Changes in headache characteristics with oral appliance treatment for obstructive sleep apnea

Effect of chronic intermittent hypoxia on ocular and intraoral mechanical allodynia mediated via the calcitonin gene-related peptide in a rat

STUDY OBJECTIVES

Obstructive sleep apnea, a significant hypoxic condition, may exacerbate several orofacial pain conditions. The study aims to define the involvement of calcitonin gene-related peptide (CGRP) in peripheral and central sensitization and in evoking orofacial mechanical allodynia under chronic intermittent hypoxia (CIH).

METHODS

Male rats were exposed to CIH. Orofacial mechanical allodynia was assessed using the eyeblink test and the two-bottle preference drinking test. The CGRP-immunoreactive neurons in the trigeminal ganglion (TG), CGRP-positive primary afferents projecting to laminae I-II of the trigeminal spinal subnucleus caudalis (Vc), and neural responses in the second-order neurons of the Vc were determined by immunohistochemistry. CGRP receptor antagonist was administrated in the TG.

RESULTS

CIH-induced ocular and intraoral mechanical allodynia. CGRP-immunoreactive neurons and activated satellite glial cells (SGCs) were significantly increased in the TG and the number of cFos-immunoreactive cells in laminae I-II of the Vc were significantly higher in CIH rats compared to normoxic rats. Local administration of the CGRP receptor antagonist in the TG of CIH rats attenuated orofacial mechanical allodynia; the number of CGRP-immunoreactive neurons and activated SGCs in the TG, and the density of CGRP-positive primary afferent terminals and the number of cFos-immunoreactive cells in laminae I-II of the Vc were significantly lower compared to vehicle-administrated CIH rats.

CONCLUSIONS

An increase in CGRP in the TG induced by CIH, as well as orofacial mechanical allodynia and central sensitization of second-order neurons in the Vc, supported the notion that CGRP plays a critical role in CIH-induced orofacial mechanical allodynia.

Obstructive sleep apnea treatment improves temporomandibular disorder pain

PURPOSE

The existence of a bidirectional relationship between poor sleep and pain intensity has been studied, and good sleep quality has been found to be a key factor underlying pain control. The purpose of this prospective cohort study was to observe if OSA treatment provides a reduction in temporo-mandibular disorder (TMD) pain and headache attributed to TMD in patients with obstructive sleep apnea (OSA) after 18 months of OSA treatment.

METHODS

A prospective cohort study was conducted on consecutive patients suffering from OSA. Patients underwent polysomnography and TMD examination according to the DC/TMD protocol at baseline and after 18 months. Intensity of TMD pain and headache attributed to TMD were analyzed.

RESULTS

Of 40 patients (31 men, mean age 51.3 ± 10.3 years), 33 underwent OSA treatment. At the follow-up examination after 18 months, significant improvements in the intensity of pain-related TMD and headache attributed to TMD were observed (p < 0.05). Seven patients did not start treatment for OSA or discontinued treatment. These patients did not show any significant difference in intensity of TMD-pain or headache attributed to TMD after 18 months (p > 0.05).

CONCLUSIONS

Significant reductions in intensity of pain-related TMD and headache attributed to TMD were observed in patients with OSA after 18 months of OSA treatment onset, while no difference was observed in subjects not undergoing or discontinuing OSA treatment.

TRIAL REGISTRATION

The protocol was registered on ClinicalTrials.gov database with number NCT04948541.

The role of oral appliance therapy in obstructive sleep apnoea

There is now widespread recognition within the world of sleep medicine of the increasing importance of dental sleep medicine and, in particular, the role of oral appliance therapy (OAT) in the management of adults with obstructive sleep apnoea (OSA). For the purpose of this review, the term OAT refers to a custom-made intra-oral appliance, which acts to posture the mandible in a forward and downward direction, away from its natural resting position. Whilst nasally applied continuous positive airway pressure remains the "gold standard" in nonsurgical OSA management, OAT remains the recognised alternative treatment.This review of OAT aims to provide an evidence-based update on our current understanding of their mode of action, exploring the potential anatomical and physiological impact of their use in preventing collapse of the upper airway; the current clinical practice guidelines, including the recently published National Institute of Clinical Excellence 2021 guidance, in conjunction with the American Academy of Sleep Medicine and American Academy of Dental Sleep Medicine; optimal design features, comparing the role of custom-made versus noncustom OAT devices and the importance of titration in achieving a dose-dependent effect; patient predictors, preference and adherence to OAT; its impact on a range of both patient- and clinician-centred health outcomes, with a comparison with CPAP; the limitations and side-effects of providing OAT; and, finally, a look at future considerations to help optimise the delivery and outcomes of OAT.

Clinical application of headache impact test (HIT)-6 and epworth sleepiness scale (ESS) for sleep apnea headache

Background

Sleep apnea headache is a major symptom accompanying obstructive sleep apnea (OSA), but relatively little evidence has been reported on the magnitude of its negative effects on patients or the evaluation of therapeutic effects. We quantitatively assessed sleep apnea headache using the Epworth sleepiness scale (ESS) and headache impact test (HIT)-6.

Methods

The first part of this study enrolled 86 patients (72 male; mean [± standard deviation] age 53.2 ± 13.8 years) who had been diagnosed with OSA by polysomnography in our sleep center and investigated the prevalence and characteristics of sleep apnea headache. The second part enrolled 21 patients (12 male; mean age, 47.5 ± 13.0 years) diagnosed with sleep apnea headache by polysomnography and/or peripheral arterial tonometry and evaluated the effects of OSA therapy on headache. Medical records including ESS, HIT-6, and polysomnographic data were retrospectively analyzed.

Results

The prevalence of sleep apnea headache among OSA patients was 22.1%, and was higher in female (50.0%) than in male (16.7%). The proportion of N3 and HIT-6 score showed a significant negative correlation (Pearson’s R = -0.51, p < 0.05). In female, median apnea–hypopnea index (AHI) was significantly lower in patients with headache (26.1 /h [interquartile range 21.4–29.6 /h]) than in patients without (54.2 /h [41.3–73.9 /h], p < 0.05, Wilcoxon rank-sum test). HIT-6 and ESS scores improved from 56.4 ± 9.7 to 45.9 ± 8.4 and from 9.0 ± 4.4 to 5.3 ± 4.2 in patients with oral appliance (OA), and from 54.3 ± 10.7 to 44.6 ± 6.1 and from 10.0 ± 4.0 to 4.9 ± 2.9 with continuous positive airway pressure (CPAP). In patients with good CPAP adherence, these scores improved from 58.1 ± 10.8 to 44.0 ± 6.0 and from 9.6 ± 3.8 to 3.6 ± 1.7.

Conclusion

Among patients with OSA, prevalence of sleep apnea headache was higher in female than in male. In female, headache was associated with relatively mild OSA. OA showed substantial effects on headache in mild to moderate OSA patients. CPAP adherence was important for improving the headache. HIT-6 score appears useful for the diagnosis and management of sleep apnea headache.

More than sleepiness: prevalence and relevance of nonclassical symptoms of obstructive sleep apnea

PURPOSE OF REVIEW

The purpose of this review is to describe the nonclassical symptoms and manifestations occurring in patients with obstructive sleep apnea (OSA), both from a standpoint of prevalence and in terms of clinical relevance. Particular emphasis will be given to nightmares, comorbid insomnia, restless legs syndrome and periodic limb movement disorder, bruxism, morning headache, nocturia, acid reflux, chronic cough and dysphagia.

RECENT FINDINGS

A review of the recent literature suggests that nonclassical symptoms have a high prevalence, are underestimated, and can interact with quality of life. Although these disturbances may occur together by mere coincidence, they may interact reciprocally. However, the degree of symptoms is not always correlated with OSA severity.

SUMMARY

OSA is a heterogeneous disease with variable clinical manifestations. This review highlights the need for detailed evaluation of patients with OSA to diagnose other important sleep disorders and clinical manifestations, given their frequent association.

The multisystemic effects of oral appliance therapy for obstructive sleep apnea: A narrative review

Obstructive sleep apnea (OSA) is a chronic condition accompanied by repeated obstruction of the upper airway during sleep despite respiratory efforts, resulting in intermittent hypoxemia, altered sleep structure, and sympathetic activation. Previous studies have shown a significant association between OSA and general health issues such as cardiovascular diseases, endocrine disorders, neurocognitive function decline, and poor quality of life. Continuous positive airway pressure (CPAP) has been considered as the first line treatment for OSA. However, accumulating evidence supports the role of oral appliance (OA) therapy, including mandibular advancement devices, as an alternative option for snoring and OSA patients who do not comply with or refuse CPAP usage. Despite a generally favorable outcome of OA therapy for OSA related respiratory indices, studies focusing on the impact of systemic effects of OA therapy in OSA patients are relatively scarce compared with the extensive literature focusing on the systemic effects of CPAP. Therefore, this article aimed to provide an overview of the current evidence regarding the multisystemic effects of OA therapy for OSA.

Pediatric Chronic Orofacial Pain: A Narrative Review of Biopsychosocial Associations and Treatment Approaches

Pediatric chronic orofacial pain (OFP) is an umbrella term which refers to pain associated with the hard and soft tissues of the head, face, and neck lasting >3 months in patients younger than 18 years of age. Common chronic pediatric OFP diagnoses include temporomandibular disorder, headaches, and neuropathic pain. Chronic OFP can adversely affect youth's daily functioning and development in many areas of well-being, and may be associated with emotional stress, depression, functional avoidance, and poor sleep, among other negative outcomes. In this mini-review, we will discuss common psychological comorbidities and familial factors that often accompany chronic pediatric OFP conditions. We will also discuss traditional management approaches for pediatric orofacial pain including education, occlusal appliances, and psychological treatments such as relaxation, mindfulness-based interventions, and cognitive-behavioral treatments. Finally, we highlight avenues for future research, as a better understanding of chronic OFP comorbidities in childhood has the potential to prevent long-term pain-related disability in adulthood.

Metabolic Aspects of Migraine: Association With Obesity and Diabetes Mellitus

Migraine is a disabling neurovascular disorder, characterized by moderate to severe unilateral headaches, nausea, photophobia, and/or phonophobia, with a higher prevalence in women than in men, which can drastically affect the quality of life of migraine patients. In addition, this chronic disorder is related with metabolic comorbidities associated with the patient's lifestyle, including obesity and diabetes mellitus (DM). Beyond the personal and socioeconomic impact caused by migraine, obesity and DM, it has been suggested that these metabolic disorders seem to be related to migraine since: (i) they are a risk factor for developing cardiovascular disorders or chronic diseases; (ii) they can be influenced by genetic and environmental risk factors; and (iii) while clinical and epidemiological studies suggest that obesity is a risk factor for migraine, DM (i.e., type 1 and type 2 DM) have been reported to be either a protective or a risk factor in migraine. On this basis, and given the high worldwide prevalence of migraine, obesity, and DM, this article provides a narrative review of the current literature related to the association between the etiology and pathophysiology of migraine and these metabolic disorders, considering lifestyle aspects, as well as the possible involvement of neurotransmitters, neuropeptides, and/or sex hormones. While a link between migraine and metabolic disorders has been suggested, many studies are contradictory and the mechanisms involved in this association are not yet sufficiently established. Therefore, further research should be focused on understanding the possible mechanisms involved.

Prevalence and factors correlated with hypertension secondary from obstructive sleep apnea

Background

In 2003, the JNC 7 reported obstructive sleep apnea (OSA) as a cause of secondary hypertension. The prevalence of OSA in hypertension ranges from 30-80%. There are limited data on the prevalence and risk factors of OSA in hypertensive patients. This study thus aimed to evaluate prevalence and clinical predictors of obstructive sleep apnea (OSA) in these patients.

Methods

This was a cross-sectional study and conducted at the hypertension clinic at Khon Kaen University’s Srinagarind Hospital, Thailand. We enrolled patients with hypertension treated at the clinic. OSA was defined as apnea-hypopnea index of 5 events/hour or over according to cardiopulmonary monitoring. Patients whose hypertension was due to any other causes were excluded. The prevalence of OSA was calculated and risk factors for OSA were analyzed using multivariate logistic regression.

Results

There were 726 hypertensive patients treated at the clinic. Out of those, 253 (34.8%) were randomly studied and categorized as either non-OSA (147 patients, 58.1%) or OSA (106 patients, 41.9%). There were four independent factors associated with OSA-induced hypertension: age, sex, history of snoring, and history of headache. Headache had an adjusted odds ratio (95% confidence interval) of 3.564 (95% confidence interval of 1.510, 8.411).

Conclusion

Age, male sex, history of snoring, and headache were independent predictors of hypertension caused by OSA.