This is the first glimpse of characteristics of headache disorders in Pakistan classified and diagnosed according to ICHD-2. More than 80% of the patients who sought treatment were between 15 and 49 years of age, the most productive age group and majority of these patients were women. Similar gender distributions have been reported previously. Jensen and Stovner reported male to female ratios of 1
3 and 4
5 in migraine and tension-type headache respectively and an earlier study from Pakistan reported that all types of headache are over three times more common in women
Migraine and tension-type headache were the two most common presentations in this clinical sample. Epidemiological evidence from around the world suggests TTH is the most common cause of primary headache
. However, migraine was seen as the most common reason for presentation to a headache neurologist in our study and published clinical reports agree with this observation. Several possible explanations can be offered for this disparity including under-recognition of primary headache especially TTH as a “real disease” by patients and health practitioners, lower individual morbidity of TTH and the lack of a medical referral system in Pakistan. It can also be speculated that TTH presents less frequently than migraine because of a lower community prevalence. While local epidemiological data is needed to test these explanations, patients with TTH who sought medical care suffered from more frequent episodes of headache that those with migraine in our study. Literature reports suggest that amount of disability associated with TTH on a societal level is much higher than that with migraine especially when measured as absence from work
. Increasing awareness and improving the capability of primary care physicians to manage TTH and migraine is likely to help decrease the associated burden.
Menstrually Related Migraine (MRM) was associated with increased morbidity with headache episodes lasting days. In our sample, 11% of female migraine patients suffered from menstrually related migraine. These women are known to have longer lasting headache episodes with increased severity of pain
. Hence, menstrually related migraine that presents to primary care needs to be recognized to initiate specific therapy.
First-degree family history of migraine was associated with an earlier onset of the disease. This is consistent with the findings of Rainero et al, who compared the clinical, psychological and pharmacological characteristics of the disease between the two groups of patients and reported that the only significant difference was an earlier onset of disease
. It is also in accordance with a study of pediatric migraine patients which showed an earlier onset of migraine in patients with a higher familial impact than in those without a positive family history of the disease
. Common migraine is a polygenic disease i.e. several genes have minor contributions to its pathophysiology and genetic predisposition combines with environmental triggers to cause clinical symptoms. The search for genes that predispose to migraine has not yielded uniform results till date most likely due to heterogeneity of patients studied and lack of a reliable endophenotype to classify the disease
. Demonstration of the effect of genetic loading on onset of migraine in the Pakistani population is an important finding in this aspect. This is a highly inbred population with a 60% prevalence of consanguinity, over 80% of which are between first cousins
. Therefore, genetic studies of migraine conducted in this population may be more likely to demonstrate minor gene effects.
Chronic daily headache was reported by 39% of the patients. Two clinical studies in the South Asian population found a similar or higher prevalence amongst headache patients but the proportions of migraine and tension-type headache differed between the two. Ravi et al reported 37% patients suffered from CDH and tension-type headache was the most prevalent within this group
. In an earlier study, Chakravarty reported that almost 50% of headache clinic patients were diagnosed with CDH and 82% of them suffered from chronic migraine followed by 16% from chronic TTH
. The latter results are replicated in this study to some extent.
This study characterizes patients with headache disorders who sought medical treatment with a headache neurology specialist. Therefore, it is inappropriate to generalize the results of this study to headache disorders in the community. The concept of a specialist headache clinic is relatively new in Pakistan. Combined with lack of a established medical referral system, most patients who suffer from headaches are unaware of diagnostic and therapeutic options. In addition, patients in this study had financial and physical access to an urban tertiary care hospital and they may not be entirely representative of the general population in the country.
Nevertheless, this study highlights characteristics of headache patients who seek medical treatment and presents factors that predict headache associated morbidity. It is one of the first few clinical reports of headache disorders from South Asia. Local epidemiological evidence is required to guide public health and research policies.