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Biomedical subjects

M Bratzlavsky

Publications and source records attributed to M Bratzlavsky.

At least 19 recordsLinked to original sources
PubMed1984

Electrophysiological evidence for crossed oligosynaptic trigemino-facial connections in normal man.

A crossed short latency component (R1) of the human blink reflex could be elicited in orbicularis oculi muscles to stimulation of the contralateral supraorbital nerve, when infraliminal conditioning stimuli were applied to various cutaneous afferents of the body (facial, upper and lower limbs). The crossed R1 responses appeared when the time interval between the conditioning and the test stimuli was of 30 to 40 ms, 50 to 65 ms and 95 to 110 ms for facial, upper and lower limbs afferents respectively. For the same time intervals, these conditioning volleys also exerted a facilitatory effect on the ipsilateral R1 responses. Furthermore, crossed R1 responses were also obtained during supraspinal facilitation induced by a voluntary contraction of the eyelids. These data show that crossed oligosynaptic trigemino-facial reflex connections exist in normal subjects, which become functional when adequate conditioning stimuli are available.

Adult↗
PubMed1982

Visualization of muscles involved in unilateral tremor using 13N-ammonia and positron emission tomography.

Using positron emission computerized tomography (PCT), a high uptake of IV injected 13N-ammonia was observed in the muscles of the right forearm and leg of a patient with a rightsided static tremor. In some muscles the concentration of 13NH3 was 8.5 times higher than in the symmetrical normal limb. Confrontation of the clinical, neurological, and electromyographic findings with the results of the PCT proved that the muscles with the high uptake corresponded to the muscles responsible for the tremulous movements. There is strong evidence that the high uptake of 13NH3 was related to the increased blood flow produced by the continuous rhythmic exercise of the muscles involved in the tremor. To our knowledge a similar observation has not been described before. It is suggested that the combined use of suitable positron emitters and PCT might provide a valuable tool for the noninvasive study of perfusion of individual skeletal muscles.

Aged↗
PubMed1982

Abnormal Tl-201 limb scan due to unilateral tremor.

A abnormal intra- and interextremity distribution pattern on Tl-201 was observed on the limb scan of a patient with a unilateral tremor. This is ascribed to the increased blood flow in the muscles responsible for the tremor. The suggestion is made that the existence of tremor should be considered as a possible explanation for unexpected abnormalities on Tl-201 limb scintigrams.

Aged↗
PubMed1980

[Post paralytic facial spasm: new pathogenetic findings (author's transl)].

The study of the early blink and lip reflex components in patients with postfacial palsy contracture and mass contractions shows changes in the synaptic organization of the facial nucleus. The possible contribution of nuclear factors to the altered function of reinnervated facial muscles is discussed.

Adult↗
PubMed1980

[Pathophysiology of tetanus rigidity (author's transl)].

Brainstem reflexes have been studied electrophysiologically in six patients with generalized tetanus. The selective impairment of reflexes with long polysynaptic pathways supports the assumption of an interneuronal dysfunction in tetanus. The behaviour of proprioceptive reflexes suggests that hyperactivity of gamma-motoneurons contributes to the rigidity in an early stage of the disease.

Adult↗
PubMed1977

Altered synaptic organization in facial nucleus following facial nerve regeneration: an electrophysiological study in man.

Seven patients with postfacial palsy contracture and mass contractions were investigated electrophysiologically. In 3 patients the early blink reflex showed an unusually high amplitude, which can be attributed to enhanced excitability of facial motor neurons. In 5 patients the early blink reflex had acquired a crossed character. It is assumed that changes in organization of the facial nucleus contribute to the altered function of reinnervated facial muscles.

Action Potentials↗
PubMed1976

Medullary actions of tetanus toxin. An electrophysiological study in man.

Brain-stem reflexes have been studied in four patients with generalized tetanus. Inhibitory cutaneous reflexes were abolished or severely depressed. The same held true, to a lesser degree, for excitatory cutaneous reflexes with long polysynaptic pathways. Proprioceptive reflexes behaved variably. The observations are discussed in regard to the possible sources of enhanced motoneuronal activity in tetanus. It is concluded that, besides depression of inhibitory synapses on motoneurons, interneuronal damage may contribute to the tetanus symptomatology.

Adult↗