**6.5 Electro encephalogram (EEG)**

A specific pattern of hyperventilation-induced diffuse monophasic slow waves called "build-up" and post-hyperventilation "rebuild-up" waves similar to build-up waves in patients without MMD may be observed in patients with MMD [34].

Perfusion CT, xenon-enhanced CT, perfusion-weighted MRI, positron emission tomography (PET), and single-photon emission CT (SPECT) with acetazolamide challenge are other modalities rarely used in diagnosis [12].
