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At least 613 records · Page 34Linked to original sources
PubMed1996

The use of orthotopic neobladders in women undergoing cystectomy for pelvic malignancy.

Since June 1990, 21 women aged from 31 to 78 years (mean, 62 years) have undergone lower urinary tract reconstruction by means of an orthotopic Kock ileal reservoir following cystectomy. The indication for cystectomy included 15 patients with transitional-cell carcinoma of the bladder, 2 patients with urachal adenocarcinoma, 1 patient with cervical carcinoma, 1 patient with a mesenchymal tumor of endometrial origin, 1 patient with interstitial cystitis, and 1 patient with a fibrotic irradiated bladder. A total of four complications (two early and two late) have occurred in this group of patients. Excellent continence has been achieved during the day and night in 95% and 89% of the patients, respectively. In all, 16 of 20 patients void volitionally per urethra without a residual urine volume, whereas 4 patients require intermittent catheterization to empty the neobladder. All patients are completely satisfied. One patient died of metastatic transitional-cell carcinoma without a pelvic recurrence. Of the remaining 20 patients, 18 are currently alive without evidence of recurrent disease. Tumor recurrence has occurred in two patients: one patient with an extensive mesenchymal tumor developed a sigmoid recurrence necessitating conversion to a continent cutaneous diversion, and one patient developed a right iliac recurrence. This initial experience with lower urinary tract reconstruction in women has yielded extraordinary results, and we feel that the option of orthotopic reconstruction following cystectomy can safely be offered to selected female patients.

Adult↗
PubMed1984

Speech suppression without aphasia after bilateral perisylvian softenings (bilateral rolandic operculum damage).

The authors describe a patient who suffered two successive, right and left, strokes that caused bilateral rolandic operculum damage. The clinical picture was characterized by selective impairment of volitional facio-pharyngo-glosso-masticatory movements with sparing of automatic and reflex motor activity (Foix-Chavany-Marie syndrome). Though completely speechless, the patient was not aphasic. This dissociation is discussed in the light of the peculiar localization of lesions evidenced by CT-scan.

Cerebral Infarction↗
PubMed1995

Personality antecedents of alcoholism in a national area probability sample.

Kraepelin viewed alcoholism as a symptom complex caused by heritable individual differences in emotional predisposition and volitional control. Recent clinical and genetic research has distinguished subtypes of alcoholics with different personality traits, symptoms, course, mode of inheritance, and response to treatment. The heritable personality traits that influence the initiation, continuation, and severity of alcoholism were examined by interview of a national area probability sample of 1019 non-institutionalized adults across the continental United States of America. We found that harm avoidance inhibits the initiation and frequency of drinking, but increases the risk of developing problems once frequent drinking has begun. Novelty seeking increases the initiation of drinking and the probabilities of frequent and problem drinking. This supports Kraepelin's description of the etiology and course of alcoholism as a symptom complex related to individual differences in emotional predisposition.

Adolescent↗
PubMed1992

Electromyographic studies of neck muscles in the intact cat. I. Patterns of recruitment underlying posture and movement during natural behaviors.

Natural head movements in alert, unrestrained cats were studied using video-filming, videofluoroscopy and electromyographic (EMG) recording methods. In each cat, up to sixteen neck muscles or neck-muscle compartments were implanted with recording electrodes. Patterns of muscle recruitment were examined during systematically-selected behavioral epochs in which the cat held a range of stationary postures, and when it performed volitional and exploratory behaviors such as flexion-extension or turning, grooming, eating, or headshaking. Patterns of muscular activity were interpreted with reference to simultaneous video images of head and neck movements. In separate, videofluoroscopic analysis, flexion-extension movements were examined to gain insight into the underlying movements of the skull and cervical vertebrae. These and other movements were found commonly to depend upon changes in joint angles between lower as well as upper cervical joints. Stationary postures in which the neck was held vertically were consistently associated with tonic EMG activity in only two long dorsal muscles, biventer cervicis and occipitoscapularis. Less consistent activity was also present in dorsal intervertebral muscles crossing lower cervical joints. When the neck was held horizontally, the long dorsal muscles increased their EMG activity and moderate activity was also recorded in deeper intervertebral and suboccipital muscles. When flexion-extension occurred around upper cervical joints, greatest activity was recorded in rectus capitis posterior and complexus, but when it involved the lower cervical joints, large changes in EMG activity could also be detected in biventer cervicis, occipitoscapularis, and the intervertebral muscles crossing lower cervical joints. During specialized, sagittal-plane movements such as grooming, well-defined patterns of synergy could be recognized that varied according to the degree of involvement of upper and lower cervical joint-sets. Movements in the horizontal plane were associated with EMG activity in a largely different subset of neck muscles including splenius, longissimus capitis and obliquus capitis inferior. The levels of EMG activity during flexion-extension or turning movements were much lower than those observed during other more vigorous behaviors, such as head shaking. Some neck muscles, such as clavotrapezius and sternomastoideus, could only be recruited during forceful or ballistic head movements. Results showed that the patterns of muscular activation were linked not only to the speed and trajectory of the movements of the skull, but also to the kinematics of the motion occurring across different parts of the cervical column.

Animals↗
PubMedDate not supplied

Interaction foci, information synthesis, and mental activity.

The cerebral organization of mental activity is based on neural integration, specialization of functions, and the combination of rigid and flexible connections. These principles are embodied in dynamic structures, interaction foci that are detectable in the cortex during intellectual activity by means of the intracortical interaction mapping technique. Interaction foci comprise centers of cortical connections. A focus consists of neuronal groups connected by rigid connections, based on structural changes in the synapses. Each of the groups has its own frequency characteristics and is connected by flexible connections constructed on the principle of iso-lability, with neural elements at the periphery which are isorhythmic to it. The construction of interaction focus supports the synthesis of information arriving from sense organs and centers of motivations, and extractable from memory. Information synthesis underlies mental functions, the cerebral basis for which includes a rigid nucleus and a system of peripheral connections, the configuration of which may vary, thus controlling the uniqueness of a given mental experience. The principle of specialization of functions is manifested in the fact that the topography of interaction foci varies for different mental acts. In the case of perception the projection cortex is the integration center; in the case of thinking, the associative zones of the cortex are the integrative center. Imaginal thinking is primarily associated with the parietotemporal, and abstract thinking with the frontal, divisions of the cortex. Evidently, the two principle functions of consciousness are also spatially separated: integration of the "Self", which includes the volitional principle, and communication.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1993

Biomechanical approach to quantifying anticipatory postural adjustments in the elderly.

The paper outlines a biomechanical approach to quantifying anticipatory postural adjustments in the elderly. The measurement problems that occur in applying the biomechanical approach to elderly subjects are described and the 'signal-to-noise' properties of three candidate measures are compared, using data from volitional unilateral arm-raise tests performed on 100 elderly subjects. The results suggest that changes in vertical ground reaction force provide the greatest potential for accurate measurement of anticipatory adjustments, in comparison with changes in horizontal force or centre-of-pressure displacement. By normalising the anticipatory change in vertical ground reaction force with respect to the vertical perturbation force induced by the arm motion, a measure of relative anticipatory response is derived. The use of this measure, as well as its limitations, are demonstrated by analysing its relationship to actual falling risk, monitored prospectively in the elderly subject population. The findings showed evidence of larger relative anticipatory adjustments in the subjects who experienced recurrent falls, and it is suggested that these responses may be indicative of disordered motor programming. However, to detect these differences, it was necessary to average responses over multiple trials and to exclude trials with very small arm acceleration or very large baseline 'noise' (associated with ongoing postural sway). The need to screen and exclude data would seem to limit the practical utility of this approach in testing elderly populations.

Aged↗
PubMed1995

Identification of nonlinear model of ankle joint dynamics during electrical stimulation of soleus.

The mechanical impedance of the ankle joint was estimated in two conditions: during submaximal surface electrical stimulation of the soleus muscle, and with no stimulation applied. Both neurologically intact (n = 5) and spinal cord injured subjects (n = 4) were used. The mechanical impedance was measured by applying angular step and constant velocity (13-100 degrees s-1) perturbations at 10 degrees to the ankle and measuring the resulting changes in torque. A five-element lumped model consisting of an inertial element, a parallel elastic element, and an elastic element in series with a viscous element and a pure tension generator produced a good fit for predicting the compliance characteristics of the ankle for both the relaxed and stimulated conditions. The elastic elements were piecewise linear with different values for the dorsiflexion and plantarflexion directions. The viscous element was velocity-dependent and it decreased in value as the velocity increased. The average torque error between the measured and model's response during soleus stimulation was 10.56% for the dorsiflexed and 11.93% for the plantarflexed perturbations. However, the average error was skewed by several subjects who had excessive error, due to volitional intervention or flexor withdrawal reflex. The average model error for the perturbations without stimulation was 7.12% for dorsiflexed and 5.58% for plantarflexed perturbations.

Ankle Joint↗
PubMed1994

Biomechanical and reflex responses to joint perturbations during electrical stimulation of muscle: instrumentation and measurement techniques.

A test device is developed to measure ankle joint compliance and muscle activity when the ankle is subjected to perturbations in angular position (or torque) from bias positions achieved volitionally or via electrical stimulation. The ankle measurement system uses a pivoting footplate and is operable with the subject sitting or supine. A companion platform for the knee is developed that uses a rotary arm and attached leg brace and is operable with the subject's leg in the horizontal or vertical plane. The knee fixture's pivoting arm can slide to account for the cam-like movement of the knee during rotation. The devices use similar hardware and share common instrumentation and control. Precise torque or position perturbations are delivered by a computer-controlled torque motor to the ankle or knee. Angular displacement, torque, acceleration, knee fixture moment arm and electromyographic data are collected on analogue tape and simultaneously digitised and stored. A special stimulator/recording amplifier permits the recording of electromyographic signals from the stimulated muscle. Experimental data indicate that the ankle and knee devices, operated horizontally, are purely inertial systems. Sample ankle and knee joint responses to perturbations are presented.

Ankle Joint↗
PubMed1999

Temporal and spatial complexity measures for electroencephalogram based brain-computer interfacing.

There has been much interest recently in the concept of using information from the motor cortex region of the brain, recorded using non-invasive scalp electrodes, to construct a crude interface with a computer. It is known that movements of the limbs, for example, are accompanied by desynchronisations and synchronisations within the scalp-recorded electroencephalogram (EEG). These event-related desynchronisations and synchronisations (ERD and ERS), however, appear to be present when volition to move a limb occurs, even when actual movement of the limb does not in fact take place. The determination and classification of the ERD/S offers many exciting possibilities for the control of peripheral devices via computer analysis. To date most effort has concentrated on the analysis of the changes in absolute frequency content of signals recorded from the motor cortex. The authors present results which tackle the issues of both the interpretation of changes in signals with time and across channels with simple methods which monitor the temporal and spatial 'complexity' of the data. Results are shown on synthetic and real data sets.

Computer User Training↗
PubMedDate not supplied

An account of consciousness in physical and functional terms: a target for research in the neurosciences.

The neurophysiology of mental events cannot be fully understood unless that of consciousness is understood. As the first step in a top-down approach to that problem, one needs to find an account of consciousness as a property of the biological organism that can be clearly defined as such. However, if it is to deliver what must be expected of it, it should address what is commonly meant by the word consciousness. Unless the last condition is satisfied, the theory will fail to deliver what must ultimately be expected of it. Although current interest lies mainly in the higher functions of consciousness, such as its role in language and social relationships, the common usage of the word relates to modes of awareness that are not denied to creatures lacking language or social relationships. The basic features to be covered include awareness of the surrounding world, of the self, and of one's thoughts and feelings; the subjective qualities of phenomenal experience (qualia); the conditions a brain event must satisfy to enter consciousness; and the main divisions of mental events, such as sensations, feelings, perceptions, desires, volitions, and mental images. In the first four chapters we argue that these basic features of consciousness can all be accounted for in terms of just three categories of internal representations, each supported by the empirical evidence and each accurately definable in physical and functional terms. In the fifth, and last, chapter we take a closer look at two of the categories and what these in particular suggest as the most relevant lines of research in the contemporary spectrum of the neurosciences.

Animals↗
PubMed1997

Lateral pharyngeal wall motion during swallowing using real time ultrasound.

B-mode ultrasound imaging has been used primarily to detect temporal and spatial movements of the tongue during the oral preparatory and oral stages of swallowing. The purpose of this study was to investigate the application of M-mode (motion mode) ultrasound imaging as a method to quantify the duration and displacement of single regions along the lateral pharyngeal wall during swallows of two bolus volumes and during three swallow maneuvers (supraglottic, super-supraglottic and Mendelsohn maneuver). In 5 normal subjects, simultaneous B/M-mode images were captured at two regions along the lateral pharyngeal wall. Computer-assisted video analysis of each swallow sequence provided spatial coordinates and durational measures. Results indicated no significant differences in displacements of the lateral pharyngeal wall across bolus volumes, swallow maneuvers, or recording sites. Significant differences (p < 0.001) in lateral pharyngeal wall duration occurred as a function of volitional swallow maneuvers. Greater durations (p < 0.05) were found for the Mendelsohn and super-supraglottic swallow maneuvers. The data demonstrate that B/M-mode ultrasound imaging provides a simple, noninvasive method to visually examine movements of the lateral pharyngeal wall and may provide a clinical method for assessing the effects of direct swallowing therapies at the level of the mid-oropharynx.

Adult↗
PubMed2004

[Anorexia nervosa. Implications for emergency medical services].

We discuss emergency medical service implications of eating disorders using the case of CPR in a 30-year-old female with severe anorexia nervosa and offer a literature review of potential lethal complications. Despite therapeutical advances, anorexia nervosa is still an illness with considerably high mortality. Potential severe complications of this illness can have life-threatening implications. Emergency medical service decisions have a prognostic impact on the further course of the illness. Whether patients should be treated against their own volition is of particular importance.

Adult↗
PubMed2005

[Exercise therapy as a therapeutic concept].

Lack of exercise is a primary cause for today's level of morbidity and mortality in the Western world. Thus, exercise as a therapeutic modality has an important role. Beneficial effects of exercise have been extensively documented, specifically in primary and secondary prevention of coronary heart disease (CHD), diabetes mellitus, hypertension, disorders of fat metabolism, heart insufficiency, cancer, etc. A regular (at least 3 x per week) endurance training program of 30-40 min duration at an intensity of 65-70% of VO(2)max involving large muscle groups is recommended. The specific exercise activity can also positively affect individuals with orthopedic disease patterns, i.e., osteoporosis, back pain, postoperative rehabilitation, etc. Endurance strength training in the form of sequential training involving approx. 8-10 different exercises for the most important muscle groups 2 x per week is a suitable exercise therapy. One to three sets with 8-12 repetitions per exercise should be performed until volitional exhaustion of the trained muscle groups among healthy adults and 15-20 repetitions among older and cardiac patients. Apart from a positive effect on the locomotor system, this type of strength training has positive effects on CHD, diabetes mellitus, and cancer.

Coronary Disease↗
PubMed1998

Neuronal control of mammalian vocalization, with special reference to the squirrel monkey.

Squirrel monkey vocalization can be considered as a suitable model for the study in humans of the neurobiological basis of nonverbal emotional vocal utterances, such as laughing, crying, and groaning. Evaluation of electrical and chemical brain stimulation data, lesioning studies, single-neurone recordings, and neuroanatomical tracing work leads to the following conclusions: The periaqueductal gray and laterally bordering tegmentum of the midbrain represent a crucial area for the production of vocalization. This area collects the various vocalization-triggering stimuli, such as auditory, visual, and somatosensory input from diverse sensory-processing structures, motivation-controlling input from some limbic structures, and volitional impulses from the anterior cingulate cortex. Destruction of this area causes mutism. It is still under dispute whether the periaqueductal region harbors the vocal pattern generator or merely couples vocalization-triggering information to motor-coordinating structures further downward in the brainstem. The periaqueductal region is connected with the phonatory motoneuron pools indirectly via one or several interneurons. The nucleus retroambiguus represents a crucial relay station for the laryngeal and expiratory component of vocalization. The articulatory component reaches the orofacial motoneuron pools via the parvocellular reticular formation. Essential proprioceptive feedback from the larynx and lungs enter the vocal-controlling network via the solitary tract nucleus.

Animals↗
PubMed1996

[Clinically pure motor variant of Guillain-Barré polyneuritis. Report of 3 cases].

We report three patients with severe Guillain-Barré syndrome (GBS). On clinical examination, no sensory deficit was elicited. Electromyography (EMG) and motor nerve conduction velocity (NCV) studies were indicative of an axonal lesion. In two patients, we found total peripheral conduction block without volitional EMG activity. Sensory NCV and cortical median nerve evoked potentials remained normal. Sural nerve biopsy revealed unequivocal alterations of sensory nerve fibers, some in the form of primary demyelination. Therefore, these cases must bei classified as combined motor-sensory syndromes despite the clinical and electrophysiological findings. Although total denervation of the extremity muscles occurred, causing tetraparalysis, this manifestation appears to be attributable to the secondary axonal variant. In contrast to positive reports in literature, immunomodulatory treatment proved ineffective in all three cases.

Aged↗
PubMed1998

[Polygraphic validation of distraction tasks in clinical differential tremor diagnosis].

In a total of 30 tremor patients (14 with Parkinson's disease, 6 with cerebellar tremor, 4 with essential tremor, 4 with psychogenic tremor, 2 with enhanced physiological tremor), tremor was electromyographically recorded before, during and after contralateral distraction tasks (tapping with the index finger or the tip of the foot, sequential flexion of the 2nd to 5th finger towards the thumb, "keyboarding", and sensory discrimination). 22 of 26 patients with organic tremors spontaneously choose a volitional tapping frequency independent from their tremor frequency. In 4 patients with psychogenic tremor, frequencies of tremor and tapping were locked (n = 3), or tremor disappeared abruptly (n = 1) when contralateral tapping was started. Contralateral "keyboarding" and sensory discrimination revealed no clear differences between organic and psychogenic tremors. Contralateral tapping in further 23 patients (22 with organic tremors and 1 with psychogenic tremor) confirmed these findings. Contralateral tapping appears as the most valid distraction task and may help to differentiate psychogenic from organic tremors.

Adult↗
PubMed2006

The effects of fluoxetine on the subjective and physiological effects of 3,4-methylenedioxymethamphetamine (MDMA) in humans.

OBJECTIVE: The purpose of this study was to investigate the role of serotonin (5-HT) in the effects of oral 3,4-methylenedioxymethamphetamine (MDMA) in humans. MATERIALS AND METHODS: The subjective and physiological effects of 1.5 mg/kg MDMA were evaluated after 20 mg fluoxetine in eight recreational MDMA users in a double-blind, placebo-controlled study. During phase 1, participants were maintained on placebo for at least 5 days and tested with MDMA and placebo on separate sessions. In phase 2, the procedure was the same except fluoxetine was administered daily for at least 5 days. During sessions, placebo or fluoxetine was given 1 h before the session drug and effects were measured over the next 7 h. RESULTS: MDMA increased positive-like subjective effects on all the Addiction Research Center Inventory scales; Arousal, Elation, Positive Mood, and Vigor on the Profile of Mood States; Drug Liking, Friendly, Good Drug Effect, High, Stimulated, and Talkative on the Visual Analog Scale; and End-of-Session Liking and Crossover Point on the Multiple Choice Procedure. MDMA also increased measures of anxiety. On the Hallucinogenic Rating Scale, all scales except Volition were increased. MDMA also increased blood pressure and heart rate. Fluoxetine treatment attenuated most of the positive-like subjective effects including the Affect and Soma scales of the Hallucinogen Rating Scale. In addition, heart rate but not blood pressure increases were reduced. CONCLUSIONS: These results suggest that blockade of 5-HT reuptake by fluoxetine can dampen the effects of MDMA and further supports the role of 5-HT in its behavioral effects in humans.

Adult↗
PubMed1996

Effects of bromocriptine on self-administration of sweetened ethanol solutions in rats.

The effect of bromocriptine (BRO), a D2 receptor agonist, on chronic oral ethanol (ETOH) self-administration was tested in a home-cage environment. Male Wistar rats (n = 77) were food deprived for 24 h. Then, a period of 15 days of limited-access (1 h/day) to food and to a sweetened ETOH solution was started [3% w/v of glucose and several concentrations of ETOH depending upon the group: 0% (control group). 1.5%, 5% or 10% v/v]. Later, another period started in which rats were maintained in a free-choice, two-bottle situation with food, tap-water and the sweetened solution available for 24 h/day, for 14 days. Following this period, BRO (5 mg/kg, SC) was administered, once daily, for 5 days, in the same continuous free-access conditions. ETOH consumption was also studied for 4 days after the last BRO injection. BRO increased ETOH self-administration throughout the 5-day period, regardless of the ETOH concentration available, in the rats with previous higher ETOH intake, without effect in the control animals. In the control rats, water intake was increased, whereas in the group that had access to the lowest ETOH concentration a decrease in water consumption was found. The enhanced ETOH drinking was maintained after BRO treatment for the animals with previous higher ETOH intake. BRO effects on water consumption were also maintained. These data suggest that BRO can potentiate ETOH intake and provide further support for the role of dopamine (DA) systems in mediating volitional oral intake of ETOH.

Animals↗