The aim of the present study was to investigate the possible relationships between the presence of headache-related photophobia and migraine-associated allodynia--a hallmark of central sensitization--among patients with different migraine types. A sample of 456 migraineurs was studied. Our results showed that photophobia was present in a high proportion of patients, with similar figures in patients with episodic migraine or CM, and confirmed that the prevalence of allodynia was higher among CM patients than in those with episodic migraine. We found a clear association between migraine-related allodynia and photophobia only in CM patients. Overall, these findings suggest that light stimulation may contribute to central sensitization of pain pathways in migraineurs, possibly contributing to progression into chronic forms. The possible connections underlying this type of sensitization is offered by the recently published data on a non-image-forming visual retino-thalamo-cortical pathway which may allow photic signals to converge on a thalamic region which is selectively activated during migraine headache.

The purpose of this study is to review the current literature on the use of hyaluronic acid (HA) specifically applied to the treatment of osteoarthritis (OA) secondary to primary inflammatory rheumatic diseases. Osteoarthritis should be carefully considered because it has potentially devastating effects on health-related quality of life. Locally injected HA seems to be an effective treatment for OA but it is not clear how to place this treatment in the context of inflammatory rheumatic disorders. To retrieve relevant articles, we conducted the search through MEDLINE, EMBASE and Cochrane Databases performing the PICO strategy. We finally selected four randomized clinical trials and six observational studies and grouped them in accordance with its main objective within three focuses: the clinical effect of HA therapy in joints without any signs of inflammation, the clinical effects of HA therapy in joints with active synovitis, and the involvement and changes of synovial fluid in the treatment of secondary OA. Our qualitative analysis clearly showed that the current literature is marked by high levels of heterogeneity and therefore difficult to interpret. Therefore, our hypothesis that viscosupplementation should be considered as a treatment for chronic moderate symptomatic OA secondary to inflammatory rheumatic diseases, and not for flares with joint swelling, cannot be definitely supported. Welldesigned studies are necessary to definitively clarify the range of application of intra-articular HA injections in the treatment of inflammatory rheumatic disorders.

Chronification transforms episodic migraine into the pathologic chronic form. Biological characteristics of the migrainous brain progressively change, in predisposed subjects, under the repetition of external and internal stimuli. Modifications involve neurons, synapses, neurotransmitters, receptors, connectivity and pain control. f-MRI is a promising way to explore the still unclear biology of this progression. Areas covered: Data included were obtained from the most relevant and updated works available on PubMed about this topic. We summarized the pathophysiology of migraine chronification and of brain plasticity, and we described the different fMRI techniques and their main evidences about migraine transformation. Expert commentary: Functional-MRI has revealed many aspects regarding the peculiarity of the migrainous brain and its tendency toward chronicity but a series of questions are still open: What are the hallmarks of the predisposition to chronification? Which elements are the cause and which the consequence of this process?

Hip osteoarthritis affects a substantial and growing number of people worldwide. Its incidence and prevalence are increasing due to ageing and obesity. It is estimated that it affects between 10 and 18% of individuals over 60 years of age and up to 1 in 3 patients over the age of 85 with a substantial proportion of them experiencing persistent pain, loss of function and decline in health-related quality of life. Our work was aimed at updating the latest data on this field. We searched the following terms on PubMed: ‘injection therapy’, ‘osteoarthritis’ and ‘hip’. We limited our search to the period from 1-1-2018 until 22-6-2019 and to the English language. We retrieved 31 works. We decided to divide the works into three groups: hyaluronic acid in hip OA, other therapies in hip OA and emerging radiological techniques to measure the efficacy of injection therapy. So far, in the literature there is no solid evidence that supports the efficacy of intra-articular infiltration therapies in hip osteoarthritis. The international guidelines reflect this lack of solid scientific evidence. We believe that only original works that show high-level evidence can highlight the benefits of these therapies.