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Biomedical subjects

M R Caccia

Publications and source records attributed to M R Caccia.

At least 37 records · Page 2Linked to original sources
PubMed1976

Effects of threshold, low frequency, long lasting stimulation on single motor unit electrical responses from the extensor digitorum brevis muscle in normal and myasthenic subjects.

The authors studied the recruitment of motor units of EDB muscle by long lasting threshold intensity stimulation at 1 c/sec of external popliteal nerve at the ankle in healthy subjects and in myasthenic patients. In the healthy volunteers, at steady intensity of threshold stimuli, maximum number of motor units never exceeded 5--6 electrical increments with a final incremental response of constant amplitude during 60 min of stimulation. In myasthenic patients, both an early exhaustion of threshold motor units and a marked facilitation phenomenon occurred with massive recruitment of incremental responses, while in a small number of cases no changes were observed. These data are discussed in the light of various morphofunctional hypotheses regarding the localization of the myasthenic impairment.

Edrophonium↗
PubMed1976

Spinal evoked responses recorded from the epidural space in normal and diseased humans.

In 22 subjects, including normal subjects and patients with radicular or spinal cord lesions, the authors studied the spinal evoked responses recorded extradurally after stimulating mixed limb nerves. The responses obtained are discussed with particular reference to the clinical value of the changes in amplitude and latency of the spinal evoked potential with particular lesions.

Adolescent↗
PubMed1976

Axonal excitability and motor propagation velocity of peripheral nerves in patients with acute vascular lesions of the brain.

From measurements of maximum and minimum motor nerve propagation velocity and neuronal excitability we conclude that there is a functional loss of motor units and distal nerve "dying back" in persons affected with unilateral acute cerebral vascular lesions. The study also suggests that transynaptic degeneration affects the lower motor neurone function on both sides.

Acute Disease↗
PubMed1975

Nerve supply and experimental myotonia in rats.

20, 25-Diazacholesterol does not induce myotonia in denervated mammalian skeletal muscle, and cordotomy also renders the muscles resistant to the induction of myotonia. Denervation of muscle already rendered myotonic, has no effect on the intensity of the phenomenon. Finally, tenotomy and posterior rhizotomy leave the myotonic activity in the "deafferentated" muscles unchanged. These findings are discussed in relation to "trophic" influences of the motor pathways on the postsynaptic structures of skeletal muscle.

Action Potentials↗
PubMed1975

Electrophysiological evidence for a neurohormonal dependence in the changes of the late glabellar response in man.

In 19 normal adults reserpine administration induced significant changes in the parameters of the second glabellar response (R2): shortening of the latency and duration; decrease of the excitability threshold and complete blockade of the physiological habituation of R2 to the electrical and mechanical stimulation. No changes in the first response (R1) were observed. All the R2 changes disappeared within about 3 days of drug administration. The Parkinson-like effect of reserpine on the glabellar reflex is discussed in the light of a neurohormonal hypothesis in the control of the polysynaptic pathways biasing R2.

Adolescent↗
PubMed1975

Clonazepam in facial neuralgia and cluster headache. Clinical and electrophysiological study.

Clonazepam seems to be an effective drug in idiopathic trigeminal neuralgia. Electrophysiological investigations support the idea that this neuralgia is due to a loss of central inhibition. During the first 1-2 weeks of treatment marked drowsiness is observed in the majority of cases. In one case, presence of a synergism between Clonazepam and L-dopa+ inhibitor was also observed.

Adult↗
PubMed1973

Cutaneous reflexes in small muscles of the hand.

A study has been made of the responses of motoneurones innervating small muscles of the hand to electrical and mechanical stimulation of the skin. Both excitatory and inhibitory effects could be observed in the same muscle after a single stimulus to a given area of skin. The earliest excitatory and inhibitory responses are probably mediated by group III and the smaller group II afferent nerve fibres. A later inhibition results from activity in the larger group II fibres which are connected to cutaneous mechanoreceptors, especially those in the tips of the fingers and thumb. This late inhibitory reflex may operate through the fusimotor system. The possible roles of these reflexes are discussed in relation to previous investigations in man and the cat.

Action Potentials↗