cerebral edema vs oedema

cerebral edema and oedema both are nouns.

Word	Noun	Adjective	Verb	Adverb
cerebral edema	Yes	No	No	No
oedema	Yes	No	No	No

As nouns, oedema is a hypernym of cerebral edema; that is, oedema is a word with a broader meaning than cerebral edema:

cerebral edema: swelling of the brain due to the uptake of water in the neuropile and white matter
oedema: swelling from excessive accumulation of watery fluid in cells, tissues, or serous cavities

Other hypernyms of cerebral edema include dropsy, edema, hydrops.

cerebral edema (noun)	oedema (noun)
swelling of the brain due to the uptake of water in the neuropile and white matter	swelling from excessive accumulation of watery fluid in cells, tissues, or serous cavities