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Biomedical subjects

G Sandrini

Publications and source records attributed to G Sandrini.

At least 55 records · Page 3Linked to original sources
PubMed1993

Effects of dothiepin on nociceptive flexion reflex and diffuse noxious inhibitory controls in humans.

The analgesic activity of dothiepin (an antidepressant interacting with serotonin receptors) was studied (double-blind) in humans. A significant increase in nociceptive flexion reflex threshold and subjective pain threshold was observed after a 14-day dothiepin treatment. The effects of dothiepin on diffuse noxious inhibitory controls were also investigated using the cold-pressor test as conditioning stimuli. After dothiepin a reduced inhibition of nociceptive flexion reflex during the cold-pressor test and a significant facilitation immediately after the cold-pressor test were observed, while the subjective pain perception was normally inhibited. Our data suggest a serotonergic modulation of diffuse noxious inhibitory controls in humans.

Adolescent↗
PubMed1993

Changes in motoneuron excitability of masseter muscle following exteroceptive stimuli in Parkinson's disease.

Changes in motoneuron activity of masseter muscle to exteroceptive stimuli were evaluated in parkinsonian patients. Two different electrophysiological procedures were applied, consisting of exteroceptive suppression of the masseter or excitability curves of the masseteric reflex obtained by using exteroceptive conditioning stimuli. Seven patients not yet treated with dopaminergic or anticholinergic drugs were compared with 10 age-matched normal volunteers. Only the second phase of exteroceptive suppression was examined because correct measurement of the first phase was impossible due to the stimulus artefact. No significant differences were observed in exteroceptive suppression between parkinsonian patients and normals. Early and late inhibitory phases of the excitability curve of the masseteric reflex were obtained in both normals and patients. However, parkinsonians showed less inhibitory change than normals in both early and late phase of the curve. This study confirms that reduced inhibition of the masseteric reflex to exteroceptive stimuli is present in Parkinson's disease. The excitability curve of the masseteric reflex represents a more reliable method than exteroceptive suppression in detecting these abnormalities.

Adult↗
PubMed1993

The nociceptive flexion reflex as a tool for exploring pain control systems in headache and other pain syndromes.

The authors review the neural pathways mediating nociceptive flexion reflexes, the method for analyzing these reflexes in human beings, and available data on their modulation by supraspinal, opioid as well as serotonergic systems. They present results of studies of the biceps femoris flexion reflex (RIII) in pain syndromes and various types of headache. Nociceptive flexor reflexes appear to be interesting for studying the pathophysiology of head pain mechanisms and possibly for evaluating analgesic treatment.

Endorphins↗
PubMed1993

The trigemino-pupillary response in cluster headache.

Central impairment of the integrative neural systems controlling vegetative function and pain perception has been demonstrated in cluster headache (CH). Recently, we described the human pupillary response (trigeminal reflex) to quantified (painless and painful) corneal stimulation with a combined neurophysiological and pharmacological technique. In this study, the trigeminal reflex was evaluated in 26 subjects with episodic cluster headache. During the active phase of the disease, on the side of the pain we observed reduced mydriasis to electrical stimuli with an intensity equal to the corneal reflex threshold, and on both sides to stimuli with intensity that equalled the pain threshold. No difference was found when amplitude of the miotic phase was compared in the different groups. These suggest disordered pupillary activation in response to pain, probably sympathetic in origin, which is bilateral, detectable also during the remission phase and which cannot be explained simply by the antidromic release of pain-related peptides.

Adult↗
PubMed1993

An epidemiological approach to the nosography of chronic daily headache.

Chronic daily headache (CDH), a heterogeneous group of headaches, includes different forms that occur daily, or almost daily, over a prolonged period of time. The nosography of this group is still a matter of debate, and in the most recent classification of the IHS (1988) only a few types of CDH are included: chronic tension-type headache, coexisting migraine. This study is an epidemiological approach to identifying the clinical features of CDH and the possible factors involved in changing episodic headache in CDH. Ninety CDH outpatients were investigated using a computerized record chart. The main observed forms were: (a) chronic tension-type headache--migraine with interparoxysmal headache, an evolved form of migraine in which a constant low severity headache develops between attacks; (b) transformed migraine, an evolved form of migraine with progressive worsening of the disease which reaches the level of continuous pain with the disappearance of typical migraine attacks. Interval headaches in migraine with interparoxysmal headache partly fulfil the IHS criteria for chronic tension-type headache. Analgesic drug abuse plays a prominent role in inducing CDH and in determining its clinical features.

Adult↗
PubMed1992

The trigemino-pupillary reflex: a model of sensory-vegetative integration.

Trigeminal stimulation can induce pupillary changes. In vivo and in vitro studies have demonstrated that electrical impulses applied at the trigeminal level can provoke a miotic response, whose nature has been ascribed to the anti-dromic release of neuropeptides (substance P in particular). In order to better define the pupil response to trigeminal stimulation, we investigated the human pupil response to quantified (painless and painful) corneal stimuli by means of a combined (neurophysiological and pharmacological) technique. The response to corneal stimulation was bilateral, direct and consensual. It had a biphasic progression with an initial mydriasis (which directly correlated with the stimulus intensity), followed by a miotic phase. The mydriatic phase disappeared after thymoxamine application, while homatropine pre-treatment prevented occurrence of the miotic phase. The data obtained indicate that the pupillary response to corneal stimulation (trigemino-pupillary reflex) is a multisynaptic reflex with an afferent branch involving the trigeminal system, and an afferent branch involving both the sympathetic and the parasympathetic system. Other pathways, such as the SP-mediated release of acetylcholine, cannot be excluded. Thus the reflex appears to be a potentially useful tool for investigating pain/vegetative interactions in various clinical conditions. In turn, the description of its changes in pathologies characterized by a sympathetic/parasympathetic deficit or by a SP-ergic imbalance will allow us to better describe its inner mechanisms.

Adult↗
PubMed1992

Multimodal evoked potentials in myotonic dystrophy (MyD).

By means of multimodal evoked potentials (EPs), we evaluated the central nervous system (CNS) involvement in 25 subjects suffering from myotonic dystrophy: brainstem auditory evoked potentials (BAEPs), middle-latency auditory evoked potentials (MLAEPs) and somatosensory evoked potentials (SEPs) from the upper limb were performed on all subjects, whereas only the 19 patients, whose clinical ocular abnormalities were slight, underwent pattern-electretinograms (PERGs) and pattern visual-evoked potentials (VEPs) in order to identify the site of lesion among visual pathways (retinal and/or retroretinal). PERGs were abnormal in 8/19 subjects, VEPs in 8/19 subjects (the two techniques were simultaneously abnormal in 8 eyes), BAEPs in 7/25 subjects, MLAEPs in 4/25 subjects (in one subject both BAEps and MLAEPs were abnormal) and SEPs were abnormal in 1/25 subjects. 13/25 of our subjects showed at least one EP that revealed a CNS involvement. The electrophysiological alterations were not correlated either with subject age or with disease duration. Multimodal EPs enabled us to demonstrate that CNS involvement in myotonic dystrophy is important and mainly affects the visual and auditory system.

Adult↗
PubMed1992

Accompanying symptoms of cluster attacks: their relevance to the diagnostic criteria.

Two-hundred-and-fifty-one consecutive cluster headache (CH) patients referred to the Pavia and Parma Headache Centers were evaluated in order to verify the presence and recurrence of one or more autonomic symptoms. Data obtained show that in 2.8% of patients cluster attacks were not accompanied by localized autonomic symptoms, thus confirming the report of Ekbom. We observed a high prevalence of photophobia, nausea and vomiting. The IHS diagnostic criteria for CH may need to be modified. The high frequency of "general" autonomic symptoms seems to suggest a component of "central" drive in the physiopathology of cluster headache.

Adult↗
PubMed1992

Hemicrania continua: a case responsive to piroxicam-beta-cyclodextrin.

The case of a 53-year-old woman is described, who since the age of 38 years had been suffering from a unilateral headache that was at first remitting, but then evolved into an unremitting course. The headache was burning in quality, located in the left forehead and face, and was accompanied by mild ipsilateral autonomic symptoms. The clinical picture, as well as the absolute response to indomethacin, suggested a diagnosis of hemicrania continua. The presence of mild gastric discomfort on continuous indomethacin administration made us transfer the patient to another NSAID (piroxicam-beta-cyclodextrin). With this drug, complete relief and good tolerability was obtained.

Chronic Disease↗
PubMed1992

Central analgesic activity of ibuprofen. A neurophysiological study in humans.

Ibuprofen is a widely used non-steroidal anti-inflammatory drug (NSAID). Inhibition of prostaglandin biosynthesis is considered to be the main mechanism of action of this substance. Recently, a central analgesic activity was described in an experimental study. In order to explore the possibility that ibuprofen induces analgesia at central level in humans, we investigated, in a double-blind design, the effects of orally-given 600 mg granular ibuprofen or placebo on nociceptive flexion reflex in normal volunteers. Ibuprofen produced a significant increase, as compared to placebo, in the threshold of the nociceptive reflex. The ratio between subjective pain threshold (Tp) and reflex threshold (Tr) was unchanged after either ibuprofen or placebo administration, indicating that Tp strictly paralleled Tr. These results indicate that ibuprofen displays a central antalgic activity in humans. Different supraspinal structures are probably involved, but the exact mechanisms are still to be clarified.

Administration, Oral↗
PubMed1992

Electrically elicited short and long-latency responses of intrinsic hand muscles in hereditary ataxias. Effects of isometric and ballistic isotonic voluntary contractions.

Short- and long-latency responses (HR and LLR) from thenar muscles were studied in patients with Friedreich's ataxia and pure cerebellar ataxia with later onset by applying electrical stimuli on the median nerve at the wrist. HR and LLR were examined during two different voluntary activities of the opponens pollicis muscle: isometric ("hold") and isotonic ballistic ("move") conditions. A preliminary conventional study of motor and sensory conduction of the median nerve was also carried out. Patients with Friedreich's ataxia had reduced or absent HR and LLR. Furthermore, those who preserved both responses had prolonged HR-LLR interpeak latency. All patients with Friedreich's ataxia also showed peripheral nerve conduction abnormalities, mainly in sensory fibers. These data can be accounted for by the widespread degeneration of many neural structures in this disorder. No abnormalities in HR were observed in pure cerebellar ataxia with later onset, whereas LLR was grossly enlarged in most patients, notably during "move" condition. Since cerebellar structures (especially the cerebellar cortex) are the only ones involved in this disorder, the cerebellum may play a role in modulating LLR. In particular, this effect could be more evident in isotonic ballistic movements.

Adolescent↗
PubMed1991

Cluster headache. Recent developments in clinical characterization and pathogenesis.

The preliminary results of some new studies on cluster headache (CH) point to: (a) the existence of a form, secondary episodic CH, which should be included in the classification of headache; (b) the significant role played by air temperature variations and the number of daylight hours on the onset of CH active periods. Data from the evaluation of pupil response to corneal stimuli suggest a widespread alteration of the pain/autonomic integrative processes at the level of the central nervous system. Finally, data on new preventive (i.e., verapamil and ozone) and symptomatic (i.e., hyperbaric oxygen and sumatriptan) treatments are reported.

Autonomic Nervous System↗
PubMed1990

Devic's neuromyelitis optica: long-term follow-up and serial CSF findings in two cases.

Sixteen cerebrospinal fluid (CSF) specimens serially obtained during long-term follow-up of two patients with Devic's neuromyelitis optica (DNO) were compared with 65 CSF samples from patients with multiple sclerosis (MS). By statistical analysis, the CSF profile in DNO was found to differ from that observed in MS, mainly showing pleocytosis, blood-brain barrier damage, and absence of persistent immunoglobulin G synthesis within the central nervous system. Oligoclonal bands, detected with isoelectric focusing, were present in CSF of 92% of the patients with MS, and in three CSF specimens from one patient with DNO during the first 6 months after disease onset. The bands disappeared in two subsequent samples. This finding has never been described in MS. One patient with DNO had an apparent chronic-relapsing course probably due to steroid dependence. The clinical and CSF features of our cases favour the nosographic independence of DNO and MS.

Adult↗
PubMed1990

A new 5-HT2 antagonist (ritanserin) in the treatment of chronic headache with depression. A double-blind study vs amitriptyline.

The exact relationship between depression and chronic headache remains unclear. Considerable clinical and pharmacological evidence suggests the existence of a common biological terrain. Many antidepressant drugs are effective in the treatment of migraine and chronic headache disorders. Ritanserin, a new very selective serotonin-2 (5-HT2) antagonist, has recently shown both analgesic and antidepressant properties. The present study compares in a double-blind design, the effectiveness of ritanserin and amitriptyline, a well-known antidepressant extensively used in migraine prophylaxis. Thirty-eight patients (30 females and 8 males ranging in age from 20 to 50 yrs) were classified according to the International Headache Society criteria as: patients with chronic tension-type headache (CTH) (11 cases) and patients with coexisting migraine and CTH (MCTH) (27 cases). Only patients with a score equal to or higher than 18 on the Hamilton Rating Scale for Depression (HRSD) were included. Ritanserin was highly effective in reducing Pain Total Index and analgesic consumption in chronic headache, and its activity was similar to that observed during amitriptyline treatment. A significant improvement of HRSD and HRSA (Hamilton Rating Scale for Anxiety) scores was observed during both treatments. The main results of our study concern the demonstration of antiheadache and antidepressive properties of ritanserin. To better define the profile of the patients and their clinical responsiveness to the treatment, dexamethasone suppression test, clonidine test and nociceptive flexion reflex were investigated in our patients. Our data confirm the usefulness of these methods as markers of chronic headache with depression.

Adult↗
PubMed1990

Abnormalities of central motor conduction in asymptomatic HIV-positive patients. Significance and prognostic value.

Percutaneous magnetic stimulation of the brain and spinal cord is a technique developed to demonstrate early and subclinical abnormalities in corticomotoneuron pathways. Central motor conduction time (CMCT) was evaluated in 58 HIV-seropositive patients neurologically asymptomatic (CDC groups II and III) and in two control groups. CMCT was abnormal in about 50% of HIV-seropositive patients. These electrophysiological abnormalities seem to have a negative prognostic value since about 64% of the patients with abnormal parameters seem to progress more rapidly to AIDS stages.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Pupil responsiveness in cluster headache: a dynamic TV pupillometric evaluation.

In this study the variations in pupil diameter induced by different stimuli (dark-light adaptation, light reflex, electric stimulation of the sural nerve) were investigated in episodic (in the active or remission phases) and in chronic cluster headache (CH) patients. Pupil size monitoring was performed with a monocular, infrared TV pupillometer, and sural nerve stimuli were applied after the pain threshold had been measured as the flexion reflex threshold of the biceps femoris muscle (RIII reflex). The results were compared with those obtained in patients with "peripheral" (third neuron) Horner's syndrome and in healthy sex- and age-matched controls. On the symptomatic side we found an impairment of pupil response to light flashes and nociceptive stimuli; similar findings were sometimes evident on the pain-free side, too. These results substantiate previous observations that in cluster headache a dysfunction of the integrative central nervous system pathways also exists intercritically and mostly bilaterally, involving both autonomic regulation and pain perception mechanisms.

Adult↗