Assessment of International Headache Society diagnostic criteria: a reliability study

In 1988 the International Headache Society (IHS) introduced new diagnostic criteria for headaches and craniofacial pain. Since headaches can be diagnosed solely on the basis of information provided by the patient, it is essential that the criteria are reproducible and consistent. Two neurologists evaluated the clinical records of 100 consecutive outpatients and transferred the data on headache and associated phenomena to a form designed to reflect the IHS criteria. Interobserver concordance (kappa statistics) in the application of the diagnostic criteria of primary headaches was: (i) "perfect" to "substantial" for the first IHS digit, being kappa = 1.0 for cluster headache and paroxysmal hemicrania; kappa = 0.88 for migraine; kappa = 0.75 for tension-type headache; (ii) "almost perfect" to "substantial" for the second digit (kappa = 0.94 for cluster headache; kappa = 0.90 for migraine with aura; kappa = 0.81 for episodic tension-type headache; kappa = 0.78 for migraine without aura; kappa = 0.71 for chronic tension-type headache; kappa = 0.66 for cluster headache-like disorder not fulfilling the criteria; (iii) "moderate" for migrainous disorder (kappa = 0.48) and headache of the tension-type (kappa = 0.43) not fulfilling the criteria. These results show that the IHS diagnostic criteria are satisfactorily applicable to high quality medical records abstracted by experienced neurologists.     

Classification of chronic daily headache by International Headache Society criteria: limits and new proposals

We conducted a retrospective study of 150 patients with chronic daily headache (CDH) to determine how to categorize their headache according to the classification of the International Headache Society (IHS). All patients were first evaluated at Parma and Pavia Headache Centres (from January 1992 to March 1993) and had had headache for at least 15 days a month during the previous 6 months. Four patients were thereafter excluded due to poor reliability. The 146 patients who met our CDH criteria (92 with and 54 without clear-cut migraine attacks) could be classified into four groups: (i) chronic tension-type headache (CTTH)-27 patients; (ii) coexisting migraine plus CTTH-65 patients; (iii) unclassifiable daily headache-27 patients; and (iv) migraine and an unclassifiable interval headache-27 patients. Seventy-two percent of patients with CDH had migraine as the initial form of their headache. We therefore propose to revise the IHS classification for migraine, taking into account its evolution, and add two subcategories, migraine with interparoxysmal headache and chronic migraine.     

From hemicrania lunaris to hemicrania continua: an overview of the revised International Classification of Headache Disorders

The International Headache Society's (IHS) Classification of Headache Disorders, published in 1988, is largely responsible for stimulating the rapid scientific and therapeutic advances that have revolutionized the field of headache. By establishing consistent operational diagnostic criteria for primary and secondary headache disorders, the IHS Classification has facilitated epidemiological and genetic studies as well as the multinational clinical trials that provide the basis for our present treatment guidelines. Fifteen years after its original release, a revised 2nd edition has been unveiled. Modifications are small but significant. We hope to introduce clinicians to the salient changes in the 2nd edition by highlighting the newly included headache types, acknowledging the renamed headache types, and reviewing the modifications in diagnostic criteria for existing headache types. Physicians involved in the care of headache patients need to be aware of these changes and should continue to consult the IHS criteria to ensure accurate diagnosis, to continue to refine the diagnostic criteria, and to contribute to the body of knowledge necessary to make further advances in the classification as well as in the field of headache.     

Headache associated with dialysis: the International Headache Society criteria revisited

The International Headache Society (IHS) criteria for headache related to haemodialysis consider that the headaches must begin during haemodialysis and terminate within 24 h. Twenty-eight patients whose headaches started by the time they entered the dialysis programme were prospectively studied. We were not able to classify eight patients that presented the headaches between the sessions. Despite the small number of patients in our study being too low to provide a basis for change in the IHS classification, it serves as an observational report demonstrating possible varieties of headache related to haemodialysis.     

Prevalence of primary headaches in people with multiple sclerosis

The aim was to investigate the lifetime prevalence of headache and primary headache (diagnoses according to International Headache Society criteria) in multiple sclerosis (MS). The relationships between headache and clinical features of MS and MS therapy were also investigated. We studied 137 patients with clinically definite MS; 88 reported headache, 21 of whom developed headache after the initiation of interferon. The prevalence of all headaches in the remaining 116 patients was 57.7%. Migraine was found in 25.0%, tension-type headache in 31.9%, and cluster headache in one patient. A significant correlation (P = 0.007, Fisher's exact test) between migraine and relapsing-remitting MS was found. Primary headaches are common in MS patients. Further studies are needed to clarify the mechanisms underlying this association, particularly the association between migraine and relapsing-remitting MS, and the role of interferon in the development of new headache.     

Migraine without aura and migrainous disorder in children; International Headache Society (IHS) and revised IHS criteria

The widely used criteria of the IHS to define migraine without aura in children are highly specific but show poor sensitivity, with a large percentage of headaches being classified as migrainous disorder (MD). The objective of this study was to assess how many headache patients in a series of children met the diagnostic criteria of the IHS for migraine without aura or MD and to determine the changes required to convert the greatest number of MD into migraine without aura, without affecting classification of the remaining headache types. A prospective study was undertaken of 131 patients under 15 years old referred to our centre for headache. Patients were classified according to the IHS criteria and according to a modification of these criteria consisting of: (1) reduction of minimum time required for classification into migraine without aura from 2 h to 1 h; (2) acceptance of bifrontal location in addition to hemicranial; (3) acceptance of either phonophobia or photophobia as valid criteria instead of requiring presence of both. Using the IHS criteria, 51 (39%) children were diagnosed as having migraine without aura and 26 (20%) as having MD. According to our revised IHS criteria, 68 (52%) were diagnosed as migraine without aura and nine (7%) as MD. When the three modified criteria were applied, three tension headaches and one unclassifiable headache changed category. When only reduced duration and bifrontal location were applied, none of the headaches other than MD changed category. Application of two modifications to the IHS criteria--reduction in duration of headache to 1 h and acceptance of bifrontal location--increased sensitivity without reducing specificity in classifying migraine without aura in children.     

Application of the International Headache Society classification criteria in 652 cluster headache patients

We applied the International Headache Society (IHS) classification coding parameters to a study population of 652 cluster headache (CH) patients, in order to determine how many patients did not fulfil the diagnostic criteria for group 3.1 and to find out any diagnostic elements that could be changed in the upcoming revision of the classification to make it more relevant to current clinical practice. Ninety-nine patients were found to have cluster-like disorder (3.3), including 74 (74.7%) who did not fulfil the diagnostic criteria for CH, because either pain was not associated with any of the accompanying autonomic phenomena listed in the classification or it was not located orbitally, supraorbitally and/or temporally. A review of our total sample showed that 72.0% of patients reported frontal and occipital pain location; in 61.8%, 33.4% and 39.1% of cases, attacks were also accompanied by restlessness/agitation, nausea and photophobia, respectively. In a coding system that took into account the diagnostic elements that we considered in our study, group 3.1 of the existing IHS classification would actually include 51 of the 99 patients currently coded as 3.3.     

Osmophobia in primary headaches

This study evaluates osmophobia (defined as an unpleasant perception, during a headache attack, of odours that are non–aversive or even pleasurable outside the attacks) in connection with the diagnosis of primary headaches. We recruited 775 patients from our Headache Centre (566 females, 209 males; age 38±12 years), of whom 477 were migraineurs without aura (MO), 92 with aura (MA), 135 had episodic tension–type headache (ETTH), 44 episodic cluster headache (ECH), 2 chronic paroxysmal hemicrania (CPH) and 25 other primary headaches (OPHs: 12 primary stabbing headaches, 2 primary cough headaches, 3 primary exertional headaches, 2 primary headaches associated with sexual activity, 3 hypnic headaches, 2 primary thunderclap headaches and 1 hemicrania continua). Among them, 43% with MO (205/477), 39% with MA (36/92), and 7% with CH (3/44) reported osmophobia during the attacks; none of the 135 ETTH and 25 OPH patients suffered this symptom. We conclude that osmophobia is a very specific marker to discriminate adequately between migraine (MO and MA) and ETTH; moreover, from this limited series it seems to be a good discriminant also for OPHs, and for CH patients not sharing neurovegetative symptoms with migraine. Therefore, osmophobia should be considered a good candidate as a new criterion for the diagnosis of migraine.     

Classification of headaches

It was not until 1962 that the Ad-Hoc Committee of the National Institute of Health first published a classification of headache syndromes by brief glossary definitions. The general disadvantage of such glossary definitions is that they require subjective interpretation. Therefore under the chairmanship of Prof. Jes Olesen, Copenhagen, the International Headache Society published in 1988 on the basis of empirical findings a first ever headache classification using operationalized criteria. The headache classification of the International Headache Society was immediately translated into the world's major languages and was adopted by all national headache societies represented in the International Headache Society, the World Health Organisation and the World Federation of Neurology. The new classification proved so successful and enjoyed such rapid international acceptance that no revision was undertaken until 1999. The second edition, again under the chairmanship of Prof. Jes Olesen, will probably be completed in 2002. The classification produced such a high degree of inspiration and motivation of pathophysiological and epidemiological research work that knowledge in the field of headache has displayed growth unparalleled in any other field of neurological research. This development was made possible by the determined work of the Chairman of the Headache Classification Committee, Prof. Jes Olesen. He succeeded in bringing together international researchers, motivating them and jointly turning the current fund of knowledge into a evidence-based classification. Prof. Jes Olesen thus performed the decisive pioneering work for all those who have to do with headaches-patients, doctors and scientists. The IHS classification is the most frequently cited text and one of the most important milestones in the history of the scientific study of headaches.     

A community-based study of headache diagnosis and prevalence in Singapore

We present the results of a community survey based on the diagnostic criteria of the International Headache Society (IHS) describing headache prevalence and symptomatology in the Singapore population. A questionnaire administered by trained personnel was completed by 2096 individuals from a randomized sample of 1400 households. The overall lifetime prevalence of headache was 82.7%. The migraine prevalence was 2.4% in males and 3.6% in females; for episodic tension-type headache and chronic tension-type headache the corresponding figures were 11.1%/11.8% and 0.9%/1.8%, respectively. Inclusion of borderline cases (IHS codes 1.7 and 2.3) resulted in prevalences of 9.3% for migraine, 39.9% for episodic tension headache and 2.4% for chronic tension headache. Headaches described by 31.2% of the respondents were unclassifiable. The different premonitory symptoms, precipitants and aggravating factors in migraine and tension-type headache in our study population suggest that they represent two distinct syndromes rather than opposite ends of a clinical spectrum.     

Headache characteristics and race in Singapore: results of a randomized national survey

This study presents the first account of the racial differences in headache prevalence and characteristics in the Singapore population. A questionnaire was administered to 2096 individuals from a randomized sample of 1400 households to test the hypothesis that race was independently correlated with headache diagnosis and morbidity. The overall lifetime prevalence of headaches in the study population was 82.7%; this did not vary between racial groups. The modal age of headache onset in all races was in the second decade and was similar in all races. Multivariate analysis showed that headache morbidity was independent of age, sex, income level, marital status, shift duties, and educational level, and correlated only with race and a positive family history of severe headache. Non-Chinese were more likely to suffer from severe headaches than Chinese, were more likely to seek medical attention, and were more likely to require medical leave for their symptoms. Non-Chinese had more migrainous headaches than Chinese, although characteristics of headache both groups experienced that were unrelated to severity differed only in a few aspects. We conclude that racial factors account for differences in headache classification, perception of headache severity and health-seeking behavior.     

Sonographic features of benign thyroid nodules: interobserver reliability and overlap with malignancy.

OBJECTIVE: To prospectively determine the sonographic findings of nodular hyperplasia of the thyroid, to compare these with reported findings associated with malignancy, and to assess interobserver reliability. METHODS: Seventy thyroid nodules were scanned, and then biopsies of the nodules were performed under sonographic guidance with fine-needle cytologic analysis; in all cases images were reviewed by 2 experienced radiologists without knowledge of clinical outcome. Findings reported associated with malignancy were specifically assessed. Interobserver agreement between the expert and secondary readers for each finding was calculated by the kappa or weighted kappa statistic and the Fisher exact test of independence. RESULTS: There were 68 benign and 2 malignant nodules in a population of 63 female and 7 male patients. The mean benign nodule size was 2.9 cm; 60% were solid; 54% were hypoechoic; 59% were microlobulated or macrolobulated; 47% had central vascularity; 24% contained calcifications; and 82% were elliptical in shape. There was very good interobserver reliability for the presence of calcium (kappa = 0.91) and good agreement for the presence and location of vascularity (kappa = 0.75) and the amount of cystic components (kappa = 0.62; all P < .01). CONCLUSIONS: Sixty-nine percent of benign nodules had at least 1 finding reported previously as associated with malignancy. The interobserver reliability of the sonographic findings was good to very good for 3 of the 5 findings assessed.     

15th International Headache Congress: basic science highlights

The 15th Congress of the International Headache Society was held in Berlin from June 23rd to 26th of 2011. Interesting new data from several areas of the basic sciences of headache were presented. This is a review of some of the most exciting platform and poster presentations of the meeting. Research addressing 3 general areas of interest is presented in this review: pathophysiology, pharmacology, and genetics.     

Validation of the classification of migraine without aura (IHS A1.1) proposed in ICHD-2

OBJECTIVE: This study attempts to validate the alternative criteria for classification of migraine without aura (International Headache Society [IHS] A1.1) proposed in the appendix of The International Classification of Headache Disorders, 2nd edition. This method uses at least two of the associated symptoms (nausea, vomiting, photophobia, phonophobia, and osmophobia) in category D of the IHS classification. BACKGROUND: In the appendix of The International Classification of Headache Disorders, 2nd edition, an alternative method of classification of migraine without aura is proposed. This method of classification has never been validated. METHODS: A total of 1480 consecutive headache patients in a tertiary care setting were evaluated at first visit. Headache-associated features, such as intensity, lifetime duration, frequency per month, duration, triggers, prodrome, percentage recurrence, and postdrome frequency, were recorded. In addition, medication satisfaction, acute and monthly disability, grading of headache days, sleep normality, mood, and habits were documented. RESULTS: Of the 1480 patients, 901 were initially classified as having migraine IHS 1.1. Using the proposed alternative method (IHS A1.1), 885 (98.2%) of these patients were reclassified as having migraine. The remaining 16 (1.8%) patients not classified had only nausea and none of the other specified associated symptoms. They also exhibited different characteristics from the IHS migraine population as a whole regarding their headache and other features. CONCLUSIONS: This classification of migraine in a headache center population shows that the proposed use of any two of nausea, vomiting, photophobia, phonophobia, and osmophobia in category D of the classification may be a valid alternative method of classification. This study also demonstrates that the standard IHS methodology includes a very small group of patients who appear to be different from other migraine patients.     

Clinical Features of Chronic Daily Headache

Patients with chronic daily headaches are commonly encountered in headache specialty centers but their clinical characteristics have rarely been documented. We studied 100 consecutive patients with chronic daily headache to determine their presenting characteristics and other associated features. Half of the patients described their headache as a steady ache but throbbing pain was reported in about one third. About half estimated the degree of pain as moderate but one third claimed the typical pain was severe. A consistently unilateral site was noted in only 2 percent. Associated features characteristic of migraine were often noted: Including photophobia (37 percent), photophobia (42 percent), and nausea (24 percent). Many also reported aggravating and ameliorating factors commonly associated with migraine. We conclude that the manifestations of chronic daily headache are extremely diverse, probably reflecting the heterogeneous mechanisms which underlie this condition.     

The International Headache Society classification of chronic daily and near-daily headaches: a critique of the criticism

The classification of the International Headache Society (IHS) published in 1988 has been positively received throughout the world. However, the classification of headaches occurring daily or almost daily has been criticized repeatedly. This criticism is discussed in the present review. It is possible to classify virtually all chronic headache patients using the IHS Classification and there seems to be more need for emphasizing a correct application of the classification than for a revision in this regard. The entity of transformed migraine is disputed and so is the existence of hemicrania continua. Neither of these syndromes has been adequately defined nor studied. Chronic daily headache of sudden onset (new persistent daily headache) is not adequately classified at present and should be included as a separate entity in the next edition of the IHS Classification. In a future revision it should also be possible to classify drug-related headache simply on the basis of drug consumption and without mandatory demands for withdrawal. Better longitudinal studies of patients with chronic daily headache are necessary to evaluate finally whether a revision of the classification of these headache syndromes is necessary. Eventually the ongoing discovery of migraine genes is likely to change radically the classification of migraine.     

Headache and Self-assessed Depression Scores in Singapore University Undergraduates

A self-administered questionnaire covering the diagnostic criteria of the International Headache Society was completed by 1208 undergraduates of the National University of Singapore to determine the prevalence and characteristics of headaches in this population. The relationship between headaches and depressive illness was investigated with the Zung Self-assessed Depression Scale. The mean age of respondents was 20.9 ± 1.6 years; 50.3% were men and 46.4%, women. Ten point nine percent had migraine without aura, 29.8% had tension-type headaches, 1.1% had headaches consistent with migraines with aura, and in 56.3% the headaches could not be classified. The lifetime prevalence of headache in this population was 98.1%. Significantly higher mean Zung scores were found in subjects who had more intense and frequent headaches than in those without headaches and less severe symptoms, al though the clinical relevance of this finding is uncertain Zung scores did not differ significantly with diagnostic group, sex, or race.     

The International Classification of Headache Disorders, 3rd Edition (ICHD III) – Changes and Challenges

In order to effectively study and manage headache disorders, diagnosis is essential. In both research and clinical arenas, separating secondary causes from primary headache disorders is a crucial first step, followed by further specificity within these broader categories. Historical approaches to classifying headache disorders culminated in the International Classification of Headache Disorders (ICHD), completed and published in 1988. This was revised as the International Classification of Headache Disorders, 2nd Edition (ICHD II) in 2004. The International Headache Society's Subcommittee on Classification began work on the 3rd edition in 2010, and has just published this online and in the journal Cephalalgia. The diagnostic criteria for more than 200 causes of headaches are based upon evidence when available, and fortunately, recent research in the field of headache medicine has produced data applicable to the refinement of classification of a number of primary and secondary headache disorders. Some areas, however, await further study, making classification more challenging. This article will attempt to provide an overview of the rationale behind the ICHD, a guide to its use, and a summary of important diagnostic features of the primary and secondary headaches, particularly where these have changed significantly in the ICHD III from ICHD II.     

Application of the ICHD-II criteria to the diagnosis of primary chronic headaches via a computerized structured record

BACKGROUND: The authors recently developed a software program designed to analyze clinical data from patients affected by primary headache. The program is based exclusively on the International Classification of Headache Disorders 2nd edition (ICHD-II) criteria. This software examines all the diagnoses of primary headaches on the basis of the variables needed to fulfill these mandatory criteria. METHODS: We tested the software, Primary Headaches Analyser 1.0 INT (PHA), by entering and analyzing clinical data from 200 consecutive patients affected by primary chronic headaches and evaluating the corresponding output diagnoses. RESULTS: The diagnosis of chronic migraine (1.5.1) was obtained in 68 cases (34 %) and that of probable chronic migraine (1.6.5) plus probable medication-overuse headache (8.2.8) in 46 (23%). Chronic tension-type headache (2.3) and probable chronic tension-type headache (2.4.3) plus probable medication-overuse headache (8.2.8) were diagnosed in 24 (12%) and 2 (1%) patients, respectively. Moreover, 4 and 12 patients, respectively, received both the diagnosis of chronic migraine (1.5.1) plus chronic tension-type headache (2.3) and of probable migraine (1.6.1) without aura plus chronic tension-type headache (2.3). In the remaining 44 cases (22%), none of the chronic primary headaches disorders defined by ICHD-II received an output diagnosis from the program. This was due mainly to the fact that the criteria fulfilled were insufficient for the diagnoses of migraine without (1.1) aura plus chronic migraine or, more infrequently, chronic tension-type headache. CONCLUSIONS: Our software program permitted diagnoses of chronic migraine, chronic tension-type or their probable forms (with or without MOH) in 78% of 200 patients with headache 15 or more days per month. In the remaining cases the inability to provide a specific diagnosis may be explained in part by the fact that the criteria for both diagnoses are too stringent and do not accurately reflect variations of the headache pattern in these chronic forms.     

North Staffordshire Headache Survey: development,reliability and validity of a questionnaire for use in a general population survey

The North Staffordshire Headache Survey aims to measure the effect and impact of headaches, medicine use and healthcare utilization in a general population sample. A self-reporting questionnaire was piloted in a general population sample, with reliability being tested in a sample of pilot responders after one month and validity by comparing pilot responders with primary and secondary care headache consulters. One hundred and twenty-two (61%) responded to the pilot survey, with 56% of items having completion rates of 90% or more, and tests showed good internal consistency (>90%). One-month test-retest data showed good agreement, though questions relating to specific time periods (with partial or no overlap between survey periods) showed expected lower agreement. The headache consulters reported greater frequency, duration and severity of headaches than the population sample suggesting good construct validity. Results from these studies indicate that the questionnaire is a reliable and valid instrument to collect data about headaches in the general population.