Psychiatric comorbidities in allodynic migraineurs

Neurobiology of migraine progression

Chronic migraine is one of the most devastating headache disorders. The estimated prevalence is 1.4-2.2% in the population. The factors which may predispose to the process of migraine progression include high frequency of migraine attacks, medication overuse, comorbid pain syndromes, and obesity. Several studies showed that chronic migraine results in the substantial anatomical and physiological changes in the brain. Despite no clear explanation regarding the pathophysiologic process leading to the progression, certain features such as increased sensory sensitivity, cutaneous allodynia, impaired habituation, identify the neuronal hyperexcitability as the plausible mechanism. In this review, we describe two main mechanisms which can lead to this hyperexcitability. The first is persistent sensitization caused by repetitive and prolonged trigeminal nociceptive activation. This process results in changes in several brain networks related to both pain and non-pain behaviours. The second mechanism is the decrease in endogenous brainstem inhibitory control, hence increasing the excitability of neurons in the trigeminal noceptive system and cerebral cortex. The combination of increased pain matrix connectivity, including hypothalamic hyperactivity and a weak serotonergic system, may contribute to migraine chronification.

CGRP Administration Into the Cerebellum Evokes Light Aversion, Tactile Hypersensitivity, and Nociceptive Squint in Mice

The neuropeptide calcitonin gene-related peptide (CGRP) is a major player in migraine pathophysiology. Previous preclinical studies demonstrated that intracerebroventricular administration of CGRP caused migraine-like behaviors in mice, but the sites of action in the brain remain unidentified. The cerebellum has the most CGRP binding sites in the central nervous system and is increasingly recognized as both a sensory and motor integration center. The objective of this study was to test whether the cerebellum, particularly the medial cerebellar nuclei (MN), might be a site of CGRP action. In this study, CGRP was directly injected into the right MN of C57BL/6J mice via a cannula. A battery of tests was done to assess preclinical behaviors that are surrogates of migraine-like symptoms. CGRP caused light aversion measured as decreased time in the light zone even with dim light. The mice also spent more time resting in the dark zone, but not the light, along with decreased rearing and transitions between zones. These behaviors were similar for both sexes. Moreover, significant responses to CGRP were seen in the open field assay, von Frey test, and automated squint assay, indicating anxiety, tactile hypersensitivity, and spontaneous pain, respectively. Interestingly, CGRP injection caused significant anxiety and spontaneous pain responses only in female mice, and a more robust tactile hypersensitivity in female mice. No detectable effect of CGRP on gait was observed in either sex. These results suggest that CGRP injection in the MN causes light aversion accompanied by increased anxiety, tactile hypersensitivity, and spontaneous pain. A caveat is that we cannot exclude contributions from other cerebellar regions in addition to the MN due to diffusion of the injected peptide. These results reveal the cerebellum as a new site of CGRP actions that may contribute to migraine-like hypersensitivity.

Cutaneous Allodynia in Migraine: A Narrative Review

Objective

In the present work, we conduct a narrative review of the most relevant literature on cutaneous allodynia (CA) in migraine.

Background

CA is regarded as the perception of pain in response to non-noxious skin stimulation. The number of research studies relating to CA and migraine has increased strikingly over the last few decades. Therefore, the clinician treating migraine patients must recognize this common symptom and have up-to-date knowledge of its importance from the pathophysiological, diagnostic, prognostic and therapeutic point of view.

Methods

We performed a comprehensive narrative review to analyze existing literature regarding CA in migraine, with a special focus on epidemiology, pathophysiology, assessment methods, risk for chronification, diagnosis and management. PubMed and the Cochrane databases were used for the literature search.

Results

The prevalence of CA in patients with migraine is approximately 60%. The mechanisms underlying CA in migraine are not completely clarified but include a sensitization phenomenon at different levels of the trigemino-talamo-cortical nociceptive pathway and dysfunction of brainstem and cortical areas that modulate thalamocortical inputs. The gold standard for the assessment of CA is quantitative sensory testing (QST), but the validated Allodynia 12-item questionnaire is preferred in clinical setting. The presence of CA is associated with an increased risk of migraine chronification and has therapeutic implications.

Conclusions

CA is a marker of central sensitization in patients with migraine that has been associated with an increased risk of chronification and may influence therapeutic decisions.

Osmophobia in primary headache patients: associated symptoms and response to preventive treatments

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01327-2.

Functional connectivity of the visual cortex differentiates anxiety comorbidity from episodic migraineurs without aura

Background

Migraine is a common neurological disease that is often accompanied by psychiatric comorbidities. However, the relationship between abnormal brain function and psychiatric comorbidities in migraine patients remains largely unclear. Therefore, the present study sought to explore the correlations between the resting-state functional deficits and psychiatric comorbidities in migraine without aura (MwoA) patients.

Methods

Resting-state functional magnetic resonance images were obtained. In addition, the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) values were obtained. Thereafter regional abnormalities in MwoA patients with and without anxiety (MwoA-A and MwoA-OA) were chosen as seeds to conduct functional connectivity (FC) analysis.

Results

Compared to the healthy controls (HCs), the MwoA-A and MwoA-OA patients had abnormal ALFF and ReHo values in the right lingual gyrus (LG). They also had abnormal FC of the right LG with the ipsilateral superior frontal gyrus (SFG) and middle cingulate cortex (MCC). Additionally, the MwoA-A patients showed higher ReHo values in the left posterior intraparietal sulcus (pIPS) and abnormal FC of the right LG with ipsilateral pIPS and primary visual cortex, compared to the MwoA-OA patients. Moreover, the MwoA-OA patients showed an increase in the FC with the right posterior cingulate cortex/precuneus (PCC/PCUN), left middle frontal gyrus (MFG) and left inferior temporal gyrus (ITG) relative to the HCs. Furthermore, the ALFF values of the right LG positively were correlated with anxiety scores in MwoA-A patients. The abnormal LG-related FCs with the PCC/PCUN, MFG and ITG were negatively associated with the frequency of headaches in MwoA-OA patients.

Conclusions

This study identified abnormal visual FC along with other core networks differentiating anxiety comorbidity from MwoA. This may therefore enhance the understanding of the neuropsychological basis of psychiatric comorbidities and provide novel insights that may help in the discovery of new marks or even treatment targets.

An underrepresented majority: A systematic review utilizing allodynic criteria to examine the present scarcity of discrete animal models for episodic migraine

BACKGROUND

Despite increasing evidence differentiating episodic and chronic migraine, little work has determined how currently utilized animal models of migraine best represent each distinct disease state.

AIM

In this review, we seek to characterize accepted preclinical models of migraine-like headache by their ability to recapitulate the clinical allodynic features of either episodic or chronic migraine.

METHODS

From a search of the Pu bMed database for "animal models of migraine", "headache models" and "preclinical migraine", we identified approximately 80 recent (within the past 20 years) publications that utilized one of 10 different models for migraine research. Models reviewed fit into one of the following categories: Dural KCl application, direct electrical stimulation, nitroglycerin administration, inflammatory soup injection, CGRP injection, medication overuse, monogenic animals, post-traumatic headache, specific channel activation, and hormone manipulation. Recapitulation of clinical features including cephalic and extracephalic hypersensitivity were evaluated for each and compared.

DISCUSSION

Episodic migraineurs comprise over half of the migraine population, yet the vast majority of current animal models of migraine appear to best represent chronic migraine states. While some of these models can be modified to reflect episodic migraine, there remains a need for non-invasive, validated models of episodic migraine to enhance the clinical translation of migraine research.

Prevalence and characteristics of cutaneous allodynia in probable migraine

Cutaneous allodynia (CA) is a pain in response to non-nociceptive stimulation and a marker of central sensitisation. Probable migraine (PM) is a migraine subtype that fulfils all but one criterion of migraine. Headache intensity and the disability of individuals with PM are similar or lower than individuals with migraine. This study compared CA prevalence and characteristics of PM and migraine using a nationally representative sample in Korea. The Allodynia Symptom Checklist-12 (ASC-12) was used to assess CA (ASC-12 score ≥ 3). PM and migraine prevalence were 11.6% and 5.0%, respectively. CA prevalence did not significantly differ between PM and migraine (14.5% vs. 16.0%, p = 0.701). Participants with PM with CA reported a higher monthly headache frequency (3.3 ± 4.3 vs. 1.8 ± 3.6, p = 0.044), more severe headache intensity (Visuals Analogue Scale, 6.0 [4.0–7.0] vs. 5.0 [3.0–6.0], p = 0.002), and higher impact of headache (Headache Impact Test-6, 56.3 ± 7.2 vs. 48.3 ± 8.0, p < 0.001) than those without CA. Multiple regression analyses revealed that headache frequency and intensity, anxiety, and depression were significant factors for CA in participants with PM. In conclusion, CA prevalence among participants with PM and migraine were comparable. Anxiety, depression, and headache frequency and intensity were significant factors for CA in participants with PM.

TRPM8 genetic variant is associated with chronic migraine and allodynia

Background

Many single nucleotide polymorphisms (SNPs) have been reported to be associated with migraine susceptibility. However, evidences for their associations with migraine endophenotypes or subtypes are scarce. We aimed to investigate the associations of pre-identified migraine susceptibility loci in Taiwanese with migraine endophenotypes or subtypes, including chronic migraine and allodynia.

Methods

The associations of six SNPs identified from our previous study, including TRPM8 rs10166942, LRP1 rs1172113, DLG2 rs655484, GFRA1 rs3781545, UPP2 rs7565931, and GPR39 rs10803531, and migraine endophenotypes, including chronic migraine and allodynia were tested. Significant associations in the discovery cohort were validated in the replication cohort. The adjusted odds ratios (aOR) were calculated after controlling for confounders.

Results

In total, 1904 patients (mean age 37.5 ± 12.2 years old, female ratio: 77.7%) including 1077 in the discovery cohort and 827 in the replication cohort were recruited. Of them, 584 (30.7%) had chronic migraine. Of the 6 investigated SNPs, TRPM8 rs10166942 T allele-carrying patients were more likely to have chronic migraine than non-T allele carriers in both discovery and replication cohorts and combined samples (33.7% vs. 25.8%, p = 0.004, aOR = 1.62). In addition, T allele carriers reported more allodynic symptoms than non-T allele carriers (3.5 ± 3.7 vs. 2.6 ± 2.8, p < 0.001). However, allodynia severity did not differ between episodic and chronic migraine patients. No further correlations between genetic variants and endophenotypes were noted for the other SNPs.

Conclusions

TRPM8 may contribute to the pathogenesis of chronic migraine. However, our study did not support allodynia as a link between them. The underlying mechanisms deserve further investigations.

Migraine with active headache was associated with other painful physical symptoms at two-year follow-up among patients with major depressive disorder

BACKGROUND

Few studies have investigated the associations of comorbid migraine with other painful physical symptoms (PPS) in patients with major depressive disorder (MDD) at the two-year follow-up point. This study aimed to investigate this issue.

METHODS

At baseline, 155 outpatients with MDD were enrolled. Migraine was diagnosed at baseline according to the International Classification of Headache Disorders. At follow-up, data of 101 subjects were analyzed. The average intensities of head, bone and/or joints, back, chest, abdomen, neck and/or shoulder, general muscle, and limb pain in the past week were evaluated using a visual analog scale (VAS). At follow-up, active headache was defined as a score on the VAS > 3. Multiple linear regressions were used to investigate the associations of migraine at baseline with other PPS at follow-up.

RESULTS

Compared with the migraine with inactive headache group and the non-migraine group, patients with migraine with active headache had significantly higher intensities of other PPS and a lower remission rate of depression. There were no significant differences in the pain intensities of the other seven PPS between the migraine with inactive headache group and the non-migraine group. Headache intensity was significantly correlated with the intensities of other PPS at baseline and follow-up. Migraine with active headache independently predicted other PPS after controlling for depression and anxiety at baseline.

CONCLUSIONS

Migraine with active headache among MDD patients could predict other PPS. Prevention and treatment of headache might help to decrease other PPS and improve the prognosis of depression. Integration of treatment for depression and headache is indicated.

Animal Models of Chronic Migraine

PURPOSE OF REVIEW

Chronic migraine (CM) is a recalcitrant subtype of migraine which causes high degrees of disability, poor treatment responses, and frequent recurrences in sufferers. However, the pathophysiological mechanisms underlying the development and chronification of migraine attacks remain incompletely understood. A validated animal model could help to decipher the pathogenic mechanism of the disease, facilitating the development of possible therapeutic strategies for CM. In this review, we aimed to summarize current animal models of CM and discuss the validity of these models.

RECENT FINDINGS

Several methods have been available to induce recurrent headache-like behaviors or biochemical changes in rodents, including repeated dural application of inflammatory soup, chronic systemic infusion of nitroglycerin, repeated administration of acute migraine abortive treatment to simulate medication overuse headache, or genetic modification. These models exhibit some features that are believed to be associated with migraine; however, none of the model can recapitulate all the clinical phenotypes found in humans and each has its own weakness. The complex features of CM increase the difficulty of constructing a proper animal model. Nonetheless, currently available models are valid to certain degrees. Future directions might consider simulating the spontaneity and chronicity of migraine by combining known genetic substrates and allostatic loads into the same model.

Association of depressive symptoms with allodynia in patients with migraine: A cross-sectional study

Aims

Migraine and depression have a strong association. We aimed to determine whether this relationship was particularly evident in migraineurs with allodynia.

Methods

A cross-sectional study was carried out of 98 consecutive patients with episodic migraine presenting for their first evaluation in an outpatient clinic. The participants completed a demographic questionnaire, the Allodynia Symptom Checklist and the Hospital Anxiety and Depression Scale (HADS).

Results

Among the migraineurs, 75 (77%) reported allodynia. Allodynia was associated with higher median HADS-Anxiety (9 vs. 6, p = 0.038) and HADS-Depression (6 vs. 4, p = 0.014) scores. In a multiple regression model, the HADS-Depression scores were independently associated with allodynia (odds ratio 1.236, 95% confidence interval 1.046–1.461). An increased severity of allodynia correlated with higher depression scores ( r = 0.224; p = 0.027).

Conclusion

Anxious and depressive symptoms are more common in migraineurs with allodynia than in those without allodynia. Further studies are necessary to clarify the relationship between depressive symptoms and allodynia, as well as its therapeutic implications in migraine.

Osmophobia and allodynia are critical factors for suicidality in patients with migraine

Background

Sensory hypersensitivities are common phenomena in migraine. We examined the role of sensory hypersensitivities on suicidality in patients with migraine.

Methods

Patients with migraine (with or without aura) were consecutively recruited from our headache clinic. We asked them if they experienced photophobia, phonophobia, osmophobia, and allodynia during migraine attack. The Mini International Neuropsychiatric Interview was used to diagnose current major depressive disorder (MDD), current generalized anxiety disorder (GAD) and suicidality.

Results

Among 220 subjects, 25.5 % had current MDD, 17.3 % had current GAD, and 31.8 % had suicidality. Patients with suicidality were more like to have a low household income, chronic migraine (CM), medication overuse headache, high headache intensity, osmophobia, allodynia, high disability, MDD, and GAD than those without suicidality. The strongest risk factor for suicidality by multivariate analyses was osmophobia (adjusted Odds Ratio [AOR] 3.12, 95 % confidence interval [CI] 1.57-6.21, p = 0.001), followed by current MDD (AOR 2.99, 95 % CI 1.33-6.76, p = 0.008), CM (AOR 2.48, 95 % CI 1.21-5.09, p = 0.013), current GAD (AOR 3.11, 95 % CI 1.22-7.91, p = 0.017), and allodynia (AOR 2.72, 95 % CI 1.19-6.21, p = 0.018).

Conclusions

Osmophobia and allodynia are critical factors for suicidality in patients with migraine, after controlling for depression, anxiety, and CM.

Allodynia is associated with a higher prevalence of depression in migraine patients

Introduction

There is a strong association between migraine and depression. The aim of this study is to identify migraine-specific factors involved in this association.

Methods

We conducted a cross-sectional study in a large, well-defined cohort of migraine patients ( n = 2533). We assessed lifetime depression using validated questionnaires, and diagnosed migraine based on the International Classification of Headache Disorders III-beta criteria. Multivariate regression analyses were conducted.

Results

Of the 2533 migraineurs that were eligible, 1137 (45%) suffered from lifetime depression. The following independent factors were associated with an increased depression prevalence: i) migraine-specific risk factors: high migraine attack frequency and the presence of allodynia, ii) general factors: being a bad sleeper, female gender, high BMI, being single, smoking, and a low alcohol consumption.

Conclusion

This study identified allodynia, in addition to high migraine attack frequency, as a new migraine-specific factor associated with depression.