Magnetoencephalography (MEG): Its Application to Moyamoya Disease
The re-build-up phenomenon in electroencephalography (EEG) was first described as a pathognomonic phenomenon of moyamoya disease in 1977 (in Japanese)  and in 1979 (in English) . Slow wave discharges are known to “build-up” during hyperventilation used as a routine provocation method in clinical EEG. Moreover, slow wave discharges also appear a few minutes after the termination of hyperventilation exclusively in patients with moyamoya disease. This “re-build-up” phenomenon was once thought to occur only in pediatric patients [1, 2], but was later also found in adult patients. Interestingly, the re-build-up phenomenon is often accompanied by ischemic symptoms. However, the cortical or deep structural origin of the generator mechanism remains controversial.
KeywordsSlow Wave Moyamoya Disease Ischemic Symptom Arterial pCO2 Equivalent Current Dipole
This work was supported by the Open Competition for the Development of Innovative Technology (No. 12208) from the Ministry of Education, Culture, Sports, Science and Technology, Japan. We thank Drs. Ken-ichi Nagamatsu and Masaki Iwasaki (Tohoku University Graduate School of Medicine) for the technical help during the measurement of EEG, MEG, and arterial gas.