Is there hope for chronic pain and headache?

Molecular mechanism underlying orofacial antinociceptive activity of Vanillosmopsis arborea Baker (Asteraceae) essential oil complexed with β-cyclodextrin

BACKGROUND

Vanillosmopsis arborea Baker has recognized economic value owing to the high content of (-)-α-bisabolol (BISA) in the essential oil of its stem (EOVA). The antinociceptive effect of EVOA has already been demonstrated, and β-cyclodextrin (βCD) is known to improve the analgesic effect of various substances.

PURPOSE

Thus, we aimed to evaluate the orofacial antinociceptive effect of a complex containing EOVA-βCD in rodents.

METHODS

EOVA was obtained by simple hydrodistillation, and the essential oil was complexed with βCD. The animals (n = 6/group) were treated orally with EOVA-βCD (10 or 50 mg/kg), or vehicle (control), and subjected to cutaneous orofacial nociception (formalin, capsaicin, acidic saline or glutamate), corneal (hypertonic saline) or temporomandibular (formalin) tests. The expression of FOS protein was analyzed in the spinal cord. Molecular docking was performed using the 5-HT₃ and M₂ receptors and BISA.

RESULTS

The oral administration of EOVA-βCD reduced nociceptive behaviour. Moreover, EOVA-βCD decreased FOS expression. The molecular docking study indicates that BISA interacts with 5-HT3 and M2 receptors, indicating the potential mechanism of action of the tested compound.

CONCLUSIONS

Our results indicate that EOVA-βCD possesses orofacial antinociceptive effect, indicating that this complex can be used in analgesic drug development.

Factors associated to chronic migraine with medication overuse: A cross-sectional study

BACKGROUND AND AIM

Factors implicated in the evolution of episodic migraine into chronic migraine are largely elusive. Medication overuse is considered to be one of the main determinants, but other possible clinical and psychological factors can play a role. The aim of this study is to identify factors that are associated with chronic migraine with medication overuse.

METHOD

We enrolled consecutive migraine patients, subdividing them in two groups: Subjects with a long history of episodic migraine and subjects with chronic migraine and medication overuse. We then compared their clinical and psychological variables in a cross-sectional study.

RESULTS

Three hundred and eighteen patients were enrolled, of which 156 were episodic migraine and 162 were chronic migraine and medication overuse patients. The mean age was 42.1 ± 10.3, 80.8% were female. The duration of migraine was 24.6 years in episodic migraine and 24.0 years in chronic migraine and medication overuse ( p = 0.57). After the multivariate analysis, the factors associated to chronic migraine and medication overuse were: Marital status (married vs. unmarried, OR 3.65, 95% CI 1.63-8.19, p = 0.002; separated/divorced/widowed vs. unmarried, OR 4.19, 95% CI 1.13-15.47, p = 0.031), physical activity (OR 0.42, 95% CI 0.19-0.91, p = 0.029), age at onset of migraine (OR 0.94, 95% CI 0.89-0.98, p = 0.016), use of at least one migraine preventive medication (OR 2.36, 95% CI 1.18-4.71, p = 0.014), history of depression (OR 2.91, 95% CI 1.25-6.73, p = 0.012), insomnia associated with the use of hypnotics (OR 5.59, 95% CI 1.65-18.93, p = 0.006), traumatic head injuries (OR 3.54, 95% CI 1.57-7.99, p = 0.002), snoring (OR 2.24, 95% CI 1.05-4.79, p = 0.036), previous and/or actual use of combined oral contraceptives (OR 3.38, 95% CI 1.10-10.3, p = 0.031) and higher scores in the Childhood Trauma questionnaire (OR 1.48, 95% CI 1.09-2.02, p = 0.012).

CONCLUSION

We considered several aspects that may be involved in the development of chronic migraine and medication overuse. A multivariate analysis identified 10 factors belonging to five different areas, to suggest that chronic migraine and medication overuse onset is likely influenced by a complex mixture of factors. This information is useful when planning strategies to prevent and manage chronic migraine and medication overuse.

Evaluation and management of orofacial pain

Challenging to diagnose and manage, orofacial pain is a common and costly problem with a profound effect on quality of life. Delayed diagnosis and management can lead to prolonged patient suffering and disability. This article describes the background, assessment, differential diagnosis, management, and referral of patients with orofacial pain.

Orofacial pain management: current perspectives

Some of the most prevalent and debilitating pain conditions arise from the structures innervated by the trigeminal system (head, face, masticatory musculature, temporomandibular joint and associated structures). Orofacial pain (OFP) can arise from different regions and etiologies. Temporomandibular disorders (TMD) are the most prevalent orofacial pain conditions for which patients seek treatment. Temporomandibular disorders include a number of clinical problems that involve the masticatory musculature, the temporomandibular joint (TMJ) or both. Trigeminal neuropathic pain conditions can arise from injury secondary to dental procedures, infection, neoplasias, or disease or dysfunction of the peripheral and/or central nervous system. Neurovascular disorders, such as primary headaches, can present as chronic orofacial pain, such as in the case of facial migraine, where the pain is localized in the second and third division of the trigeminal nerve. Together, these disorders of the trigeminal system impact the quality of life of the sufferer dramatically. A multidisciplinary pain management approach should be considered for the optimal treatment of orofacial pain disorders including both non-pharmacological and pharmacological modalities.