MIGRÂNEA ABDOMINAL

Abdominal migraine is characterized by recurrent episodes of abdominal pain in a previously healthy child who is normal between attacks. The pain is typically midline or poorly localized, dull and moderate to severe in intensity; headache is not a prominent feature during attacks. Photophobia or phonophobia are not common. Temperature elevation and diarrhea do not occur. Abdominal pain is associated with at least two additional features that may include anorexia, nausea, vomiting, and pallor. Protracted vomiting is more consistent with cyclic vomiting. Precipitating factors are often searched for but not commonly identified; concerns often include dietary and psychological stress.

Abdominal migraine affects 2 to 4 percent of children, and 4 to 15 percent of children with chronic periodic abdominal pain. The age at presentation is usually between 2 to 10 years.

Abdominal migraine is a clinical diagnosis; there are no confirmatory diagnostic tests. The diagnosis with the first event is challenging. The many causes of acute abdominal pain need to be considered in the differential diagnosis with the first attack. Testing is determined by the history and physical examination but the search for a mechanical process such as obstruction, kidney disorder, infection or metabolic condition may be in order.

The pathophysiology of abdominal migraine is uncertain, with consideration to central nervous system, endocrine imbalance, or ionic channel disorders. A genetic factor is suggested; 60 percent are said to have a positive family history of migraine.

Management remains empiric. Excluding serious abdominal conditions and making the correct diagnosis of migraine may provide some reassurance to the family. Good sleep habits, proper hydration, avoidance of foods high in amines or xanthines, and avoidance of stressful situations when possible may be helpful. Although data are limited regarding pharmacologic treatment for abdominal migraine, analgesics such as ibuprofen or acetaminophen may be useful as abortive therapy if given early during an attack. Antiemetics are indicated if there is significant nausea or vomiting. During an attack, medication administered by suppository is preferable. Daily preventive medication is usually reserved for the child with frequent attacks. Nonanalgesic migraine medications such as propranolol, cyproheptadine and pizotifen (the latter not available in the United States) may be effective as prophylaxis. There are also case reports of abdominal migraine responsive to triptans and to intravenous valproic acid given in the emergency room.

The long-term prognosis is good for the intermittent abdominal pain. Most children stop having attacks by early adolescence, but rarely attacks may persist into adulthood. However, most children with abdominal migraine evolve to develop migraine headaches. In one study of 54 children with abdominal migraine who were followed for 7 to 10 years, current or previous migraine headache was identified in 70 percent. The prognosis for the clinical course of migraine headache in such children is thought to be similar to migraine that develops without preceding abdominal spells