Electroencephalography (EEG) in moyamoya disease

Moyamoya disease (MMD) is one of the most common causes of cerebrovascular disease in East Asian populations, especially of Japan, China and Republic of Korea. This condition is characterized by progressive stenosis of both terminal internal carotid arteries in the supracli-noid portion with the development of a network of cerebral collaterals, referred to as the moy-amoya vessels. Interestingly, clinical symptoms are different between children and adults. Children present most frequently with the symptoms of episodic cerebral ischemia like transient reversible hemiplegia, which are often precipitated by hyperventilation situation such as when crying, playing the harmonica, eating hot and spicy food, and taking a deep breath when emotionally upset, while in adults, they are intracranial hemorrhages. We can diagnose the patients by brain magnetic resonance (MR) imaging, an MR angiography, an electroencepha-lography (EEG), and a cerebral angiography without any difficulties [1-3].