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Biomedical subjects

M G Marciani

Publications and source records attributed to M G Marciani.

At least 37 records · Page 2Linked to original sources
PubMed2000

Gabapentin as add-on therapy in focal epilepsy: a computerized EEG study.

OBJECTIVES: Gabapentin (GBP) possesses a well documented clinical efficacy in those types of focal epilepsy otherwise resistant to conventional antiepileptic drugs (AEDs); on the basis of this, it appears important to investigate the drug effects on the EEG epileptiform and background activity. METHODS: Twenty-five patients with cryptogenic or symptomatic partial epilepsy resistant to conventional AED treatment were included in the study. All patients underwent long-term video-EEG recordings before and after GBP addition (900-1200 mg/day). RESULTS: Quantitative analysis of the interictal EEG paroxysms revealed that GBP had no effect on the rate of occurrence of interictal and ictal EEG abnormalities. GBP was active in delimiting the spatial extent of the interictal spiking activity in those patients who displayed a significant reduction (> or =50%) in seizure occurrence (32% of the patients). EEG background activity recorded under rest condition from 18 out of 25 epileptic patients, before GBP therapy, was characterised by a higher content of the slow spectral components (delta and theta) with respect to control subjects. After GBP addition, the increase of theta relative power was also evident during task performance. CONCLUSIONS: These findings suggest that GBP does not interfere with the generation of interictal EEG spiking while it appears to reduce the susceptibility to seizures concomitantly with a limiting effect on the spiking activity spatial extent. The utilization of GBP in controlling focal seizures is reinforced by the absence of negative influence on cognitive functioning.

Acetates↗
PubMed2000

Effects of lamotrigine on nocturnal sleep, daytime somnolence and cognitive functions in focal epilepsy.

OBJECTIVES: The aim of our study was to evaluate possible changes in nocturnal sleep, daytime somnolence and cognitive functions induced by add-on therapy with lamotrigine (LTG). MATERIAL AND METHODS: Thirteen patients affected by seizures resistant to common antiepileptic drugs (AEDs) underwent nocturnal polysomnographic monitorings, daytime somnolence evaluations and a neuropsychological battery before and after 3 months of treatment with LTG. RESULTS: With LTG therapy we observed a significant increase in REM sleep and a significant reduction in the number of entries into REM and stage shifts. No significant correlation was observed between the decrease in nocturnal epileptiform activity and the increase in REM sleep. Other sleep parameters were unmodified. No significant changes were observed in daytime somnolence and in cognitive performances. CONCLUSION: LTG may produce positive effects on epileptic seizures and interictal abnormalities without interfering negatively on REM sleep, with improvement of sleep stability and without changes in daytime somnolence and neuropsychological performances. For these reasons it could be an important drug for improving epileptic patients' quality of life.

Adolescent↗
PubMed2000

Linear classification of low-resolution EEG patterns produced by imagined hand movements.

Electroencephalograph (EEG)-based brain-computer interfaces (BCI's) require on-line detection of mental states from spontaneous EEG signals. In this framework, surface Laplacian (SL) transformation of EEG signals has proved to improve the recognition scores of imagined motor activity. The results we obtained in the first year of an European project named adaptive brain interfaces (ABI) suggest that: 1) the detection of mental imagined activity can be obtained by using the signal space projection (SSP) method as a classifier and 2) a particular type of electrodes can be used in such a BCI device, reconciling the benefits of SL waveforms and the need for the use of few electrodes. Recognition of mental activity was attempted on both raw and SL-transformed EEG data from five healthy people performing two mental tasks, namely imagined right and left hand movements.

Adult↗
PubMed2000

Effect of anticonvulsants on nocturnal sleep in epilepsy.

Our objective was to determine, in three separate studies, the effects of controlled-release carbamazepine (CBZ-CR), lamotrigine (LTG), and gabapentin (GBP) on nocturnal sleep in epilepsy. Antiepileptic drugs (AEDs) control seizures and also modify hypnic structure. Despite widespread clinical use, their effects on sleep are not well known. PSG was performed in all three studies as follows: CBZ-CR: at baseline, after initial administration of CBZ-CR 400 mg, and after 1 month of CBZ-CR treatment (400 mg BID) in a sample of seven temporal lobe epileptic (TLE) patients. Results were compared with those of nine healthy volunteers; LTG: at baseline, after 3 months of stable treatment with LTG (300 mg/day); GBP: at baseline, after 3 months of stable treatment with GBP (1800 mg/day). Significant findings are as follows for each study. The acute administration of CBZ-CR increased number of stage shifts, reduced REM sleep, and increased REM sleep fragmentation. In the TLE group, these effects were almost completely reversed after chronic treatment. LTG increased REM sleep, reduced number of entries into REM sleep, decreased number of phase shifts, and decreased percentage of slow-wave sleep. GBP increased REM sleep percentage, increased mean duration of REM periods, reduced number of awakenings, and reduced stage 1 sleep percentage. We conclude that CBZ-CR disrupts REM sleep, but only during acute administration. LTG and GBP improve sleep stability while reducing seizures.

Acetates↗
PubMed1998

Changes in cerebral blood flow velocities during childhood absence seizures.

A simultaneous recording of mean flow velocity in the right middle cerebral artery by transcranial Doppler ultrasonography and electroencephalographic activity was performed in 5 children with multiple daily typical absence seizures. Twenty-eight absence episodes were recorded. Mean flow velocity increased gradually a few seconds before the clinical and electroencephalographic manifestations of each seizure and reached the maximum values (range of increase: 25.5-42.8% with respect to baseline) within 2-3 seconds from their onset. This increase was then followed by a fast reduction in flow velocity, with the lowest levels (range of decrease: 30.8-44.0% with respect to baseline) recorded within 4-6 seconds from the end of each absence seizure. These findings suggest that changes in cerebral blood flow and activity are quite complex during absence seizures and that they do not fully correlate with clinical and electroencephalographic manifestations.

Analysis of Variance↗
PubMed1998

Changes of the EEG paroxysmal pattern during felbamate therapy in Lennox-Gastaut syndrome: a case report.

We report a case of a 43-year old woman with Lennox-Gastaut syndrome who exhibited atypical absence seizures, atonic seizures and generalized toniclonic seizures which were not controlled by antiepileptic drug (AED) treatment. Because of this, felbamate (FBM) (1800 mg per day) was progressively added to the pre-existent therapy. The patient underwent a 24-hour-video-EEG monitoring before and after 4 months of FBM therapy. Analysis of the video-EEG signal recorded during wakefulness revealed the presence of ictal activity represented by repetitive, bilateral, slow spike and wave bursts underlying atypical absence seizures; the ictal activity occurring during non-REM sleep was characterized by runs of bilateral, rapid, high-voltage spikes followed by slow spike and wave complexes corresponding to brief tonic seizures. FBM therapy induced disappearance of the EEG ictal slow, spike and wave complexes leaving rather unaffected the runs of spikes. Computerized analysis of both the EEG background activity and the sleep structure displayed a better organization of the global cerebral rhythms under FBM treatment. Our findings suggest a selective effect of FBM on the ictal atypical spike and wave pattern. The differential effect of FBM on ictal patterns may be a reflection of a different action on the excitatory and inhibitory systems.

Adult↗
PubMed1997

Nocturnal sleep and daytime somnolence in untreated patients with temporal lobe epilepsy: changes after treatment with controlled-release carbamazepine.

PURPOSE: To define sleep disturbances in patients with temporal lobe epilepsy (TLE) and explore the association between carbamazepine (CBZ) therapy, sleep, and daytime somnolence. METHODS: We recorded nocturnal polysomnography and measured subjective and objective daytime somnolence in a group of newly diagnosed TLE patients, who had no evidence of anatomic brain lesion on neuroimaging and had never been treated before. Recordings were performed at baseline, after the initial administration of 400 mg CBZ-controlled release (CR) and after 1 month of treatment (400 mg twice daily b.i.d.). The findings were compared with those of a group of young healthy volunteers, both at baseline and after the first administration of CBZ. The chronic effect of CBZ-CR treatment was evaluated only in TLE patients. RESULTS: At baseline, nocturnal sleep patterns of TLE patients did not show marked alterations when the influence of seizures, cerebral lesions, and drugs had been ruled out. In both the TLE and the control groups, initiation of CBZ therapy provoked a reduction and a fragmentation of rapid eye movement (REM) sleep and an increase in the number of sleep stage shifts. In the TLE group, these effects were almost completely reversed after 1 month of treatment, and no significant difference was noted between baseline condition and long-term follow-up. With regard to daytime sleepiness, initial administration of the drug caused an increase in objective sleepiness only in the control group. Subjective sleepiness was higher in the control group than in the TLE group but was not modified by the drug. CONCLUSIONS: We conclude that CBZ-CR has negative effects on REM sleep during initial administration but chronic treatment does not significantly modify nocturnal sleep or daytime somnolence.

Adult↗
PubMed1997

Movement-induced seizures: a case report.

Reflex seizures induced by movement are typically evoked by sudden or unattended motor actions. However, tonic seizures may also be triggered by slow movements as observed in nonketotic hyperglycemia or in "praxis-induced epilepsy." We report the case of a young, nondiabetic patient affected by recurrent partial tonic postural seizures precipitated by slow movements which were unrelated to cognitive tasks. Ictal EEG did not permit location of the epileptogenic brain region. However, the clinical features suggest possible involvement of the supplementary motor area.

Adolescent↗
PubMed1997

EEG changes induced by vigabatrin monotherapy in focal epilepsy.

The effect of vigabatrin (GVG) monotherapy on EEG interictal abnormalities and on background activity recorded at rest and during mental tasks was studied in 14 patients suffering from focal epilepsy. A long-term EEG monitoring was performed in each patient before and 3 months after the beginning of GVG therapy. Ictal and interictal EEG abnormalities (IEA) were quantified by specific computer programs. Background activity was evaluated by spectral analysis at rest with eyes closed (EC), during blocking reaction (BR) and during fixation of cartoons (FIX). During treatment, IEA was either decreased or unmodified independently from seizure occurrence, which clearly improved in the majority of patients. The only EEG modifications induced by GVG monotherapy were a more pronounced slowing of the background activity at rest with EC and a reduced responsiveness to BR. EEG data suggest a GVG monotherapy induced mild "sedative" action on attentive tasks rather than on cognitive function.

4-Aminobutyrate Transaminase↗
PubMed1996

Primary CNS demyelinating diseases in childhood: multiple sclerosis.

We report on five children (three female and two male, age span 11-16 years) with laboratory-supported definite multiple sclerosis or clinically definite multiple sclerosis, diagnosed on the basis of Poser and Paty criteria. All patients were subjected to serial clinical examinations, magnetic resonance investigations, CSF biochemical and immunological studies, and neurophysiological and neuropsychological assessments. Four of the five examined subjects underwent steroid treatment. Over a period of 3 years relapses have been observed in three of them. The first symptoms and signs of multiple sclerosis may be subtle and misleading; careful assessment of them may be crucial for an early diagnosis of the disease.

Adolescent↗
PubMed1996

Effect of lamotrigine on EEG paroxysmal abnormalities and background activity: a computerized analysis.

1. Little information is available about the action of lamotrigine (LTG) on EEG paroxysmal abnormalities and background activity. On the contrary, several clinical trials have shown the therapeutic efficacy of the drug in preventing partial and generalized seizures. 2. We performed computerized EEG monitoring in 21 patients suffering from focal and generalized epilepsy before and 4 months after addition of LTG. The anticonvulsant modified the EEG ictal events by reducing their frequency and duration. A statistically significant decrease of the interictal spikes was observed. The decrease involved mainly the spreading component of the interictal events leading to a better spatial definition of the epileptic focus. 3. In the presence of LTG, generalized tonic-clonic attacks were completely controlled, whereas partial seizures were decreased. 4. The EEG background activity was not modified by the addition of the drug. 5. Our findings suggest a specific role for LTG in the generation and propagation processes of epileptiform activity without interfering with the EEG background activity.

Adolescent↗
PubMed1996

Sleep in healthy elderly subjects: a 24-hour ambulatory polysomnographic study.

It is still debated whether the deterioration of the sleep pattern, frequently reported by elderly subjects, is due only to aging per se. Other factors associated with aging or modifications of biological rhythms could also be involved. Elderly subjects frequently complain of daytime sleepiness, but it is not clear whether this actually represents a return to a polyphasic structure of sleep, or only a consequence of a disturbed night sleep. Ten healthy, independent and active elderly subjects (age > 72 years) were elevated by means of 24-hour ambulatory polysomnography. Findings of nocturnal sleep were compared with sleep of the same group in the 24-hour period and with sleep of young healthy controls. We observed a fragmentation of nocturnal sleep, but a fairly good representation of stages and a preservation of cyclicity. Except for three cases, with early or late times of sleep onset and wake-up, sleep disruption did not seem to be related to modification of circadian rhythms. Only three subjects presented undesired daytime naps, whereas the others either did not show daytime sleep at all, or were used to having their siesta after lunch since their young adulthood. In normal aging, daytime sleep does not constitute a social problem. Ambulatory polysomnography is a valid alternative to laboratory recordings in the identification of daytime sleep.

Aged↗
PubMed1996

Rapidly progressive form of Creutzfeldt-Jakob disease without dementia: a case report.

We describe a case of a patient with Creutzfeldt-Jakob disease (CJD) characterized by a rapid clinical course lasting one and a half months, by: presence of focal dystonic movements at onset, absence of mental deterioration in the period preceding the impairment of consciousness, ataxia, myoclonus and periodic EEG abnormalities. The autopsy confirmed subacute spongiform encephalopathy, but no evident neuronal loss was observed. An acute clinical course of CJD may explain this latter histological finding which, in turn, probably provides an explanation for the absence of intellectual impairment.

Aged↗
PubMed1996

Cognitive performances in newly referred patients with temporal lobe epilepsy: comparison with normal subjects in basal condition and after treatment with controlled-release carbamazepine.

In order to verify whether the performance of patients with temporal lobe epilepsy (TLE) were different from those of the normal controls in various cognitive tasks, we conducted a neuropsychological study in the two groups, excluding the presence of other confounding factors in the group of TLE patients (newly referred, previously untreated, without cerebral lesions at neuroimaging, with low recurrence of seizures). In basal condition, no significant difference was found between the nine healthy controls and the eight TLE patients. The second aim of the study was to investigate the effect of the first administration of 400 mg controlled-release carbamazepine (CBZ-CR). The drug caused a significant decrease in verbal memory (short and long-term) in TLE patients, whereas, in the control group, the first administration of CBZ-CR caused only a less significant impairment of long-term verbal-memory. Finally, the cognitive effects of CBZ-CR were assessed after one month of therapy, only in the group of patients. Our data suggest that: 1) differences between patients and controls in basal conditions are not relevant, once the influence of seizures, of treatment and of anatomical lesions has been ruled out. In other words, our patients did not perform differently from controls simply because they had become epileptic 2) also in the controlled-release preparation, adverse effects of CBZ on cognitive function are minimal and limited to the beginning of treatment.

Adult↗
PubMed1995

Action of GP 47779, the active metabolite of oxcarbazepine, on the corticostriatal system. II. Modulation of high-voltage-activated calcium currents.

GP 47779, the active metabolite of oxcarbazepine (OCBZ) inhibits glutamatergic excitatory postsynaptic potentials (EPSPs) in rat striatum (described in the accompanying article). This effect was presumed to involve the modulation of the calcium (Ca2+) signals at either pre- or postsynaptic level. Therefore, we directly tested whether GP 47779 could modulate Ca2+ conductances in cortical as well as in striatal neurons. GP 47779 produced a reversible dose-dependent decrease in high-voltage-activated (HVA) Ca2+ currents evoked by membrane depolarization in isolated cortical pyramidal cells. GP 47779-mediated reduction in HVA Ca2+ currents, if occurring also at corticostriatal axon terminals, might explain the reduction of glutamate release in the striatum. An inhibitory action of GP 47779 on HVA Ca2+ currents was also observed in isolated striatal neurons. The effect of HVA Ca2+ currents in cortical and striatal neurons persisted in the presence of nifedipine, suggesting that dihydropyridine-sensitive channels were not involved in the GP 47779-mediated responses. We propose that the modulation of HVA Ca2+ channels by this carbamazepine (CBZ) analogue may account for its inhibitory action on transmitter release.

Animals↗
PubMed1995

Development of myoclonus in patients with partial epilepsy during treatment with vigabatrin: an electroencephalographic study.

In the context of a study of the effects of gamma-vinyl-GABA (GVG) on seizure occurrence and on EEG abnormalities we present three cases with focal epilepsy in which new clinical and EEG paroxysmal manifestations were observed during GVG therapy. At that time, whereas an amelioration or no change in patients' habitual seizures were observed, myoclonic jerks appeared with related changes in the EEG paroxysmal abnormalities, represented by generalized polyspike and wave complexes. An electroclinical correlation was recorded in one case. These data indicate that, although occurring rarely, it is possible to have epileptic myoclonus during GVG treatment. Mechanisms underlying these manifestations are difficult to explain. Probably a shift in the anti/proconvulsant GABAergic balance towards the latter may compromise the therapeutic effect of GVG.

Adolescent↗