In the presence of the following features, the diagnosis of migraine is fairly secure: (1) a positive family history of similar illness; (2) a typical history of migraine; (3) a normal examination; (4) normal health between attacks. Other combinations may suggest alternative diagnoses. For example, if a neurologic aura lasts longer than 60 minutes, or if headaches typically awaken a child from sleep, a structural brain lesion may be responsible. In the emergency department, about 10% of headaches in children are thought to be primary headaches, mostly migraine, and most of the remainder are due to concurrent illness or minor head trauma (Kan et al 2000). Disorders that may have migraine-like headaches include the following:
Chronic daily headaches. These children typically have continuous daily headaches (or at least 15 or more headache days per month) that evolve from episodic migraine headaches, from episodic tension-type headaches, or begin without a prior history for headaches; they are sometimes associated with an infection or physical stress, and uncommonly associated with idiopathic intracranial hypertension without papilledema (Beri et al 2010). In some cases, the evolution to daily headaches is related to medication overuse or to concurrent psychological problems. Over time, the frequency of the headaches often improves to that of episodic migraine headaches. The improvement might take years, and some patients shift over the years between episodic migraine and chronic daily headaches (Wang et al 2009).
Brain tumors. Other manifestations of a tumor usually develop within 4 months of headache onset (Honig and Charney 1982).
Vascular malformations. Headaches are always on 1 side, and sometimes a cranial bruit is heard.
Hydrocephalus. Check the head circumference for macrocephaly.
Idiopathic intracranial hypertension (pseudotumor cerebri). Other clinical features may include papilledema, sixth nerve palsy, and episodes of transient visual obscuration. Less commonly, there is no papilledema (Beri et al 2010).
Posterior reversible encephalopathy syndrome. Headaches have been associated with white matter lesions and related to various disorders, including hypertension, renal disease, chemotherapeutic agents, and malignancies. More commonly in children, renal disease, extreme hypertension, and papilledema are combined with occipital edema (Kandt et al 1995).
Various inflammatory disorders.
Mitochondriopathies. Including mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS).
Seizures. Epilepsy is the favored diagnosis when the aura is especially brief, consciousness is altered, and there is a focal epileptiform discharge. A therapeutic trial with antimigrainous or antiepileptic drugs is rarely helpful in differential diagnosis because many of these drugs can be used for either migraine or epilepsy (eg, valproate).
Cluster headaches or chronic paroxysmal hemicrania. These headache types are rare in children.
Abdominal disorders. Primary abdominal disorders may cause recurrent episodes of prominent vomiting and abdominal pain, whereas metabolic disorders (eg, heterozygous ornithine transcarbamylase deficiency) may add severe headache to the abdominal symptoms.