Search PubMed⌕ Search

Biomedical subjects

Giorgio Sandrini

Publications and source records attributed to Giorgio Sandrini.

29 records · Page 2Linked to original sources
PubMed2002

Electrophysiological evidence for trigeminal neuron sensitization in patients with migraine.

The electrically elicited corneal reflex is a useful tool for exploring the trigeminal system in humans and it may provide additional evidence pointing to a dysfunction of this system in migrainous patients. Tactile perception, corneal reflex and pain thresholds were studied in 48 migraine without aura patients during pain-free periods and compared with those observed in 24 controls. Twenty-eight of the patients had strictly unilateral headache, while the other 20 had bilateral or side-shifting pain during attacks. Both migraine subgroups (bilateral and unilateral) showed significantly lower thresholds compared with controls. The lowest values were observed on the symptomatic side of unilateral migraine patients. These findings suggest that sensorimotor mechanisms and/or pain control systems at the trigeminal level are impaired in migraine. The bilateral location of these abnormalities seems to point to a centrally located dysfunction.

Adult↗
PubMed1991

Impairment of corneal pain perception in cluster headache.

Despite many studies, the mechanisms underlying the pathogenesis of pain in cluster headache (CH) still remain obscure. An involvement of substance P (SP) containing neurons of the Gasserian ganglion and/or of the spinal trigeminal nucleus has recently been suggested, e.g., by impairment of inhibitory descending pathways on trigeminal nociceptive neurons. The electrically elicited corneal reflex was studied in 21 CH patients (15 in active phase, 6 in remission). This method allows simultaneous measurements of the trigemino-facial reflex and corneal pain perception. A significant reduction of pain thresholds (more evident on the pain side) was observed in CH during the active phase, while normal values were recorded during the remission phase. Ten out of 15 patients in the active phase showed a significantly reduced corneal pain threshold on the pain side, while tactile sensibility was normal. Moreover, latency, amplitude and duration of the corneal reflex were normal for both painful and painless stimulations during both phases. The threshold of the nociceptive muscular response in the active phase was significantly reduced, suggesting that the excitability of trigeminal nociceptive neurons or of the motor neurons is increased in CH. The results agree with the hypothesis that a reversible impairment of several integrative functions, including the activity of trigeminal pain control system, exists in CH during the active phase.

Adult↗
PubMed1986

Circadian variations of human flexion reflex.

We investigated 8 healthy male volunteers, evaluating RII and RIII thresholds every 6 h starting from noon, for a 24-h period. Both reflex responses exhibited a circadian rhythmicity: the lowest values were found in the early morning (9.1 +/- 3.0 and 13.1 +/- 4.4 mA, respectively), while the highest values were observed at midnight (13.1 +/- 3.5 and 18.5 +/- 5.3 mA). Also mean cosinor analysis indicated the existence of a significant rhythm with acrophase at 20:12 for RII and 22:29 for RIII. In 4 subjects, beta-endorphin plasma (beta-EP) level was tested during the day. No correlation was observed between circadian changes of beta-EP and RIII threshold. Other factors are likely to be involved in the circadian variation of nociceptive flexion reflex in man.

Adult↗
PubMed1984

Concomitant increase in nociceptive flexion reflex threshold and plasma opioids following transcutaneous nerve stimulation.

In order to evaluate the role of endogenous opioids in sustaining analgesia induced by transcutaneous nerve stimulation (TNS), we measured plasma beta-lipotropin (BLPH), beta-endorphin (BEP), ACTH and cortisol changes concomitantly with nociceptive flexion reflex (RIII) threshold after TNS (80 microseconds rectangular waves at 85 Hz) in a group of healthy volunteers (A). The same protocol was carried out in another group of volunteers using placebo stimulation (0.5 Hz) (B). RIII threshold significantly increased 0.5 h after TNS in group A and no changes were recorded in group B. Similarly, both BLPH and BEP plasma levels increased at the end of TNS only in group A. ACTH and cortisol concentrations show only random variations after both high and low frequency TNS. A positive linear correlation was found between the maximum percentage increase of RIII threshold after high frequency TNS and the maximum percentage increase of BLPH plasma levels occurring 20 min beforehand (r = 0.856, P less than 0.001). A less positive correlation was found between RIII and BEP levels (r = 0.574, P less than 0.05). These data indicate that the so-called post-stimulation analgesia could be supported by the enhancement of the endogenous opioid system.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Changes in nociceptive flexion reflex threshold across the menstrual cycle in healthy women.

OBJECTIVE: We assessed the influence of changes in steroid hormones across the menstrual cycle on the spinal nociceptive reflex. METHOD: We studied in 14 healthy women during the follicular and luteal phase the nociceptive flexion reflex (RIII reflex), an objective neurophysiological method that allows exploring possible abnormal functioning of the pain-control system. The basal body temperature (BBT) was used to evaluate the different phases of the ovarian cycle. The menstrual distress questionnaire (MDQ) was also applied for monitoring somatic and psychological symptoms during the cycle. RESULTS: During the luteal phase, the threshold of the RIII reflex (Tr) and the psychophysical threshold for pain (Tp) were both significantly reduced compared with the follicular phase. Moreover, the reflex threshold in the luteal phase was negatively correlated to the total MDQ score of the recording day. CONCLUSIONS: A higher sensitivity to pain stimuli was observed during the luteal phase of the menstrual cycle, which probably results from a reduction in the inhibitory descending control on spinal nociceptive flexion reflex. Complex neuromodulatory interactions of ovarian steroids with other systems of neurotransmission (especially serotonergic) may account for these observations.

Adult↗
PubMedDate not supplied

Report of eight new cases of hypnic headache and mini-review of the literature.

Hypnic headache is a rare condition first described by Raskin in 1988. This headache is not included in the first edition of the International Headache Society classification (IHC 1st Edition). We describe eight new Italian hypnic headache cases and consider our findings in the light of literature data. Our cases do not completely fulfil the diagnostic criteria for the syndrome proposed in 1997 by Goadsby and Lipton: four of our patients reported an attack duration longer than 60 minutes (ranging from 3 to 10 hours) and five reported unilateral pain. These data are in line with an analysis of all 61 cases published in the literature to date, which reveals a pain duration of over 60 minutes in 45.9% of the cases and unilateral attacks in 36%. Hypnic headache will be included in the fourth chapter (Other Primary Headaches) of the revised edition of the above-mentioned classification (IHC 2nd Edition).

Acetates↗
PubMedDate not supplied

Instrumental investigations in primary headache. An updated review and new perspectives.

While some instrumental techniques are clearly useful for differentiating symptomatic forms from primary headache, the usefulness of certain other techniques, neurophysiological investigations in particular, in clinical practice is still debated. A Task Force of the European Federation of Neurological Societies has recently proposed guidelines and recommendations on the use of neurophysiological tests and neuroimaging procedures in non-acute headache. This article reviews many of the most important literature references relevant to this topic and looks at the prospects for future research.

Blinking↗
PubMedDate not supplied

Differences in the EMG pattern of leg muscle activation during locomotion in Parkinson's disease.

In this pilot study, EMG patterns of leg muscle activation were studied in five parkinsonian patients with (B1) and five without (B2) freezing. Gastrocnemius medialis (GM) and tibialis anterior (TA) activity was analysed, by means of surface electromyography (EMG), during treadmill walking at two different belt speeds. Both groups showed reduced GM activity and an overactive TA at the lower speed compared with controls. Upon increasing the speed, the B2 patients showed a marked GM response (increment index 100%), while a moderate change was observed in the B1 group. Poor recruitment of the GM characterises parkinsonian gait in general; this pattern is much more marked in parkinsonian patients with freezing of gait, who show a loss of GM adaptation to variation of locomotion speed.

Adaptation, Physiological↗
PubMedDate not supplied

Planning availability in stroke rehabilitation units.

The sequelae of cerebrovascular diseases constitute, and in the coming years will increasingly constitute, a major health problem. Stroke is already the leading cause of permanent invalidity, the second leading cause of dementia, and the third (on course to become the second) leading cause of death, after cardiovascular diseases and cancer. In view of the aging of the population and of the fact that stroke is strictly age-related, the incidence of stroke, in Italy, looks set to rise progressively over the coming years. In recent years, units have been set up for the specialist inpatient treatment of stroke victims, both in the acute phase (known as stroke units) and in the subsequent rehabilitative phase (stroke rehabilitation units), the aim being to improve both the management of these patients and, as a result, their functional outcome. Health policies and programming will have to take into account the need for more beds in both types of stroke unit.

Health Facility Planning↗
PubMedDate not supplied

Lower limb manual muscle testing in the early stages of Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth disease (CMT) is a genetically and clinically heterogeneous disorder that affects approximately one in 2,500 individuals. CMT 1A, which is due to a duplication in the area containing the PMP-22 gene on chromosome 17, is the most frequent CMT subtype. To date, there is no consensus among authors about which muscles are weakened in the early stages of CMT, even though this knowledge would be crucial for deciding the most appropriate interventions to restore balance between muscles and prevent the development of deformities. The aim of this study was to evaluate the strength of several lower limb muscles in the early stages of CMT 1A. In a series of 45 patients (age 10-72 years; 21 males, 24 females) affected by CMT 1A, we evaluated 83 non-operated lower limbs that corresponded to the two milder stages of a five-level functional classification. The strength of two foot muscles, seven leg muscles, two thigh muscles, and three pelvic girdle muscles was graded using the manual muscle testing techniques of Daniels and Worthingham; the power of the triceps surae was graded, in the prone position, using a 4-level scale of ability to raise the heel from the floor. Muscle strength was determined on the basis of interobserver agreement estimated by kappa statistics between two observers. The flexor hallucis brevis and lumbricals were very weak in all the limbs; the leg muscles were strong in more than 90% of limbs, except the peronei (strong in 83.13%); all the triceps surae were strong in the prone test, but 16.87% were weak in the standing test; all the proximal muscles were strong. In the large majority of patients in the early stages of CMT 1A, the intrinsic foot muscles are very weak and the leg and proximal muscles are strong.

Adolescent↗