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Biomedical subjects

G F Rossi

Publications and source records attributed to G F Rossi.

At least 55 records · Page 3Linked to original sources
PubMed1987

Neurological improvement in chronic ischemic stroke following surgical brain revascularization.

50 patients suffering from completed ischemic stroke in the carotid territory for at least two months (17 mild, 31 moderate, 2 severe strokes) underwent extra-intracranial arterial bypass surgery. Neurological improvement was obtained in 43 cases; it persisted in time in 40 cases. Quantitative evaluation of motor performance in 21 patients showed that the degree of improvement was highly significant. Several factors strongly indicate a causal relation between surgical revascularization and neurological restoration. The positive surgical result is strictly dependent on correct patient selection and, in particular: i) on the documentation of local hemodynamic insufficiency; ii) on the occurrence of transient neurological (and to a certain extent EEG) improvement following hyperbaric oxygenation. The latter can also provide reliable information on the minimum degree of improvement to be expected from surgery.

Adolescent↗
PubMed1987

Intracranial pressure behaviour and its relation to the outcome of surgical CSF shunting in normotensive hydrocephalus.

Twenty-four patients with suspected normotensive hydrocephalus were surgically treated by cerebrospinal fluid (CSF) ventriculoatrial or peritoneal shunt. The results of surgery were considered in relation to clinical history and different diagnostic examinations: pneumoencephalography, CT scan, isotope cisternography, transfer from CSF to blood of isotope-labelled serum albumin, constant infusion manometric test, intraventricular pressure recording. Intracranial pressure (ICP) was analysed during both resting conditions and spontaneously (REM phase of sleep) or artificially induced (jugular compression) increases. The ventricular enlargement (as shown by CT scan) and the slope of the intracranial elastance (the ratio of the differences between the maximum and minimum values of pulse ICP and the correspondent values of the diastolic ICP under the same dynamic conditions) provided the most reliable data for diagnosis and surgical prognosis.

Cerebrospinal Fluid Shunts↗
PubMed1986

Spinal cord stimulation affects the central mechanisms of regulation of heart rate.

The effect of spinal cord stimulation (SCS) on heart rate (HR) was studied in 25 patients without cardiological symptoms, who were undergoing SCS for various reasons. HR at rest significantly decreased during SCS. Physiological and pharmacological maneuvers of sympathetic and parasympathetic activation or blockade before and during SCS indicate that SCS interferes with the central mechanisms of regulation of HR mainly by inducing a functional sympathectomy, and that such an effect is mediated by an action on spinal cord ascending fibers.

Adult↗
PubMed1986

Electrocerebral and behavioural analysis of systemic kainic acid-induced epilepsy in the rat.

A systematic study of the epileptic electrocerebral and behavioural effects of intraperitoneal kainic acid (KA) was carried out in 92 adult albino Wistar rats. The doses of KA ranged from 3 to 20 mg/kg. Chronic epidural and stereotaxically implanted cerebral electrodes (hippocampus, amygdala and thalamic reuniens nucleus) were used. All animals were studied for 5-12 after KA injection; in 20 animals the study was extended to 10 days. Sporadic spiking was the early EEG manifestation of epilepsy. Subsequently, ictal discharges were recorded. Both types of epileptic discharges were at first focal and then generalized. In the majority of animals, both types of electrographic events were first recorded from the limbic structures; in 7 to 35% of cases, however (depending on the dose of KA), they first appeared in the neocortex. Two groups of behavioural manifestations were observed: searching, staring spells, wet-dog shaking and gnawing: these could be independent of any recorded EEG epileptic event; and rearing, head nodding, forelimb clonus and tonic-clonic spells: these were always related to EEG epileptic activity, mostly generalized discharges. Spiking was still recorded from various structures 10 days after the KA injection.

Animals↗
PubMed1985

Peripheral nerve autografts to the injured spinal cord of the rat: an experimental model for the study of spinal cord regeneration.

Regenerated central axons have been shown experimentally to penetrate in peripheral nerve segments transplanted into the spinal cord (SC). However, if the nerves are transplanted between the stumps of the transected SC regeneration is impaired by local cavitation and scarring. Our experiment was designed to study whether nerve grafts bridging a severe transverse SC lesion might provide to central regenerating axons a pathway to by-pass the lesion. To this purpose, 2 segments of autologous peripheral nerves were inserted through small dural openings into dorsal longitudinal myelotomies rostral and caudal to a transverse SC lesion in rats. Eighteen weeks after transplantation a large number of well myelinated fibres filled the grafted nerves. Only a few of these fibres, however, could be followed into the SC; they were located in the outer layers of the dorsal white matter. The problems regarding the origin and destination of these fibres are discussed.

Animals↗
PubMed1985

Epileptogenic cerebral low-grade tumors: effect of interstitial stereotactic irradiation on seizures.

15 patients with various types of surgically inaccessible epileptogenic cerebral neuroepithelial tumors were treated with stereotactic interstitial irradiation. Epilepsy was improved in all cases, being abolished in 6 and markedly reduced in another 7. The effects which became apparent soon after the radioisotope implant persisted. Possible mechanisms of the phenomenon are discussed.

Adolescent↗
PubMed1984

Interictal epileptic activity during sleep: a stereo-EEG study in patients with partial epilepsy.

Cerebral electrical activity was recorded through chronic stereotactically implanted electrodes in 19 epileptic patients suffering from different types of severe and medically refractory partial seizures and who were considered for surgical treatment. 213 brain sites, in all cerebral lobes, in neocortical as well as in archicortical structures, were explored. The behaviour of the interictal spiking across wakefulness and nocturnal physiological sleep was analysed, using automatic elaboration. (i) Spike rate is affected by the occurrence of sleep and by the passage from one sleep phase to another. The degree and direction of the phenomenon differ remarkably in the various patients and, in the same patient, in the different cerebral sites explored. Generally, interictal spiking increases at the beginning of sleep, reaches its maximum during the deep non-REM phases and returns to a level slightly lower than that in wakefulness during REM. (ii) The nocturnal spike rate is hardly influenced by spike location. In most cases, however, the variations recorded during sleep are more significant in the frontal regions than elsewhere. (iii) Spike rate across wakefulness and sleep is affected by the local level of epileptogenicity: spiking variations are less in the most epileptogenic cerebral zone (identified by the origin of the seizure discharges and by the disappearance of seizures following its surgical removal) than elsewhere. The physio-pathological meaning and the diagnostic value of these findings, and particularly of the peculiar stability or autonomy of the electrical epileptic activity of the most epileptogenic cerebral zone, is discussed.

Adolescent↗
PubMed1981

Sodium nitroprusside and intracranial pressure.

The effects of sodium nitroprusside on intracranial pressure were studied in 10 patients, candidates for surgical treatment, prior to anaesthesia. Blood pressure was lowered to at least 50% of its initial value. In all cases, at the beginning of nitroprusside infusion, both the mean and the pulse intracranial pressures increased (mean increase: 83.2% of the initial value). At a certain moment, however, while the blood pressure continued to fall, the mean intracranial pressure did not increase any more; on the contrary, it decreased. On the other hand, in many cases, the pulse intracranial pressure continued to increase. No neurological or EEG changes were observed. The possible changes of cerebral circulation and CSF dynamics underlying the phenomena observed are discussed.

Adult↗
PubMed1980

Epidural spinal cord stimulation for the treatment of neurogenic bladder.

The effect of percutaneous epidural spinal cord stimulation on neurogenic bladder has been evaluated on the basis of objective clinical and urodynamic criteria. Seven patients suffering from stable bladder and sphincter dysfunction due to spinal cord diseases of different causes of non-evolutive nature were examined. In some of them chronic pain or substantially improved micturition in six of our seven patients. Complete or almost complete relief of bladder spasticity, marked increase of bladder capacity, and reduction or abolition of residual urine were recorded. The beneficial effect on bladder and sphincter function is strictly dependent on the stimulation, though it can outlast it. It requires some weeks to reach its maximum. It is still obtained after 22 months of treatment (longest present follow-up). No changes of straital activity and detrusor reflex were produced by spinal cord stimulation in two additional patients, treated for chronic pain but having intact bladder function.

Adult↗