Thank-you for the new ideas.
The problem with a vital infection is that the organism enters a cell and after replicating within the cell, destroys the structure. A virus has a number of odd structural protrusions, that seek matching protrusions, as well as certain unknown electrical attractions to certain types of cell structures. When nerve tissue is destroyed, it may be destroyed to the point where it cannot be regenerated. Curiously, some research suggests that small intestine pig mucosa may cause these nerve connections to regrow. The Veteran's Administration now uses this substance to regrow combat-damaged muscle tissue. To use this substance, the nerve would have to be exposed without damage, and this is near impossible. I might also add that two etiologies may be possible. The initial damage might be due to a viral infection and diabetes may cause the damage to increase. Again a recent hba1c is in order. There is some anecdotal evidence that alpha-lipoic acid may cause some progression to reverse.
Thanks for comment. I just wanted to find the latest research. Of course I have read a wide array of information on BP, noting that both cause and treatment are largely elusive. Prompting my inquiry is a patient who has had a droopy eye for decades, suggesting a possible chronic wearing away of nerve tissue. A few weeks ago, the right eyelid, eyebrow, mouth, etc.lost function. Indeed, this patient has a history of shingles and other herpes symptoms and seems to be slowly responding to a Rx of antiviral and prednisone. Nevertheless, I want to make sure that possible Rx ideas are not being overlooked.
I'm not sure what answer you are seeking. The problem is inflamation of the cranial nerves. That has been known for a long time. This may be caused by infection (such as Herpes Zoster), diabetic neuropathy, or infection by any number of possible viral agents. It usually takes several days to develop and usually subsides within two to three months, but often returns. There are surgical treatments of dubious value. For the latest treatments go to the U.S. database "Pubmed", which will provide hard concise info mn double-blind studies. A large problem is determining the exact agent causing the problem, as well as the fact, if the agent is viral, we have few pharmaceuticals that can control these infections, which tend to become encapsulated. As I am sure you are aware, steroids are often prescribed in the short run. This a very serious problem because of the facial distortion and, in some cases, interference with speech. An hba1c is in order and if abnormal, tight control of blood glucose is essential.