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Biomedical subjects

N Bathien

Publications and source records attributed to N Bathien.

At least 37 records · Page 2Linked to original sources
PubMed1982

The abdominal cutaneous reflex circuit in the rat: a spinobulbo-spinal reflex in phenobarbital-anesthetized animals.

A description is given of an abdominal reflex (ACR) in the rat evoked by cutaneous stimulation. Latency of the ACR in response to stimulation of the contralateral hindlimb was 28.5 +/- 3.2 msec. Data from the analysis of discharges in dorsal and ventral roots and from bulbar reticular neurons triggered by ACR stimuli reveal that a spino-bulbo-spinal loop seems to be implicated. This is also supported by the chronic effects of pontile and spinal transections. ACR-concomitant discharges were also recorded in other axial (digastric m. and internal intercostal m.) and proximal limb muscles. The possible spino-bulbo-spinal mechanism of this cutaneous reflex is discussed.

Abdominal Muscles↗
PubMed1982

Peripheral neuropathies and tremor.

We studied 14 patients with tremor and acquired peripheral neuropathies of different origin. Minimal weakness was the only clinical finding common to all patients. Sensory changes, etiology, and course of the neuropathy varied. NO unique pattern of peripheral nerve histopathology could be demonstrated. Slowing of conduction velocity of Ia fibers was found, but the role played by impairment of sensory inputs remains unclear. Tremor associated with peripheral neuropathy seems to be due to enhancement of physiologic tremor by minimal weakness.

Adult↗
PubMed1981

[Electrophysiological and pharmacological analysis of L-dopa-induced dyskinesia and tardive dyskinesia (author's transl)].

Electrophysiological and pharmacological analysis of L-Dopa-induced dyskinesia and tardive dyskinesia (L.DD) due to neuroleptics was performed on 12 patients with Parkinson's disease and on 12 others with psychotic diseases. This analysis included the examination of spinal reflexes, monosynaptic H reflex, polysynaptic cutaneous reflex of the lower limb, muscular responses to passive movement [stretch reflex and shortening reaction (SR)] and the study of the motor response to a dopaminergic stimulus (I.V. injection of Piribedil (PBD), a dopamine agonist). There was no difference in EMG activity between L.DD and TD. Three EMG patterns can be distinguished: anarchic discharge pattern (ADA), tonic grouping discharge pattern (AST) and rhythmic burst pattern (ABR). PBD effects indicate a possible relationship between the EMG patterns and the sensitivity level of the motor dopamine receptors. During L-Dopa dyskinesia and tardive dyskinesia, the same changes in spinal reflexes were observed. Muscle tone tested by muscular responses to passive movement (shortening and myotatic reaction) was normal. Monosynaptic excitability explored by H/M ratio was within the normal range. In contrast, the polysynaptic nociceptive reflex was increased in every case. In Parkinsonian patients with L-Dopa dyskinesia, this pattern of the spinal reflexes was significantly different in comparison to the rigid phase. Intravenous infusion of PBD suppressed tremor and provoked the occurrence of dyskinetic activity in Parkinsonian patients with L-Dopa dyskinesia during the rigid phase. During the dyskinetic phase, as in tardive dyskinesia, PBD increases these phenomena and changes EMG activity in rhythmic pattern. It is suggested that L-Dopa dyskinesia and tardive dyskinesia can be determined by testing EMG activity, spinal reflexes and dopaminergic reactivity. There is evidence to suggest that the various types of involuntary abnormal movement represent a single entity, and that dopamine receptor supersensitivity may be involved.

Antipsychotic Agents↗
PubMed1980

Inhibition and synchronisation of tremor induced by a muscle twitch.

The effects of a muscle twitch on the tremor of the extensor indicis muscle and of the tibial anterior muscle have been recorded in 14 patients with essential tremor and in 10 patients with Parkinson's disease. The muscle twitch evoked by the electrical stimulation of the motor nerve inhibits the tremor and synchronises it. The mean duration of the inhibition is 92.1 +/- 6.8 ms for essential tremor and 183.0 +/- 16.8 ms for Parkinsonian tremor. This inhibitory phase lasts longer when the muscle twitch is induced during the second half of the Parkinsonian tremor cycle. The effects of voluntary contraction and of unloading suggest that inhibition and resetting of the tremor can be attributed to the autogenic mechanism induced by Ib fibres discharges. The presence of a rhythmic inhibition in the cycle of Parkinsonian tremor accounts for the longer duration of the inhibitory phase. In practice, these techniques aid the diagnosis of tremor in these two conditions, for example they assist the identification of low frequency essential tremor and of postural tremor in Parkinson's disease.

Aged↗
PubMed1979

[Abnormal movements induced by psychotropic drugs].

The abnormal movements produced by the psychotropic drugs are related to various physiopathological mechanisms: -- dopaminergic receptors blockage provokes neuroleptic parkinsoniam tremor; -- neuroleptic-induced tardive dyskinesia is similar to 1. Dopa abnormal movements; tardive dyskinesia is due to denervation induced hypersensitivity of the dopamine receptor; the 1. Dopa dyskinesia is probably related to altered responsiveness of these receptors due to an increase in dopaminergic receptor sensitivity; -- antidepressant drugs, particularly lithium, provoke tremor, alleviated by beta blockage; it is probably caused by an abnormal sensitivity of the beta noradrenergic receptors.

Chorea↗
PubMed1978

[Effects of percutaneous heterosegmental electric stimulation (electro-acupuncture) on the nociceptive flexion reflex in man].

A comparative study of the effects of electro-acupuncture of the HO KU point and of a placebo control point were carried out in man, taking as an objective test of pain the threshold of a pain induced flexion reflex. In the absence of electrical stimulation of the HO KU point, or of the control point, no variation in the painful reflex threshold was seen. This remained stable throughout the experimental session. However, electrical stimulation of the HO KU point resulted in a 115 p. 100 increase in the reflex threshold, whilst that of the control point resulted in an increase of 20 p. 100 in the threshold of the same reflex. These results are discussed on the basis of data in the literature.

Acupuncture Therapy↗
PubMed1978

[Inhibition in neurophysiology].

In Neurophysiology, inhibition is the effect of one neuron upon another tending to prevent it from initiating impulses. At cellular level, there are 3 modes of inhibition: postsynaptic inhibition, presynaptic inhibition and electrical inhibition. The formers are mediated by chemical transmitter. Examples of functional inhibition are presented. They explain its role in the coordination of movement and posture, in the integration of the sensation and in the behaviour.

Animals↗
PubMed1977

Pharmacological modulations on the nociceptive flexion reflex in man.

Pharmacological actions on the nociceptive flexion flexes of the hindlimb were investigated in 14 normal subjects. These reflexes were used as an index of pain and were recorded in the biceps femoris muscle, elicited by electrical stimulation of the ipsilateral sural nerve (RIII,su) and of the skin in the distal receptive field of this nerve (RIII,Cu). The ratio of the threshold of RIII,Cu/RIII,Su was calculated since it gives an indication on the mechanism and the efficacy of the drug. During control periods, the mean values of RIII,Su threshold (10 mA) and of RIII,Cu threshold (5 mA) remained stable, as RIII,Cu/RIII,Su threshold (50%). Cutaneous application of naphthalene provoked a decrease in the RIII,Cu threshold and relative pain threshold, whereas lignocaine increased them. No changes in the RIII,Su, threshold and relative pain were observed. The ratio RIII,Cu/RIII,Su threshold and relative pain were observed. The ratio RIII,Cu/RIII,Su was lowered to 10% with naphthalene and increased to 110% with lignocaine. Intravenous injection of acetylsalicylic acid increased only the RIII,Cu threshold and relative pain threshold. The ratio RIII,Cu/RIII,Su was 90% at the maximal effect of the drug. In contrast, pethidine provoked a decrease in the RIII,Su threshold and an increase in RIII,Cu threshold, parallel with an increase in pain threshold sensation. The ratio was found to be 190% at the maximal effect. Practical implications of these results, concerning a method for testing the efficacy and mechamisms of an analgesic, are then discussed.

Adult↗
PubMed1977

Reciprocal continuous inhibition in rigidity of Parkinsonism.

A reciprocal continuous inhibition by flexor on extensor muscles was proved during Parkinsonian rigidity. Extensor motoneurone excitability was tested by Hoffmann's reflex and flexor activity was altered by lidocaine anaesthesia of the peroneal nerve (PN). During PN anaesthetic block, a gradual increase of Hoffmann's reflex was noted. It was statistically significant at the 15th minute after lidocaine injection, and was maximum at the 30th minute. The reciprocal inhibition was considerable in 16 patients with Parkinsonism, as recorded before treatment. In normal subjects, it was small and non-significant. After one month's treatment with L-dopa at the usual therapeutic dose, this reciprocal inhibition greatly decreased in the same patients. The origin of this reciprocal continuous inhibition is discussed.

Adult↗
PubMed1977

[Rhythmic quadriceps myoclonia related to sarcomatous involvement of the crural nerve].

A case of rhythmic myoclonus of the quadriceps related to involvement of the crural nerve by a schwann-cell sarcoma of the thigh is reported. The rhythm of involuntary contractions varies between 35 and 300 per minute. The myoclonic jerks occur rhythmically in the quadriceps only during full extension of the knee. The jerks are inhibited during lengthening of the quadriceps by active or passive flexion of the knee. Clonazepam is very effective in controlling the myoclonus. It is suggested that the myoclonus is the consequence of a response of alpha-motoneurons of the spinal cord to the excitation of Ia fibers of the crural nerve by the tumor. This activation appears to be enhanced by descending excitation pathway and inhibited by activation of Golgi tendon organs of the quadriceps.

Adult↗
PubMed1976

Blink reflex in hemiplegia.

An electrophysiological study of the blink reflex was undertaken in 20 normal subjects and in 28 patients complaining of central facial palsy caused by unilateral hemispheral damage. In normal subjects, the latency, amplitude and organization of R1 and R2 responses are well known. Habituation of R2 responses occurred between 1 and 2 c/sec stimulation rate. R1 responses habituated at a higher stimulation rate (5 c/sec). In patients with unilateral hemispheral lesion, our results showed that changes in the blink reflex responses were bilateral. On the hemiplegic side the responses showed a decreased amplitude, while they were facilitated on the "normal" side. However, there was no change in latency of the two components of the reflex, on both sides. On the other hand, habituation of the late component occurred on the hemiplegic side for low stimulation rates: (0.5--1 c/sec), while on the "normal" side there was less habituation (3--4 c/sec), as compared with normal subjects. These results agree with those of experimental studies on cortical modulatory influences on brain-stem nuclei. They suggest a tactile origin of the two components of the blink reflex.

Adult↗
PubMed1976

Two patterns of results in polyneuropathies investigated with the H reflex. Correlation between proximal and distal conduction velocities.

The Hoffman (H) reflex of the soleus muscle has been used to study peripheral neurological disorders in 79 cases of chronic renal insufficiency prior to the initiation of haemodialysis, and in 94 cases of chronic alcoholism. In both groups, care was taken to ensure that the subjects examined could not be suspected of any other type of neuropathy. The results have been compared with those obtained in 42 normal subjects. The nerve conduction velocity in the reflex pathway was evaluated by an H index formula in which the conduction time (interval between M and H responses) is related to the length of the nervous pathway (a function of the subject's height). This method demonstrated a marked reduction in the conduction velocity of the proximal parts of the peripheral nerves, in both uraemic and alcoholic subjects. The maximal amplitude of the reflex response was evaluated in relation to the maximal amplitude of the direct motor response (H max/M max). It was shown that this ratio diminishes very greatly and very rapidly in the course of alcoholic polyneuritis, while, at comparable conduction velocities, the amplitude of the reflex response is much less changed in chronic renal insufficiency. These results prove that there is a noteworthy difference between uraemic and alcoholic polyneuropathy. Its significance is discussed in the context of currently knwon histopathological and electrophysiological data on the polyneuritides. From a practical point of view, the H reflex appears to be an effective tool for the investigation of peripheral neuropathy in man.

Adolescent↗
PubMed1976

[Effect of psychotropic drugs on physiological variations and psychometric scores during attention].

A study was undertaken to determine the activation profile and psychometric performances in 10 adult volunteer subjects. The activation profile was evaluated by measuring heart and respiratory rates and also the H reflex (motor response). Psychometric performances during two attention tests were measured by the subjects' scores. The subjects were then submitted to a per os psychotrope drug treatment at a liminar therapeutic dose. Psychometric performances were decreased in subjects given a strong psychoactivator drug (amphetamine, genozolone), while they could be increased to an optimal level with a less active psycho-activation (Pyrisuccidéanol). Under the same conditions, the motor response, tested using the H-reflex, varied in the same way as the psychometric performance curve. However, the cardiac and respiratory rates show changes induced by the administered drugs. These results show some conditions were performance and activation are dissociated under the effect of psycho-active drugs.

Adult↗