By Donald W. Lewis, M.D.
Children’s Hospital of the King’s Daughters, Norfolk, Virginia
Q. My child gets stomach pain often enough that I took him to the doctor. To my surprise, the doctor diagnosed my child with abdominal migraine. I don’t get it—he doesn’t even get headaches!
A. In 2004, the International Headache Society published its updated classification system for headache and headache-related disorders and included within the spectrum of migraine a group of three disorders under a category of “Periodic syndromes of childhood that represent precursors of migraine.” These three childhood conditions are benign paroxysmal vertigo (short periods of dizziness), cyclic vomiting syndrome, and abdominal migraine.
Benign paroxysmal vertigo and cyclic vomiting syndrome are quite distinctive clinical entities; few would argue about their existence. Abdominal migraine, however, often generates some spirited debate between proponents, particularly European, and the “doubting Thomas” yanks who often pooh-pooh the disorder. Why is this diagnosis so readily accepted in the UK and Europe, but causes doubt among US pediatricians? Are US physicians under-diagnosing abdominal migraine? Does it really exist? Let’s examine the evidence.
Abdominal migraine is defined as a “recurrent disorder seen mainly in children and characterized by episodic midline abdominal pain manifesting in attacks lasting 1-72 hours with normality between episodes.” Each attack is similar, with the pain being described as moderate-to-severe in intensity and associated with nausea and vomiting.
Now, here is where the confusion begins. The pain is located around the naval and has a vague, “just sore” quality. To qualify as abdominal migraine, the pain should be accompanied by autonomic symptoms such as nausea, vomiting, decreased appetite or paleness—non-specific symptoms that are common with many gastrointestinal ailments. The episodes themselves have little that might distinguish them from the host of other causes of belly pain.
The other curiously absent diagnostic feature is headache. How do we reconcile these symptoms as being migraine without any headaches happening with at least some of the attacks?
Like typical migraine, abdominal migraine represents a recurrent, episodic, short-lived disorder that produces disabling symptoms, but has intervals of wellness. If we accept attacks of cyclic vomiting and episodic vertigo as migraine precursors, why not recurrent abdominal pain? Abdominal pain, after all, is a criterion for migraine diagnosis.
A second supportive body of data comes from family history. In a 10-year prospective study, D. Bentley, MD and colleagues identified 70 children whose symptoms were consistent with abdominal migraine —90% had a positive family history of migraines in a first-degree relative.
A third line of evidence arises from longitudinal studies. In one 10-year follow-up study of children diagnosed with abdominal migraine, F. Dignan, MD and colleagues found that 61% reported resolution of abdominal symptoms, while 70% developed migraine headaches with aura.
A fourth inferential line of support comes from treatment responses. Although data from controlled trials is lacking, treatment recommendations and response rates for abdominal migraine parallel those for typical childhood migraine.
The most compelling evidence is emerging from our understanding of the pathogenesis of migraine. Migraine is now understood to include activation of multiple regions of the brainstem, some of which would be involved in producing symptoms such as nausea, vomiting and paleness, which are associated with a typical migraine attack.
Therefore, if we accept the premise that a migraine attack could manifest itself predominantly with episodic abdominal pain, and accept the longitudinal, familial and treatment associations, then at least a subset of children with recurrent abdominal pain are probably experiencing attacks of abdominal migraine.
We recently reviewed the records of over 600 children who came to our gastrointestinal clinic with recurrent abdominal pain to see if any proportion fulfilled the diagnostic criteria for abdominal migraine. Not a single child in our clinic had been diagnosed with abdominal migraine, but about 15% of children met the criteria.
Clearly then, we in the US are under-diagnosing abdominal migraine—and your child’s physician may be right!