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Biomedical subjects

F Pierelli

Publications and source records attributed to F Pierelli.

At least 73 records · Page 4Linked to original sources
PubMed1986

Early auditory evoked potential changes during hypoxic hypoxia in the rabbit.

Early auditory evoked potentials and electroencephalograms were recorded in 10 rabbits during hypoxic hypoxia (5% O2 in N2 gas mixture) and after reoxygenation. In all experiments EEG flattening preceded the disappearance of the early evoked potential, whose recovery after reoxygenation was more rapid than that of the EEG. Significant increases in P3-P4 and P1-P3 interpeak latencies were observed during hypoxic conditions before the complete flattening of the early auditory evoked potential. In addition, negative relationships were found between the P3-P4 interpeak latency increase and mean arterial pressure reduction, and between the former and metabolic acidosis.

Animals↗
PubMed1985

Pain, anxiety, and contingent negative variation: a clinical and pharmacological study.

Contingent negative variation (CNV) behavior was studied in 16 volunteers who were suffering from spontaneous recurrent pain syndromes (idiopathic trigeminal neuralgia, classic migraine). The subjects were divided into two groups, "more anxious" and "less anxious," based on psychometric tests (MMPI and STAI X2). The CNV recordings were carried out, respectively, in basal resting state, during an episode of pain, while under anxiolytic treatment, and lastly, during an episode of pain while under anxiolytic therapy. CNV voltage decrease and frequent appearance of postimperative negative variation (PINV) were observed when pain was present during the recording session. These phenomena were more marked when the pain was accompanied by a greater degree of anxiety. Finally, our results suggest that this slow evoked potential is sensitive to various degrees of anxiety and to pain perception in man, making it useful in the investigation of pain as a complex sensation.

Adult↗
PubMed1985

Pattern visual evoked potentials and flash electroretinogram in clinically definite multiple sclerosis.

The authors have studied, by means of pattern visual evoked potential (VEP) and flash electroretinogram (ERG) recordings, a group of 15 patients affected by definite multiple sclerosis. All of the subjects examined presented a clinical history indicating involvement of the visual pathways; VEPs were altered in a high percentage of eyes examined (93.3%), while a lower percentage of abnormal ERGs was seen (20% of eyes examined). The only type of ERG alteration found consisted of a pathologic b wave voltage increase, observed mainly with red flash stimuli. This finding could be attributed to an involvement of centrifugal optic nerve fibers having inhibitory functions on retinal cells.

Adult↗
PubMed1983

Subjective posttraumatic syndrome. A comparison of visual and brain stem auditory evoked responses.

Evoked responses testing including pattern visual evoked potentials (VEPs) and brain stem auditory evoked potentials (BAEPs) were performed in 57 subjects suffering from subjective posttraumatic syndrome (SPTS). 36 of them had loss of consciousness after head injury. Abnormalities were found in 12 subjects out of 57 (21%). In addition, the pathological findings by percentage were: 25% in subjects who had loss of consciousness after head injury (9 cases out of 36) and 14% in subjects without loss of consciousness (3 cases out of 21). Evoked response alterations were more frequent in subjects with frontal and/or occipital trauma; BAEP abnormalities were found to be more frequent than VEPs. Our findings suggest that evoked responses testing could be a useful noninvasive technique to evidence an organic dysfunction of CNS in some subjects with SPTS.

Adult↗
PubMed1982

Electrophysiological measures (CNV--EEG) and nitrous oxide at low doses in man.

Nitrous oxide (N2O) is a widely used inhalational anesthetic gas, but its exact mode of action and its distribution in the CNS are not yet well known. The aim of this research was to study the effects of N2O at low doses (10 percent) in the CNS of humans. Five healthy volunteers were tested. Contingent Negative Variation (CNV), Reaction time (RT) and quantified EEG recordings were taken while subjects were breathing air and then N2O. A significant reduction of the post-imperative positive CNV components during N2O inhalation was observed; no changes in EEG power spectrum and RT values were seen. These results could be consistent with an early N2O interference with processes underlying CNV resolution, while vigilance and attention were still maintained.

Adult↗
PubMed1980

Brain slow potentials and hypnosis.

Contingent negative variation behavior was studied in 12 voluntary normal subjects in basal conditions and in the hypnotic trance state under different emotional suggestions. A CNV voltage decrease and the appearance of a PINV were observed in the hypnotic state. Furthermore 12 nonhypnotizable control subjects were tested under the same experimental conditions and no CNV modification was found.

Adult↗
PubMed1979

A longitudinal CNV study in a group of five bipolar cyclothymic patients.

The authors carried out a longitudinal study in five subjects with bipolar cyclothymic psychosis, recording contingent negative variations in the same patients in the different phases of illness and under normal clinical conditions. An average voltage decrease was found in the depressive phases and a more conspicuous decrease in the manic phases. Furthermore, an evident postimperative negative variation was present in four subjects during the manic phase. The authors set forth tentative psychological and neurophysiological interpretation of their results.

Adult↗
PubMedDate not supplied

Assessing the relative incidence of mitochondrial DNA A3243G in migraine without aura with maternal inheritance.

OBJECTIVE: To determine whether patients with migraine without aura with maternal "inheritance" are affected by a monosymptomatic form of the MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes) or carry the most common mitochondrial DNA (mtDNA) mutation associated with MELAS, namely the A3243G transition in the transfer RNA (tRNA)Leu(UUR) gene. BACKGROUND: The association between migraine and abnormal mitochondrial function has been suggested on clinical, biochemical, and neuroradiological grounds. Migraine attacks with vomiting and cerebral infarctions, most often in the posterior cerebral regions, which are reminiscent of complicated migraine, are typical features of MELAS. The observation that migrainous patients have affected mothers more often than affected fathers suggests a possible role for maternally transmitted genetic factors. METHODS: We studied 25 patients with migraine with aura whose mothers were also affected. A sensitive polymerase chain reaction restriction fragment length polymorphism analysis was used to detect mutated genomes. CONCLUSIONS: We failed to detect the MELAS mutation, but migraine may still be associated with point mutations of mtDNA other than A3243G or with as-yet-unidentified nuclear DNA factors related to mitochondrial function.

Adolescent↗
PubMedDate not supplied

Gabapentin treatment for muscle cramps: an open-label trial.

To evaluate the efficacy and safety of gabapentin in the treatment of muscle cramps, we engaged an open-label trial with a group of 30 patients with frequent (> 5 cramps/week), stable, long-lasting cramps, associated with different diseases. Gabapentin was effective in reducing the frequency and severity of muscle cramps and associated sleep disturbances (clinical outcome measures) within the first 2 weeks of medication at 600 mg/d. At the 1 month control (mean dosage, 825 +/- 35 mg), almost every patient had responded to treatment and two thirds experienced a total remission of symptoms. After 3 months of therapy (mean dosage, 892 +/- 180 mg), cramps disappeared in 100% of patients and this benefit persisted as long as 6 months. Additionally, we evaluated in 10 patients the Cramps Threshold Frequency (CTF) (neurophysiological outcome measure) before and during gabapentin treatment. Gabapentin significantly increased the CTF, returning it to normal values. With the limitation of an open-label methodology, our clinical and neurophysiologic experience suggests that a gabapentin dose of 600-1200 mg/d would be helpful in the treatment of muscular cramps.

Acetates↗
PubMedDate not supplied

Antiepileptic effects of a calcium antagonist (nimodipine) on cefazolin-induced epileptogenic foci in rabbits.

The epileptogenic properties of cefazolin (CFZ) were utilized to induce an electrophysiological pattern of epilepsy in the rabbit. CFZ, cortically applied in different concentrations (2 or 4%), produced epileptic activity in a degree proportional to the concentration of the substance. In this experimental epilepsy model, we evaluated the effects of increasing doses (0.025, 0.05, and 0.1 mg/kg i.v.) of the calcium antagonist nimodipine (Bay e 9736). In the evaluation of nimodipine effects, the spike-and-wave burst frequency per minute was taken into account. These data were compared with those of placebo-treated (Bay e 9736 control test) control groups and statistically evaluated by two-tailed t test. In 2% CFZ-induced epilepsy, nimodipine at the 0.025- and 0.05-mg/kg doses did not produce significant changes in the EEG pattern. A statistically significant reduction (p less than 0.001) in epileptic activity was observed at the 0.1-mg/kg nimodipine dose. This reduction was seen first in the contralateral focus leads and persisted for the entire time of observation. In the more intense epileptic form (4% CFZ), nimodipine at the doses employed did not induce noteworthy EEG modifications. These data indicate that nimodipine exerts an antiepileptic effect. The possible mechanisms involved in this activity of a calcium antagonist are discussed.

Animals↗
PubMedDate not supplied

Long-term EEG-video-audio monitoring: detection of partial epileptic seizures and psychogenic episodes by 24-hour EEG record review.

Twenty-seven patients with medically refractory paroxysmal disorders underwent EEG-video-audio (EVA) monitoring in an inpatient neurology-neurosurgery unit over 1-15 (mean 8.9) days. Fast visual review of all EEG records (5,784 h) and subsequent analysis of synchronized EVA patterns demonstrated a total of 208 partial epileptic seizures (ES) in 12 individuals and 87 psychogenic episodes (PE) in 15 subjects. Clinical ES lasted 83.3 s on the average and were most frequent from day 7 to 9 of monitoring (42.3%) and during sleep (56.4%). PE were longer in duration (mean 724.5 s), most numerous during the first 2 days of monitoring (41.4%), and occurred exclusively during wakefulness. Subjects with PE signaled (by pressing on a push button) more events (35.6%) than did the individuals with ES (27.9%). Multiple observers raised the proportion of alarms to 69.0% of PE compared to 39.9% of ES. Following the alarm, nurses reached the patients' bedside within a brief time (mean 22.2 s). To differentiate partial ES from PE or to establish the association of these disorders, EVA monitoring is best performed around the clock over a period of 1-2 weeks. The limited number of paroxysmal events, especially ES, signaled by the patients should be considered when designing studies of the effectiveness of pharmacologic, surgical, and other treatments.

Adolescent↗
PubMedDate not supplied

Wolfram's syndrome: a clinical, diagnostic, and interpretative contribution.

Four cases (belonging to two different families) of Wolfram's syndrome (WS), a rare congenital disease characterized in its complete form by insulin-dependent diabetes mellitus, optic atrophy, diabetes insipidus, deafness, and dilation of the urinary tracts are presented, and a review of the literature is included. Three of four patients are characterized by HLA-DR2 haplotype, which is rare in IDDM. The neurodegenerative nature of some symptoms and the possible pathogenesis of diabetes mellitus connected with it are discussed.

Diabetes Mellitus, Type 1↗