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Biomedical subjects

M De Mattei

Publications and source records attributed to M De Mattei.

32 records · Page 2Linked to original sources
PubMed1985

[Tardive dyskinesia].

Neuroleptic drug treatment can produce tardive dyskinesia of which the incidence, risk factors, clinical characteristics and problems of differential diagnosis are described. Possible therapeutic approaches are then considered in the light of the hypothesis that the condition may derive from a physiopathological hypersensitivity of the dopamine receptors.

Antipsychotic Agents↗
PubMed1984

[Neuroendocrine correlations in the pathogenesis and pathology of Parkinson disease].

In Parkinson's disease the decrease of dopamine in the nigro-striatal pathway is allied to modifications of other neuromodulation systems. The biochemical disorder of cholinergic, gabaergic and epinephrinergic pathways is present. Moreover the alteration of certain neuropeptides such as endorphins or enkefalins have been found. The Authors analyse the functional repercussions of these important biochemical modifications in the T.I.D.A. tract. In particular the variation of PRL synthesis and secretion due to dopamine deficiency during basal conditions and after pharmacological treatment is discussed.

Benserazide↗
PubMed1983

[An unusual case of focal symptomatology, monoparalysis of the abducent nerve and vertebrobasilar ectasia].

Ectasia of the basilar artery is a well-defined form with a complicated clinical symptomatology. Angiography has made it possible to show that its pathogenesis springs from marked changes in the diameter and length of the artery. A case is presented in which the usual array of symptoms was replaced by homonymous diplopia only. It showed that CT can on its own provide information both for diagnosis of the specific lesion, and for assessment of changes in the bone structures, the cerebral parenchima, and the ventricular system.

Abducens Nerve↗
PubMed1983

Preliminary experiences with "real-time" intraoperative ultrasonography associated to the laser and the ultrasonic aspirator in neurosurgery.

Twelve cerebral lesions were operated upon with various laser sources (carbon dioxide, neodymium-yttrium-argon-garnet, and argon) and with an ultrasonic aspirator utilizing the intraoperative "real-time" ultrasonography. With the last method, the tumor was imaged just as well through the intact dura mater as on the brain surface itself, allowing a precise localization of deep intracranial lesions. A sharp selectivity on the healthy tissues is, in this way, achievable to reach the tumor, which is successively removed with the laser and ultrasonic aspirator checking the surgical maneuvers on the visual control of the ultrasonograph.

Adult↗
PubMed1982

Preliminary observations on the neuromelanic pigment in the substantia nigra nucleus of the cat.

The AA. study the behaviour of neuromelanic pigment in the substantia nigra of cats' mesencephalon. To this aim they suppress a first group of animals with MgSO4; a second group with a substance whose action is narcotic and curare-like. They carry out the observations on mesencephalon microtomic sections, some stained with hematoxylin, some treated with PAS reaction and some with Sudan Black. The results are: 1)- in the perikaryon of substantia nigra pars compacta neurons of cats suppressed with MgSO4, the pigment, absent in the early age of life, appears in adult age. It is characterized by brownish-yellow granulations, either scattered or clustered together. This finding is substantially similar to that observed in dogs' substantia nigra. 2)- The substantia nigra neurons of the mesencephalon taken from cats suppressed with a curare-like substance, appear instead, almost wholly, without the peculiar neuromelanic granulations. However intracytoplasmic bodies stained with hematoxylin and PAS positive, can be observed. In order to establish the morphological and histochemical events which occur in the substantia nigra neurons in depigmentation induced in this way the AA. consider further investigations absolutely necessary.

Aging↗
PubMedDate not supplied

Inadequacy of transcranial magnetic stimulation in the neurophysiologic assessment of Bell's palsy.

Transcranial magnetic stimulation is a non-invasive procedure which to stimulate the brain cortex and the peripheral nerve pathways. A new technique was recently introduced to record the muscle action potential of facial muscles by means of transcranial magnetic stimulation of the facial nerve. The experimental data that was obtained indicate that this technique allows to stimulate the facial nerve above the stylomastoid foramen: a greater tract of the nerve can therefore be explored than what was possible with the traditional electrical stimulation at the mastoid. Until now no comparison data was available on the clinical usefulness of the two methods. We decided to study 14 normal controls and 26 patients suffering from unilateral idiopathic facial palsy (Bell's palsy) and to submit these two groups to magnetic transcranial stimulation and electrical stimulation of the facial nerve in the mastoid region, to the purpose of observing where the nerve is stimulated by the magnetic impulse and which of the two techniques can be of accurate prognostic value in the study of the evolution of the clinical lesion. The electromyographic responses were elicited by the electrical stimulation at the mastoid and by transcranial stimulation after positioning the coil on the parieto-occipital scalp. A recording was taken from the ipsilateral orhicularis oculi muscle utilising two cupped electrodes. The latency and the amplitude of the compound muscle action potential were measured bilaterally in order to compare the results obtained on both the affected and the healthy sides. The patients were scheduled to two neurophysiological and clinical evaluations at about 30 days interval one from the other: the first test was not carried out before 20 days from the onset of the deficit; further clinical examination was carried out only 6 months later. The analysis of the results obtained in the normal controls submitted to transcranial magnetic stimulation indicate that the nerve is activated at the point where it originates from the brainstem. The study carried out showed that transcranial magnetic stimulation of the facial nerve, does not provide data which can be correlated to the clinical situation observed at the time of the study; furthermore, transcranial magnetic stimulation does not supply any prognostic data on the clinical evolution of the lesion.

Action Potentials↗
PubMedDate not supplied

[Transcranial magnetic stimulation of the facial nerve: evaluation of a new method in neurophysiological study of Bell's palsy].

Transcranial magnetic stimulation is a new technique used to stimulate brain areas as well as peripheral nerves in healthy, waking persons. To date this technique has appeared safe. The aim of the present study was to assess the clinical application of this method in patients with Bell's palsy. Electromyographic responses were elicited by electrical and magnetic transcranial stimulation of the facial nerve in 26 patients affected by Bell's palsy. Electrical stimulation: stimuli of 0.1 ms duration, and up to 15 V, were delivered through surface electrodes set 2.5 cm apart over the facial nerve at the stylomastoid foramen. Magnetic stimulation: the coil was placed tangent to the parieto-occipital surface of the scalp. The stimulus intensity was then increased stepwise until a supramaximal response was obtained. Recording: the focal recording electrode was placed ipsilateral to the side stimulated over the superior orbicularis oculi; the reference electrode was placed over the nasal bone. The patients were tested with two neurophysiological determinations: the first 15-30 days from the onset of the palsy; the second 30-60 days after the first. A clinical follow-up was performed six months after the second determination. The results indicate that, contrary to traditional electroneurography, transcranial magnetic stimulation is not able to supply useful neurophysiological indications in patients with Bell's palsy. Although the absence of compound muscle action potential upon stimulation of the side with the lesion did demonstrate some impediment to conduction, it did not have any prognostic value since it was also present in patients who were clinically well at the time of the second check-up.

Adult↗
PubMedDate not supplied

Preliminary spectroscopic studies on the neuromelanic pigment of human substantia nigra nucleus.

The neuromelanic pigment obtained from human mid-brain Substantia Nigra Nucleus was studied by I.R. spectroscopy and compared with synthetic dopamine melanin. Natural neuromelanin and synthetic dopamine melanin show very similar features in two characteristic I.R. absorption regions: 1400 cm-1, typical of phenolic OH groups, and 3200 cm-1 band, typical of aminic groups. Natural mid-brain neuromelanin shows a different absorption in the I.R. region at 3000 cm-1 and in the 1300-900 cm-1 range probably due to the presence of lipidic residues bound to the molecule. The results of the U.V. spectroscopic analysis suggest a correlation between the optical density of human neuromelanic pigment and the different ages of the subjects providing the specimens.

Adult↗