Strokes in Parrots, some questions.

Over the last few weeks I have heard of and seen parrots who have suffered strokes. I never knew such a thing could happen, although it is logical to assume. My questions are basically,

How frequent are these events?

Can they be prevented?

Is there an age when they become more likely to occur?

You probably need to look at age, diet and exercise... genetics will also be a factor...

I reckon a flighted bird on a varied diet, would have less risk than a clipped bird on a seed only diet (or pellet only diet, for that matter)

My moms 40+ y/o green cheek amazon had a stroke last summer. He just came crashing off his perch in the dead of night and was totally limp on his left side. It was kind of a shock when the vet told her he had suffered a stroke, it's not really something one would think would happen to a parrot. He has been recovering quite well, and is able to perch and take short flights again (he spent a few months with no perches because he would fall and wasn't allowed to fly). I just saw him yesterday, and he looks pretty good, his left wing is still a little droopy and his foot a little curled, but he's getting around fine and pretty much back to himself.

Strokes in parrots probably happen more often than they are recorded, as many birds would probably just fall over dead and no one would ever know the reason was a stroke. Just like humans, I would assume strokes are more likely in older birds than younger ones, or birds with unhealthy diets. A proper diet and reasonable amounts of activities are the best preventative measures of any disease or medical problems, but sometimes things just happen (Barney has a healthy diet and is very active, but he still had a stroke). I don't think it's something you really need to worry about if your feeding your bird right and they are an active parrot. If he/she does have a stroke, there wouldn't be anything else you could've done to prevent it, and it's probably still a relatively rare thing anyways.