A study on the chronification of headache postulates that this relationship might become a vicious circle, which could explain why episodic headache changes to chronic headache in some individuals [57].
Second, it is the only study on the impact of headache in the young applying an identical design in two different countries.
Study Design: An unselected population-based prospective follow-up study on the occurrence of headache in school-aged children was carried out in 1290 children aged 8 to 9 years.
A more recent study on the cost of headache disorders in Europe estimated an annual per-person cost of €1,177 for migraine, with 93%% of this cost attributed to indirect cost (e.g. work absenteeism) [58].
A large population-based study on the prevalence of primary headache (PH) disorders in Germany estimated that 2.6% of the general population suffer from headache ≥15 days/month, and 1.1% from chronic migraine [2].
In his 1995 extensive study on the chronic forms of headache in the rural community of Ethiopia, Tekle-Haimanot [32] did not mention anything about the occurrence of OM.
Since most of the human studies that include data on the headache incidence focus on symptom complex and do not specifically focus on headache, search condition was optimized to obtain as many human study data with MSG administration as possible.
In our study on the treatment of primary headaches in Croatia, the results have shown that less than half of patients were taking triptans, majority were taking simple analgesics and NSARs, and only 14% was ever taking any kind of prophylactic therapy [ 28].
The main aim of the present study was to do an update on studies on headache epidemiology as a preparation for the multinational European study on the prevalence and burden of headache and investigate the impact of different methodological issues on the results.
A recent study on headache yesterday in Russia showed that headache yesterday reduced productivity in 70%% of the patients [28]; likewise in an African cohort 68%% of patients with headache lost workdays [29].
