Migraine without Aura

Migraine without aura is the most common form of migraine in both children and adults. The ICHD-II (see Table 588-2) requires this to be recurrent (at least 5 headaches that meet the criteria, but there is no time limit over which this must occur). The recurrent episodic nature helps differentiate this from a secondary headache, as well as separates migraine from tension-type headache, but may limit the diagnosis in children as they may just be beginning to have headaches.

The duration of the headache is defined as 4-72 hr for adults. It has been recognized that children may have shorter duration headaches, so an allowance has been made to reduce this duration to 2-72 hr or 1-72 hr with diary confirmation. Note that this duration is for the untreated or unsuccessfully treated headache. Furthermore, if the child falls asleep with the headache, the entire sleep period is considered part of the duration. These duration limits help differentiate migraine from both short duration headaches, including the trigeminal autonomic cephalalgias, and prolonged headaches, like those due to pseudotumor cerebri. Some prolonged headaches may still be migraine, but a migraine that persists beyond 72 hr is classified as a variant termed status migrainosus.

The quality of migraine pain is often, but not always, throbbing or pounding. This may be difficult to elicit in young children and drawings or demonstrations may help confirm the throbbing quality.

The location of the pain has classically been described as unilateral (hemicrania); in children it is more commonly bilateral. A more appropriate way to think of the location would therefore be focal in location to differentiate it from the diffuse location of tension-type headaches. Of particular concern is the exclusively occipital headache as, although these can be migraines, they are more frequently secondary to another, more proximate etiology.

Migraine, when allowed to fully develop, often worsens in the face of and secondarily results in altered activity level. This has been classically identified in adults as resulting from worsening of pain when, for example, going up or down stairs. This history is often not elicited in children. A change in the child’s activity pattern, however, can be easily observed by a reduction in play or physical activity. For older children, sports or exercise may be limited or restricted during a headache attack.

Migraine may have a variety of associated symptoms. In younger children, nausea and vomiting may be the most obvious symptoms and often outweigh the headache itself. This often leads to the overlap with several of the gastrointestinal periodic diseases, including recurrent abdominal pain, recurrent vomiting, cyclic vomiting, and abdominal migraine. The commonality of all of these related conditions is an increased propensity for the later development of migraine. Oftentimes, early childhood recurrent vomiting may in fact be migraine, but the child is not asked about headache pain or is unable to describe headache pain. Once this becomes clear, the earlier diagnosis of a gastrointestinal disorder is no longer appropriate. When headache is present, vomiting raises the concern of a secondary headache, particularly related to increased intracranial pressure. One of the red flags for this is the daily or near daily early morning vomiting that increases in intensity as the intracranial pressure continues to build. When the headache with vomiting episodes are episodic and not worsening, it is more likely that the diagnosis is migraine. Vomiting and headache due to increased intracranial pressure are frequently present on first awakening and remit with maintenance of upright posture. In contrast, if a migraine is present on first awakening (a relatively infrequent occurrence in children), getting up and going about normal, upright activities usually makes the headache and vomiting worse.

As the child ages, light and sound sensitivity (photophobia and phonophobia) may become more apparent. This is either by direct report of the patient, or the interpretation by the parents of the child’s activity. These symptoms are likely a component of the hypersensitivity that develops during an acute migraine attack and may also include smell sensitivity (osmophobia) and touch sensitivity (cutaneous allodynia with central sensitization). Although only the photophobia and phonophobia are components of the ICHD-II criteria, these other symptoms are helpful in confirming the diagnosis and may be helpful in understanding the underlying pathophysiology and determining the response to treatment.

The final ICHD-II requirement is the exclusion of causes of secondary headaches, and this should be an integral component of the headache history.

Although not part of the ICHD-II criteria, it has been recognized migraine typically runs in families with reports up to 90% of children having a first- or second-degree relative with recurrent headaches. Given the underdiagnosis and misdiagnosis in adults, this is often not recognized by the family and a headache family history is required. When a family history is not identified, this may be due to either unawareness of migraine within the family or an underlying secondary headache in the child. Any child whose family, upon close and both direct and indirect questioning, does not include individuals with migraine or related syndromes (e.g., motion sickness, cyclic vomiting, menstrual headache), should have an imaging procedure performed to look for anatomic etiologies for headache.

In addition to the classifying features, there may additional markers of a migraine disorder. These include such things as triggers (skipping meals, inadequate or irregular sleep, dehydration and weather changes are the most common), pattern recognition (associated with menstrual periods in adolescents or Monday morning headaches due to change in sleep patterns over the weekend and nonphysiologic early waking on Monday mornings for school), and prodromes (a feeling of irritability, tiredness, and food cravings prior to the start of the headache). Although these additional features may not be consistent, they do raise the index of suspicion for migraine and provide a potential mechanism of intervention. In the past, food triggers were considered widely common, but the majority of these have either been discredited with scientific study or represent such a small number of patients that they only need to be addressed when consistently triggering the headache.

Migraine with Aura

The aura associated with migraine is a neurologic warning that a migraine is going to occur. In the common forms this can be the start of a typical migraine or a headache without migraine, or it may even occur in isolation. For a typical aura, the aura needs to be visual, sensory, or dysphasic, lasting longer than 5 min and less than 60 min with the headache starting within 60 min (see Table 588-2). The importance of the aura lasting longer than 5 min is to differentiate the migraine aura from a seizure with a postictal headache, while the 60 min maximal duration is to separate migraine aura from the possibility of a more prolonged neurologic event such as a transient ischemic attack.

The most common type of visual aura in children and adolescents is photopsia (flashes of light or light bulbs going off everywhere). These photopsias are often multiple colored and when gone, the child may report not being able to see where the flash occurred. Less likely in children are the typical adult auras including fortification spectra (brilliant white zigzag lines resembling a starred pattern castle) or shimmering scotoma (sometimes described as a shining spot that grows or a sequined curtain closing). In adults the auras typically involve only half the visual field, while in children they may be randomly dispersed. Blurred vision is often confused as an aura, but is difficult to separate from photophobia or difficulty concentrating during the pain of the headache.

Sensory auras are less common. They typically occur unilaterally. Many children describe this sensation as insects are worms crawling from their hand, up their arm to their face with a numbness following this sensation. Once the numbness occurs, the child may have difficulty using the arm as they have lost sensory input, and a misdiagnosis of hemiplegic migraine may be made.

Dysphasic auras are the least common type of typical aura and have been described as an inability or difficulty to respond verbally. The patient afterwards will describe an ability to understand what is being asked, but cannot answer back. This may be the basis of what in the past has been referred to a confusional migraine and special attention needs to be paid to asking the child about this possibility and their degree of understanding during the initial phases of the attack.

Much less commonly, atypical forms of aura can occur, including hemiplegia (true weakness, not numbness, and may be familial), vertigo or lower cranial nerve symptoms (basilar-type, formerly thought to be due to basilar artery dysfunction, now thought to be more brainstem based), and distortion (Alice in Wonderland syndrome). Whenever these rarer forms of aura are present, further investigation is warranted.

Hemiplegic migraine