Criteria For Headache Research Articles

Migraine Features in Patients with Persistent Postural-Perceptual Dizziness.

To evaluate the presence of migraine features in patients with persistent postural-perceptual dizziness (PPPD). In a retrospective survey study, consecutive patients presenting to a tertiary care neurotology clinic during an 18-month period were given questionnaires about headache and dizziness symptoms. The survey responses plus history and examination of the patient were used to diagnose patients with PPPD. The prevalence of migraine headache, vestibular migraine (VM), and migraine characteristics was evaluated. In total, 36 subjects with PPPD were included in the study. The mean age of the subjects was 56 ± 16 years with a female (72%) predominance. A total of 19 (53%) patients met the International Classification of Headache Disorders criteria for migraine headache, and 6 of those (17%) met the criteria for definite VM. Of the patients who did not meet full migraine headache criteria, 6 (17%) patients met 4 of 5 criteria, and 5 (14%) patients met 3 of 5 criteria. There was no significant difference between PPPD patients who fulfilled full migraine headache criteria and those who did not in sensitivity to light, sound, smells, weather changes, feelings of mental fog/confusion, and sinus pain/facial pressure. This study demonstrates that a majority of patients with PPPD fulfill the criteria for migraine headache. A large proportion of PPPD patients who do not meet the full criteria for migraine headache still meet a majority of the migraine headache criteria. This suggests an association between the 2 conditions. PPPD may be a part of the spectrum of otologic migraine, where migraine manifests as otologic symptoms.

Characterization of thunderclap headache in a reversible cerebral vasoconstriction syndrome case series.

To empirically address how thunderclap headache (TCH) is described in a relevant real-world setting. TCH refers to a highly recognizable description of a severe headache that reaches maximum severity within 1minute and endures for at least 5minutes. The use of a numerical rating scale (NRS) to appraise TCH severity, as well as assessment of TCH progression in patients with pre-existing headache at the time of TCH onset has not been previously evaluated. This was a retrospective case series of adults with a diagnosis of reversible cerebral vasoconstriction syndrome (RCVS), identified through a search of the electronic health record. Individuals meeting International Classification of Headache Disorders, 3rd Edition criteria for acute headache attributed to RCVS were included. Attacks described using a verbal descriptor scale (VDS), NRS, or both were recorded to evaluate acute headache characteristics. In all, 56 individuals with available descriptions of 120 acute headaches were included in the study analysis. Patients were female (35, 62.5%) with a median age of 46 (range: 19-67). The majority of patients reported a RCVS trigger (39, 69.6%). Acute headaches were characterized using a VDS (52, 43.3%), NRS (51, 42.5%), or both (17, 14.1%). Acute headaches were always described as severe when a VDS was utilized, and with a median NRS of 10 (range: 4-10). Four patients (7%) did not have a single headache characterized as either severe or with a NRS 8 or greater. In the 10 cases for which there was a pre-TCH baseline headache, it was either rated as mild or with a median NRS of 3 (range: 2-6). TCH in RCVS can be recognized using either VDS or NRS, with a broader range of peak intensities than previously recognized. TCH remains recognizable despite pre-existing baseline headache.

Psychiatric Morbidities in Patients With Primary Headache

Background: 
 Headache is a pain that occurs above the eyes or the ears, behind the head in the occiput or the cervical region of neck. A primary headache is a type of headache that is caused by overactivity of the problems with pain-sensitive structures in your head and is not a symptom of an underlying disease condition in a patient. This study highlights on the association of Primary Headaches with psychiatric morbidities and stressful life events that may cause or increase the severity of Primary Headache and its psychiatric co-morbidities.Descriptive, Cross-Sectional, Hospital Based study was done in 75 patients who met the diagnostic criteria for Primary Headache.
 
 Results: Patients presenting with primary headache were of the age group 26-30(26.7%) followed by 21-25 and 31-35. 57.3% were female patients and 69.3% were married. 29.3% of the patients were housewives, 25.3% were into service and 21.4% were students. Majority of the patients had literacy upto Bachelors degree (32%). Anxiety and depression were the major diagnosis with 22.3 and 17.4 % respectively, they were also the major co-morbid conditions. Illness in the family and self or family member unemployment were the major stressful life events. There was a significant relation of Psychiatric Morbidity with Primary Headache.
 
 Conclusion: Anxiety disorder was the major morbid and comorbid psychiatric condition found in patient with Primary Headache followed by depression. This was seen majorly in female and of the age group 26-30 years of age and the patients who were married. Thus is it is necessary to screen Primary Headaches and reduce the stressful life events in these patients and limit the consequences and outcome of Primary Headache to prosper the health and living standard of the patients and the population as a whole.

Phenotypic characterization of acute headache attributed to SARS-CoV-2: An ICHD-3 validation study on 106 hospitalized patients.

IntroductionHeadache is a common symptom of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this study, we aimed to characterize the phenotype of headache attributed to SARS-CoV-2 infection and to test the International Classification of Headache Disorders (ICHD-3) phenotypic criteria for migraine and tension-type headache.MethodsThe study design was a cross-sectional study nested in a cohort. We screened all consecutive patients that were hospitalized and had a positive SARS-CoV-2 test. We included patients that described headache if the headache was not better explained by another ICHD-3 diagnosis. Patients were interviewed by two neurologists.ResultsWe screened 580 patients and included 130 (mean age 56 years, 64% female). Headache was the first symptom of the infection in 26% of patients and appeared within 24 hours in 62% of patients. The headache was bilateral in 85%, frontal in 83%, and with pressing quality in 75% of patients. Mean intensity was 7.1, being severe in 64%. Hypersensitivity to stimuli occurred in 57% of patients. ICHD-3 criteria for headache attributed to systemic viral infection were fulfilled by 94% of patients; phenotypic criteria for migraine were fulfilled by 25% of patients, and tension-type headache criteria by 54% of patients.ConclusionHeadache attributed to SARS-CoV-2 infection in hospitalized patients has severe intensity, frontal predominance and oppressive quality. It occurs early in the course of the disease. Most patients fulfilled ICHD-3 criteria for headache attributed to systemic viral infection; however, the phenotype might resemble migraine in a quarter of cases and tension-type headache in half of the patients.

Reason to doubt the ICHD-3 7-day inclusion criterion for mild TBI-related posttraumatic headache: A nested cohort study.

Posttraumatic headache is difficult to define and there is debate about the specificity of the 7-day headache onset criterion in the current definition. There is limited evidence available to guide decision making about this criterion. A nested cohort study of 193 treatment-seeking veterans who met criteria for persistent headache attributed to mild traumatic injury to the head, including some veterans with delayed headache onset up to 90 days post-injury, was undertaken. Survival analysis examined the proportion of participants reporting headache over time and differences in these proportions based on sex, headache phenotype, and mechanism of injury. 127 participants (66%; 95% CI: 59-72%) reported headache onset within 7 days of head injury and 65 (34%) reported headache onset between 8 days and 3 months after head injury. Fourteen percent of participants reported pre-existing migraine before head injury, and there was no difference in the proportion of veterans with pre-existing migraine based on headache onset. Headache onset times were not associated with sex, headache phenotype, or mechanism of injury. There were no significant differences in proportion of veterans with headache onset within 7 days of head injury based on headache phenotype (70% migraine onset within 7 days, 70% tension-type headache within 7 days, 56% cluster headache within 7 days; p ≥ .364). Similar findings were observed for head injury (64% blast, 60% blunt; p = .973). There were no significant differences observed between headache onset groups for psychiatric symptoms (Posttraumatic Stress Disorder Checklist for DSM-5 = 1.3, 95% CI = -27.5, 30.1; Patient Health Questionnaire-9 Item = 3.5, 95% CI = -6.3, 3.7; Generalized Anxiety Disorder Screener = 6.5, 95% CI = -2.7, 15.6). Although most of the sample reported headache onset within 7 days of head injury, one-third experienced an onset outside of the diagnostic range. Additionally, veterans with headache onset within 7 days of head injury were not meaningfully different from those with later onset based on sex, headache phenotype, or mechanism of head injury. The ICHD-3 diagnostic criteria for 7-day headache onset should be expanded to 3 months. NCT02419131.

Validation of an algorithm for automated classification of migraine and tension-type headache attacks in an electronic headache diary

BackgroundThis study evaluates the accuracy of an automated classification tool of single attacks of the two major primary headache disorders migraine and tension-type headache used in an electronic headache diary.MethodsOne hundred two randomly selected reported headache attacks from an electronic headache-diary of patients using the medical app M-sense were classified by both a neurologist with specialisation in headache medicine and an algorithm, constructed based on the ICHD-3 criteria for migraine and tension-type headache. The level of agreement between the headache specialist and the algorithm was compared by using a kappa statistic. Cases of disagreement were analysed in a disagreement validity assessment.ResultThe neurologist and the algorithm classified migraines with aura (MA), migraines without aura (MO), tension-type headaches (TTH) and non-migraine or non-TTH events. Of the 102 headache reports, 86 cases were fully agreed on, and 16 cases not, making the level of agreement unweighted kappa 0.74 and representing a substantial level of agreement. Most cases of disagreement (12 out of 16) were due to inadvertent mistakes of the neurologist identified in the disagreement validity assessment. The second most common reason (3 out of 16) was insufficient information for classification by the neurologist.ConclusionsThe substantial level of agreement indicates that the classification tool is a valuable instrument for automated evaluation of electronic headache diaries, which can thereby support the diagnostic and therapeutic clinical processes. Based on this study’s results, additional diagnostic functionalities of primary headache management apps can be implemented. Finally, future research can use this classification algorithm for large scale database analysis for epidemiological studies.

Headache Attributed to Temporomandibular Disorders. Case Report

The goal of this article was to review the most common temporomandibular disorders according to the Diagnostic Criteria for Temporomandibular disorders (DC/TMD) emphasizing in the criteria for headache attributed to TMD. By presenting a clinical case that shows the characteristics of a patient with masticatory myofascial pain, arthralgia of the temporomandibular joint and headache attributed to TMD. A case of a 34-year-old female patient is presented, the diagnostic process and its approach: self-care, modification of parafunctional habits and behaviors, physical therapy and pharmacological support.

Cervicogenic headache and migraine: differential diagnosis and therapy

Cervicogenic headache (CH) is a syndrome of referred pain that originates in the neck structure. Despite the apparent simplicity of its determination, there is still no consensus on diagnostic criteria for cervicogenic headache amongst physicians of various specialties. In what cases is headache concurrent with neck pain a consequence of the pathology of the neck region, and in what cases is neck pain a consequence of a migraine attack? The review deals with the diagnosis, differential diagnosis, and therapy of CH.

Orofacial pain resembling hypnic headache: A case report

The International Classification of Orofacial Pain (ICOP) classifies orofacial pain resembling primary headache as orofacial migraine and tension-type, trigeminal autonomic, and neurovascular orofacial pain. We used the ICOP classification style to make a diagnosis on a 76-year-old woman with orofacial pain, which developed only during sleep three times per week, caused awakening, and lasted 3–4 h without cranial autonomic symptoms or restlessness. Except for the pain area, her symptoms fulfilled the diagnostic criteria for hypnic headache. We diagnosed her with orofacial pain resembling hypnic headache. We should review the cases of such patients and classify them according to the ICOP.

Improvement of the quality of headache information and the appropriate hospital selection rate for hemorrhagic stroke by educating paramedics about the diagnostic criteria of thunderclap headache

Improvement of the quality of headache information and the appropriate hospital selection rate for hemorrhagic stroke by educating paramedics about the diagnostic criteria of thunderclap headache

A High Performance System for the Diagnosis of Headache via Hybrid Machine Learning Model

Headache has been a major concern for patients, medical doctors, clinics and hospitals over the years due to several factors. Headache is categorized into two major types:(1) Primary Headache, which can be tension, cluster or migraine, and (2) Secondary Headache where further medical evaluation must be considered. This work presents a high performance Headache Prediction Support System (HPSS). HPSS provides preliminary guidance for patients, medical students and even clinicians for initial headache diagnosis. The mechanism of HPSS is based on a hybrid machine learning model. First, 19 selected attributes (questions) were chosen carefully by medical specialists according to the most recent International Classification of Headache Disorders (ICHD-3) criteria. Then, a questionnaire was prepared to confidentially collect data from real patients under the supervision of specialized clinicians at different hospitals in Jordan. Later, a hybrid solution consisting of clustering and classification was employed to emphasize the diagnosis results obtained by clinicians and to predict headache type for new patients respectively. Twenty-six (26) different classification algorithms were applied on 614 patients’ records. The highest accuracy was obtained by integrating K-Means and Random Forest with a migraine accuracy of 99.1% and an overall accuracy of 93%. Our web-based interface was developed over the hybrid model to enable patients and clinicians to use our system in the most convenient way. This work provides a comparative study of different headache diagnosis systems via 9 different performance metrics. Our hybrid model shows a great potential for highly accurate headache prediction. HPSS was used by different patients, medical students, and clinicians with a very positive feedback. This work evaluates and ranks the impact of headache symptoms on headache diagnosis from a machine learning perspective. This can help medical experts for further headache criteria improvements.

Trigeminal neuralgia and other autonomic cephalgias

To have general idea about diagnostis criteria for TAC headache and how common they are. Epidimiology of TAC headache Medical and non medical approach for TAC headache. Recent updates on management of TAC headache.

Rationale and design for a randomized, single-center, double-blind, sham-controlled study of non-invasive vagus nerve stimulation for treatment of post-traumatic headache

ObjectiveEvaluate the efficacy and safety of non-invasive vagus nerve stimulation (nVNS) for the treatment of post-traumatic headache (PTH).BackgroundWorldwide, ∼69 million people per year sustain a traumatic brain injury (TBI), many of whom develop PTH. Clinicians often treat PTH with drugs approved for primary headache disorders, and many patients self-treat with over-the-counter agents but have inadequate pain relief. There has been little study of therapies for PTH, and safe, effective treatments are needed.Design/MethodsThis randomized, double-blind, sham-controlled, parallel-group pilot study is enrolling adults who present 1–4 weeks after a head injury, meet International Classification of Headache Disorders 3rd edition (ICHD-3) criteria for acute headache attributed to mild TBI, and have ≥2 headaches/week with a migraine or probable migraine phenotype. After a 2-week run-in period, subjects are randomly assigned (1:1 allocation) to receive daily preventive therapy and as-needed acute treatment with nVNS or a sham device. Preventive therapy consists of two 120-second stimulations 3 times daily. Acute treatment comprises 2 stimulations at headache onset and 2 stimulations 20 minutes after the start of initial treatment. Subjects are not to use acute rescue medication for 120 minutes post-treatment. One North American site will enroll ≤80 subjects. The expected duration is 12 months (enrollment, 9 months; participation, 14 weeks).ResultsThe primary effectiveness end point is decrease in pain (on a 7-point scale) 60 minutes post-treatment for all treated headache attacks. Secondary end points include decrease in the frequency of headache days between the run-in period and the last 2 weeks of the double-blind period and responder rates (ie, percentages of subjects with ≥50% decrease in attack frequency). The primary safety end point is the incidence of treatment-related serious adverse events.ConclusionsThis study will assess the efficacy and safety of nVNS as a novel therapy for PTH.

New diagnostic criteria for headache attributed to transient ischemic attacks

BackgroundThe International Classification of Headache Disorders diagnostic criteria for Headache Attributed to Transient Ischemic Attack (TIA) and many other secondary headaches are based primarily on the opinion of experts. The aim of this study was to field test, for the first time, the diagnostic criteria for headache attributed to TIA of the International Classification of Headache Disorders, 3rd edition (ICHD-3) and in case of their weaknesses to propose new diagnostic criteria.MethodsConsecutive patients with Transient Ischemic Attack and a simultaneous control group were extensively interviewed soon after admission. Data were collected on previous headaches, headaches around the time of Transient Ischemic Attack and characteristics of the TIA using validated neurologist conducted semi-structured interview forms. The evidence of relevant infarction were excluded in patients with Transient Ischemic Attack using magnetic resonance imaging with diffusion-weighted imaging (n = 112) or computed tomography (n = 8).ResultsOne hundred twenty patients with Transient Ischemic Attack and 192 controls were included. A new type of headache occurred within 24 h in 16 (13%) of patients with Transient Ischemic Attack and in no controls, a preexisting type of headache with altered characteristics occurred in 9 (7.5%) of patients with Transient Ischemic Attack and no in controls, headache without altered characteristics occurred in 8 (6.6%) of patients with Transient Ischemic Attack and in 9 (4.6%) controls. Only 24% of the headaches in patients with Transient Ischemic Attack (8 of 33 patients) fulfilled the diagnostic criteria of International Classification of Headache Disorders-3 and no control patients. We propose new criteria fulfilled by 94% of the headaches. Specificity remained excellent as only one of 192 controls had a headache fulfilling the proposed criterion C.ConclusionsExisting diagnostic criteria for headache attributed to TIA of the International Classification of Headache Disorders are too insensitive. We suggest new diagnostic criteria with high sensitivity and preserved specificity.

Headache

Headaches are one of the most common complaints of patients seen by emergency physicians. They can be classified as primary headaches, which have no identifiable underlying cause, and secondary headaches, which are classified according to their cause. The majority of headaches are benign in origin, and most patients with headache can be treated successfully in the emergency department and discharged home; however, some have potentially life-threatening causes, and consideration of a broad differential diagnosis for all patients is essential. This review covers the primary headache disorders, pathophysiology, stabilization and assessment, diagnosis and treatment, and disposition and outcomes. The figure shows areas of the brain sensitive to pain. Tables review differential diagnosis of headache, International Headache Society primary headache criteria, clinical characteristics of secondary headaches, high-risk clinical characteristics among patients with a headache peaking in intensity within 1 hour, drugs associated with headache, and parenteral treatment of acute migraine. This review contains 1 figure, 9 tables, and 58 references. Key words: migraine, calcitonin gene related peptide, greater occipital nerve block, venous sinus thrombosis, reversible cerebral vasoconstriction syndrome, Ottawa, subarachnoid, cluster headache, trigeminal autonomic cephalalgias, post-traumatic headache

Headache attributed to cranial venous sinus stenting: A case series and literature review.

The diagnostic criteria for headache attributable to cranial venous sinus stenting were first formalized in the recently published third edition of the International Classification of Headache Disorders (ICHD-3). However, the diagnostic criteria for headache caused by cranial venous sinus stenting are based on very few data and the condition is poorly characterized. To validate the diagnostic criteria for cranial venous sinus stenting headache by retrospectively studying the characteristics of headache in patients with isolated pulsatile tinnitus who underwent curative cranial venous sinus stenting and who had not previously complained of headache. We retrospectively studied clinical, radiological, and manometric data from patients with isolated venous pulsatile tinnitus who had not previously reported headache. All patients underwent lateral sinus stenting in our institution between October 2010 and February 2018. Forty eight patients, 47 females and one male, were enrolled. The mean age at symptom onset was 36.2 ± 8.7 years and the mean body mass index was 24.0 ± 3.2 kg/m2. Lateral sinus stenosis was evident in 47 patients and a sigmoid diverticulum in one. Fourteen patients experienced headaches after recovering from general anesthesia. All were female, with a mean age of 35.5 ± 9.6 years. Headache persisted for less than 3 days in six patients (42.8%); for 3 days to 3 months in four (28.6%); and for longer than 3 months in four (28.6%). The headaches were located on the same sides as the cranial venous sinus stents in 13 patients (92.9%) and were principally occipital, being oppressive in nine patients (64.3%) and of moderate intensity in seven (50%). Age at onset of pulsatile tinnitus and body mass index were significantly associated with headache (p < 0.05; t-test). To the best of our knowledge, this is the first study to describe cranial venous sinus stenting headache in detail. We found that de novo headache developed after cranial venous sinus stenting, and was usually mild to moderate, unilateral, but oppressive; almost one-third of such headaches persisted for more than 3 months. Researchers and clinicians must become familiar with this headache spectrum; further prospective studies are required.

Do you really have sinus headache?

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Headache is a common symptom. Correct diagnosis of the etiology is the key to successful treatment. Chronic headache are misdiagnosed as sinus headache because of presence of overlapping symptoms leading to unnecessary treatment with no relief to the patient. We decided to undertake this study with the objective of evaluating patients with chronic headache for presence of chronic rhinosinusitis and hence assess the contribution of sinus headache to chronic headache.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The present study was conducted at Adichunchanagiri Institute of Medical Sciences, BG Nagara during the period January 2018 to December 2018. Patients presenting to OPD with chronic headache previously diagnosed as sinus headache were included in the study. A total of 174 patients were studied. All patients underwent detailed history taking, detailed ENT examination, and diagnostic nasal endoscopy. AAOHNS criteria for rhinosinusitis and IHS criteria for migraine and tension type headache were used for diagnosis. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; We found that only 13% (n=23) cases had chronic rhinosinusitis and hence diagnosed as sinus headache. 53% (n=92) had migraine, 31% (n=54) had tension type headache and 3% (n=5) could not be categorized.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Prevalence of sinus headache in our study was found to be 13%. There are high chances of misdiagnosing chronic headache as sinus headache because primary forms of headache can present with nasal symptoms. The AAOHNS criteria for rhinosinusitis and IHS criteria for migraine and tension type headaches are very useful and effective in making an accurate diagnosis.&lt;/p&gt;

A prospective study of headache and neuropeptides in patients with pituitary adenomas

To evaluate clinical criteria for headache associated with pituitary adenoma (HaPA) in the International Classification of Headache Disorders (ICHD) 3rd edition version criteria and further determine whether elevations of plasma calcitonin gene-related peptide and pituitary adenylate cyclase-activating peptide 1-38 (PACAP1-38) concentration contribute to HaPA. Demographic and clinical features of consecutive patients with pituitary adenoma were recorded. Plasma calcitonin gene-related peptide and PACAP1-38 concentrations in pituitary adenoma patients within 72 h pre- and post-operation were measured. Primary outcome for HaPA patients were 50% reduction of moderate-to-severe headache days at 3 months after discharge. Sixty-three patients with pituitary adenoma were recruited, 33 (52.4%) of whom had headache. The patients who had HaPA presented with migraine-like (32.9%), tension-type-like (12.1%), and stabbing headache (9.1%). Non-functional adenoma was present in the majority of cases (82.5%). Surgical resection improved headache in 83.3% of cases at 3 month follow-up. Pre- and post-operative calcitonin gene-related peptide and PACAP1-38 levels were significantly higher in patients with headache than in those without headache (p < 0.05). Plasma calcitonin gene-related peptide and PACAP1-38 levels at 72 h post-operation were lower at 72 h after operation in patients who had greater improvement in headache compared with those who had little improvement, while plasma calcitonin gene-related peptide and PACAP1-38 levels were similar between these two groups preoperatively. Most pituitary adenoma patients have non-functional adenoma, and half of this group have HaPA, indicating that the ICHD-3 criteria for HaPA with the emphasis on secretion status need further modifications. Lower plasma calcitonin gene-related peptide and PACAP1-38 concentrations at 72 h after operation may predict a better outcome in patients with HaPA.

Headache attributed to IIH: clinical evolution in IHS criteria through the years.

Idiopathic intracranial hypertension (IIH) is a condition characterized by increased intracranial pressure without a detectable cause. The most common symptom of IIH is a headache, which occurs in almost all cases at the time of diagnosis with various headache phenotypes. In clinical practice, diagnosis of headache attributed to IIH is given referring to the International Headache Society (IHS) criteria of the International Classification of Headache Disorders. In the present publication, we consider how the IHS diagnostic criteria for headache attributed to intracranial idiopathic hypertension have evolved through the years.

Field testing the diagnostic criteria of cluster headache in the third edition of the International Classification of Headache Disorders: A cross-sectional multicentre study.

*These authors are shared first authors. The recently published third edition of the International Classification of Headache Disorders (ICHD-3) revised the criteria for accompanying symptoms of cluster headache (CH) and the remission period of chronic cluster headache (CCH). This study aimed at testing the validity of the ICHD-3 criteria for CH by using data from the Korean Cluster Headache Registry. Consecutive patients with CH and probable cluster headache (PCH) were prospectively recruited from 15 hospitals. We analysed the validity of the revised ICHD-3 criteria for CH against the beta version of the third edition of the ICHD (ICHD-3β). In total, 193 patients were enrolled: 140 (72.5%), 5 (2.6%) and 22 (11.4%) had episodic cluster headache (ECH), CCH, and PCH, respectively. The remaining 26 (13.5%) had CH with undetermined remission periods. One patient with ECH and one with PCH had only forehead and facial flushing and were diagnosed with PCH and non-cluster headache, respectively, according to the ICHD-3. Four participants with ECH according to the ICHD-3β had remission periods of > 1 month and between 1 and 3 months and were newly diagnosed with CCH according to the ICHD-3. The change from ICHD-3β to ICHD-3 resulted in few differences in the diagnoses of CH and PCH.