Clinical Correlates of Osmophobia in Primary Headaches: An Observational Study in Child Cohorts

Primary headaches, especially migraines, have a significant impact on physical and mental health, as well as on the scholarly performance and quality of life of children and adolescents. Osmophobia could be a potential diagnostic marker of migraine diagnosis and disability. This multicenter observational cross-sectional study included 645 children, aged 8-15, with a diagnosis of primary headaches. We took into consideration the duration, intensity and frequency of headaches, pericranial tenderness, allodynia and osmophobia. In a subgroup of migraine children, we evaluated the migraine-related disability, Psychiatric Self-Administration Scales for Youths and Adolescents, and the Child Version of the Pain Catastrophizing Scale. Osmophobia was found to be present in 28.8% of individuals with primary headaches, with children suffering from migraines having the highest prevalence (35%). Migraine patients with osmophobia also showed a more severe clinical picture, with enhanced disability, anxiety, depression, pain catastrophizing, and allodynia symptoms (F Roy square 10.47 p < 0.001). The presence of osmophobia could help in identifying a clinical migraine phenotype coherent with an abnormal bio-behavioral allostatic model that is worthy of prospective observations and careful therapeutic management.

Polygenic risk provides biological validity for the ICHD-3 criteria among Finnish migraine families

Background

Migraine is diagnosed using the extensively field-tested International Classification of Headache Disorders (ICHD-3) consensus criteria derived by the International Headache Society. To evaluate the criteria in respect to a measurable biomarker, we studied the relationship between the main ICHD-3 criteria and the polygenic risk score, a measure of common variant burden in migraine.

Methods

We used linear mixed models to study the correlation of ICHD-3 diagnostic criteria, underlying symptoms, and main diagnoses with the polygenic risk score of migraine in a cohort of 8602 individuals from the Finnish Migraine Genome Project.

Results

Main diagnostic categories and all underlying diagnostic criteria formed a consistent continuum along the increasing polygenic burden. Polygenic risk was associated with the heterogeneous clinical picture starting from the non-migraine headache (mean 0.07; 95% CI 0.02–0.12; p = 0.008 compared to the non-headache group), to probable migraine (mean 0.13; 95% CI 0.08–0.18; p < 0.001), migraine headache (mean 0.17; 95% CI 0.14–0.21; p < 0.001) and migraine with typical visual aura (mean 0.29; 95% CI 0.26–0.33; p < 0.001), all the way to the hemiplegic aura (mean 0.37; 95% CI 0.31–0.43; p < 0.001). All individual ICHD-3 symptoms and the total number of reported symptoms, a surrogate of migraine complexity, demonstrated a clear inclination with an increasing polygenic risk.

Conclusions

The complex migraine phenotype progressively follows the polygenic burden from individuals with no headache to non-migrainous headache and up to patients with attacks manifesting all the features of the ICHD-3 headache and aura. Results provide further biological support for the ICHD-3 diagnostic criteria.

A prospective study on osmophobia in migraine versus tension-type headache in a large series of attacks

Background

In literature, osmophobia is reported as a specific migrainous symptom with a prevalence of up to 95%. Despite the International Classification of Headache Disorders 2nd edition proposal of including osmophobia among accompanying symptoms, it was no longer mentioned in the ICHD 3rd edition.

Methods

We conducted a prospective study on 193 patients suffering from migraine without aura, migraine with aura, episodic tension-type headache or a combination of these. After a retrospective interview, each patient was asked to describe in detail osmophobia, when present, in the following four headache attacks.

Results

In all, 45.7% of migraine without aura attacks were associated with osmophobia, 67.2% of migraineurs reported osmophobia in at least a quarter of the attacks. No episodic tension-type headache attack was associated with osmophobia. It was associated with photophobia or phonophobia in 4.3% of migraine without aura attacks, and it was the only accompanying symptom in 4.7% of migraine without aura attacks. The inclusion of osmophobia in the ICHD-3 diagnostic criteria would enable a 9.0% increased diagnostic sensitivity.

Conclusion

Osmophobia is a specific clinical marker of migraine, easy to ascertain and able to disentangle the sometimes challenging differential diagnosis between migraine without aura and episodic tension-type headache. We recommend its inclusion among the diagnostic criteria for migraine as it increases sensitivity, showing absolute specificity.

Nosographic analysis of osmophobia and field testing of diagnostic criteria including osmophobia

INTRODUCTION

Osmophobia has been suggested as an additional symptom of migraine without aura, and a high prevalence of osmophobia of up to 50% has been reported in the literature. We conducted a nosographic study of osmophobia in all migraineurs and tension-type headache patients and a field testing of suggested diagnostic criteria of osmophobia, presented in the appendix of the second edition of The International Classification of Headache Disorders and suggested by Silva-Néto et al. and Wang et al ., in migraine without aura and tension-type headache patients (n = 1934).

MATERIALS AND METHODS

Each patient received a validated semi-structured interview. All subjects fulfilled the diagnostic criteria of the second edition of The International Classification of Headache Disorders for migraine or tension-type headache. Statistical analyses were performed using statistical software R. The statistical R package "Caret" was used to construct a confusion matrix and retrieve sensitivity, which is defined as the suggested criteria's ability to correctly diagnose migraine without aura patients, and specificity, defined as the suggested criteria's ability to not wrongly diagnose tension-type headache patients.

RESULTS

Osmophobia was present in 33.5% of patients with migraine with aura, in 36.0% of patients with migraine without aura, and in 1.2% of patients with tension-type headache. All migraineurs with osmophobia also fulfilled the current criteria for migraine by having nausea or photophobia and phonophobia. The appendix criteria had a sensitivity of 0.96 and a specificity of 0.99 for migraine without aura, and a sensitivity of 0.65 and a specificity of 0.99 for probable migraine without aura. Both the criteria by Silva-Néto et al. and Wang et al. had a sensitivity of 0.98 and a specificity of 0.99 for migraine without aura, and a sensitivity of 0.66 and a specificity of 0.99 for probable migraine without aura.

DISCUSSION

This study demonstrates the remarkable specificity of osmophobia. The criteria by Silva-Néto et al. and Wang et al. both had a higher sensitivity than the appendix criteria for migraine without aura; all three criteria had a low sensitivity for probable migraine without aura. However, neither the appendix criteria nor the criteria by Silva-Néto et al. or Wang et al. added any extra patients that would not have been diagnosed by the current diagnostic criteria for migraine. Osmophobia is a valuable symptom that may be useful to differentiate between migraine without aura and tension-type headache in difficult clinical cases.

CONCLUSION

Our results do not suggest that alterations of the current diagnostic criteria for migraine without aura are needed.

Headache Diagnosis in Children and Adolescents

PURPOSE OF REVIEW

Headache phenotypes can differ between adults and children. While most headaches are due to primary headache disorders, in a small population, they can be an indication of a potentially life-threatening neurologic condition. The challenge lies in identifying warning signs that warrant further workup. This article reviews different types of pediatric headaches and headache evaluation in children and teens, and focuses on the approach for diagnosis of secondary headaches.

RECENT FINDINGS

Common thought is that increased frequency and severity of headache may reflect secondary pathology; however, headache phenotype may not be fully developed and can evolve in adolescence or adulthood. Headache location, particularly occipital headache alone, does not necessarily signify secondary intracranial pathology. Certain warning signs warrant neuroimaging, but others only warrant imaging in certain clinical contexts. Brain MRI is the neuroimaging modality of choice, though there is a high rate of incidental findings and often does not change headache management. A stepwise approach is essential to avoid missing secondary headaches. There are several differences between adults and children in clinical manifestations of headache. Evaluation and diagnosis of pediatric headache starts with a thorough headache and medical history, family and social history, and identification of risk factors. A thorough physical and neurologic exam is important, with close attention to features that could suggest secondary headache pathology. Neuroimaging and other testing should only be performed if there is concern for secondary headache.