Biomedical subjects

C A Galimberti

Publications and source records attributed to C A Galimberti.

31 records · Page 2Linked to original sources

PubMed1992

Six-year follow-up study on the efficacy and safety of vigabatrin in patients with epilepsy.

Twenty-five patients with epilepsy (mostly with partial seizures) who had responded favourably to a short-term trial of add-on vigabatrin entered maintenance treatment. After 52 to 78 months, 15 patients continue to take the drug with good therapeutic response. Median monthly seizure frequency during the last 2 months on vigabatrin in all patients, including drop-outs, was 3.5 (range 0-74) as compared with 10 (range 3-98) during an initial placebo period (p < 0.01). Drop-outs were caused by adverse events in 2 cases (ataxia and psychotic symptoms respectively), seizure breakthrough in 4 cases and reasons unrelated to treatment in 4 patients. In most patients, side effects were absent or mild, the most frequent complaint being weight gain. It is concluded that the antiepileptic efficacy and good clinical tolerability of vigabatrin are generally maintained during long-term treatment for up to 6 years.

Adolescent↗

PubMed1991

Nocturnal sleep and oxygen balance in Duchenne muscular dystrophy. A clinical and polygraphic 2-year follow-up study.

A long-term, clinical and polygraphic investigation of nocturnal sleep was performed in nine non-ambulatory Duchenne muscular dystrophy patients (mean age 16.2 years, range 10-20) with normal daytime blood gas tensions. The data show that nocturnal sleep has some adverse influence on oxygen balance in these patients as suggested by the occurrence of arterial oxyhaemoglobin desaturation occurring mainly during REM stages. This adverse effect tended to worsen significantly within a 2-year period in the absence of any sleep-related symptoms. A significant correlation between the degree of oxygen imbalance during sleep and the degree of restrictive thoracic syndrome during wakefulness was shown.

Adolescent↗

PubMed1991

Daytime sleepiness in healthy university students: a multiparametric study.

A multiparametric investigation of daytime sleepiness was performed in 18 healthy young university students. After undergoing a standard polysomnographic recording at home the night before, all subjects were evaluated by Multiple sleep latency test (MSLT) at 10.00, 12.00, 14.00, 16.00, 18.00. Subjective sleepiness (by using Visual Analogue Rating Scale) and performance tasks (Cancellation Test, Digit Symbol Substitution, Choice Reaction Time, Critical Flicker Fusion Threshold) were also assessed at the same times. Mean daily sleep latency was found to be about 10 minutes, with several individual values in the borderline range (greater than 5 less than 10 minutes). Subjects did not rate themselves as excessively sleepy and there was no correlation between subjective and objective estimates of sleepiness. No consistent correlation was found between subjective-objective sleepiness and results of performance tests. Anxiety trait (Spielberg State Anxiety Trait) did not correlate with sleepiness, but higher anxiety scores were significantly associated with poor performance. These results confirm the occurrence of fairly marked objective drowsiness in healthy young subjects which, however, was not associated with subjective sleepiness and did not adversely affect performance on a variety of tests of CNS function.

Adult↗

PubMed1991

Differential effects of valproic acid and enzyme-inducing anticonvulsants on nimodipine pharmacokinetics in epileptic patients.

1. The single dose pharmacokinetics of orally administered nimodipine (60 mg) were investigated in normal subjects and in two groups of epileptic patients receiving chronic treatment with hepatic microsomal enzyme-inducing anticonvulsants (carbamazepine, phenobarbitone or phenytoin) and sodium valproate, respectively. 2. Compared with the values found in the control group, mean areas under the plasma nimodipine concentration curve were lowered by about seven-fold (P less than 0.01) in patients taking enzyme-inducing anticonvulsants and increased by about 50% (P less than 0.05) in patients taking sodium valproate. 3. Nimodipine half-lives were shorter in enzyme-induced patients than in controls (3.9 +/- 2.0 h vs 9.1 +/- 3.4 h, means +/- s.d., P less than 0.01), but this difference could be artifactual since in the patients drug concentrations declined rapidly below the limit of assay, thus preventing identification of a possible slower terminal phase. In valproate-treated patients, half-lives (8.2 +/- 1.8 h) were similar to those found in controls.

Adult↗

PubMed1989

Time-dependent pharmacodynamic effects of phenobarbital in humans.

The relationship between the serum concentration of phenobarbital and its pharmacodynamic effects was assessed in a double-blind controlled study in eight normal volunteers who were given single oral doses of phenobarbital (200 mg) and placebo according to a randomized cross-over design. Compared with the placebo session, phenobarbital was found to induced CNS-depressing effects as assessed by visual analogue rating scales (VARS) and critical flicker fusion tests (CFF), whereas no significant effects were detected on choice reaction times, tappings, and digit symbol substitutions. There was a clear-cut dissociation between the time course of serum phenobarbital levels, which remained at a plateau throughout most of the period of observation (up to 72 h) and its subjective (VARS) and objective (CFF) effects, which could be documented only for up to 9 h after administration. These data suggest that pharmacodynamic tolerance develops rapidly even after a single oral dose of the drug. Multiple Sleep Latency Tests (MSLTs) were also performed in the same subjects and showed that phenobarbital increases diurnal drowsiness and attenuates the circadian variation in drowsy state that is seen under control conditions. MLSTs appeared to be superior to other tests in documenting the sedative effects of the barbiturate.

Adult↗

PubMed1989

Effects of vigabatrin on evoked potentials in epileptic patients.

1. Somatosensory (SEP) brainstem auditory (BAEP) and visual (VEP) evoked potentials were determined before and after add-on administration of vigabatrin (GVG) in patients with epilepsy. 2. At pre-treatment assessment SEP and BAEP parameters were usually found to be within normal limits, while P100 latencies of the VEP were abnormally prolonged in a considerable proportion of patients. 3. In a double-blind, placebo-controlled trial in 22 patients GVG (1-3 g day-1 stratified according to body weight) given for 7 weeks did not modify any of the evoked potential parameters evaluated. 4. Eighteen patients were evaluated prospectively at regular intervals during long-term GVG (2-4 g day-1) therapy with a mean follow up of 24 months (range 13-42 months). SEP, BAEP and especially VEP parameters showed some interindividual variability, but the within patient variation was relatively small. No consistent important changes were seen in association with GVG, although a possible trend towards a shortening of BAEP latencies and P100 latencies was observed. 5. The relevance of these findings with respect to GVG safety is discussed.

Adolescent↗

PubMed1989

Vigabatrin in the treatment of epilepsy: a long-term follow-up study.

Twenty-five adult epileptic patients who had shown a satisfactory clinical response to add-on vigabatrin under placebo-controlled conditions continued on long-term treatment for up to 47 months (median 22 months). The initially favourable therapeutic response was generally maintained throughout the observation period with an overall good clinical tolerance. No evidence of neurotoxicity was detected by multimodal evoked potentials monitoring.

Adult↗

PubMed1988

Effect of vigabatrin (gamma-vinyl-GABA) on visual, brainstem auditory and somatosensory evoked potentials in epileptic patients.

Visual (V), somatosensory (S) and brainstem auditory (BA) evoked potentials (EPs) were determined in 22 epileptic patients, mostly with partial seizures, who received add-on treatment with vigabatrin (1-3 g/day, stratified according to body weight) and placebo, each given for 7 weeks according to a double-blind, randomized cross-over design. At pretreatment assessment, BAEPs and SEPs were found to be within normal limits in most of the patients tested, while for VEPs several abnormal responses were found, including a marked prolongation of P100 latency values in the majority of cases. None of the EP parameters examined was significantly influenced by vigabatrin treatment. These results support the evidence that enhancement of GABA-ergic transmission does not substantially affect the functional state of afferent sensory pathways as assessed by EP analysis. The significance of these findings with respect to the safety of vigabatrin therapy is discussed.

Adolescent↗

PubMedDate not supplied

Comparative pharmacokinetics and pharmacodynamics of eterobarbital and phenobarbital in normal volunteers.

The comparative pharmacokinetics and pharmacodynamics of single oral doses of eterobarbital (N,N'-dimethoxymethylphenobarbital, DMMP, 400 mg) and phenobarbital (200 mg) were evaluated in a double-blind study in 8 normal volunteers. Following administration of DMMP, no unchanged drug could be detected in serum. The active monomethoxymethyl metabolite (MMP) appeared rapidly in the circulation but its concentration remained generally low and declined below the limit of detection (0.5 micrograms/ml) usually before 9.5 h. Serum levels of DMMP-derived PB increased slowly and reached a peak between 24 and 48 h in most cases. One subject showed an atypical pharmacokinetic profile, characterized by relatively high levels of MMP and a delayed appearance of low levels of PB. After administration of PB, serum drug levels peaked within 1.5 h and remained, at all sampling times, higher than those observed after intake of DMMP. Compared with DMMP, PB induced greater sedative effects as assessed by visual analogue rating scale, critical flicker fusion frequency and multiple sleep latency tests.

Administration, Oral↗

PubMedDate not supplied

Sleep patterns in patients with late onset partial epilepsy receiving chronic carbamazepine (CBZ) therapy.

A night-time polygraphic sleep recording was performed in 14 patients with late onset partial epilepsy receiving chronic carbamazepine monotherapy. All patients had unstable nocturnal sleep patterns as indicated by significantly altered sleep continuity parameters compared with normal controls. Patients with poor seizure control tended to show greater alterations of sleep stability compared to patients in complete clinical remission but the difference failed to reach statistical significance. Epileptic patients also showed less REM sleep and longer REM latencies compared with normal controls, the most altered REM values being observed in patients with poor seizure control. These data confirm that polygraphic sleep alterations are seen in patients with symptomatic focal epilepsy and indicate that these abnormalities occur irrespective of seizure recurrence.

Adult↗

PubMedDate not supplied

Vigabatrin in the treatment of epilepsy: a double-blind, placebo-controlled study.

The efficacy and tolerability of vigabatrin (gamma-vinyl GABA, GVG), given as add-on therapy to 23 adult outpatients with severe drug-resistant epilepsy (17 with partial seizures), were studied using a double-blind, placebo-controlled, crossover design. The study consisted of two 7-week periods during which vigabatrin and placebo were administered in random sequence. Dosage was 1.0 g twice daily for patients weighing less than or equal to 65 kg and 1.5 g twice daily for patients weighing greater than 65 kg. Three patients were dropped from the study, two for reasons unrelated to treatment and one because of the appearance of vertigo, headache, dysarthria, and ataxia, which subsided rapidly when vigabatrin was stopped (3 g daily). Sixteen of the 20 patients available for analysis showed a decrease in the total number of seizures as compared with the placebo period. Of these, 12 showed a greater than 50% reduction in seizure frequency and 4 of the 12 showed a greater than 75% reduction. Both the total number of seizures and the number of partial seizures were significantly reduced by vigabatrin (p less than 0.01). Only in the patient who dropped out were severe adverse effects seen. The most frequently reported unwanted effect was mild drowsiness, which developed in seven patients on vigabatrin and in one on placebo. Positive effects, however, were also seen with six patients who reported an improved sense of well-being while receiving vigabatrin as compared with only 1 during the placebo period. No consistent changes in electrocardiogram (ECG), electroencephalogram (EEG), and visual-, auditory-, and somatosensory-evoked potentials were seen during the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Nocturnal partial seizures and arousals/awakenings from sleep: an ambulatory EEG study.

The architecture of nocturnal sleep in twenty subjects (9 males, 11 females, mean age 27 years) affected by partial cryptogenic epilepsy was investigated by means of ambulatory EEG (A-EEG) recording performed at home. The study aimed in particular to ascertain the immediate effects of nocturnal partial epileptic seizures on sleep stability and continuity. Data for a total of 49 recorded seizures indicate that 72% of the partial seizures which occurred during sleep were followed by arousal and awakening, and that sleep interruption lasted significantly longer when the seizure occurred between 4 and 7 a.m.

Adolescent↗

PubMedDate not supplied

Effects of valproate, phenobarbital, and carbamazepine on sex steroid setup in women with epilepsy.

Serum levels of sex-hormones, sex-hormone binding globulin, gonadotropin, and prolactin were evaluated during the follicular and the luteal phases in 65 women with epilepsy and in 20 healthy controls. Twenty-one patients were treated with sodium valproate (VPA), 21 with phenobarbital (PB), and 23 with carbamazepine (CBZ). VPA does not stimulate liver microsome enzymes, whereas PB and CBZ do. Patients on VPA therapy showed higher body weight and body mass index, but no significant differences in hirsutism score, or in ovary volume or polycystic ovary prevalence (at ultrasound examination). Estradiol levels were lower in all patient groups than in healthy controls in the follicular but not in the luteal phases. VPA affected luteal progesterone surge in 63.6% of cases. This effect was significantly lower in the CBZ and PB groups. Furthermore, increases in testosterone and delta 4-androstenedione levels and in free androgen index, along with a higher luteinizing hormone-follicle-stimulating hormone ratio in the luteal phase, were observed in women treated with VPA. Although sex-hormone binding globulin levels were higher in CBZ and PB than in VPA-treated patients, the differences were not significant because of the wide dispersion of the carrier protein levels. Inducer antiepileptic drugs decreased dehydroepiandrosterone sulfate levels, which remained unchanged during VPA treatment. No significant differences occurred in basal gonadotropin and prolactin levels.

Adolescent↗