners by a cable and two magnets. Sudden release of the magnets on three sides of the platform (leaving one side attached) induces rotational perturbations in either the pitch or roll plane. Release of all magnets causes a purely vertical displacement. By varying the slack in the supporting cables, the platform can generate small (0.5 degrees ) to very destabilising (19 degrees ) rotations. Experiments in healthy subjects showed that the platform generated standardised and reproducible perturbations. The peak rotation velocity well exceeded the threshold required to elicit postural responses in the leg muscles. Onset latencies were comparable to those evoked by torque motor-driven platforms. Randomly mixed multidirectional perturbations of large amplitude forced the subject to use compensatory steps (easily possible on the large support surface), with little confounding influence of habituation. We conclude that this gravity-driven multidirectional platform provides a useful and versatile tool for dynamic posturography.

Adult↗
PubMed2003

Effect of positional change and inhalant anesthesia on parameters of acoustic reflectometry.

OBJECTIVE: Purpose of this study was to find out the effect of positional change and inhalant anesthesia on acoustic reflectometry (AR) parameters (reflectivity and curve angle). METHOD: AR parameters were measured on 58 ears with otitis media in sitting position before anesthesia and in supine position under inhalant anesthesia, subsequently. RESULTS: Under anesthesia, ears with effusion disclosed more changes in reflectivity (Chi-squared analysis, chi2-test; P<0.05) and curve angle (P>0.1) than those without effusion. Further, inhalant anesthesia caused more changes in the false negative ears (63.63%) than in those with effusion having positive test before anesthesia (12.90%) (P<0.001). CONCLUSIONS: From the data of this study, it could be said that reflectivity shows changes according to the amount of effusion which is in contact with the tympanic membrane under anesthesia, and that curve angle becomes more sensitive to detect effusion when anesthetic gas diffuses into the middle ear with effusion, probably due to the pushing of effusion towards the tympanic membrane.

Anesthesia, Inhalation↗
PubMed1999

Posturography does not test vestibulospinal function.

The clinical usefulness of posturography is unknown, despite its costing more than +500 per test in some areas of the United States, including Boston. We cross-sectionally and prospectively studied blinded vestibulo-ocular and vestibulospinal tests from 29 stable patients with chronic vestibular hypofunction; 22 patients were affected bilaterally (BVH), and 7 were affected unilaterally (UVH). Vestibulo-ocular function was assessed by electronystagmographic caloric stimulation and sinusoidal vertical axis rotation gains at 0.05 Hz. Vestibulospinal function was assessed by moving-platform and visualsurround posturography sensory organization tests (SOTs), paced and free gait in a gait laboratory, and clinical tests of timed gait and standing. Posturography SOT moving-platform tests 4 through 6, designed to assess vestibular function, correlated significantly (r < or = 0.72, P > or = 0.01) with vestibulo-ocular tests in 5 of 6 comparisons among BVH patients. Posturography SOT results, however, correlated poorly with other vestibulospinal measures: correlations were statistically significant for only 7 of 18 comparisons with clinical balance and gait function (r < or = 0.69, P > or = 0.01) and with 2 of 12 comparisons for gait laboratory dynamic stability measures (r < or = 0.55, P > or = 0.01) among the BVH patients. When both the platform and visual surround moved (SOT 6), however, correlations were statistically significant with static standing clinical measures (r = 0.51 to 0.69, P < 0.01) and with whole-body maximum moment arm during paced gait (r = 0.55, P < 0.01). Posturography scores for the UVH patients did not significantly correlate with any vestibulo-ocular or other vestibulospinal measures. These data indicate that among patients with BVH posturography SOT scores relate at best modestly with accepted measure of vestibulo-ocular function, less well with clinical measures of balance control, and poorly with dynamic gait-performance measures. We conclude that posturography SOT does not assess vestibulospinal function.

Adult↗
PubMed1998

Spaceflight influences on ocular counterrolling and other neurovestibular reactions.

Exposure to extended periods of weightlessness in orbital flight has profound effects on the neurovestibular system and influences head and eye movements, postural control, and spatial orientation. The associated space motion sickness is among the earliest of the signs of adaptation to this new environment. This report both reviews the prominent neurovestibular phenomena associated with going into space and returning to earth and relates the issues to vestibular compensation and rehabilitation. New results from the Spacelab SLS-2 mission are included, showing significant reductions in postflight ocular counterrolling and changes in ocular counterrolling left/right asymmetries after 2 weeks in space.

Humans↗
PubMed1981

The neurologic examination.

With practice, an orderly routine, and a basic understanding of neuroanatomy, the clinician should be able to tentatively localize lesions in the nervous system. Once the lesion is localized, ancillary studies are usually necessary to identify the disease process. In difficult cases when referral is impractical, an accurate description of the findings from the neurologic examination will greatly improve the value of consultation.

Animals↗
PubMed1999

Interobserver variability of the neurological optimality score.

OBJECTIVE: To assess the interobserver reliability of the neurological optimality score. STUDY DESIGN: The neurological optimality score of 21 full term healthy, neurologically normal newborn infants was determined by two well trained observers. RESULTS: The interclass correlation coefficient was 0.31. Kappa for optimality (score of 58 or higher) was 0.19. A systematic difference of 1.3 points between the two observers was present. CONCLUSIONS: The interobserver variability of the neurological optimality score of the newborn infant is substantial. The subtle judgement of elicited responses as optimal or non-optimal proved to be especially critical in this concordance study. A difference of at least two points in the score is considered as a valid endpoint for comparative studies. If two or more observers are involved in the neurological examination of the newborn infant in a study to assess influences on perinatal morbidity, frequent re-instruction sessions are recommended.

Birth Weight↗
PubMed2002

Mood states and anxiety influence abilities to maintain balance control in healthy human subjects.

Previous studies have shown that anxiety and balance disorders could be related; however, the association between psychological processes and equilibrium remains ambiguous. In this study, we have examined whether mood states and anxiety may influence the ability to use the somatosensory, visual and vestibular systems and affect balance control in healthy subjects. Seven male students were submitted to a program testing equilibrium over a 12-day period, during which moods and anxiety states were assessed using self-evaluated questionnaires. Significant negative correlations were found between moods, including anxiety, and the subject's sensory and motor systems of balance control, suggesting that low moods may alter balance performance. However, depending on the type of mood, it is likely that adverse changes in mood states may affect balance in different ways, either through the sensory organization or motor control.

Adult↗
PubMed2003

Impact of upper limb complex regional pain syndrome type 1 on everyday life measured with a novel upper limb-activity monitor.

Complex regional pain syndrome type 1 (CRPS1) often leads to serious activity limitations in everyday life. To date, however, limitations in patients with CRPS1 of an upper limb have not been objectively measured.Therefore, the aim of this study was to determine the long-term impact of upper limb CRPS1 on general mobility and upper limb usage during everyday life, as measured with a novel upper limb-activity monitor (ULAM). In ten female chronic CRPS1 patients and ten healthy control subjects, 24-h activity patterns were measured with the ULAM. This ULAM consists of body-fixed acceleration sensors, connected to a recorder worn around the waist. The ULAM automatically detects upper limb activity during mobility-related activities. Several outcome measures related to general mobility and upper limb usage were compared between patients and controls. The results showed that CRPSI in the dominant upper limb had modest impact on general mobility; i.e. on the percentages spent in body positions and body motions and on mean intensity of body activity. For upper limb usage outcome measures during sitting, there was a marked difference between CRPS1 patients and controls. Especially patients with dominant side involvement clearly showed less activity of their involved limb during sitting, indicated by significant differences for the mean intensity (P=0.014), percentage (P=0.004), and proportion (P=0.032) of upper limb activity. It is concluded that these ten chronic CRPS1 patients still had limitations in upper limb usage during everyday life, 3.7 years (average) after the causative event.

Activities of Daily Living↗
PubMed1997

Motor and cognitive deficits in apolipoprotein E-deficient mice after closed head injury.

Previous studies suggest that traumatic brain injury is associated with increased risk factor for developing Alzheimer's disease. Furthermore, the extent of the risk seems to be most pronounced in Alzheimer's disease patients who carry the epsilon4 allele of apolipoprotein E, suggesting a connection between susceptibility to head trauma and the apolipoprotein E genotype. Apolipoprotein E-deficient mice provide a useful model for investigating the role of this lipoprotein in neuronal maintenance and repair. In the present study apolipoprotein E-deficient mice and a closed head injury experimental paradigm were used to examine the role of apolipoprotein E in brain susceptibility to head trauma and in neuronal repair. Apolipoprotein E-deficient mice were assessed up to 40 days after closed head injury for neurological and cognitive functions, as well as for histopathological changes in the hippocampus. A neurological severity score used for clinical assessment revealed more severe motor and behavioural deficits in the apolipoprotein E-deficient mice than in the controls, the impairment persisting for at least 40 days after injury. Performance in the Morris water maze, which tests spatial memory, showed a marked learning deficit of the apolipoprotein E-deficient mice when compared with injured controls, which was apparent for at least 40 days. At this time, histopathological examination revealed overt neuronal cell death bilaterally in the hippocampus of the injured apolipoprotein E-deficient mice. The finding that apolipoprotein E-deficient mice exhibit an impaired ability to recover from closed head injury suggests that apolipoprotein E plays an important role in neuronal repair following injury and highlights the applicability of this mouse model to the study of the cellular and molecular mechanisms involved.

Alzheimer Disease↗
PubMed2000

Transient cardio-respiratory responses to visually induced tilt illusions.

Although the orthostatic cardio-respiratory response is primarily mediated by the baroreflex, studies have shown that vestibular cues also contribute in both humans and animals. We have demonstrated a visually mediated response to illusory tilt in some human subjects. Blood pressure, heart and respiration rate, and lung volume were monitored in 16 supine human subjects during two types of visual stimulation, and compared with responses to real passive whole body tilt from supine to head 80 degrees upright. Visual tilt stimuli consisted of either a static scene from an overhead mirror or constant velocity scene motion along different body axes generated by an ultra-wide dome projection system. Visual vertical cues were initially aligned with the longitudinal body axis. Subjective tilt and self-motion were reported verbally. Although significant changes in cardio-respiratory parameters to illusory tilts could not be demonstrated for the entire group, several subjects showed significant transient decreases in mean blood pressure resembling their initial response to passive head-up tilt. Changes in pulse pressure and a slight elevation in heart rate were noted. These transient responses are consistent with the hypothesis that visual-vestibular input contributes to the initial cardiovascular adjustment to a change in posture in humans. On average the static scene elicited perceived tilt without rotation. Dome scene pitch and yaw elicited perceived tilt and rotation, and dome roll motion elicited perceived rotation without tilt. A significant correlation between the magnitude of physiological and subjective reports could not be demonstrated.

Adult↗
PubMedDate not supplied

[Evoked brain stem potentials in cases of traumatic coma of: value in determining the degree of brain stem dysfunction (author's transl)].

Auditory brainstem potentials were recorded in 22 comatose patients in whom the level of brainstem dysfunction was defined by the clinical assessment of brainstem reflexes and posture. The patients with cortico-subcortical or diencephalic levels showed normal brainstem potentials. The other patients showed a relationship between the abnormalities of the different components of the brainstem potentials and the clinical levels of brainstem dysfunction caused by the rostro-caudal evolution. Alteration of wave V seemed to be related to a midbrain dysfunction, alteration of wave III to a pontine dysfunction and alteration of waves I and II to a lower brainstem dysfunction.

Brain Injuries↗