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Biomedical subjects

S Ferracuti

Publications and source records attributed to S Ferracuti.

18 recordsLinked to original sources
PubMed2001

Diazepam effects on the cerebral responses to tonic pain: a SPET study.

RATIONALE: Pain is a complex phenomenon with a strong affective-emotional component in addition to a sensory-discriminative one. This causes the activation of multiple brain areas, which process different aspects of pain simultaneously. OBJECTIVES: We investigated the effects of diazepam (DZ) on a well-known pattern of brain regions activated by cold, tonic pain stimuli. METHODS: Quantitative cerebral blood flow (CBF) was assessed by single photon emission tomography (SPET) and the Xe-133 inhalatory method, at rest and during tonic pain activation in eight normal, right-handed, male volunteers. The cold pressor test (CPT) was performed by immersion of the left hand in cold water twice, first during CPT alone, and again 30 min after intravenous administration of diazepam (CPT+DZ). RESULTS: During CPT we observed a significant CBF increase in the right thalamus, primary sensory-motor cortex (S1/M1), frontal and temporal regions, and in the left temporal region and anterior cingulate cortex (ACC). During CPT+DZ, the average CBF was significantly lower than during the CPT state (-11%, P<0.05). After normalisation, during CPT+DZ we again observed a significant CBF increase in the right thalamus, S1/M1 and frontal regions, and in the left ACC, though not in the temporal regions. DZ administration first causes a global reduction in CBF, then modifies the pattern of brain activation. CONCLUSIONS: During CPT, activation of the temporal regions has been interpreted as part of the affective-emotional component of pain response. DZ seems to affect the "pain-related" pattern of activation by abolishing the CBF increase in the temporal regions, without, however, modifying the pain perception or determining a sedating effect.

Adult↗
PubMed1999

Rorschach findings for patients with pseudoseizures.

This study used the Rorschach test to investigate the possible differences between a carefully selected group of 16 patients with pseudoseizures, defined as spontaneous behavior resembling partial complex epilepsy and with or without tonic clonic generalization, and a group of 12 epileptic patients with partial complex seizures. Analysis of the structural data of protocols does not support a significant difference in the Rorschach findings between the two groups.

Adult↗
PubMed1997

Corneal reflex responses to mechanical and electrical stimuli in coma and narcotic analgesia in humans.

The corneal reflex, a bilateral eye-blink, can be elicited in humans either by mechanical or electrical corneal stimulation. Both in comatose patients and in normal subjects injected with the opiate fentanyl, the electrically-evoked corneal reflex was more suppressed than the mechanically-evoked reflex. We propose that the mechanical input yields a reflex more resistant to depression of the corticoreticular drive and to narcotic analgesia, because it exploits temporal summation at central synapses, whereas the electrical input exploits spatial summation.

Adult↗
PubMed1996

Dissociative trance disorder: clinical and Rorschach findings in ten persons reporting demon possession and treated by exorcism.

Although dissociative trance disorders, especially possession disorder, are probably more common than is usually though, precise clinical data are lacking. Ten persons undergoing exorcisms for devil trance possession state were studied with the Dissociative Disorders Diagnostic Schedule and the Rorschach test. These persons had many traits in common with dissociative identity disorder patients. They were overwhelmed by paranormal experiences. Despite claiming possession by a demon, most of them managed to maintain normal social functioning. Rorschach findings showed that these persons had a complex personality organization: Some of them displayed a tendency to oversimplify stimulus perception whereas others seemed more committed to psychological complexity. Most had severe impairment of reality testing, and 6 of the participants had an extratensive coping stile. In this group of persons reporting demon possession, dissociative trance disorder seems to be a distinct clinical manifestation of a dissociative continuum, sharing some features with dissociative identity disorder.

Adult↗
PubMed1994

Quantitative EEG modifications during the Cold Water Pressor Test: hemispheric and hand differences.

In a study designed to investigate the neurophysiological correlates of the Cold Water Pressor Test, a standardized experimental model of tonic pain, spectral EEGs were examined during the test in 15 young right-handed adults. Each subject performed a "cold water" and a "warm water" session. The subject immersed in cold water (0 degree C) either the right or the left hand alone, in a randomized way. EEG activity was recorded for an initial 3 min baseline and for the first and second minute epochs after immersion. A further EEG recording was obtained after a 30-min rest. Pain intensity was measured with a visual analogue scale. The EEG recordings showed several patterns of cortical activation during the test. Alpha 2 desynchronization was more evident on the contralateral parietal electrodes of the stimulated hand and lasted longer over all the right hemisphere. Delta activity increased bilaterally, predominantly in the frontal leads. Stimulation of the left hand resulted in a higher delta increase during the second minute after immersion.

Adult↗
PubMed1994

Analgesic-antiinflammatory drugs inhibit orbicularis oculi reflexes in humans via a central mode of action.

1. A cross-over single blind study examined the possible central effects of non-opioid analgesic drugs on the trigeminal reflexes. 2. The corneal reflex and blink reflex (R1, R2) were recorded electromyographically and response areas measured in healthy volunteers before and after intramuscular injection of piroxicam (40 mg); and after intravenous injection of lysine acetylsalicylate (500 mg). After the last drug recording the subjects received intravenous naloxone (2 mg) followed 5 minutes later by further reflex testing. Saline was used as a placebo in control experiments. 3. Both analgesics reduced the corneal reflex: piroxicam induced a 27% and lysine acetylsalicylate a 21% a reduction that naloxone did not reverse. Neither drug reduced the early or the late component of the blink reflex. 4. The marked inhibitory changes that the two non-narcotic analgesics produced on the corneal reflex--a nociceptive response--indicate a centrally-mediated action. 5. Naloxone's failure to reverse the induced analgesia argues against opiate receptor mediation.

Adult↗
PubMed1992

Piroxicam-induced analgesia: evidence for a central component which is not opioid mediated.

Piroxicam is a nonsteroidal anti-inflammatory drug with a potent analgesic effect. In order to establish whether the analgesic action of Piroxicam has a central component, we studied the effect of the drug on the nociceptive orbicularis oculi reflexes evoked by electrical stimulation of the cornea and supraorbital nerve in healthy subjects. Piroxicam significantly suppressed the corneal reflex and R3 component of the blink reflex by 28% (p < 0.05) and 50% (p < 0.01), respectively. This effect was not reversed by the i.v. injection of naloxone. Beta-endorphin levels did not change. Piroxicam administration induces distinct inhibitory changes in nociceptive reflexes, which suggests that the analgesic action of the drug has a central component. The ineffectiveness of naloxone, and the lack of beta-endorphin changes, indicate that this central action is independent of the opioid system; other pain regulatory systems are probably involved.

Adult↗
PubMed1992

Hemimegalencephaly and normal intellectual development.

Hemimegalencephaly is a rare congenital malformation characterised by overgrowth of one hemisphere. Although it is commonly thought to be associated with neurological deficits, developmental delay, and intractable epilepsy, the clinical expression of hemimegalencephaly, can vary widely. This patient was neurologically and neuropsychologically normal apart from rare partial seizures.

Adult↗
PubMed1991

Nociceptive quality of the orbicularis oculi reflexes as evaluated by distinct opiate- and benzodiazepine-induced changes in man.

The corneal reflex and the three components of the blink reflex (R1, R2, and R3) were recorded electromyographically in volunteers. The area of these responses was measured before and after administration of the narcotic-analgesic fentanyl (1.5 mg i.m.) and its antagonist naloxone, and after administration of the benzodiazepine diazepam (10 mg i.v.) and its antagonist flumazenil. Saline was given as a control placebo. The corneal reflex was 71% reduced by fentanyl, 43% by diazepam. R1 was 35% reduced and R2 was 60% reduced by diazepam. R3 was abolished by both drugs. Whereas the fentanyl-induced changes were completely reversed by naloxone, the diazepam-induced changes were only partly reversed by flumazenil. The corneal reflex appears to be a 'nociceptive' reflex under all points of view. Recording of the orbicularis oculi reflexes in man may be valuable in the evaluation of central-acting neurotropic drugs.

Adult↗
PubMed1990

Computer-analyzed EEG (CEEG) and dynamic brain mapping in AIDS and HIV related syndrome: a pilot study.

In a group of HIV positive young male patients without any significant neuropsychiatric signs, computer-analyzed EEG (CEEG) and Dynamic Brain Mapping evaluations were conducted. These patients, who only had micro-neuropsychiatric symptoms, demonstrated CEEG profiles that more closely resemble those of patients diagnosed as suffering from mild dementia than age-related normals from our CEEG data base. The CEEGs of patients diagnosed as having Acquired Immune Deficiency Syndrome (AIDS), compared to patients with HIV positive, showed greater similarity in CEEG patterns to severely demented patients than to normal control groups. The findings of this pilot study suggest that CEEG may be useful for early determination of the Central Nervous System's (CNS) involvement with the AIDS virus and monitoring the progress of the illness.

AIDS Dementia Complex↗
PubMed1990

[Electric stimulation of the dental pulp in the evaluation of the central effect of analgesics].

We conducted a double-blind cross-over study in ten volunteers aged from 19 to 30 years, to compare the pain control effects of a single oral dose of two analgesic compounds (drug A: propyphenazone mg 250, ethylmorphine mg 5, caffeine mg 5; drug B: dipyrone mg 500, diphenhydramine mg 12.5, adiphenine mg 5, ethyl aminobenzoate mg 2.5) in an experimental pain model using stimulation of dental pulp. Constant voltage stimuli were delivered through silver chloride electrodes placed in contact with the vestibular surface of the upper medial incisor. At the beginning of the session, the pain input was graded by asking the subject to identify the weakest stimulus perceived (threshold level) and the strongest stimulus endurable (tolerance level). The range between threshold and tolerance level was divided in nine steps plus a subliminal step. The ten steps were delivered randomly, and each series of steps was repeated eight times. The subjects were instructed to rate the pain sensation in an arbitrary scale of 5 degrees. The procedure was repeated at 60 min and 180 min after drug administration. Each subject received two tablets of drug A or drug B in two different sessions at weekly intervals. Statistical analysis of the procedures showed that neither drug A nor drug B significantly affected the pain threshold. Drug A significantly reduced the total pain score (P less than 0.01) and its action peaked 60 min after administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Modulation using racemic and levo-rotary baclofen of the trigeminal reflex in man].

Baclofen (Lioresal), a muscle relaxant, exerts a specific action on the trigeminal system by depressing excitatory synaptic transmission in the spinal trigeminal nucleus. To evaluate the effects of racemic and L-baclofen on the human trigeminal reflexes, the area of the blink reflex was measured in seven normal subjects, before and after i.v. administration of racemic baclofen (25 mg.) and oral administration of L-baclofen (15 mg.). The blink reflex is a trigeminal facial reflex consisting of two components (R1 and R2): R1 has a shorter latency and is mediated by an oligosynaptic pontine circuit; R2 has a longer latency and is believed to be relayed via a polysynaptic circuit through the lateral bulbar reticular system. Whereas the R1 response was scarcely affected by administration of racemic baclofen, it was significantly reduced by L-baclofen (P less than 0.01). R2 was depressed by both drugs (P less than 0.01). These results indicate that both racemic and L-baclofen inhibit trigeminal transmission in man, probably because they interfere with excitatory transmission through the interneurons of the lateral reticular formation. In addition, since L-baclofen reduced both R1 and R2 this form of the drug presumably has a more powerful effect than its racemic counterpart, on the few interneurons of the short latency component.

Adult↗
PubMed1990

[Changes in the RIII response of the flexion reflex with painful maneuvers].

In the search for reliable indirect indices of pain sensation, interest has recently focused on the nociceptive flexion reflex and late components of the brain evoked potentials. In ten volunteers with sciatica, the nociceptive flexion reflex (RIII) and the late component (N150-P220) of the evoked potentials were recorded, with the subjects at rest and during pain produced by the Lasegue manoeuvre. In recordings with the subjects at rest, both responses were stable. During the Lasegue manoeuvre, the RIII response was markedly suppressed, with a mean reduction in area of 40% (P less than 0.001). In contrast, the amplitude of the N150-P220 components did not change significantly. Our results indicate that, of the two parameters tested, RIII alone is a reliable index for measuring pain sensation.

Adult↗