Search PubMed⌕ Search

Biomedical subjects

U Thoden

Publications and source records attributed to U Thoden.

At least 55 records · Page 3Linked to original sources
PubMed1979

Mesencephalic chronic electrodes in pain patients. An electrophysiological study.

Early components of lemniscal potentials after contralateral median nerve or mechanical stimulus are due to lemniscal pathways, whereas later components, after 70 msec appearing bilaterally and at higher stimulus intensities probably express extralemniscal activity. Evoked potentials in the central gray matter show much smaller amplitudes compared with somatosensory cortical evoked potentials (SSEP). The strongest component is a negative wave after 70--100 msec. Longer conditioning stimulation of the lemniscal system inhibits late components in the median nerve evoked cortical potentials. On the contrary, stimulation of the nonspecific periaqueductal gray matter produces inhibition of early components of cortical SSEP together with facilitation of late components.

Afferent Pathways↗
PubMed1978

Co-activation of the M. transversus auris with eye movements (Wilson's oculo-auricular phenomenon) and with activity in other cranial nerves.

Extreme lateral gaze induces a perceptible backward movement of the upper part of the pinna (Wilson, 1908). In 29 subjects (15 normal controls and 14 patients with peripheral eye-muscle or facial paresis) electromyographic (EMG) investigation of the transverse auricular muscle with simultaneous electronystagmographic (ENG) recording of the various ocular movements was carried out. Tonic activity was detected in the transverse auricular muscle during extreme horizontal eye movements, but was detected in only a few subjects during convergent or vertical movement of the eyes, or in the primary position. Investigation of the other cranial nerves revealed that EMG activity of the transverse auricular muscle is also occasionally present during chewing, coughing, swallowing, straining, inspiration, and vestibular stimulation.

Cranial Nerves↗
PubMed1978

Forelimb reflexes modulated by tonic neck positions in cats.

The modulation of monosynaptic forelimb reflexes by tonic neck positions was investigated in cats with the head fixed. Lateral flexion of the body in a horizontal plane markedly facilitates reflexes of the deep radial nerve (DR) in the ipsilateral forelimb, while the antagonistic ulnar nerve (ULN) reflexes are strongly inhibited. Opposite effects are seen after contralaternal body movement. Dorsiflexion of the body clearly increases DR-reflexes and exerts a reciprocal although more pronounced inhibition on ULN reflexes. Opposite effects appear after ventriflexion. The reflex modulation starts with head-body displacements of approximately 5 degrees and increases with increasing angles. Furthermore reflex modulation does not depend on the intact cerebrum and cerebellum. The comparison of forelimb and hindlimb reflexes shows a decrease of the neck influences along the spinal cord.

Animals↗
PubMed1978

Pain perception in man after long term spinal cord stimulation.

Thresholds of non-painful and painful perception for electrical stimuli are not altered significantly during dorsal column stimulation either in the area of induced paresthesia or outside it. After long term stimulation of the dorsal column the thresholds for stimuli are significantly higher within the area of induced paresthesia but not outside it. Median nerve evoked somatosensory cortical potentials are not altered by conditioning or simultaneous DC stimulation. During DCS in three of eight patients only the vibration evoked cortical potentials were attenuated in the early three components of the potential.

Adult↗
PubMed1978

Electrical spinal cord stimulation for spastic movement disorders.

Spinal cord stimulation seems today a promising method to improve spasticity. The experiences of two different clinics (Zürich and Freiburg i.Br.) are reported with long-term assessment up to 28 months. The objective data with measurement of stretch and H reflexes support the clinical results. An experimental study on animals does not permit a definitive explanation, but some hypotheses can be suggested.

Adult↗
PubMed1977

Influence of transcutaneous nerve stimulation (TNS) on acute pain.

Using transcutaneous nerve stimulation (TNS) simple surgical procedures such as tooth extractions and nerve biopsies can be performed without the usual anesthetics. Estimation of threshold and suprathreshold intensities of painful electrical stimuli show no significant change during TNS. Only the threshold for non-painful electrical stimuli is slightly increased. Cortical potentials evoked by electrical peripheral nerve stimulation are not significantly modulated by TNS. Latencies of the early components 0, I--III are unchanged, the amplitudes only slightly reduced. These observations are in contradiction to the 'gate-control' theory of pain.

Acute Disease↗
PubMed1977

Direction-specific optokinetic modulation of monosynaptic hind limb reflexes in cats.

The excitability of hindlimb extensor and flexor motoneurons is tonically modulated by animal tilt and a large visual stimulus rotating about the animal's line of sight. This direction-specific modulation is opposite for extensor and flexor motoneurons and opposite for optokinetic and vestibular stimuli, thus combining to a functionally significant pattern of postural reflexes.

Animals↗
PubMed1977

Modulation of hindlimb reflexes by tonic neck positions in cats.

In cats with the head fixed in a stereotactic frame a slight facilitation of the gastrocnemiussoleus (GS) monosynaptic reflexes in the ipsilateral hindlimb, accompanied by an inhibition of the monosynaptic reflex of the antagnostic deep peroneal nerve (DP), occurs following lateral flexion and rotation around the body axis at an angle of 25 degrees. Following dorsiflexion of the body a moderate inhibition of the extensor reflexes (GS) up to 10% and a reciprocal slight excitation in the same range of the monosynaptic reflexes of flexor muscles (DP) is recorded. On the other hand after ventriflexion of the body there is a marked inhibition in the range of 50% of all the monosynaptic extensor and flexor reflexes for all the stimulus intensities used. This inhibition can already be demonstrated in ventriflexion of 10 degrees-15 degrees. All these patterns of reflex modulation are similar in cortically intact, ischemically decorticated and precollicularly decerebrated cats. Furthermore these patterns are not essentially influenced by cerebellectomy, although all reflex amplitudes are reduced. However, the spinal reflexes can not be modulated by these body movements after acute spinalization.

Afferent Pathways↗
PubMed1977

[Neurological aspects of the differential diagnosis of low back pain (author's transl)].

The close relationships between the bony spinal column, spinal marrow and the emerging nerve roots explain the frequency of neurological symptoms of diseases in the region of the lumbar vertebrae, the sacrum and the pelvis. After a short description of the local diagnostic signs in lumbosacral pains, further important differential diagnostic aspects of the changes in the vertebral column besides those of the intervertebral disks, inflammatory changes in the vertebrae, intramedullary tumors as well as a few rare pain syndromes in peripheral nerve diseases are discussed.

Back Pain↗
PubMed1977

Influence of dorsal column stimulation (DCS) on spastic movement disorders.

Dorsal column stimulation in two spastic patients with upper motor neurone disease showed the following effects: 1. The subjective feeling of stiffness decreased. During DCS patients were able to walk longer distances without rest. 2. The ability to perform fast alternating or synchronous "pedal-pressing" foot movements improved by 15%. 3. The threshold of H-reflexes was enhanced up to 12%, and outlasted the end of stimulation by two minutes. 4. The H-reflex amplitude was depressed in relation to intensity and duration of DC-stimulation up to 10 minutes after the end of DCS. 5. A late second facilitatory wave at 300 msec in the curve for H-reflexes conditioned by a short tibial stimulus was inhibited during DCS. Although the hyperexcitability of the H-reflex was dampened significantly during DCS the whole motor disturbance improved only slightly.

Adult↗
PubMed1977

[Early electroneurographic diagnosis of carpal tunnel syndrome (author's transl)].

A comparison of distal motor latencies after stimulation of the median and ulnar nerves proximal to the ligamentum carpi transversum and recording from the thenar muscles shows: a) in normal subjects (99 measurements) a 0,7 msec longer latency after stimulation of the ulnar nerve, b) in generalized polyneuropathies in 46% (n = 48) a reversal of the two motor latencies, i.e., a longer median than ulnar nerve latency. c) in manifest carpal tunnel syndromes with pathologically prolonged motor latencies this reversal in all cases; d) in carpal tunnel syndromes with only pathologically prolonged sensory latencies in 11 out of 13 patients a reversal of motor latencies; e) in patients with carpal tunnel syndromes a reversal of motor latencies in 65% (n = 46) on the clinically symptom-free side. It is concluded that a reversal of distal motor latencies may be the earliest sign of a carpal tunnel syndrome, if a generalized polyneuropathy is excluded and typical symptoms are reported.

Carpal Tunnel Syndrome↗