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Biomedical subjects

R Ferri

Publications and source records attributed to R Ferri.

At least 19 recordsLinked to original sources
PubMed1992

Tuberous sclerosis and Down syndrome: a casual association?

This paper reports on the clinical, neurophysiological and neuroradiological characteristics of a patient with Down syndrome unusually associated with tuberous sclerosis. In particular, epilepsy is investigated in detail and its polygraphic study and etiopathological factors are discussed. The most interesting findings are those related to the presence of a structural abnormality of the rolandic-parietal cortex, bilaterally, in the form of pachygyria.

Adult↗
PubMed1991

Modulation of the interictal epileptiform EEG activity during sleep: from oscillations to complex dynamics.

Polygraphic sleep recordings (EEG, EMG, and EOG) were performed in two groups of epileptic subjects, six with fragile-X syndrome and six with symptomatic epilepsy. Recordings were visually scored for sleep stages and number of spikes/min. Subjects with fragile-X syndrome showed a well defined pattern of production of interictal epileptiform activity with the lowest values during REM sleep; symptomatic epileptic subjects showed less defined and more variable spike/min diagrams. The spectral analysis of the outline of such diagrams confirmed these differences showing shorter periodicities (80-100 min) in the fragile-X group compared to those of the symptomatic group (160-220 min). Finally, a model with multiple feedback circuits is proposed in order to explain the different patterns observed.

Activity Cycles↗
PubMed1991

Actuarial analysis of the occurrence of remissions following thymectomy for myasthenia gravis in 400 patients.

The role of thymectomy in the treatment of myasthenia gravis (MG) was analysed in 400 patients affected with generalised MG operated on between 1974-83, and prospectively followed up for five years after surgery. The occurrence of stable remission (SR) (that is, complete clinical drug-free remission that remains stable for all the subsequent follow up) was the endpoint of survival analyses and the distribution of SR time (SRT, that is, the interval from thymectomy to the occurrence of SR) was assessed by actuarial and Cox multivariate analyses. SRT distribution after surgery showed a slow progressive increase of cumulative SR rate that could both be ascribed to a delayed effect of thymectomy as well as reflect the natural history of MG, itself characterised by an increasing probability of spontaneous remission with time. SRT distribution was similar after stratification for all variables studied except when patients without thymoma were stratified for the need for immunosuppressive treatment in addition to thymectomy. Patients without thymoma who did not require additional immunosuppressive therapy (n = 130) had the highest SR rate occurring in the two years after thymectomy, and differed from patients treated with immunosuppressive drugs who showed the highest SR rate five years after surgery. Actuarial analysis has therefore identified a subgroup of patients where SR, occurring in the first years after surgery, is more likely to be ascribed to thymectomy than merely reflect the natural course of the disease.

Actuarial Analysis↗
PubMed1989

A simple electronic and computer system for automatic spindle detection.

The authors present a new system for the automatic detection of sleep spindles. The electronic and computer analysis are described and a comparison between automatic and visual analysis, performed by two independent readers, was carried out with the aim of evaluating the reliability of the system. Results are discussed and compared with those of different systems already described.

Electroencephalography↗
PubMed1989

Comparison between the results of an automatic and a visual scoring of sleep EEG recordings.

In this paper, results from the visual scoring of nocturnal polygraphic recordings, carried out by nine different groups of readers from different Italian sleep laboratories, are analyzed; inter-and intragroup variability is shown and statistically discussed. Data are then compared with the results of an automatic scoring of the same recordings, carried out by the Medilog Sleep Stager. The validity of this automatic method of scoring is discussed. Finally, an epoch by epoch analysis is described, with the aim of achieving a more detailed evaluation of the intergroup variability.

Adolescent↗
PubMed1987

Butoctamide hydrogen succinate and intensive learning sessions: effects on night sleep of Down's syndrome patients.

Mentally retarded children present a reduction in percentage of REM sleep and of oculomotor frequencies. These sleep patterns are probably relevant for their cognitive activities. The effects of butoctamide hydrogen succinate and intensive learning sessions on the night sleep of five Down's syndrome patients was studied by the authors. They found an increase in percentage of REM sleep after pharmacological treatment and an increase in oculomotor frequencies after learning sessions. The authors' hypotheses of REM sleep as a neurophysiological indicator of cerebral "plasticity" and of oculomotor frequencies as an indicator of "organization" abilities are discussed in this article. Pedagogical implications and therapeutical perspectives are also outlined.

Amides↗
PubMed1986

Sleep patterns of Down's syndrome children: effects of butoctamide hydrogen succinate (BAHS) administration.

Several investigators have described the altered sleep patterns in Down's syndrome subjects. The most relevant findings have been a reduction in percentage of REM sleep, a prolonged latency to the first REM episode, an increase in undifferentiated sleep, and a reduced ratio of the oculomotor frequencies. Because it is of interest to identify new drugs able to increase the percentage of REM sleep in mentally retarded subjects, we studied the effects of butoctamide hydrogen succinate (BAHS) on nocturnal sleep in eight young institutionalized Down's syndrome subjects. BAHS produced a significant increase in the percentage of REM sleep as well as a decrease in undifferentiated sleep and latency to the first REM.

Amides↗
PubMed1985

Visual evoked potential recordings in hepatic encephalopathy and their variations during branched chain amino-acid treatment.

In fourteen subjects with various stages of hepatic encephalopathy (HE), Visual Evoked Potential (VEP) recording and blood ammonia (NH3), octopamine (OCT) and phenylethanolamine (PEA) determinations were performed before and during a four-day treatment with branched chain amino acid (BCAA) i.v. infusion. All the subjects with HE showed significant basal VEP alterations, namely an increased latency and a lowered amplitude of the P100 wave, in comparison with a control group of 26 normal subjects. A significant improvement in P100 wave amplitude occurred just about 60' after the beginning of BCAA infusion, while P100 latency was still unaffected, as were OCT, PEA and NH3 levels. After the fourth day of BCAA treatment, both P100 wave amplitudes and latencies were strongly improved, together with OCT, PEA and NH3 levels. VEP improvements seemed to be well correlated with HE clinical evolution, and were able to detect modifications of central nervous system reactivity earlier than serum parameters.

Adult↗
PubMedDate not supplied

Prevalence of a novel epileptogenic EEG pattern in the Martin-Bell syndrome.

In this paper, we describe a study aiming at establishing the prevalence, specificity, and the sensitivity of a characteristic sleep EEG pattern in patients with Martin-Bell syndrome, in comparison with a sample of etiologically different mentally retarded patients. The estimation of the prevalence (11% among the total sample), the specificity, and the sensitivity, allows us to propose this pattern as an important "marker", useful in the diagnosis of the Martin-Bell syndrome.

Adolescent↗
PubMedDate not supplied

Epilepsy and fragile X syndrome: a follow-up study.

This paper describes EEG and clinical findings resulting from a follow-up investigation in a group of 18 males with fragile X syndrome, in whom a characteristic paroxysmal EEG pattern was previously described. The following types of evolution were observed: (1) disappearance of the pattern (with a gradual lowering of the amplitude of spikes and in some cases with asynchrony between the two hemispheres); (2) disappearance of the quasi-rhythmic centrotemporal spikes and persistence of bisynchronous polyspike and wave complexes in the temporo-parieto-frontal regions; and (3) persistence of the previously observed pattern. These results confirm the already observed similarity between this condition and the benign childhood epilepsy with centrotemporal spikes, also from the maturational point of view; on the other hand, they also indicate some difference (i.e., mental retardation, slow background EEG activity, brain atrophy). Moreover, these findings are encouraging for the possible development of research in the field of molecular genetics in epilepsy, because they provide a precise site of investigation on the X chromosome.

Adolescent↗
PubMedDate not supplied

Fragile-X syndrome: a particular epileptogenic EEG pattern.

A clinical and EEG study of 12 fragile-X syndrome subjects (six with epilepsy) is presented. All subjects had clinical-family history examinations, EEG evaluations, and karyotyping. Spikes were present in the sleep EEG of one nonepileptic and four epileptic subjects: these spikes were similar in location, occurrence, voltage, frequency, and morphology (and similar to those of the Rolandic spikes). These data, together with the clinical similarities (type of epilepsy, responses to drugs, ages of seizure onset, etc.), have resulted in the postulation of EEG characteristics of epileptic and nonepileptic fragile-X patients. However, further studies with fragile-X patients are needed to confirm this hypothesis.

Adolescent↗