An adolescent male with an arteriovenous malformation presenting with reproducible seizures.

The patient who presents with new onset seizure is a difficult but common problem in emergency medicine. It is more difficult to make a specific etiologic diagnosis when the seizure patient is without fever, focal neurological deficit, prior medical history, electrolyte or acid-base imbalance. Such a patient with new onset seizures presented to our emergency department. The seizures were induced by a specific right arm position. The patient's initial evaluation included a normal physical examination, screening chemistries, and an unenhanced computed tomography (CT scan) of the head. Subsequent contrast-enhanced head CT scan and eventual magnetic resonance imaging (MRI) of the brain revealed a large arteriovenous malformation (AVM). The differential diagnosis of seizures is long and involved, but a majority of these diagnoses can be ruled in or out by simple and inexpensive screening examinations. Occasionally, more involved studies are indicated than the routine electroencephalogram (EEG) and CT scan. CT scan with contrast, angiography, and magnetic resonance imaging (MRI) may be required to elucidate the cause of the seizure. Of these, angiography and MRI are the most sensitive for AVM, but contrast CT scan is the most readily available with acceptable sensitivity and is therefore potentially more beneficial.