Studies show that in children and adolescents, migraine tends to be of shorter duration. The duration of head pain was reported to be less than 2 h in 11–81% and less than one hour in 8 to 25% in different studies (Maytal et al. 1997; Mortimer et al.1992b). Similarly Metsahonkala (1994) reported that when duration was omitted as a criterion the prevalence of migraine increased by 25.9%. In fact Gherpelli and colleagues (1998) found that entirely excluding duration criterion increased the sensitivity without decreasing the specificity of pediatric migraine diagnosis. This study supports the suggestion of decreasing the criterion on the minimal duration of head pain to less than one hour for migraine without aura in children.
In this study, 1402 children reported recurrent activity affected head pain lasting 5 to 45 minutes with one of the associated diagnostic migraine features of nausea / vomiting / phonophobia / and or photophobia. It was difficult to get the symptoms of both phonophobia and photophobia from majority of these children at first consultation and interviewing both the parents, family members and class mates were necessary in eliciting both the symptoms. This is usually not possible and practical in countries like India, where huge volumes of patients (up to 250 /day) have to be examined on a daily basis. The behaviour during head pain episodes like switching off TV and radio, closing the door and putting off lights, covering the heads with blanket or cloth when lying down with head pain, getting angry or shouting at family members or classmates when they try to talk etc. were indirect evidences suggestive of both.
All of them were getting the headpain attacks when exposed to one or more of the common migraine triggers (Francis 2002, 2004, 2009) in this region. Exposure to sunlight and traveling by bus were the most common triggers. Mortimer et al. (1992b) reported that a migraine trigger could be identified in 44.4% of the children aged 8–11 years. In children more than 8 years tiredness, exercise, noise, glaring light, missing a meal were all reported as migraine precipitants by different studies. Rossi et al. (1989) documented psychological stress followed by physical stress as the commonest precipitating factors in childhood migraines. This is the first study to document common migraine triggers in a region to aid in the migraine without aura diagnostic work up. Majority of the children and their parents reported same common triggers with exposure to sunlight precipitating migraine in nearly 90% of them. Trigger factors are less common or less obvious in patients with episodic tension type headaches. It is documented that emotional stress, lack of sleep (Blau 1990) and menstruation can trigger or aggravate both TTH and migraine but activity getting affected, other common migraine triggers precipitating pain and family history will favour a diagnosis of migraine in such clinically confusing scenario (Francis 2009). This study didn’t consider stress and menstruation as triggers and lack of sleep is found to be one of the very common triggers for ICHD2 migraine in this region of India.
Family history revealed mother (82%), father or sibling suffering from ICHD2 migraine with or without aura. Migraine is a familial disorder, although disagreement exists regarding the mode of inheritance. If one looks at the families of children with migraine, 50 to 90% of relatives also have migraine. Parents must be questioned in detail to find out migraine symptoms. Most of them considered their headaches are different from what their children are getting. The diagnoses as told to them by their medical practitioners (the first contact practitioner in their life) are sinus, low (especially if dizzy spells are associated with headaches) or high blood pressure, tension, spectacle related, ear balance dysfunction especially when dizziness or vertigo associated with recurrent headaches, anemia, vitamin deficiency or functional. Therefore leading questions like whether they get headache when exposed to sunlight, bus traveling or other known or common migraine triggers must be specifically asked to unravel migraine symptomatology. It was indeed surprising to find out that some parents considered head throbbing, severe head discomfort and head pain as different entities. Many mothers thought that sun exposure headaches are normal ordinary headaches and there is no need to mention about it to the doctor. When details of these headaches were asked typical migraine features were revealed.
This study shows that reducing the time duration to less than one hour would considerably increase the number of children diagnosed with migraine. One can argue that this time reduction might increase the overlap between the diagnostic criteria of migraine and tension type headaches but it can be easily overcome by adding one common/known migraine trigger and one family member suffering from ICHD2 migraine to the present diagnostic features. One cannot consider any other diagnoses in these children even if only one of phonophobia or photophobia is present. Other short duration activity affected headaches like cluster headaches and paroxysmal hemicranias, though reported in children, are very rare and no case was diagnosed in this age group during the study period. Short duration mild to moderate non throbbing headaches attributed to uncorrected refractive errors, phorias and tropias were diagnosed when prolonged and tiring near or far focusing precipitated peri orbital pain. Other brief headaches attributed to cough, valsalva, cold, external compression etc. were easy to diagnose clinically and was not a problem differentiating from brief migraine without aura episodes. Children and adolescents complaining of aura like manifestations were not included in this study and benign occipital epilepsies with brief colored auras with automatisms were not a diagnostic consideration in these patients.
A critical analysis of the I CHD2 diagnostic criteria for migraine and tension, exposes more than one overlapping statements. In this study, majority of the children presented with bilateral (68%) non throbbing (63%) headaches (this fulfills two diagnostic pain features for tension type headaches) and with the duration of more than 30 minutes and one associated feature (phonophobia or photophobia) one tends to diagnose episodic tension type headaches in these children (missing two criteria to diagnose ICHD 2 migraine without aura). At the same time probable migraine (missing duration criterion) (Granella et al. 1994; Rasmussen et al. 1991) too can be diagnosed because of activity affected moderate to severe intensity head pain and one associated feature. In these clinically confusing situations the following three features clearly differentiate migraine from tension type headaches. 1) activity affected head pain (motionless) 2)one common / known migraine trigger precipitating pain 3)one family member suffering from I CHD 2 migraine (definite or probable). The problem in diagnosing probable migraine is that, most of the parents are concerned about an underlying brain tumor or other serious disease and one can confidently explain to them that what their children are getting is nothing but brief migraine attacks. Pointing out the triggers and family history with a negative general, physical and neurological and neuroocular exam will be very reassuring and scientifically more convincing to both children and family.
Thus this study shows that both migraine and tension can be distinguished easily from a thorough clinical history. Therefore it is proposed that brief migraine attacks to be diagnosed in children and adolescents with less than one hour duration and must be differentiated from episodic tension type headaches. ICHD2 to be modified as - if duration of head pain is less than one hour, two additional features to be added to diagnose migraine without aura in children.
one common/known migraine trigger precipitating the attacks.
one parent or sibling suffering from I CHD2 migraine (definite or probable).