A significant body of experimental evidence has demonstrated that it is possible to induce the illusion of ownership of a fake limb or even an entire fake body using multisensory correlations. ...Recently, immersive virtual reality has allowed users to experience the same sensations of ownership over a virtual body inside an immersive virtual environment, which in turn allows virtual reality users to have the feeling of being “embodied” in a virtual body. Using such virtual embodiment to manipulate body perception is starting to be extensively investigated and may have clinical implications for conditions that involve altered body image such as chronic pain. Here, we review experimental and clinical studies that have explored the manipulation of an embodied virtual body in immersive virtual reality for both experimental and clinical pain relief. We discuss the current state of the art, as well as the challenges faced by, and ideas for, future research. Finally, we explore the potentialities of using an embodied virtual body in immersive virtual reality in the field of neurorehabilitation, specifically in the field of pain.
Migraine is a disease for which there is still no defined pathophysiological etiology and few translational models. The organic nitrate nitroglycerin has been in use as an experimental model of ...migraine in both human and animal studies for several years. The drug produces a number of effects within the head, that includes blood vessels, nerves and brain areas that may produce a response similar to a migraine attack in predisposed subjects. A better understanding of the nature of these changes and how well they parallel a true migraine attack would allow for a translational model to better understand some of the mechanisms involved in the generation of a migraine attack. The present review summarizes the known body of knowledge of nitroglycerin effects evaluated in humans and animals as it relates to potential mechanisms associated with migraine headaches.
Background
Monoclonal antibodies (mABs) targeting the calcitonin gene-related peptide (CGRP) pathway represent the first disease-specific preventive migraine therapy. Growing evidence suggests that ...they are effective in the preventive treatment of difficult-to-treat patients. In this study, we evaluated the psychological predictors of the outcome of treatment with the anti-CGRP monoclonal antibody erenumab in patients with chronic migraine (CM).
Methods
Seventy-five patients with CM who had already failed at least 3 preventive therapies received erenumab every 28 days for a period of 12 months. Before the first administration, patients received a full psychological evaluation using The Structured Clinical Interview for DSM-5 Clinician Version (SCID-5-CV) to assess personality disturbances (primary outcome), mood and anxiety disorders, and as well specific questionnaires to evaluate alexithymia traits, childhood traumas, and current stressors (secondary outcomes).
Results
After 12 months of treatment, 53 patients reported a reduction of at least 50% in headache days/per month (Responders), whereas 22 did not (Non Responders). When compared to Responders, Non Responders were characterized by a higher prevalence of personality disorders belonging to Cluster C (avoidant, dependent, and obsessive-compulsive) (77% vs 37%,
p
= .001). Non Responders were also characterized by a higher prevalence of anxiety disorders (90% vs 60%,
p
= 0.007), showed more alexithymic traits (51.7 ± 13.7 vs 42.9 ± 14.3,
p
= 0.017), and reported a higher number of 'at least serious' current stressors (3.2 ± 4.0 vs 0.8 ± 1.4,
p <
.0001) than Responders. At the multivariate analysis, higher prevalence of Cluster C personality disorders (OR 3.697;
p
= 0.05) and higher number of ‘at least serious’ life events (OR 1.382;
p
= 0.017) arose as prognostic factors of erenumab failure.
Conclusions
Erenumab confirmed its effectiveness in a population of difficult-to-treat migraine. The presence of “anxious-fearful” personality together with current stressors and anxiety represent negative predictors of treatment outcome.
Trial registration
The study protocol was registered at clinicaltrials.gov (
NCT04361721
).
Purpose
To evaluate secondary outcomes including changes in functioning and disability associated with galcanezumab, a humanized monoclonal antibody to calcitonin gene-related peptide, in patients ...with chronic migraine.
Methods
Patients randomly received galcanezumab (120 mg
n
= 278, 240 mg
n
= 277) or placebo (
n
= 558) during 3 months of double-blind treatment, followed by a 9-month open-label extension. The Migraine-Specific Quality-of-Life Questionnaire v2.1 (MSQv2.1) measured the impact of migraine on patient functioning. The Migraine Disability Assessment (MIDAS) quantified headache-related disability. Changes from baseline were analyzed with mixed model repeated measures or analysis of covariance.
Results
Total MSQ score at baseline was 44.88 ± 18.02 (mean ± SD), indicating significant functional impairment. At Month 3, least squares (LS) mean change ± SE in total MSQ for galcanezumab-treated patients were 20.51 ± 1.49 (120 mg) and 20.49 ± 1.49 (240 mg), both statistically significantly greater vs placebo-treated patients (14.55 ± 1.21; both
P
< 0.001). Total MIDAS score at baseline was 67.24 ± 57.31 (mean ± SD). At Month 3, LS mean change ± SE from baseline in total MIDAS for galcanezumab-treated patients was statistically significantly greater than placebo for 120 mg group (placebo: − 11.53 ± 3.38 vs 120 mg: − 20.27 ± 4.07;
P
< 0.05) but not for 240 mg group (− 17.02 ± 4.05). At Month 12, within-group mean changes from baseline for total MSQ (28.56 ± 1.19 previous placebo; 29.53 ± 1.51 previous 120 mg; 25.83 ± 1.49 previous 240 mg) and MIDAS scores (− 28.47 ± 2.95 previous placebo; − 31.47 ± 3.69 previous 120 mg; − 31.13 ± 3.62 previous 240 mg) were statistically significant (
P
< 0.001) for the open-label treatment population regardless of previous double-blind treatment assignment.
Conclusions
Galcanezumab-treated patients with chronic migraine reported statistically significant improvements in functioning and disability, representing a clinically significant change.
Trial registration
ClinicalTrials.gov registry: NCT02614261. Registered 25 November 2015.
Inhibiting the activity of fatty-acid amide hydrolase (FAAH), the enzyme that deactivates the endocannabinoid anandamide, enhances anandamide-mediated signaling and holds promise as a molecular ...target for the treatment of human pathologies such as anxiety and pain. We have previously shown that the peripherally restricted FAAH inhibitor, URB937, prevents nitroglycerin-induced hyperalgesia – an animal model of migraine - and attenuates the activation of brain areas that are relevant for migraine pain, e.g. trigeminal nucleus caudalis and locus coeruleus. The current study is aimed at profiling the behavioral and biochemical effects of URB937 in animal models of acute and chronic migraine. We evaluated the effects of URB937 in two rat models that capture aspects of acute and chronic migraine, and are based on single or repeated administration of the vasodilating drug, nitroglycerin (NTG). In addition to nocifensive behavior, in trigeminal ganglia and medulla, we measured mRNA levels of neuropeptides and pro-inflammatory cytokines along with tissue levels of anandamide and palmitoylethanolamide (PEA), an endogenous agonist of peroxisome proliferator-activated receptor type-a (PPAR-a), which is also a FAAH substrate. In the acute migraine model, we also investigated the effect of subtype-selective antagonist for cannabinoid receptors 1 and 2 (AM251 and AM630, respectively) on nocifensive behavior and on levels of neuropeptides and pro-inflammatory cytokines. In the acute migraine paradigm, URB937 significantly reduced hyperalgesia in the orofacial formalin test when administered either before or after NTG. This effect was accompanied by an increase in anandamide and PEA levels in target neural tissue, depended upon CB1 receptor activation, and was associated with a decrease in calcitonin gene-related peptide (CGRP), substance P and cytokines TNF-alpha and IL-6 mRNA. Similar effects were observed in the chronic migraine paradigm, where URB937 counteracted NTG-induced trigeminal hyperalgesia and prevented the increase in neuropeptide and cytokine transcription.
The results show that peripheral FAAH inhibition by URB937 effectively reduces both acute and chronic NTG-induced trigeminal hyperalgesia, likely via augmented anandamide-mediated CB1 receptor activation. These effects are associated with inhibition of neuropeptidergic and inflammatory pathways.
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•Peripheral FAAH inhibitor, URB937, increased availability of anandamide and PEA.•URB937 counteracted hyperalgesia in the rat models of episodic and chronic migraine.•The reduced trigeminal nociception depended upon CB1 receptor activation.•URB937 prevented the NTG-induced increase in neuropeptide and cytokine transcription.
The aim of this study was to determine which supervised machine learning (ML) algorithm can most accurately classify people with Parkinson's disease (pwPD) from speed-matched healthy subjects (HS) ...based on a selected minimum set of IMU-derived gait features. Twenty-two gait features were extrapolated from the trunk acceleration patterns of 81 pwPD and 80 HS, including spatiotemporal, pelvic kinematics, and acceleration-derived gait stability indexes. After a three-level feature selection procedure, seven gait features were considered for implementing five ML algorithms: support vector machine (SVM), artificial neural network, decision trees (DT), random forest (RF), and K-nearest neighbors. Accuracy, precision, recall, and F1 score were calculated. SVM, DT, and RF showed the best classification performances, with prediction accuracy higher than 80% on the test set. The conceptual model of approaching ML that we proposed could reduce the risk of overrepresenting multicollinear gait features in the model, reducing the risk of overfitting in the test performances while fostering the explainability of the results.
Fatty-acid amide hydrolase (FAAH) is an intracellular serine hydrolase that catalyzes the cleavage of endogenous fatty-acid amides, including the endocannabinoid anandamide (AEA). We previously ...reported that the peripherally restricted FAAH inhibitor URB937, which selectively increases AEA levels outside the central nervous system, reduces hyperalgesia and c-Fos expression in the trigeminal nucleus caudalis (TNC) and the locus coeruleus in an animal model of migraine based on nitroglycerin (NTG) administration.
To further investigate the relevance of FAAH inhibition in the NTG animal model of migraine by testing the effects of the globally active FAAH inhibitor URB597.
Our experimental approach involved mapping neuronal c-Fos protein expression, measurement of AEA levels in brain areas and in trigeminal ganglia, evaluation of pain-related behavior and quantification of molecular mediators in rats that received URB597 (2 mg/kg i.p.) either before or after NTG administration (10 mg/kg, i.p.).
Pre-treatment with URB597 significantly reduced c-Fos immunoreactivity in the TNC and inhibited NTG-induced hyperalgesia in the orofacial formalin test. This behavioral response was associated with a decrease in neuronal nitric oxide synthase, calcitonin gene-related peptide and cytokine gene expression levels in central and peripheral structures. Administration of URB597 after NTG had no such effect.
The findings suggest that global FAAH inhibition may offer a therapeutic approach to the prevention, but not the abortive treatment, of migraine attacks. Further studies are needed to elucidate the exact cellular and molecular mechanisms underlying the protective effects of FAAH inhibition.
•URB597 prevents neurobiological changes induced in an animal model of migraine.•URB597 reduces c-Fos in TNC, nociceptive behavior and mRNA levels of pain mediators.•Global FAAH inhibition represents a preventive approach to migraine attacks.
To develop novel and effective treatments for ischemic stroke, we investigated the neuroprotective effects of the macrolide antibiotic azithromycin in a mouse model system of transient middle ...cerebral artery occlusion. Intraperitoneal administration of azithromycin significantly reduced blood–brain barrier damage and cerebral infiltration of myeloid cells, including neutrophils and inflammatory macrophages. These effects resulted in a dose-dependent reduction of cerebral ischemic damage, and in a remarkable amelioration of neurological deficits up to 7days after the insult. Neuroprotection was associated with increased arginase activity in peritoneal exudate cells, which was followed by the detection of Ym1- and arginase I-immunopositive M2 macrophages in the ischemic area at 24–48h of reperfusion. Pharmacological inhibition of peritoneal arginase activity counteracted azithromycin-induced neuroprotection, pointing to a major role for drug-induced polarization of migratory macrophages towards a protective, non-inflammatory M2 phenotype.
•Azithromycin dose-dependently reduces brain damage caused by MCAo in mice.•Azithromycin reduces brain infiltration of neutrophils and inflammatory macrophages.•Neuroprotection is associated with elevation of brain and peritoneal M2 macrophages.•Inhibition of arginase activity counteracted azithromycin-induced neuroprotection.
Background
Calcitonin gene related peptide (CGRP) is a key neuropeptide involved in the activation of the trigeminovascular system and it is likely related to migraine chronification. Here, we ...investigated the role of CGRP in an animal model that mimics the chronic migraine condition via repeated and intermittent nitroglycerin (NTG) administration. We also evaluated the modulatory effect of topiramate on this experimental paradigm. Male Sprague-Dawley rats were injected with NTG (5 mg/kg, i.p.) or vehicle, every 2 days over a 9-day period (5 total injections). A group of animals was injected with topiramate (30 mg/kg, i.p.) or saline every day for 9 days. Twenty-four hours after the last administration of NTG or vehicle, animals underwent tail flick test and orofacial Von Frey test. Rats were subsequently sacrificed to evaluate c-Fos and CGRP gene expression in medulla-pons region, cervical spinal cord and trigeminal ganglia.
Results
NTG administration induced spinal hyperalgesia and orofacial allodynia, together with a significant increase in the expression of CGRP and c-Fos genes in trigeminal ganglia and central areas. Topiramate treatment prevented NTG-induced changes by reversing NTG-induced hyperalgesia and allodynia, and inhibiting CGRP and c-Fos gene expression in all areas evaluated.
Conclusions
These findings point to the role of CGRP in the processes underlying migraine chronification and suggest a possible interaction with gamma-aminobutyrate (GABA) and glutamate transmission to induce/maintain central sensitization and to contribute to the dysregulation of descending pain system involved in chronic migraine.
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