<unk>  is first suspected based on symptoms. A CT scan can be used to confirm a diagnosis. This can have characteristic features, including maxillary<unk>  outlet obstruction,<unk>  opacification, and<unk>  volume loss caused by inward retraction of the<unk>  walls. Differential diagnosis<unk>  has to be distinguished from<unk>  atelectasis, and congenital<unk>  hypoplasia.
Silent sinus syndrome
Hypnic headache
Hypertensive emergency
Nasodigitoacoustic syndrome
Foreign accent syndrome
Intracranial hypertension syndrome
Heat syncope
Red wine headache