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Biomedical subjects

L Parmeggiani

Publications and source records attributed to L Parmeggiani.

At least 19 recordsLinked to original sources
PubMed1995

Frontal inhibitory spike component associated with epileptic negative myoclonus.

The aim of this study was to characterize paroxysmal EEG activities associated with epileptic negative myoclonus (ENM) in an epileptic patient presenting with ENM. ENM was predominant in the right upper limb and was correlated to a spike in the left central region. Spikes associated with ENM (SaENM) and spikes unrelated to ENM (SuENM) were identified by the temporal relation between the left central spike and the EMG silent period in the right wrist extensor. SaENM showed a significantly longer duration than SuENM (128 +/- 27 msec versus 92 +/- 21 msec, respectively; P < 0.01). SaENM and SuENM were submitted to spike averaging and topographic mapping. Spike averaging was performed averaging the EEG 640 msec before and after the peak of the spike. Both averaged SaENM and SuENM consisted of a negative spike with highest amplitude at C3 and similar topographic characteristics. The discriminant feature between the two types of spikes was the presence, in averaged SaENM, of a second smaller negative spike, 40 msec after the peak of the spike at C3, whose maxima were distributed over the left frontal region. We labeled this second spike as ENM-related component. We conclude that, in our patient, ENM was associated with a frontal cortical potential suggesting the involvement of frontal areas in the generation of negative myoclonus.

Adult↗
PubMed1995

Locating VEP equivalent dipoles in magnetic resonance images.

Pattern-reversal and diffuse flash visual evoked potentials (VEPs) were obtained from 4 normal adults. A spatiotemporal dipole model was used to determine the location of the hypothetical equivalent dipoles consistent with the scalp distribution of the VEPs. Equivalent dipoles representing ERG and VEP activity were placed within 3-D magnetic resonance images of the brain. Most of the localization error appeared to be due to inadequate sampling of the potential field in frontal and occipital areas by the 10-20 system of electrode placement. Locating electrophysiologic dipoles within magnetic resonance images of brain structure allows evaluation of dipole localization techniques.

Adult↗
PubMed1994

Dipole source localization in a case of epilepsia partialis continua without premyoclonic EEG spikes.

A 72-year-old woman with epilepsia partialis continua (EPC) of the right foot is presented. Rhythmic myoclonic jerks were localized to the 1st and 2nd toes of the right foot and persisted for 72 h. EEG/video monitoring did not show any epileptiform transient in association with myoclonic jerks. MRI and MRA demonstrated an arterio-venous malformation involving the left fronto-parietal parasagittal area. Using the EMG signal from the myoclonic jerk we back-averaged the EEG 640 msec before and after the onset of the twitch. A negative-positive deflection was observed preceding the myoclonic jerks by 128-188 msec. Voltage topographic mapping showed a negative maximum in the left centro-parietal region. A multiple spatio-temporal dipole model was applied to the back-averaged deflection preceding the myoclonus. The patient's MRI was used to determine the center of the best fitting sphere, and the model was corrected accordingly. The best dipole solution consisted of 3 dipoles localized in the parasagittal frontal cortex, in the location of the motor representation for the foot. The utilization of a combined technique of back-averaging from the myoclonus and dipole source localization supported the epileptogenic etiology in this case.

Aged↗
PubMed1992

Slowly progressive familial dementia with recurrent strokes and white matter hypodensities on CT scan.

We describe 2 normotensive sisters presenting slowly progressive dementia associated with acute or subacute focal neurological symptoms, unilateral or bilateral motor signs, and dysarthria. Their father, who died in the seventh decade, had a similar clinical picture. Computerized axial tomography (CT) scan of the head showed symmetrical hypodensities in the periventricular white matter and mild to moderate hydrocephalus. In these patients a diagnosis of Binswanger's disease was based on the clinical features supported by white matter changes on CT scan. Our study suggests that genetic factors may play a role in the etiology of Binswanger's disease.

Adult↗
PubMed1989

Caudal migration of the Günther vena caval filter.

Two cases of downward migration of the Günther vena caval filter are reported. Migration resulted in recurrent pulmonary embolism in one case; in the second, partial thrombosis of the filter precluded retrieval. Both patients were treated successfully by placement of a second Günther filter in the infrarenal vena cava. Until more experience with this filter is available, the authors recommend use of the 30-mm filter in medium- and large-size venae cavae. Radiographs should be obtained to check the position of the filter immediately and 1 week after placement. In addition anticoagulative therapy should be continued whenever possible.

Aged↗
PubMed1987

Alpha interferon in the treatment of symptomatic myelofibrosis with myeloid metaplasia.

2 patients with myelofibrosis and myeloid metaplasia had symptomatic splenomegaly and were treated with interferon alpha-2c (IFN alpha-2c). The splenic pain and pressure symptoms disappeared, accompanied by a decrease in the size of the spleen. However, the peripheral blood count worsened and no improvement in the bone marrow fibrosis could be observed.

Humans↗
PubMed1984

[Aggressive therapy in a case of Moschowitz syndrome].

We report a case of thrombotic thrombocytopenic purpura which responded spectacularly to therapy consisting of corticosteroids, prostacyclin, high doses of platelet anti-aggregants and repeated plasma exchange. There was no anomaly of the von Willebrand factor VIII. The number of schizocytes and the lactate dehydrogenase level are as important as the beta-thromboglobulin dosage.

Adrenal Cortex Hormones↗
PubMed1984

[1:1 atrial flutter in an elderly patient: one of the methods of discovering Wolff-Parkinson-White syndrome. Apropos of a case in an adult].

Atrial flutter with 1:1 atrioventricular conduction giving rise to a ventricular rhythm of 240/min in an 80 year old man was the first sign of the Wolff-Parkinson-White syndrome; all previous electrocardiogrammes had shown no evidence of pre-excitation. It was only on the fifth day of hospitalisation that the ECG showed a short PR interval with a delta wave. This case illustrates that: --all supraventricular arrhythmias with abnormally high ventricular rates (over 220/min in adults) should alert to the possibility of an accessory atrioventricular pathway; --rapid atrioventricular conduction may be the first sign of an accessory pathway; --the differential diagnosis lies between an accessory atrioventricular pathway and an atriohisian tract; --digitalis, which may shorten the refractory period of the accessory pathway, is contraindicated in patients with a Kent bundle.

Aged↗
PubMedDate not supplied

Liver system. V. Activation-extinction line of cyclic hepatocyte activities.

The excitation-extintion line of hepatocytes from an inert state towards the stabilization of a given activity is described. Within the cell, the switching on of any given activity is a competitive process among different activities. The process is driven by the influence field created in the environment of the Rappaport acinus by sinusoidal blood which changes its characteristics during its passage from the portal zone to the central vein. Every step of the excitation-extintion pathway follows the so-called law of autoisodiasostasis (AIS), i.e. it is characterized by an oscillatory motion between restoring (homopoiesis or HP) and working (homeorhesis or HR) states. Since the cyclical bistable equilibrium of AIS characterizes all conditions of hepatocyte activities, the AIS cycle can be defined a limit cycle.

Humans↗