Publications by authors named "Gaia Fragiotta"

5 Publications

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Effect of phobic visual stimulation on spinal nociception.

Physiol Behav 2019 07 19;206:22-27. Epub 2019 Mar 19.

"Sapienza" University of Rome Polo Pontino, Department of Medico-Surgical Sciences and Biotechonologies, Latina, Italy.

To explore the role of strong negative emotions in spinal nociception, we evaluated the effect of fear-relevant videos of small animals on the nociceptive withdrawal reflex (NWR) and reflex-related pain perception in healthy subjects with a specific phobia of small animals. Twenty healthy subjects with a specific phobia of small animals diagnosed according to DSM-V criteria were included in this study. The NWR was evoked in the lower limb by stimulating the sural nerve and recording EMG activity in the biceps femoris. NWR pain-related perception was quantified on an 11-point numerical rating scale (NRS). Subjects were examined during 4 recording sessions. In the baseline session, no images were projected. In the other sessions, the subjects were invited to watch a video containing either neutral or phobic content. To evaluate neurovegetative responses, we measured heart rate using a pulse oximeter during each recording session. A series of clinical rating scales were administered to subjects to evaluate disgust, fear, and anxiety. The NWR amplitude was significantly increased during the phobic video session and was associated with the fear inventory scale scores. Women showed higher NWR amplitude values during the phobic video session and a lower recovery rate during the after-effect video session than did men. The NWR amplitude and related pain perception were dissociated from each other during the phobic video session, as the NRS score remained unchanged while the NWR increased in amplitude. Emotions induced by the viewing of phobic videos seem to enhance the activation of the spinal circuitries involved in nociception and the withdrawal reaction without interfering with pain processing pathways or dissociating the reflex response from related pain perception. This effect appears to differ by sex, as it was more intense and longer lasting in women than in men. Emotions induced by phobic video viewing increase the alertness devoted to the defensive reaction by emphasizing nociceptive responses independently from pain perception. The NWR may represent an interesting tool for exploring the interaction between strong negative emotions and spinal nociception. A better understanding of this mechanism may be a theoretical prerequisite for the optimization of pain management in several chronic pain syndromes.
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http://dx.doi.org/10.1016/j.physbeh.2019.03.021DOI Listing
July 2019

Progression of Gait Ataxia in Patients with Degenerative Cerebellar Disorders: a 4-Year Follow-Up Study.

Cerebellum 2017 06;16(3):629-637

Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Via Faggiana 1668, 40100, Latina, Italy.

In the present study, the progression of gait impairment in a group of patients with primary degenerative cerebellar ataxias was observed over a period of 4 years. A total of 30 patients underwent an initial gait analysis study, and thereafter only 12 were evaluated because they completed the 2- and 4-year follow-up evaluations. Time-distance parameters, trunk and joint range of motion (RoM), and variability parameters (e.g., coefficients of variation) were measured at the baseline and at each follow-up evaluation. The scale for the assessment and rating of ataxia (SARA) was used to evaluate disease severity. We found a significant increase in the SARA score at both the 2- and 4-year follow-up evaluations. Almost all the gait variables changed significantly only at the 4-year follow-up. Particularly, we found a significant decrease in the step length and in the hip, knee, and ankle joint RoM values and noted a significant increase in the trunk rotation RoM and stride-to-stride and step length variability. Furthermore, a significant difference in ankle joint RoM was found between spinocerebellar ataxia and sporadic adult-onset ataxia patients, with the value being lower in the former group of patients. Our findings suggest that patients with degenerative cerebellar ataxias exhibit gait decline after 4 years from the baseline. Moreover, patients try to maintain an effective gait by adopting different compensatory mechanisms during the course of the disease in spite of disease progression.
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http://dx.doi.org/10.1007/s12311-016-0837-2DOI Listing
June 2017

Effect of high level of bladder filling on spinal nociception and motoneuronal excitability.

Exp Brain Res 2015 Dec 23;233(12):3459-66. Epub 2015 Aug 23.

Unit of Neurorehabilitation, Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University of Rome, ICOT, Corso della Repubblica 79, 40100, Latina, Italy.

To verify whether high level of bladder distension may counteract the inhibitory effect of descending pathways on sacral spinal cord neurons and to investigate which spinal circuitries are possibly involved in such a viscero-somatic interaction. Nociceptive withdrawal reflex (NWR), cutaneous silent period (CSP), and H-reflex were recorded in both lower and upper limbs of twenty-eight healthy subjects. Subjects were examined during baseline (empty bladder, no voiding desire), high level of bladder filling (urgency desire), and control (empty bladder, no voiding desire) sessions. Results showed that the NWR and its related pain perception were reduced in the upper limbs, while only a pain perception reduction in males was observed in the lower limbs. The H-reflex was inhibited in both limbs. No effects were found on the CSP duration. The decrease in both the NWR and its related pain perception in the upper limbs confirms the presence of a bladder distension-induced descending inhibitory modulation on nociception at spinal level. The lack of a similar inhibitory effect in the lower limbs suggests that excitatory nociceptive inputs from bladder afferents counterbalance the inhibitory effect on sacral spinal cord. The lack of the descending inhibitory effect may be a mechanism aimed at forcing the micturition phase to avoid bladder damage caused by bladder sovradistension.
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http://dx.doi.org/10.1007/s00221-015-4416-4DOI Listing
December 2015

Modular organization of the head retraction responses elicited by electrical painful stimulation of the facial skin in humans.

Clin Neurophysiol 2015 Dec 19;126(12):2306-13. Epub 2015 Feb 19.

Department of Medical-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica 79, 04100 Latina, Italy. Electronic address:

Objective: To explore whether the trigeminocervical reflexes (TCRs) show a reflex receptive field organization in the brainstem.

Methods: The facial skin of 16 healthy subjects was electrically stimulated at nine sites reflecting the distribution of the three branches of the trigeminal nerve. The reflex-evoked EMG responses were measured bilaterally from the neck muscles and the head and neck kinematic reactions were detected.

Results: TCRs are site dependent. There was a vertical gradient in the magnitude of the reflex responses. EMG and kinematic reflexes were larger when evoked from ophthalmic and maxillary sites than from mandibular ones. The reflex responses exhibited a crossed right-left behavior. Stimulation of the lateral sites evoked larger reflex responses in the contralateral trapezium muscle as well as head rotation and neck bending away from the stimulated side.

Conclusion: This modular arrangement of the TCRs seems to be related to withdrawal strategies aimed at protecting the face from injuries, in accordance with the functional role that each group of muscles plays in head and neck motion.

Significance: It is likely that the CNS may exploit the neck muscle synergies revealed by the painful stimulation of the skin face in order to control the head and neck movements.
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http://dx.doi.org/10.1016/j.clinph.2015.01.029DOI Listing
December 2015

Bladder filling attenuates spinal cord nociceptive reflexes in humans.

Clin Neurophysiol 2014 Nov 24;125(11):2271-2276. Epub 2014 Mar 24.

IRCCS Neuromed, Pozzilli, IS, Italy.

Objective: To examine the viscerosomatic interaction between bladder afferents and somatic nociception we evaluated the effect of bladder filling on the nociceptive withdrawal reflex (NWR) in 21 healthy subjects.

Methods: NWR was evoked in the lower and upper limbs by stimulating the sural and index finger digital nerves, respectively, while simultaneously recording EMG activity in the biceps femoris and biceps brachialis. NWR pain-related perception was quantified on a 10-point pain scale. Bladder filling was evaluated with suprapubic bladder sonography. Subjects were examined during empty bladder, medium and high level of bladder filling sessions.

Results: NWR magnitude in both upper and lower limbs and perceived pain for the upper limb were significantly decreased at higher levels of bladder filling compared to empty bladder sessions.

Conclusions: Reduced NWR magnitude in both upper and lower limbs during bladder filling strongly indicates that bladder control and nociception share common modulatory descending pathways. Bladder afferents may activate these pathways to suppress the micturition reflex, but they may also inhibit spinal reflexes to maintain continence during pain stimuli.

Significance: The effect of bladder filling on the NWR may represent a useful tool to investigate interactions between the neural pathways controlling the bladder and pain.
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http://dx.doi.org/10.1016/j.clinph.2014.03.014DOI Listing
November 2014