American Headache Society members' assessment of headache diagnostic criteria

OBJECTIVE: We assessed the views of physicians interested in headache as to the diagnosis of the most commonly occurring and currently controversial headaches. BACKGROUND: The International Headache Society (IHS) classification system has received wide professional endorsement and considerable empirical support, but in the United States, their adoption by clinicians may be proceeding more slowly. Questions remain, including what diagnostic criteria for migraine and tension-type headache clinicians may continue to favor over those outlined by the IHS, to what extent is the "transformed migraine" diagnosis used in clinical practice, and how is analgesic rebound headache diagnosed with regard to the various quantitative measures of analgesic use. METHODS: Members of the American Headache Society rated the importance of IHS and non-IHS diagnostic criteria for migraine and tension-type headache and for analgesic rebound headache. Respondents also described their use of the proposed transformed migraine diagnosis. RESULTS: Two-thirds (67.3%) of the respondents reported use of the IHS criteria or the IHS criteria in conjunction with clinical judgment. For migraine and tension-type headache, IHS criteria were rated with high importance, but some respondents reported using additional non-IHS diagnostic criteria and de-emphasizing certain IHS criteria. For chronic headache, almost two-thirds (63%) of respondents reported using the transformed migraine diagnosis. For analgesic rebound headache, respondents preferred to make the diagnosis based on medication consumption that is lower than amounts stipulated in the IHS classification system. CONCLUSIONS: There remains a number of physicians interested in headache who do not use the IHS classification system, who modify the IHS criteria in practice, and who use the "transformed migraine" diagnosis for patients with chronic daily headache.     

2000 Wolfe Award. Sumatriptan for the range of headaches in migraine sufferers: results of the Spectrum Study

BACKGROUND: Migraineurs experience a spectrum of headaches: migraine, migrainous, and episodic tension-type as defined by the International Headache Society (IHS). OBJECTIVE: To evaluate the effectiveness of sumatriptan, 50-mg tablets, in treating the spectrum of headaches in IHS-diagnosed migraineurs. DESIGN/METHODS: Migraineurs with severe disability (Headache Impact Questionnaire score 250 or greater) were enrolled in a randomized, double-blind, placebo-controlled, crossover study. Patients treated up to 10 headaches with sumatriptan, 50 mg, or placebo (4:1). Headache features, recorded prior to treatment, were used to classify each headache using IHS criteria. Headache response (moderate or severe pain reduced to mild or no pain) and pain-free response were recorded at 2 and 4 hours postdose (primary endpoint). Because patients treated multiple attacks, statistical methods controlling for within-subject correlation were used. RESULTS: Two hundred forty-nine migraineurs treated 1576 moderate or severe headaches: migraine (n = 1110), migrainous (n = 103), and tension-type (n = 363). Sumatriptan was superior to placebo for headache response 4 hours postdose (primary endpoint) across all headache types (migraine, 66% versus 48%; P<.001; migrainous, 71% versus 39%; P<.01; tension-type, 78% versus 50%, P<.001). Sumatriptan was also superior to placebo for pain-free response 4 hours postdose for migraine (41% versus 24%, P<.001) and tension-type headaches (56% versus 36%, P =.001). Sumatriptan provided superior pain-free response 2 hours postdose for migraine (18% versus 7%, P<.0001) and tension-type headache (28% versus 14%, P =.0005) compared with placebo. CONCLUSION: Sumatriptan, 50-mg tablets, are effective for the full spectrum of headaches experienced by patients with disabling migraine due to a sumatriptan-responsive mechanism.     

Migrainous disorder and headache of the tension-type not fulfilling the criteria: a follow-up study in children and adolescents

In this follow-up study in children and adolescents with recurrent headaches classified as migrainous disorder (IHS 1.7) and headache of the tension-type not fulfilling the criteria (IHS 2.3), 28.6% were headache-free and 71.4% still had headaches 2-5 years after the first examination. The majority remained in the same one-digit IHS diagnosis, whereas 20% changed from migraine to tension-type headache or vice versa. The number of IHS criteria fulfilled increased significantly from the first to the second examination. The reason for diagnosing IHS 1.7 and IHS 2.3 most often was a short headache duration or headache characteristics not meeting the criteria. By reducing the minimum headache duration to 1 h, 11 of 58 patients could be diagnosed as migraine without aura. There was a remarkable overlap in the diagnostic criteria for migraine without aura and tension-type headache. In IHS 1.7 and IHS 2.3 this overlap exceeded 80%, with a trend to decrease at the second examination.     

Consulting behaviour in migraine and tension-type headache sufferers: a population survey in Santiago, Chile

Migraine and tension-type headaches are the most frequent types of headaches in Santiago. The purpose of this paper is to describe the patterns of health care utilization in migraine and compare them with tension-type headache sufferers in a community-based study of the prevalence of headache in Santiago, Chile. A two-step questionnaire was administered to an age- and gender-representative sample of 1540 eligible subjects who were aged 15 years or older. Of these, 1385 (89.9%) responded. Cases were defined according to the most frequent type of headache experienced in the last year. Migraine and tension-type headaches were diagnosed according to a questionnaire-based algorithm constructed using the IHS criteria. Consultation rates in migraneurs were significantly (P < 0.01) higher (63%) than in tension-type headache suffers (39%). Migraneurs were more likely to be female, younger and less educated, and had more severe attacks than those with tension-type headache. Female sex, younger age, fewer years of education in migraneurs and younger age and moderate or severe headache in tension-type headache sufferers were found to be independently associated with the likelihood of ever consulting, respectively. Migraneurs are more likely to consult than tension-type headache suffers in this population.     

Efficacy of sumatriptan nasal spray in recurrent migrainous headache: an open prospective study

OBJECTIVE: To evaluate the effectiveness of sumatriptan 20 mg via nasal spray and 100-mg tablets in treating migrainous headache in patients without a concomitant migraine diagnosis. METHODS: We prospectively investigated the efficacy of sumatriptan 20 mg via nasal spray and 100-mg tablets in patients with a history of at least 5 moderate to severe headache attacks lasting 2 to 72 hours that consistently did not meet the International Headache Society (IHS) criteria for migraine or episodic tension-type headache. RESULTS: Nineteen headache attacks classifiable as migrainous disorder without aura (IHS 1.7) were evaluated in 13 patients using 20-mg sumatriptan nasal spray within a 10-week period. A 2-point decrease in headache severity on a four-point scale was achieved in 74% (95% confidence interval [CI], 50% to 89%) of the attacks within 2 hours. The pain-free incidence (a reduction in headache severity from moderate or severe to none) was 37% (95% CI, 17% to 63%) after 2 hours. Ten patients completed the second part of the study, taking oral sumatriptan for 14 migrainous attacks: a 2-point decrease in headache severity was achieved in 38% (95% CI, 13% to 71%) of the attacks within 2 hours and in 77% (95% CI, 48% to 92%) within 4 hours. CONCLUSION: This is the first prospective study to show that intranasal or oral sumatriptan may be effective in patients experiencing moderate to severe headache attacks which consistently do not fulfill the IHS criteria for migraine or episodic tension-type headache.     

Diagnosis of headache in childhood and adolescence: a study in 437 patients

We investigated whether the criteria for idiopathic headache published by the International Headache Society (IHS) are useful in childhood and adolescence and compared the diagnoses according to this classification with those of Vahlquist. We used a semi-structured questionnaire to examine a total of 437 children and adolescents referred consecutively to a headache outpatient clinic. Twenty-eight of 437 patients were excluded because of symptomatic or unclassifiable headache. Of 409 patients with idiopathic headache, 70.4% had definite migraine or tension-type headache (IHS 1.1, 1.2, 2.1, 2.2), 20.5% had a migrainous disorder (IHS 1.7) and 9.1% had headache of the tension-type not fulfilling the criteria (IHS 2.3). In the differential diagnosis of migraine and tension-type headache the intensity of pain, aggravation of headache by physical activity, nausea and vomiting were the most important features. The quality of pain, photo- and phonophobia were less helpful and location least important. The duration of migraine attacks was less than 2 h in 19.0% of the migraine patients. In general, the diagnostic criteria of migraine were highly specific but less sensitive, and those of tension-type headache highly sensitive but less specific. The agreement between IHS criteria and those of Vahlquist was marked (kappa = 0.57). We conclude that the IHS criteria are useful for classifying headache in children and adolescents referred to a headache outpatient clinic. A forthcoming modification of the IHS criteria should consider a reduction of the minimum duration of migraine attacks from 2 h to I h and should try to increase the sensitivity of the criteria for migraine and the specificity of the criteria for tension-type headache.     

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.     

Chronic daily headache. How should it be included in the IHS classification?

A number of patients attending specialty headache centers complain of very frequent, almost continuous or continuous headaches, which are usually grouped together under the term chronic daily headache , a category which does not appear in the International Headache Society (IHS) classification. On the basis of the IHS criteria, these patients can only be classified as having a chronic tension-type headache with the possible addition of migraine, if migrainous attacks are superimposed on the "background" headache. However, several studies have demonstrated that most patients with chronic daily headache originally suffered from migraine and that their migraine has transformed, in the course of time, into a chronic headache picture in which isolated migraine attacks may or may not persist. Despite some differences in the personal opinions of authors involved in the care of patients with chronic daily headache, some views seem to be generally accepted: (1) the great majority of chronic daily headaches are transformations of an original episodic migraine and cannot be included in the chronic tension-type headache category, (2) the current IHS classification does not allow many patients presenting with chronic daily headache to be classified correctly, (3) an important nosological category (transformed migraine) has emerged from all the studies on this subject, (4) it is impossible to diagnose transformed migraine merely by "photographing" the picture of single attacks. Although some theoretical problems remain unresolved, it seems to us that the next revision of the IHS classification can no longer ignore the existence of chronic daily headache.     

Oral sumatriptan for the acute treatment of probable migraine: first randomized, controlled study

OBJECTIVE: To evaluate the efficacy and tolerability of sumatriptan tablets in adults who meet International Headache Society (IHS) criteria for probable migraine but who do not meet IHS criteria for migraine with or without aura. BACKGROUND: Headaches with some but not all of the features of migraine meet criteria for probable migraine, a form of migraine recognized by the IHS. Probable migraine attacks are also prevalent and frequently underdiagnosed. METHODS: This was a randomized, multicenter, double-blind, placebo-controlled, parallel-group study. Adults (18 to 65 years) with a 1-year history of headaches that met 2004 IHS criteria for probable migraine without aura (same operational definition as 1988 IHS migrainous disorder) were eligible for enrollment. All patients were triptan- and ergot-na?ve and had never been diagnosed with migraine. Patients were randomized in a 1:1:1:1 fashion to receive sumatriptan 25, 50, or 100 mg conventional tablets or matching placebo and were instructed to treat a single moderate or severe probable migraine attack. A post hoc analysis was conducted to evaluate the population of patients who achieved headache relief sustained throughout the immediate posttreatment period. Patients who reported relief within 2 hours and subsequently lost headache relief within 4 hours were considered nonresponders. RESULTS: At 2 hours, more patients treated with sumatriptan achieved headache relief, the primary efficacy measure, compared with placebo, but differences only approached statistical significance for 100 mg (P= .053). The 2-hour headache relief rate in the sumatriptan 25 or 50 mg groups was not significantly different than placebo. The time to use of rescue was significantly shorter in the placebo group compared with the sumatriptan 100 mg group (P= .002). The time to use of rescue in the sumatriptan 25 or 50 mg groups was not significantly different than placebo. More patients treated with placebo (22%) lost headache relief within 4 hours compared with patients treated with sumatriptan 25 mg (17%), 50 mg (14%), or 100 mg (7%). A post hoc analysis demonstrated that at 2 hours, headache relief sustained through 4 hours (S 0-4 hours) was achieved in 44%, 49%, and 57% of patients treated with sumatriptan 25, 50, and 100 mg, respectively, compared with 34% of patients treated with placebo (P < .05 for sumatriptan 50 and 100 mg vs. placebo). All doses of sumatriptan were well tolerated and no serious adverse events were reported. CONCLUSION: These results suggest that oral sumatriptan may be effective and is well tolerated for the acute treatment of probable migraine without aura, however, the difference between sumatriptan and placebo was not statistically significant for the a priori defined primary endpoint.     

Cephalic venous congestion aggravates only migraine-type headaches

We performed the Queckenstedt's (Q)-test (compression over bilateral internal jugular veins) and a sham test on 33 patients with migraine attacks (coded as 1.1 based on headache classification proposed by International Headache Society (IHS)), 15 with migrainous attacks (IHS code 1.7), and 15 with tension-type headache (IHS code 2.1) in both supine and sitting positions. 'Migrainous headache' (code 1.7) was defined if the headache characteristics fulfilled all but one criteria for 'migraine without aura'. Migraine sufferers reported a marked increase in headache intensity after a 30-second Q-test in both supine and sitting positions. Aggravation was greater in the supine position. The intensity increase was not demonstrated in the sham test, or in patients with migrainous attacks or tension-type headaches after the Q-test. Patients with acute migraine thus appear more sensitive to increased cerebral venous pressure or intracranial pressure. The discrepancy of intensity changes between supine and sitting positions may reflect different amount of venous return through the internal jugular veins.     

Variability of reported headache symptoms and diagnosis of migraine at 12 months

Assignment of a diagnosis of migraine has been formalized in diagnostic criteria proposed by the International Headache Society. The objective of the present study is to determine the reproductibility of the formal diagnosis of migraine in a cohort of headache sufferers over a one-year period. The study was performed in a community cohort taking part in a long-term prospective health survey, the GAZEL study. Two thousand five hundred individuals reporting headache in the GAZEL cohort were sent two postal questionnaires concerning headache symptoms and features at 12-monthly intervals. Replies to the questions allowed a migraine diagnosis to be attributed retrospectively using an algorithm based on the IHS classification scheme. The response rate was 82% for the first questionnaire and 69% for both questionnaires. Of the 1733 subjects providing information at both time-points, the agreement rate for the diagnosis of strict migraine (IHS categories 1.1 or 1.2) was 77.7% (kappa = 0.48), with 62.2% of the patients with this diagnosis (IHS categories 1.1 or 1.2) at Month 0 retaining the same diagnosis at Month 12. When diagnostic criteria were widened to include IHS category 1.7 (migrainous disorder), the agreement rate of the diagnosis was similar at 77.6% (kappa = 0.52), but 82% of the patients with this diagnosis (IHS categories 1.1 or 1.2 or 1.7) at Month 0 now retained the same diagnosis at Month 12. In conclusion, the one-year reproducibility of reporting of migraine headache symptoms is only moderate, varies between symptoms, and leads to instability in the formal assignment of a migraine headache diagnosis and to diagnostic drift between headache types. This finding is compatible with the continuum model of headache, where headache attacks can vary along a severity continuum from episodic tension-type headaches to full-blown migraine attacks.     

Effect of age on the fulfilment of the IHS criteria for migraine in children at a headache clinic

In a headache clinic, 247 children suffering from severe recurrent headaches were studied in relation to the IHS criteria for migraine. Of the 247, 163 had migrainous headache, with 110 (67.5%) of these having migraine in accordance with the IHS criteria. The remaining 53 (32.5%) had headache attacks fulfilling all but one of the IHS criteria. Coverage of the IHS criteria for migraine was 93%. Symptoms of unilateral headache, aggravation by physical activity, and nausea showed the greatest differences in frequency between those with migraine and those with probable migraine. All children with aura fulfilled criteria for migraine. Children with migraine with aura (11.8, 95% CI: 11.0–12.6 years) were older than those without aura (10.1, 9.4–10.8 years; p = 0.001). Children with pulsating headache were slightly older than children without pulsating headache. No differences in age were detected for the other IHS criteria.     

Effectiveness of nasal sumatriptan in 5- to 12-year-old children

OBJECTIVE: To assess the tolerability and effectiveness of nasal sumatriptan in the treatment of migraine in 5- to 12-year-old children. BACKGROUND: Although headaches are a common disorder and occur in up to 10.6% of children, many of the new migraine abortive agents have not been well evaluated in this population. It has recently been reported that nasal sumatriptan is effective in the treatment of migraine in adolescents. In younger children, it is yet to be characterized. In addition, many children have significant amounts of vomiting with their migraines, limiting their use of oral medications. DESIGN AND METHODS: Children with headache were evaluated by a child neurologist, child psychologist, and pediatric nurse practitioner. Clinical and International Headache Society diagnoses were established for each child. Patients with headaches that were either unresponsive to oral medications or had significant vomiting were treated with nasal sumatriptan. Initial administration and tolerability were performed in the Headache Center at Cincinnati's Children's Hospital Medical Center. Patients or their parents were contacted to assess the overall effectiveness of nasal sumatriptan after home administration. RESULTS: Ten patients aged between 5 and 12 years (mean, 9.9 years) received either a 5-mg (n = 2) or 20-mg (n = 8) dose of sumatriptan. All 10 patients had a clinical diagnosis of migraine; 7 met the International Headache Society criteria for migraine. The mean age of headache onset was 6.6 years. A total of 57 headaches were treated; 47 (82.5%) responded to sumatriptan. Of the patients who treated headaches, the mean number of headaches treated was 5.2, while the mean number of responsive headaches was 4.3. One patient had no response, 2 patients had a 50% response, and 6 patients had 100% response to the nasal sumatriptan. Three patients reported persistent "bad taste." CONCLUSIONS: This report demonstrates that nasal sumatriptan may be effective in aborting migraine in young children (aged 5 to 12 years). It also suggests that there may be subgroups for which it works well. This information suggests that double-blind, placebo-controlled studies are necessary to determine the overall effectiveness of nasal sumatriptan in this age group.     

Headache in Behçet's disease

The aim of this study was to investigate the characteristics of headache in patients with Beh?et's disease (BD) seeking neurological consultation. Consecutive patients with BD seen within 1 year at the neuro-Beh?et's out-patient clinic were studied using an electronic database according to the classification criteria of the International Headache Society. During a 12-month period 118 BD patients were admitted, and 98 had headaches. Migraine was the most common type of primary headache diagnosed in 45 patients (46.4%) in the whole headache group, followed by tension-type headache (TTH) in 26 cases (26.8%). Thirty-seven patients had secondary headaches mainly due to cerebral venous thrombosis or parenchymal neurological involvement of BD. Of these patients, 15 had both primary and secondary headaches. The primary headaches of 13 patients were exacerbated with systemic BD flare-ups, and four patients had migraine attacks triggered only by systemic BD activation which showed a good response to the treatment of systemic inflammation. The majority of the headaches of patients with BD do not indicate any neurological involvement; they are usually due to migraine or TTH. In a minority of patients, migraine associated with systemic inflammation of BD is notable.     

Self-treatment of acute migraine with subcutaneous sumatriptan using an auto-injector device: comparison with customary treatment in an open, longitudinal study

In a multicenter open longitudinal clinical trial where 479 patients suffering from migraine with or without aura were recruited, patients treated at home one to three migraine attacks with their customary treatment, and subsequently, over a 3-month period, one to three migraine attacks with (5 mg sumatriptan sc using an auto-injector. The headache response to customary treatment was 19% at 1 h and 30.5% at 2 h, and was not significantly different when only attacks treated "adequately" according to accepted treatment recommendations were considered: 16% at 1 h and 35% at 2 h. In contrast, 69% and 82% of patients treated with 6 mg sumatriptan sc had mild headache or no headache at 1 and 2 h respectively, regardless of migraine type or duration of symptoms prior to treatment. Other migraine symptoms (nausea, vomiting, photo- and phonophobia) were effectively treated with sumatriptan. Recurrence of migraine was observed in 31% of patients and was well controlled by a second injection of sumatriptan. It is concluded that 6 mg sumatriptan sc, self-administered using an auto-injector, is well tolerated and more effective than most currently used acute treatments for migraine in a population of severely affected patients consulting a neurologist.     

Acute and interictal allodynia in patients with different headache forms: an Italian pilot study

OBJECTIVE: To investigate allodynia in patients with different primary headaches. BACKGROUND: Many migraineurs have allodynia during headache attacks; some may have allodynia outside attacks; allodynia may also be associated with other primary headaches. METHODS: A total of 260 consecutive primary headache patients presenting for the first time at a headache center, and 23 nonheadache controls answered written questions (subsequently repeated verbally) to determine the presence of acute and interictal allodynia. RESULTS: We divided the patients into: episodic migraine (N = 177), subdivided into only migraine without aura (N = 114) and those sometimes or always reporting migraine with aura (N = 63); episodic tension-type headache (N = 28); chronic headaches (headache > or = 15 days/month, N = 52), including chronic migraine, chronic tension-type headache, and medication-overuse headache; and other headache forms (N = 3). Acute allodynia was present in 132 (50.7%), significantly more often in patients sometimes or always suffering migraine with aura, and those with chronic headache forms, compared to patients with migraine without aura and episodic tension-type headache. Interictal allodynia was present in 63 (24.2%) patients, with significantly higher frequency in those having migraine with aura attacks than controls and common migraine patients. CONCLUSIONS: Allodynia is not specific to migraine but is frequent in all headache patients: acute allodynia was reported in half those interviewed and in over a third of patients in each headache category; interictal allodynia was reported by nearly 25%.     

The Relationship of Locus of Control and PsychosociaI-Behavioral Response in Chronic Headache

It has been suggested that patients' perceptions of the impact chronic headache has on their lives as well as perceived control of their headaches may be associated with the intensity, duration, and exacerbation of pain they experience. The present study examined associations among International Headache Society (IHS) diagnostic category, pain characteristics such as severity and duration, perceived impact and control of headaches, and adaptive response. Two hundred twenty-five patients with migraine, tension-type, or combined migraine and tension-type headache served as subjects. General activity level was related to IHS diagnosis, with migraine headache patients reporting that they are more active than tension-type headache patients (F(2, 196) = 5.69, P < .01). Headache locus of control was not significantly related to IHS diagnosis, however external headache locus of control was significantly related to headache intensity (r = .32, P < .001, r = .25, P < .001), as well as to patients' perceptions of the extent to which pain interfered with various domains of their lives (r = .33, P < .001, r = .28, P < .001), and adaptive response (F(6, 402) = 4.68, P < .001). It appeared that perceived control over headaches and perceived impact of headaches were not related to IHS diagnostic category and were not strongly related to each other, but were related to headache severity.     

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.