Involvement of the ipsilateral-to-the-pain anterior-superior hypothalamic subunit in chronic cluster headache.

BACKGROUND: Despite hypothalamus has long being considered to be involved in the pathophysiology of cluster headache, the inconsistencies of previous neuroimaging studies and a limited understanding of the hypothalamic areas involved, impede a comprehensive interpretation of its involvement in this condition. METHODS: We used an automated algorithm to extract hypothalamic subunit volumes from 105 cluster headache patients (57 chronic and 48 episodic) and 59 healthy individuals; after correcting the measures for the respective intracranial volumes, we performed the relevant comparisons employing logist regression models. Only for subunits that emerged as abnormal, we calculated their correlation with the years of illness and the number of headache attacks per day, and the effects of lithium treatment. As a post-hoc approach, using the 7 T resting-state fMRI dataset from the Human Connectome Project, we investigated whether the observed abnormal subunit, comprising the paraventricular nucleus and preoptic area, shows robust functional connectivity with the mesocorticolimbic system, which is known to be modulated by oxytocin neurons in the paraventricular nucleus and that is is abnormal in chronic cluster headache patients. RESULTS: Patients with chronic (but not episodic) cluster headache, compared to control participants, present an increased volume of the anterior-superior hypothalamic subunit ipsilateral to the pain, which, remarkably, also correlates significantly with the number of daily attacks. The post-hoc approach showed that this hypothalamic area presents robust functional connectivity with the mesocorticolimbic system under physiological conditions. No evidence of the effects of lithium treatment on this abnormal subunit was found. CONCLUSIONS: We identified the ipsilateral-to-the-pain antero-superior subunit, where the paraventricular nucleus and preoptic area are located, as the key hypothalamic region of the pathophysiology of chronic cluster headache. The significant correlation between the volume of this area and the number of daily attacks crucially reinforces this interpretation. The well-known roles of the paraventricular nucleus in coordinating autonomic and neuroendocrine flow in stress adaptation and modulation of trigeminovascular mechanisms offer important insights into the understanding of the pathophysiology of cluster headache.

European Academy of Neurology guidelines on the treatment of cluster headache.

BACKGROUND AND PURPOSE: Cluster headache is a relatively rare, disabling primary headache disorder with a major impact on patients' quality of life. This work presents evidence-based recommendations for the treatment of cluster headache derived from a systematic review of the literature and consensus among a panel of experts. METHODS: The databases PubMed (Medline), Science Citation Index, and Cochrane Library were screened for studies on the efficacy of interventions (last access July 2022). The findings in these studies were evaluated according to the recommendations of the European Academy of Neurology, and the level of evidence was established using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). RECOMMENDATIONS: For the acute treatment of cluster headache attacks, there is a strong recommendation for oxygen (100%) with a flow of at least 12 L/min over 15 min and 6 mg subcutaneous sumatriptan. Prophylaxis of cluster headache attacks with verapamil at a daily dose of at least 240 mg (maximum dose depends on efficacy and tolerability) is recommended. Corticosteroids are efficacious in cluster headache. To reach an effect, the use of at least 100 mg prednisone (or equivalent corticosteroid) given orally or at up to 500 mg iv per day over 5 days is recommended. Lithium, topiramate, and galcanezumab (only for episodic cluster headache) are recommended as alternative treatments. Noninvasive vagus nerve stimulation is efficacious in episodic but not chronic cluster headache. Greater occipital nerve block is recommended, but electrical stimulation of the greater occipital nerve is not recommended due to the side effect profile.

Different personality profiles in patients with cluster headache: a data-driven approach.

INTRODUCTION: Cluster headache (CH) is usually comorbid to mood spectrum disorders, but the psychopathological aspects are poorly explored. We aimed at identifying discrete profiles of personality traits and their association with clinical features. METHODS: Based on the personality scales of the Millon Clinical Multiaxial Inventory-III, principal component analysis (PCA) identified psychological patterns of functioning of 56 CH patients. PCA outcomes were used for hierarchical cluster analysis (HCA) for sub-groups classification. RESULTS: Eighty-seven percent of patients had personality dysfunctions. PCA found two bipolar patterns: (i) negativistic, sadic-aggressive, borderline, and compulsive traits were distinctive of the psychological dysregulation (PD) dimension, and (ii) narcissistic, histrionic, avoidant, and schizoid traits loaded under the social engagement (SE) component. PD was associated with disease duration and psychopathology. SE was related to educational level and young age. HCA found three groups of patients, and the one with high PD and low SE had the worst psychological profile. CONCLUSIONS: Personality disorders are common in CH. Our data-driven approach revealed distinct personality patterns which can appear differently among patients. The worst combination arguing against mental health is low SE and high PD. Linking this information with medical history may help clinicians to identify tailored-based therapeutic interventions for CH patients.

Trial of Galcanezumab in Prevention of Episodic Cluster Headache.

BACKGROUND: Episodic cluster headache is a disabling neurologic disorder that is characterized by daily headache attacks that occur over periods of weeks or months. Galcanezumab, a humanized monoclonal antibody to calcitonin gene-related peptide, may be a preventive treatment for cluster headache. METHODS: We enrolled patients who had at least one attack every other day, at least four total attacks, and no more than eight attacks per day during a baseline assessment, as well as a history of cluster headache periods lasting at least 6 weeks, and randomly assigned them to receive galcanezumab (at a dose of 300 mg) or placebo, administered subcutaneously at baseline and at 1 month. The primary end point was the mean change from baseline in the weekly frequency of cluster headache attacks across weeks 1 through 3 after receipt of the first dose. The key secondary end point was the percentage of patients who had a reduction from baseline of at least 50% in the weekly frequency of cluster headache attacks at week 3. Safety was also assessed. RESULTS: Recruitment was halted before the trial reached the planned sample size of 162 because too few volunteers met the eligibility criteria. Of 106 enrolled patients, 49 were randomly assigned to receive galcanezumab and 57 to receive placebo. The mean (±SD) number of cluster headache attacks per week in the baseline period was 17.8±10.1 in the galcanezumab group and 17.3±10.1 in the placebo group. The mean reduction in the weekly frequency of cluster headache attacks across weeks 1 through 3 was 8.7 attacks in the galcanezumab group, as compared with 5.2 in the placebo group (difference, 3.5 attacks per week; 95% confidence interval, 0.2 to 6.7; P = 0.04). The percentage of patients who had a reduction of at least 50% in headache frequency at week 3 was 71% in the galcanezumab group and 53% in the placebo group. There were no substantial between-group differences in the incidence of adverse events, except that 8% of the patients in the galcanezumab group had injection-site pain. CONCLUSIONS: Galcanezumab administered subcutaneously at a dose of 300 mg once monthly reduced the weekly frequency of attacks of episodic cluster headache across weeks 1 through 3 after the initial injection, as compared with placebo. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT02397473.).

Burden of headache in a HIV-positive population of sub-Saharan Africa.

BACKGROUND: About 26 million people are living with HIV in sub-Saharan Africa. The DREAM programme in sub-Saharan Africa provides free healthcare for HIV/AIDS and a range of chronic non-communicable diseases. HIV is a risk factor for neurological non-communicable diseases including stroke and epilepsy, which themselves are associated with headache, and HIV may be a direct risk factor for headache. We investigated the prevalence and burden of headache in a HIV+ population in sub-Saharan Africa. METHODS: At the DREAM Centre in Blantyre, Malawi, a low-income country with a population of 19 million and 9.2% HIV prevalence, a structured questionnaire was administered by a trained lay interviewer to consecutively attending HIV+ patients aged 6-65 years. All were monitored with regular viral load detection. RESULTS: Of 513 eligible patients invited, 498 were included (mean age 34.1 ± 12.8 years; 72% females; 15 declined). All were on antiretroviral treatment, with viral load undetectable in 83.9%. The 1-year prevalence of headache was 80.3% (females 83.6%, males 71.9%); 3.8% had ≥15 headache days/month, 1.4% had probable medication-overuse headache. Mean overall headache frequency was 4.4 ± 5.4 days/month. Those reporting headache lost means of 2.3% of paid workdays and 3.3% of household workdays because of headache. Only one third had sought advice for their headache. CONCLUSIONS: Headache is very prevalent among HIV+ patients in Malawi, imposing additional burden and costs on individuals and the community. Management of headache disorders should be implemented in HIV centres, as it is for other chronic non-communicable diseases.

Mesocorticolimbic system abnormalities in chronic cluster headache patients: A neural signature?

BACKGROUND: Converging evidence suggests that anatomical and functional mesocorticolimbic abnormalities support the chronicization of pain disorders. METHODS: We mapped structural and functional alterations of the mesocorticolimbic system in a sample of chronic cluster headache patients (n = 28) in comparison to age and sex-matched healthy individuals (n = 28) employing structural MRI and resting-state functional MRI. RESULTS: Univariate logistic regression models showed that several of the examined structures/areas (i.e., the bilateral nucleus accumbens, ventral diencephalon, hippocampus, and frontal pole, and the right amygdala) differentiated chronic cluster headache patients from healthy individuals (p < 0.05, uncorrected). Specifically, all the significant structures/areas had increased volumes in chronic cluster headache patients compared to healthy individuals. The examination of the groups suffering from left and right-sided cranial attacks showed a lateralization effect: ipsilateral to the pain ventral diencephalic regions and contralateral to the pain nucleus accumbens discriminated chronic cluster headache patients from healthy individuals. The resting-state functional MRI data analyses showed that chronic cluster headache patients compared to CTRL individuals present robust reduced functional connectivity in the right frontal pole-right amygdala pathway (p < 0.05, FDR-corrected). CONCLUSION: Our results showed that chronic cluster headache patients present anatomical and functional maladaptation of the mesocorticolimbic system, with functional data indicating a possible prefrontal areas' failure to modulate the mesolimbic structures. These results were opposite to what we hypothesized based on the previous literature on chronic pain conditions.Future studies should assess whether the observed mesocorticolimbic abnormalities are due to the neuroprotective effects of the assumed medications, or to the frequent comorbidity of CH with neuropsychiatric disorders or if they are a genuine neural signature of CH and/or chronic cluster headache condition.

Chronic cluster headache: A study of the telencephalic and cerebellar cortical thickness.

PURPOSE: Previous studies on brain morphological alterations in chronic cluster headache revealed inconsistent findings. METHOD: The present cross-sectional explorative study determined telencephalic and cerebellar cortex thickness alterations in a relatively wide sample of chronic cluster headache patients (n = 28) comparing them to matched healthy individuals. RESULTS: The combination of two highly robust state-of-the-art approaches for thickness estimation (Freesurfer, CERES), strengthened by functional characterization of the identified abnormal regions, revealed four main results: chronic cluster headache patients show 1) cortical thinning in the right middle cingulate cortex, left posterior insula, and anterior cerebellar lobe, regions involved in nociception's sensory and sensory-motor aspects and possibly in autonomic functions; 2) cortical thinning in the left anterior superior temporal sulcus and the left collateral/lingual sulcus, suggesting neuroplastic maladaptation in areas possibly involved in social cognition, which may promote psychiatric comorbidity; 3) abnormal functional connectivity among some of these identified telencephalic areas; 4) the identified telencephalic areas of cortical thinning present robust interaction, as indicated by the functional connectivity results, with the left posterior insula possibly playing a pivotal role. CONCLUSION: The reported results constitute a coherent and robust picture of the chronic cluster headache brain. Our study paves the way for hypothesis-driven studies that might impact our understanding of the pathophysiology of this condition.

Cluster headache not responsive to sumatriptan: A retrospective study.

INTRODUCTION: Subcutaneous sumatriptan, a 5HT1B/1D agonist, is the most effective drug in cluster headache acute treatment. About 25% of the patients do not respond to subcutaneous sumatriptan; the reasons for this are unknown. In this study, we compare clinical characteristics of cluster headache patients responding and non-responding to subcutaneous sumatriptan. METHODS: We retrospectively investigated the clinical records of 277 cluster headache patients. Patients reporting repeated satisfactory response to subcutaneous sumatriptan within 15 minutes were considered responders. RESULTS: Of 206 cluster headache patients who had used subcutaneous sumatriptan (mean age 45.6, 16% females, 48% chronic), 91% were responders, and 9% non-responders. Compared to responders, non-responders had longer and more frequent attacks: 60 (median; IQR 38-90) vs. 100 (60-120) minutes (p = 0.028), 4 (2.5-5) vs. 3 (2-4) attacks/day (p = 0.024). No other difference was found. CONCLUSIONS: In cluster headache attacks with long duration and high frequency, pain mechanisms not involving 5HT1B/1D receptors may play a more relevant role.

Cluster headache and TACs: state of the art.

Cluster headache (CH), paroxysmal hemicrania (PH), short-lasting unilateral neuralgiform headache attacks (including SUNCT and SUNA), and hemicrania continua (HC) compose the group of trigeminal autonomic cephalalgias (TACs). Here, we review the recent advances in the field and summarize the current knowledge about the origin of these headaches. Similar to the other primary headaches, the pathogenesis is still much obscure. However, advances are being made in both animal models and humans studies. Three structures clearly appear to be crucial in the pathophysiology of TACs: the trigeminal nerve, the facial parasympathetic system, and the hypothalamus. The physiologic and pathologic functioning of each of these elements and their interactions is being progressively clarified, but critical questions are still open.

Headache in spontaneous intracranial hypotension: an overview with indications for differential diagnosis in the clinical practice.

Headache is the most common symptom of spontaneous intracranial hypotension (SIH). The present review focuses on data regarding headache features reported in the most relevant published articles and summarizes the main SIH headache features, namely, orthostatic headache, headache triggered by Valsalva maneuver, pattern of onset of headache, and location and quality of headache. Published data indicate that the clinical suspect of this disorder may be challenging, due to its protean presentation. Among the main implications for clinical practice, we suggest to suspect SIH in all patients with a new onset headache, as different forms of primary and secondary headache should be considered in the differential diagnosis of SIH, particularly cervicogenic headache, new daily persistent headache, and headaches precipitated by Valsalva maneuver. The clinical interview must include specific questions on the possible orthostatic feature of headache, although its absence should not make clinicians to reject the SIH hypothesis as headache cannot be orthostatic in each patient and in all periods of the natural history of the disease. Other disorders with orthostatic symptoms, such as in postural tachycardia syndrome (POTS) and persistent postural-perceptual dizziness (PPPD), should be considered in the differential diagnosis. Awareness that SIH can present with acute, sudden onset requires that clinicians working in the emergency settings should consider SIH in the range of diagnoses of thunderclap headache.

Anti-CGRP in cluster headache therapy.

Cluster headache is a primary headache characterized by recurring excruciating pain and autonomic signs, leading to significant suffering and derangement of patients' life. Efficacious new preventive treatments are needed. The pathophysiology of cluster headache comprises mechanisms both in the peripheral and central nervous system, involving the trigeminovascular system, the trigemino-parasympathetic reflex, and central modulating systems. Calcitonin gene-related peptide (CGRP) has an active role throughout these systems. It is increased during spontaneous and provoked attacks, and itself can induce attacks. Recently, drugs against this neuropeptide have been developed for the treatment of different headache disorders. In particular, monoclonal antibodies vs CGRP as galcanezumab and fremanezumab have been tested in cluster headache, with promising results for the episodic form. Considering the relevance of central mechanisms in CH, drugs interfering with the CGRP pathway in the central nervous system can enlarge the therapeutic armamentarium against this highly disabling condition.

Cluster headache: insights from resting-state functional magnetic resonance imaging.

The comprehension of cluster headache (CH) has greatly benefited from the tremendous progress of the neuroimaging techniques over the last 20 years. Since the pioneering study of May et al. (1998), the neuroimaging results have indeed revolutionized the conception of this disease, now considered as a dysfunction of the central nervous system. Clinical, neuroendocrinological, and neuroimaging studies strongly suggested the involvement of the hypothalamus as the generator of cluster headache attacks. However, the latency of the improvement and the inefficacy of the hypothalamic deep brain stimulation (DBS) in the acute phase suggested that the hypothalamus might play a modulating role, pointing to the presence of some dysfunctional brain networks, normalized or modulated by the DBS. Despite the great importance of possible dysfunctional hypothalamic networks in cluster headache pathophysiology, only quite recently the scientific community has begun to explore the functional connectivity of these circuits using resting-state functional magnetic resonance imaging. This is a neuroimaging technique extensively employed to investigate the functional connectivity among separated regions of the brain at rest in the low-frequency domain (< 0.1 Hz). Here, we present a review of the few resting-state functional magnetic resonance imaging studies investigating the hypothalamic network contributing to a deeper comprehension of this neurological disorder. These studies seem to demonstrate that both the hypothalamus and the diencephalic-mesencephalic junction regions might play an important role in the pathophysiology of CH. However, future studies are needed to confirm the results and to clarify if the observed dysfunctional networks are a specific neural fingerprint of the CH pathophysiology or an effect of the severe acute pain. It will be also crucial to clarify the neural pathways of the chronicization of this disorder.

Current and emerging evidence-based treatment options in chronic migraine: a narrative review.

BACKGROUND: Chronic migraine is a disabling condition that is currently underdiagnosed and undertreated. In this narrative review, we discuss the future of chronic migraine management in relation to recent progress in evidence-based pharmacological treatment. FINDINGS: Patients with chronic migraine require prophylactic therapy to reduce the frequency of migraine attacks, but the only currently available evidence-based prophylactic treatment options for chronic migraine are topiramate and onabotulinumtoxinA. Improved prophylactic therapy is needed to reduce the high burden of chronic migraine in Italy. Monoclonal antibodies that target the calcitonin gene-related peptide (CGRP) pathway of migraine pathogenesis have been specifically developed for the prophylactic treatment of chronic migraine. These anti-CGRP/R monoclonal antibodies have demonstrated good efficacy and excellent tolerability in phase II and III clinical trials, and offer new hope to patients who are currently not taking any prophylactic therapy or not benefitting from their current treatment. CONCLUSIONS: Treatment of chronic migraine is a dynamic and rapidly advancing area of research. New developments in this field have the potential to improve the diagnosis and provide more individualised treatments for this condition. Establishing a culture of prevention is essential for reducing the personal, social and economic burden of chronic migraine.

Defective functional connectivity between posterior hypothalamus and regions of the diencephalic-mesencephalic junction in chronic cluster headache.

OBJECTIVE: We tested the hypothesis of a defective functional connectivity between the posterior hypothalamus and diencephalic-mesencephalic regions in chronic cluster headache based on: a) clinical and neuro-endocrinological findings in cluster headache patients; b) neuroimaging findings during cluster headache attacks; c) neuroimaging findings in drug-refractory chronic cluster headache patients improved after successful deep brain stimulation. METHODS: Resting state functional magnetic resonance imaging, associated with a seed-based approach, was employed to investigate the functional connectivity of the posterior hypothalamus in chronic cluster headache patients (n = 17) compared to age and sex-matched healthy subjects (n = 16). Random-effect analyses were performed to study differences between patients and controls in ipsilateral and contralateral-to-the-pain posterior hypothalamus functional connectivity. RESULTS: Cluster headache patients showed an increased functional connectivity between the ipsilateral posterior hypothalamus and a number of diencephalic-mesencephalic structures, comprising ventral tegmental area, dorsal nuclei of raphe, and bilateral substantia nigra, sub-thalamic nucleus, and red nucleus ( p < 0.005 FDR-corrected vs . control group). No difference between patients and controls was found comparing the contralateral hypothalami. CONCLUSIONS: The observed deranged functional connectivity between the posterior ipsilateral hypothalamus and diencephalic-mesencephalic regions in chronic cluster headache patients mainly involves structures that are part of (i.e. ventral tegmental area, substantia nigra) or modulate (dorsal nuclei of raphe, sub-thalamic nucleus) the midbrain dopaminergic systems. The midbrain dopaminergic systems could play a role in cluster headache pathophysiology and in particular in the chronicization process. Future studies are needed to better clarify if this finding is specific to cluster headache or if it represents an unspecific response to chronic pain.

Long-term occipital nerve stimulation for drug-resistant chronic cluster headache.

Introduction Chronic cluster headache is rare and some of these patients become drug-resistant. Occipital nerve stimulation has been successfully employed in open studies to treat chronic drug-resistant cluster headache. Data from large group of occipital nerve stimulation-treated chronic cluster headache patients with long duration follow-up are advantageous. Patients and methods Efficacy of occipital nerve stimulation has been evaluated in an experimental monocentric open-label study including 35 chronic drug-resistant cluster headache patients (mean age 42 years; 30 men; mean illness duration: 6.7 years). The primary end-point was a reduction in number of daily attacks. Results After a median follow-up of 6.1 years (range 1.6-10.7), 20 (66.7%) patients were responders (≥50% reduction in headache number per day): 12 (40%) responders showed a stable condition characterized by sporadic attacks, five responders had a 60-80% reduction in headache number per day and in the remaining three responders chronic cluster headache was transformed in episodic cluster headache. Ten (33.3%) patients were non-responders; half of these have been responders for a long period (mean 14.6 months; range 2-48 months). Battery depletion (21 patients 70%) and electrode migration (six patients - 20%) were the most frequent adverse events. Conclusions Occipital nerve stimulation efficacy is confirmed in chronic drug-resistant cluster headaches even after an exceptional long-term follow-up. Tolerance can occur years after improvement.

Abnormal tyrosine metabolism in chronic cluster headache.

Objective Episodic cluster headache is characterized by abnormalities in tyrosine metabolism (i.e. elevated levels of dopamine, tyramine, octopamine and synephrine and low levels of noradrenalin in plasma and platelets.) It is unknown, however, if such biochemical anomalies are present and/or constitute a predisposing factor in chronic cluster headache. To test this hypothesis, we measured the levels of dopamine and noradrenaline together with those of elusive amines, such as tyramine, octopamine and synephrine, in plasma of chronic cluster patients and control individuals. Methods Plasma levels of dopamine, noradrenaline and trace amines, including tyramine, octopamine and synephrine, were measured in a group of 23 chronic cluster headache patients (10 chronic cluster ab initio and 13 transformed from episodic cluster), and 16 control participants. Results The plasma levels of dopamine, noradrenaline and tyramine were several times higher in chronic cluster headache patients compared with controls. The levels of octopamine and synephrine were significantly lower in plasma of these patients with respect to control individuals. Conclusions These results suggest that anomalies in tyrosine metabolism play a role in the pathogenesis of chronic cluster headache and constitute a predisposing factor for the transformation of the episodic into a chronic form of this primary headache.

Cluster headache: present and future therapy.

Cluster headache is characterized by severe, unilateral headache attacks of orbital, supraorbital or temporal pain lasting 15-180 min accompanied by ipsilateral lacrimation, rhinorrhea and other cranial autonomic manifestations. Cluster headache attacks need fast-acting abortive agents because the pain peaks very quickly; sumatriptan injection is the gold standard acute treatment. First-line preventative drugs include verapamil and carbolithium. Other drugs demonstrated effective in open trials include topiramate, valproic acid, gabapentin and others. Steroids are very effective; local injection in the occipital area is also effective but its prolonged use needs caution. Monoclonal antibodies against calcitonin gene-related peptide are under investigation as prophylactic agents in both episodic and chronic cluster headache. A number of neurostimulation procedures including occipital nerve stimulation, vagus nerve stimulation, sphenopalatine ganglion stimulation and the more invasive hypothalamic stimulation are employed in chronic intractable cluster headache.

Personality disorders in cluster headache: a study using the Millon Clinical Multiaxial Inventory-III.

A great deal of studies suggests that cluster headache (CH) patients are usually comorbid to anxiety-mood spectrum disorders and psychopathological symptoms; however, the personality profiles reported in the literature strictly depend on type of assessment used. Psychiatric comorbidities have been extensively studied in migraine and they are recognized to represent a major risk factor associated with poorer outcome, playing a role in the headache chronification process at once as cause and consequence of it. By contrast the incidence and role of psychopathological aspects in CH is still not clarified, insufficiently explored as the striking severity of such a physical pain apparently leaves no room to psychological explanations. The aim of the present study is to describe psychopathological aspects of CH patients by means of the Millon Clinical Multiaxial Inventory-III (MCMI-III), a psychological assessment tool compatible to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) that correlates personality disorders (PDs) and clinical syndromes. We included all consecutive inward patients with CH between January 2014 and December 2016. Patients were evaluated using the MCMI-III a validated inventory assessing 14 PDs Scales (coordinate with DSM-IV Axis II disorders) and ten Clinical Syndrome Scales (coordinate with DSM-IV Axis I disorders). Twenty-six CH patients (24 chronic CH) were tested. Personality disorders were present in 92% of the patients. The most frequent PDs were: obsessive-compulsive (30.8%), histrionic (26.9%), narcissistic (11.5%), paranoid (11.5%) and avoidant (11.5%). According to the MCMI-III, patients with CH showed a high prevalence of personality disorders (Axis II-DSM-IV). PDs in CH patients can play an important role in determining CH course toward chronification. These preliminary results suggest that behavioral treatments can find room to support more conventional drug and neurostimulation therapies in these patients. In addition, the very high prevalence of PDs in our patients suggests that CH could in some cases be considered among the spectrum of somatoform and pain syndromes in patients with PDs.