Undifferentiated headache: broadening the approach to headache in children and adolescents, with supporting evidence from a nationwide school-based cross- sectional survey in Turkey

DOI: https://doi.org/10.1186/s10194- 018- 0847- 1

Abstract-Summary A new approach to these is needed: here we introduce, and investigate, a diagnostic category termed “undifferentiated headache” (UdH), defined in young people as recurrent mild-intensity headache of < 1 h’s duration.

The 1-year prevalence of UdH was 29.2%, of migraine (definite and probable)

26.7%, and of tension-type headache (TTH) (definite and probable) 12.9%.

UdH differed with respect to almost all headache features and associated symp-

toms from both migraine and TTH.

Burden of headache and use of acute medication were lower in UdH than in

migraine and TTH.

Headache yesterday was less common in UdH than migraine (OR 0.32; 95% CI

0.28–0.37) and TTH (OR 0.64; 95% CI 0.56–0.77).

Quality of life (QoL) was better in UdH (33.6 ± 5.2) than in migraine (30.3 ± 5.6; p < 0.001) and TTH (32.4 ± 5.3; p < 0.001), but worse than in pupils without head- ache (35.7 ± 4.7; p < 0.001).

This large nationwide study in Turkey of pupils aged 6–17 years has shown that many children and adolescents have a headache type that does not conform to exist- ing accepted diagnostic criteria.

UdH differs in almost all measurable respects from both migraine and TTH. Although characterised by mild headaches lasting < 1 h, UdH is associated with significant adverse impact on QoL. Longitudinal cohort studies are needed to evalu- ate the prognosis of UdH but, meanwhile, recognition of UdH and its distinction from migraine and TTH has implications for epidemiological studies, public-health policy and routine clinical practice.

Extended: Although characterised by mild headaches lasting <1  h, UdH was associated with significant burden, including adverse impact on QoL.  Crucially, UdH was common, affecting almost 30% of the pupils.

Background In the Global Burden of Disease Study 2010 (GBD2010) [31], tension-type head- ache (TTH) and migraine were revealed as second and third most prevalent disor- ders in the world.

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1 Public Health

In children (6–11 years) and adolescents (12–17 years), the prevalence of head- ache disorders is not well established and the burdens attributable to them are poorly characterised.

The ICHD diagnostic criteria for migraine in adults specify recurrent moderate- to- severe headache of 4–72 h’ duration, with a range of specific characteristics (uni- laterality, pulsating quality, aggravation by physical activity) and accompanying symptoms (photophobia and phonophobia; nausea and/or vomiting) [20].

In our pilot school-based prevalence survey conducted in Turkey and Austria, mild headache of <1  h’s duration was reported by a large proportion (37.2%) of participants aged 6–17 years, often with migraine-like features [43].

We investigate whether a new approach is required in children and adolescents, recognising that the characteristics of adult migraine (and perhaps TTH) may be undeveloped in 6–17 year-olds.

Methods Conducted nationwide in selected schools, it employed a self-completed structured questionnaire administered to entire classes.

Questions were included on demographics, headache occurrence, ICHD-3 beta diagnostic criteria (no different, with respect to migraine and TTH, from those of ICHD-3 [20]), burden attributable to headache, and QoL. A short questionnaire com- pleted by the mediator recorded details about the school and its local environment.

A further very brief questionnaire also completed by the mediator documented

non-participation.

Diagnoses were made using the HARDSHIP algorithm [50], but we modified the process to include UdH. First, we applied the criteria for UdH (duration <1 h, inten- sity mild).

Among remaining participants, we separated those reporting headache on ≥15 days/month, diagnosing probable MOH (pMOH) when acute medication was reportedly used on ≥15 days/month or, otherwise, “other headache on ≥15 days/ month” (these cases were not included in this analysis).

Results We found the following 1-year prevalences: UdH 29.2%; migraine 26.7% (7.3% definite, 19.4% probable); TTH 12.9% (definite 6.7%, probable 6.2%); pMOH 0.9%; other headache on ≥15 days/month 3.4%; unclassifiable headache 0.5%.

With concern for possible interest bias among responders, we also calculated prevalences with reference to the target sample of 7889 pupils: UdH 26.2%; migraine 23.9% (definite 6.5%, probable 17.4%); TTH 11.6% (definite 6.2%, prob- able 5.4%); pMOH 0.8%; other headache on ≥15 days/month 3.0%; unclassifiable headache 0.5%.

The proportions of pupils with UdH fulfilling none, one or two of criteria C and

D for migraine without aura were 20.7%, 45.7% and 33.5%.

Discussion The findings of our study reflect this, and support the concept of UdH as a more appropriate diagnosis among these age groups than probable migraine or prob- able TTH.

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Personal and Societal Burden

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In previous epidemiological studies of headache in children and adolescents, we were interested in whether authors classified headache in every participant who screened positively for headache or, instead, selectively reported cases fulfilling any specific set of ICHD diagnostic criteria.

Only five of the 59 studies reliably reported headache that was not classifiable by ICHD criteria [218, 241–244], with prevalences of 2.9–35.5% (mean 18.3 ± 14.1) but with participation proportions ranging between 54.0% and 98.3% (mean 76.2 ± 19.8).

There are implications in our proposal both for ICHD and for future epidemio- logical studies in these age groups, which may need to recognise UdH. There are also clinical implications if UdH, while clearly distinct from migraine, is in fact a precursor or immature form of it.

Conclusion It differs measurably with respect to almost all headache features and associated symptoms from both migraine and TTH and has significant adverse impact on QoL. This new diagnostic category in these age groups offers an alternative to jam- ming an evolving headache disorder that is neither clearly migraine nor clearly TTH into either of these diagnoses.

Future longitudinal studies will show whether UdH represents those headaches that are in a shifting state between migraine and TTH before maturing by adulthood into one or the other.

Differentiating UdH from migraine and TTH therefore has implications not only for epidemiology but also in routine clinical practice, since patients diagnosed with UdH call for closer follow-up with regard to their headache characteristics and asso- ciated symptoms, and a different therapeutic approach.

Acknowledgement A machine generated summary based on the work of Wöber, Christian; Wöber- Bingöl, Çiçek; Uluduz, Derya; Aslan, Tuna Stefan; Uygunoglu, Uğur; Tüfekçi, Ahmet; Alp, Selen Ilhan; Duman, Taşkın; Sürgün, Fidan; Emir, Gülser Karadaban; Demir, Caner Feyzi; Balgetir, Ferhat; Özdemir, Yeliz Bahar; Auer, Tanja; Siva, Aksel; Steiner, Timothy J. 2018 in The Journal of Headache and Pain.

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