Table 3.

Summary of key evidence for the etiological theory about ischemia

Key references	Summary of evidence
[46]	Endoneurial blood supply to peripheral nerves is not uneven. And endoneurial capillary density corresponds to the level of sensitivity to ischemic nerve damage in experimental and human ischemic neuropathies
[48, 49]	It is possible certainly, as is witnessed by the onset of acute facial palsy following the embolization of cerebral venous or dural arteriovenous fistula
[50]	To establish an animal model of ischemic facial nerve palsy in rats, observe the internal vascular network of facial nerve in fallopian canal, the facial nerve palsy appears within 5–15 min after selective arterial embolization, and the internal capillaries of the facial nerve appeared to be thinner, some of which are blocked by microspheres, especially in the labyrinthine segment
[52]	After removing the bony covering, researchers observed the facial nerve swelling in patients with facial paralysis, and they found nerves dilation in diameter by 12–32% (mean 21.0 ± 6.1%). Injection and exudate were also observed among these patients
[43, 55]	Among those cases that cannot recover, the facial nerve sheath become thick, forming one or more fibrous bands that cause nerve strangulation and compression, thereby hampers its recovery