Fibromyalgia (FM) is a condition characterized by chronic widespread pain whose pathogenesis is still not fully defined. Evidence based on structural and functional neuroimaging methods, ...electrophysiological, and morphological – skin biopsy – features demonstrated a central and peripheral nervous system involvement. A dysfunction in nociceptive inputs processing at the central level was highlighted as the primary cause of FM, but other data coming from different laboratories contributed to emphasize again the peripheral origin of FM. In fact, small fibers neuropathy (SFN) was observed in a large number of patients submitted to skin biopsy. The complex interaction between central and peripheral factors is opening a new scenario about the management of this neurological disorder. Whether proximal SFN is an initiating event leading to FM or is the consequence of stress-related insular hyper excitability remains unclear. Mild sufferance of peripheral afferents could function as a trigger for an exaggerated response of the so-called “salience matrix” in predisposed individuals. On the other side, the intriguing hypothesis rising from animal models could indicate that the cortical hyper function could cause peripheral small afferent damage. The research should go on the genetic origin of such peripheral and central abnormalities, the acquired facilitating factors, and the presence of different phenotypes in order to search for efficacious treatments, which are still lacking.
Scientific evidence points to a shared neural representation between performing and observing an action. The action observation notoriously determines a modulation of the observer's sensorimotor ...system, a phenomenon called Motor Resonance (MR). Fibromyalgia (FM) patients suffer from a condition characterized by generalized musculoskeletal pain in which even simple movement can exacerbate their symptoms. Maladaptive functioning of the primary motor cortex is a common finding in patients with chronic pain. Activation of the motor cortex is known to induce an analgesic effect in patients with chronic pain. In this exploratory study, we intend to verify if the mere observation of a movement could elicit activation of the motor cortical areas in patients with FM. Therefore, the purpose of this study was to examine the presence of MR in patients affected by fibromyalgia. We adopted a behavioral paradigm known for detecting the presence of MR and a neurophysiological experiment. Participants watched videos showing gripping movements towards a graspable or an ungraspable object, respectively, and were asked to press a button the instant the agent touched the object (Time-to-contact detection session). In a different experimental session, participants were only requested to observe and pay attention to the videos (Observation-only session). During each experimental session, the participants' cerebral hemodynamic activity was recorded using the functional Near-Infrared Spectroscopy method. The behavioral task analysis revealed the presence of MR in both FM patients and healthy controls. Moreover, neurophysiological findings suggested that the observation of movement during the Observation-only session provoked activation and modulation of the cortical motor networks of FM patients. These results could represent evidence of the possible beneficial effects of movement observation in restarting motor activation, notoriously reduced, in FM patients.
Background
Osmophobia, is common among primary headaches, with prevalence of migraine.
The study aimed to evaluate prevalence and clinical characteristics of patients with osmophobia in a cohort of ...primary headache patients selected at a tertiary headache center. The second aim was to verify the possible predicting role of osmophobia in preventive treatment response in a sub cohort of migraine patients.
Methods
This was an observational retrospective cohort study based on data collected in a tertiary headache center.
We selected patients aged 18–65 years, diagnosed as migraine without aura (MO), migraine with aura (MA) or Chronic Migraine (CM), Tension-Type Headache (TTH); and Cluster Headache (CH). We also selected a sub-cohort of migraine patients who were prescribed preventive treatment, according to Italian Guidelines, visited after 3 months follow up.
Patients were considered osmophobic, if reported this symptom in at least the 20% of headache episodes. Other considered variables were: headache frequeny, the migraine disability assessment (MIDAS), Allodynia Symptom Checklist, Self-rating Depression scale, Self-rating Anxiety scale, Pain intensity evaluated by Numerical Rating Scale-NRS- form 0 to 10.
Results
The 37,9% of patients reported osmophobia (444 patients with osmophobia, 726 without osmophobia).
Osmophobia prevailed in patients with the different migraine subtypes, and was absent in patients with episodic tension type headache and cluster headache (chi square 68.7 DF 7
p
< 0.0001). Headache patients with osmophobia, presented with longer hedache duration (F 4.91 p 0.027; more severe anxiety (F 7.56 0.007), depression (F 5.3 p 0.019), allodynia (F 6 p 0.014), headache intensity (F 8.67 p 0.003). Tension type headache patients with osmophobia (n° 21), presented with more frequent headache and anxiety. A total of 711 migraine patients was visited after 3 months treatment. The change of main migraine features was similar between patients with and without osmophobia.
Conclusions
While the present study confirmed prevalence of osmophobia in migraine patients, it also indicated its presence among chronic tension type headache cases, marking those with chronic headache and anxiety.
Osmophobia was associated to symptoms of central sensitization, as allodynia. It was not relevant to predict migraine evolution after first line preventive approach.
Evidence by functional imaging studies suggests the role of left DLPFC in the inhibitory control of nociceptive transmission system. Pain exerts an inhibitory modulation on motor cortex, reducing MEP ...amplitude, while the effect of pain on motor intracortical excitability has not been studied so far. In the present study, we explored in healthy subjects the effect of capsaicin-induced pain and the modulatory influences of left DLPFC stimulation on motor corticospinal and intracortical excitability. Capsaicin was applied on the dorsal surface of the right hand, and measures of motor corticospinal excitability (test-MEP) and short intracortical inhibition (SICI) and facilitation (ICF) were obtained by paired-pulse TMS on left motor cortex. Evaluations were made before and at different times after capsaicin application in two separate sessions: without and with high-frequency rTMS of left DLPF cortex, delivered 10 min. after capsaicin application. We performed also two control experiments to explore: 1: the effects of Left DLPFC rTMS on capsaicin-induced pain; 2: the modulatory influence of left DLPFC rTMS on motor cortex without capsaicin application. Capsaicin-induced pain significantly reduced test MEP amplitude and decreased SICI leaving ICF unchanged. Left DLPFC rTMS, together with the analgesic effect, was able to revert the effects of capsaicin-induced pain on motor cortex restoring normal MEP and SICI levels. These data support the notion that that tonic pain exerts modulatory influence on motor intracortical excitability; the activation of left DLPFC by hf rTMS could have analgesic effects, reverting also the motor cortex excitability changes induced by pain stimulation.
Background
Over the last decades, a considerable number of observational scales have been developed to assess pain in persons with dementia. The time seems ripe now to build on the knowledge and ...expertize implemented in these scales to form an improved, “best‐of” meta‐tool. The EU‐COST initiative “Pain in impaired cognition, especially dementia” aimed to do this by selecting items out of existing observational scales and critically re‐assessing their suitability to detect pain in dementia. This paper reports on the final phase of this collaborative task.
Methods
Items from existing observational pain scales were tested for “frequency of occurrence (item difficulty),” “reliability” and “validity.” This psychometric testing was carried out in eight countries, in different healthcare settings, and included clinical as well as experimental pain conditions.
Results
Across all studies, 587 persons with dementia, 27 individuals with intellectual disability, 12 Huntington's disease patients and 59 cognitively healthy controls were observed during rest and movement situations or while receiving experimental pressure pain, respectively. The psychometric outcomes for each item across the different studies were evaluated within an international and multidisciplinary team of experts and led a final selection of 15 items (5x facial expressions, 5x body movements, 5x vocalizations).
Conclusions
The final list of 15 observational items have demonstrated psychometric quality and clinical usefulness both in their former scales and in the present international evaluation; accordingly, they qualified twice to form a new internationally agreed‐on meta‐tool for Pain Assessment in Impaired Cognition, the PAIC‐15 scale.
Significance
Using a meta‐tool approach by building on previous observational pain assessment scales and putting the items of these scales through rigorous empirical testing (using experimental as well as clinical pain studies in several European countries), we were able to identify the best items for pain assessment in individuals with impaired cognition. These selected items form the novel PAIC15 scale (pain assessment in impaired cognition, 15 items).
Background
Fibromyalgia (FM) is a syndrome characterized by altered pain processing at central and peripheral level, whose pathophysiologic mechanisms remain obscure. We aimed at exploring the ...structural changes of peripheral nociceptor measured by skin biopsy, the functional changes of central nociceptive pathway assessed by laser‐evoked potentials (LEP), and their correlation with clinical features and comorbidities.
Methods
In all, 81 patients diagnosed with FM underwent skin biopsies with quantification of intraepidermal nerve fibre density (IENFD) at the thigh and distal leg, and LEP recording by stimulating hand, thigh and foot. Nerve conduction study (NCS), clinical features, comorbidity with migraine and mood disorders, and previous, non‐active immune‐mediated disorders were recorded.
Results
Intraepidermal nerve fibre density was reduced in 85% of patients at the thigh and in 12.3% of patients at the distal leg, whereas it was normal in 14.8% of patients. N2P2 habituation index from laser stimulation at the thigh was altered in 97.5% of patients and correlated with reduced IENFD at the thigh. LEP latencies and amplitudes did not differ among groups. No association was found between IENFD, LEP, clinical features and comorbidities.
Conclusions
Fibromyalgia patients most commonly showed a mild loss of peripheral nociceptors at the thigh rather than distal small fibre neuropathy. This finding was associated with an altered habituation index and strengthened the hypothesis that central sensitization plays a key role in the pathogenesis of the disease.
Significance
Central impairment of pain processing likely underlies FM, which in most patients is associated with mild proximal small fibre pathology.
Background
The discovery of the prominent action of Calcitonin Gene Related Peptide –CGRP- on trigeminal afferents and meningeal vessels, opened a new era in migraine treatment. However, how the ...block of nociceptive afferents could act on central mechanisms of migraine is still not clear. In this pilot study we aimed to test the effect of 3 months Galcanezumab (CGA) therapy on occipital visual reactivity in migraine patients, using the Steady State Visual Evoked Potentials-SSVEPs and Functional Near Infrared Spectroscopy –fNIRS.
Method
Thirteen migraine patients underwent clinical and neurophysiological examination in basal condition (T0), 1 h after GCA injection (T1) and after 3 months of GCA treatment (T2). Ten healthy volunteers were also evaluated.
Results
At T2, there was a reduction of headache frequency and disability. At T2, the EEG power significantly diminished as compared to T0 and T1 at occipital sites, and the topographical analysis confirmed a restoration of SSVEPs within normal values. The Oxyhemoglobin levels in occipital cortex, which were basically increased during visual stimulation in migraine patients, reverted to normal values at T2.
Conclusions
The present pilot study indicates that Galcanezumab could act on cortical targets located beyond the pain network, restoring the abnormal occipital reactivity. This effect could indicate the possible disease modifying properties of CGRP related monoclonal antibodies.
Migraine is considered a disease with diurnal and 24 h pattern, though the existence of a prevalent circadian rhythm associated to migraine frequency and severity is still not clear. This ...observational cross-sectional study aimed to: 1. Assess the circadian rhythm of migraine attacks onset in a large patients' population selected in a headache center and including episodic and chronic migraine 2. Analyze the principal characteristic of the different onset time groups 3. Verify if migraine features, particularly those associated to chronic and disabling migraine, could be discriminant factors for time of onset group.
We selected 786 consecutive migraine outpatients, who correctly completed the headache diaries for 3 consecutive months and who fulfilled the diagnosis of migraine without aura-MO, migraine with typical aura alone or associated to migraine without aura - MO/MA and chronic migraine - CM. For the time of headache onset, we considered four time slots, from 6 to 12 am (morning), from 1 to 6 pm (afternoon), from 7 to 11 pm (evening), from 12 pm to 5 am (night), and an additional category named "any time". Each time slot included the 60 min preceding the next one (e.g. an onset at 12.30 am was included in 6-12 am time slot). We evaluated in all patients the pericranial tenderness, anxiety and depression tracts, headache-related disability, sleep features, quality of life, allodynia and fatigue.
We scored a total of 16,578 attacks, distributed in the entire day. The most of patients, including CM, satisfied the criteria for the "any time" onset. Night onset was significantly less represented in the MA/MO group. Patients with prevalent night onset were significantly older, with longer migraine history and shorter sleep duration. Age and illness duration were the variables discriminating the different onset time groups.
The most of migraine patients do not report a specific circadian profile of attacks occurrence. Frequent migraine, severe disability, psychopathological tracts as well as central sensitization signs, do not match with a specific circadian rhythm of attacks onset. Night onset migraine seems to be an age related feature, emerging in the course of the disease.
Background and purpose
The aim was to provide insights to the characteristics of headache in the context of COVID‐19 on behalf of the Headache Scientific Panel and the Neuro‐COVID‐19 Task Force of ...the European Academy of Neurology (EAN) and the European Headache Federation (EHF).
Methods
Following the Delphi method the Task Force identified six relevant questions and then conducted a systematic literature review to provide evidence‐based answers and suggest specific diagnostic criteria.
Results
No data for facial pain were identified in the literature search. (1) Headache incidence during acute COVID‐19 varies considerably, with higher prevalence rates in prospective compared to retrospective studies (28.9%–74.6% vs. 6.5%–34.0%). (2) Acute COVID‐19 headache is usually bilateral or holocranial and often moderate to severe with throbbing pain quality lasting 2–14 days after first signs of COVID‐19; photo‐phonophobia, nausea, anosmia and ageusia are common associated features; persistent headache shares similar clinical characteristics. (3) Acute COVID‐19 headache is presumably caused by immune‐mediated mechanisms that activate the trigeminovascular system. (4) Headache occurs in 13.3%–76.9% following SARS‐CoV‐2 vaccination and occurs more often amongst women with a pre‐existing primary headache; the risk of developing headache is higher with the adenoviral‐vector‐type vaccines than with other preparations. (5) Headache related to SARS‐CoV‐2 vaccination is mostly bilateral, and throbbing, pressing, jolting or stabbing. (6) No studies have been conducted investigating the underlying mechanism of headache attributed to SARS‐CoV‐2 vaccines.
Conclusion
The results of this joint EAN/EHF initiative provide a framework for a better understanding of headache in the context of SARS‐CoV‐2 infection and vaccination.
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