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Biocybernetic investigations of pursuit and posture motor control--a strategy for a detailed characterization of movement disorders in brain-damaged children.

By means of a biocybernetic approach the pursuit and posture motor control of brain-damaged children with spastic hemiparesis and disturbed motor coordination of mild extent were investigated. The postural motor control system was loaded by pseudostochastic binary torque sequences applied to the wrist. The dynamics of this system were characterized on the basis of the parameters forearm displacement as well as surface-EMG of M. Biceps and Triceps (calculations of weight functions). The pursuit motor control was analyzed by a pursuit tracking method. By this way the motor capacity for fine and rough motor coordination, motor rhythm, motor adaptation, the maximal speed of movements and motor reaction time could be tested. Considering these results a characterization of movement control on different levels of motor regulation was possible (dynamics of muscular, spinal, and supraspinal components of motor control).

Brain Damage, Chronic

[Analysis of oculomotor disorders in motor neuron disease].

Oculomotor disorders have been considered to be one of the negative symptoms in motor neuron disease (MND). However, recently, ophthalmoplegia, abnormal Bell's phenomenon and disturbance of pursuit movement have been reported. We tried to evaluate 32 patients with MND (19 males and 13 females; age, 35 to 77 years; 52.4 +/- 10.1 years) by bedside examination and electro-oculography (EOG) using an eye tracking method. Twenty-three of them were classified as amyotrophic lateral sclerosis (ALS) and seven as bulbospinal muscular atrophy, and two were unclassified. One hundred healthy persons for bedside examination and twenty-two for EOG were investigated as controls. Findings by bedside examinations were as follows; 1) Slight limitations of upward only, up & downward and upward & horizontal gaze were observed in 5 cases (15.6%), 1 case (3.1%) and 1 case (3.1%), respectively. 2) Incomplete convergence was observed in 11 cases. (34.4%) 3) Horizontal gaze nystagmus was observed in 6 cases. (18.8%) 4) As regards the frequency of limitation of upward gaze and incomplete convergence, there were no statistically significant differences from those in controls. Electrooculographic results were: 1) square wave jerks (SWJs) were recorded in 3 cases. (9.4%) 2) Amplitude ratio of saccade was significantly higher in MND than that in controls with the risk less than 0.1%. 3) The degree of ocular dysmetria was significantly higher in MND than that in controls with the risk less than 0.5%. These abnormalities were not directly related to suffering period. Although the mechanism is not known, several reports of the effectiveness of thyrotropin releasing hormone (TRH) in ALS were recently published.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Ocular motor abnormalities in progressive supranuclear palsy].

Eleven patients, 7 males and 4 females, of progressive supranuclear palsy (PSP) were examined neuro-otologically for the purpose of elucidating the characteristics of ocular motor abnormalities. All cases were admitted to our hospital and age at onset was from 52 to 71 years old, duration of illness was 2 to 11 years. Range of voluntary eye movements and abnormal eye movements including nystagmus were examined on naked eyes and with electronystagmography (ENG). Smooth pursuit movements and saccadic eye movements were tested both horizontally and vertically by using visual tracking method with ENG recordings. Optokinetic nystagmus test and caloric test with visual suppression test were also performed. These neurotological examinations were made repetitively in 5 cases and their progressions were observed. Vertical gaze palsy and convergence palsy were observed in all cases as the initial symptom. In this study downward gaze was more severely disturbed than upward gaze. Using ENG, saccadic eye movements (saccades) were disturbed earlier than smooth pursuit movements. Hypometric saccades and decreased saccadic velocity were common abnormalities. In the later stage of the disease, horizontal eye movements were also disturbed. In four cases bilateral adduction palsy was added to vertical gaze paralysis so that the lesion of the MLF to oculomotor nucleus was suggested to exist. These voluntary eye movements were worsened gradually as the disease progressed. By using ENG we could find so called abnormal eye movements more frequently than the previous reports. Eight patients demonstrated horizontal gaze nystagmus, and rebound nystagmus were observed in four cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

[Organization of the median and intralaminar nuclei of the thalamus: hypotheses on their role in the onset of certain central pain].

Afferent neurons from thalamic median and intralaminar (IL) nuclei arise in the spinal cord, brain stem synapses, substantia nigra, internal pallidum and cerebral cortex, directly and through the intermediary of the reticular nucleus of the thalamus (RT). Efferent neurons terminate in the anterior thalamic nuclei, RT, striatum and cerebral cortex. Tracking methods in the rat have demonstrated that some RT neurons which project towards the IL are surrounded by endings from the posterior ventral nucleus (VP). Electrical stimulation of multiple prosencephalic structures (mainly VP) and of sensory pathways induce responses in IL of brief latency followed by inhibition. Whereas the responses appear to be related to activation of excitatory projections (under the tonic facilitating control of cerebral cortex) the inhibition phases could be related to activation of RT, since they disappear after lesion of the RT. This nucleus could act as a common final pathway of inhibitions exerted on IL in the rat. Studies in this species have demonstrated that a lateral lesion of the thalamus that includes the RT provokes the appearance in IL of abnormal neuronal hyperactivity of a tonic nature and yet still exaggerated by stimuli normally capable of inducing responses of brief duration followed by inhibition. Human studies using a tomoscintigraphic method to determine regional blood flow have shown "hyperactivity" of the thalamic region in patients with pain of central origin during a natural stimulus provoking hyperpathia. This was not observed during painful states without hyperpathia. The working hypothesis proposed is that of a central lesion inducing a hyperpathia provoking pathologic hyperactivity in certain thalamic nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

[Bathing a patient with cancer pain treated with continuous epidural blockade--subcutaneous catheter track and Lapack method].

Continuous epidural blockade is considered to be the most useful device for the management of cancer pain. However, it has the disadvantage to compel the patients to restrict their daily activities. We report a unique "Subcutaneous catheter track & Lapack-method" that enabled a patient with epidural catheter to safely bath at home. A 56-year-old male with a local recurrence of rectal cancer was suffering from perineal pain, which was well controlled by oral and epidural morphine. Since his wishing was to bath, we made a long subcutaneous catheter track with Tuohy-needle to prevent infection, and let him bath with transparent film dressings (Bioclusive) and Lapack to tightly cover and seal up the catheter. Although subcutaneous pustule occurred 7 days after the beginning of bathing, it was easily cured by local disinfection. He was able to enjoy bathing without any infection with this method at home for about 2 months after discharge, until he returned to the hospital. "Subcutaneous catheter track & Lapack-method" offers a safe and comfortable bathing to patients with epidural catheter, and contributes to the improvement of their quality of life.

Analgesia, Epidural

Orientation in birds. Satellite tracking: a new method in orientation research.

The study of bird migration by satellite tracking began in the 1980s, after transmitters had become sufficiently small to allow the monitoring of larger migrating species. The initial studies in this direction were all successful with respect to establishing this method (Section 2) of elucidating new migration patterns and various aspects of orientation. These pilot studies are summarized in Section 3, Table 1, Figures 1-4. We believe that studies on avian orientation and navigation will, in general, greatly benefit from satellite tracking if some prerequisites are fulfilled and adequate experiments planned (Section 4). In future studies, smaller transmitters with increased life expectancies are needed, and possible effects of these transmitters on bird behaviour must be examined. Considerable improvement of satellite tracking in avian orientation research is to be expected, along with the development of a new generation of satellites allowing communication between satellites and transmitters (Sections 4, 5).

Animals

The hemodynamic tracking system: a method of data management and guide for cardiovascular therapy.

In the operating room or intensive care unit, multiple measurements of circulatory function are almost mandatory in patients with significant cardiovascular disease. Use in these areas requires that the information must be easily organized, rapidly obtained, and inexpensive. A hemodynamic tracking system that meets these criteria is described. This system incorporates a hand-held programmable calculator (cost = $210 to $300) to derive variables computed from standard cardiovascular measurements. The time required to obtain a set of measurements (including thermodilution cardiac output determinations in duplicate), key the numbers into the calculator, and obtain the derived indices is 4 minutes. Two patients, who had acute mitral insufficiency and whose clinical management differed substantially are presented to illustrate the use of data obtained from the hemodynamic tracking system.

Aged

Is resistance to ischaemia of motor axons in diabetic subjects due to membrane depolarization?

The reasons for the resistance to ischaemia of peripheral nerves in diabetics are not well understood. We have now explored whether axonal depolarization underlies this phenomenon, as has previously been proposed. Resistance to ischaemia was determined by the new method of "threshold tracking". This method revealed an increase in excitability of the peroneal nerve at the popliteal fossa during ischaemia, and a decrease in excitability in the post-ischaemic period. The extent of these alterations in 28 type 1 diabetics without peripheral neuropathy showed a strong correlation with the mean blood glucose concentrations during the last 24 h before examination. To test whether the ischaemic resistance was related to membrane potential, we also measured axonal superexcitability in 11 selected diabetics, since it has been shown that post-spike changes in excitability depend on membrane potential. Changes in excitability of the peroneal nerve were measured in the period between 10 and 30 msec following a conditioning supramaximal compound action potential. Under resting conditions, no differences in the post-spike superexcitability were found between controls and diabetics, despite striking differences in their responses to a 10-min pressure cuff. These observations indicate that membrane depolarization is not involved in the resistance to ischaemia of motor axons in diabetic subjects.

Action Potentials

Phase plane tracking: a new method for shaping movements.

Study of the relation between muscular activation patterns and movements has largely been based on the control of discrete movement parameters as amplitude, duration and maximum velocity. A new method is described for shaping voluntary limb movements in order to reliably obtain movements of different dynamic characteristics. A template of the desired movement is calculated with a micro-computer. This template is displayed on a storage oscilloscope as a phase plane (velocity vs. position during movement). By moving an instrumented handle the subject reproduces the template movement. Subjects readily adapt to this display and reliably make movements of different dynamic characteristics.

Humans

An immunocytochemical method for marking microelectrode tracks following single-unit recordings in long surviving, awake monkeys.

We describe an immunocytochemical method for marking microelectrode tracks made during single-unit recordings in long surviving, awake monkeys. This procedure detects the increase in glial fibrillary acidic protein in the glial cells along a microelectrode track using commercially available antibodies. We have successfully marked electrode tracks in tissue from preparations having postrecording survival times ranging into months even though the gliosis can no longer be detected with conventional stains for cell bodies. When this method is combined with data from electrophysiological recordings in chronic preparations it will be possible to reconstruct functional architecture using chronic preparations, as has been done previously with acute preparations.

Animals

Advances in analytical techniques for neutron capture therapy: thin layer chromatography matrix and track etch thin layer chromatography methods for boron-10 analysis.

A new track etch autoradiographic technique for quantitating boron-10 containing compounds used for neutron capture therapy is described. Instead of applying solutions of Cs2B12H11SH and its oxidation products directly to solid-state nuclear track detectors, diethylaminoethyl cellulose thin layer chromatography (TLC) plates are utilized as sample matrices. The plates are juxtaposed with Lexan polycarbonate detectors and irradiated in a beam of thermal neutrons. The detectors are then chemically etched, and the resultant tracks counted with an optoelectronic image analyzer. Sensitivity to boron-10 in solution reaches the 1 pg/microliter level, or 1 ppb. In heparinized blood samples, 100 pg boron-10/microliter are detected. This TLC matrix method has the advantage that sample plates can be reanalyzed under different reactor conditions to optimize detector response to the boron-10 carrier material. Track etch/TLC allows quantitation of the purity of boron neutron capture therapy compounds by utilizing the above method with TLC plates developed in solvent systems that resolve Cs2B12H11SH and its oxidative analogs. Detectors irradiated in juxtaposition to the thin layer chromatograms are chemically etched, and the tracks are counted in the sample lane from the origin of the plate to the solvent front. A graphic depiction of the number of tracks per field yields a quantitative analysis of compound purity.

Boron

Computerized tracking for newborn screening and follow-up: a review.

In the third decade of newborn screening for phenylketonuria (PKU) and other disorders computers are being used increasingly for both the laboratory and the follow-up aspects of screening programs. In 1984 slightly less than 40% of the state programs had automated follow-up. Lack of funding is probably the major inhibitor of more widespread use of computers in tracking newborns through the newborn screening process. It is suggested that federal funds be made available to ensure wider distribution of currently used tracking systems and development of methods for tracking newborns from birth through follow-up.

Follow-Up Studies

Nanovid tracking: a new automatic method for the study of mobility in living cells based on colloidal gold and video microscopy.

We describe a new automatic technique for the study of intracellular mobility. It is based on the visualization of colloidal gold particles by video-enhanced contrast light microscopy (nanometer video microscopy) combined with modern tracking algorithms and image processing hardware. The approach can be used for determining the complete statistics of saltatory motility of a large number of individual moving markers. Complete distributions of jump time, jump velocity, stop time, and orientation can be generated. We also show that this method allows one to study the characteristics of random motion in the cytoplasm of living cells or on cell membranes. The concept is illustrated by two studies. First we present the motility of colloidal gold in an in vitro system of microtubules and a protein extract containing a kinesin-like factor. The algorithm is thoroughly tested by manual tracking of the videotapes. The second study involves the motion of gold particles microinjected in the cytoplasm of PTK-2 cells. Here the results are compared to a study using the spreading of colloidal gold particles after microinjection.

Animals