Sad Beautiful Tree.

My neighbor has trained a wisteria plant, or plants, to create this tree -- picture taken in May 2015.

Here's what it looks like today, April 22, 2016.

It's getting very late in the wisteria season...I've seen wisteria shrubs and overgrown vines in full bloom nearby. But this guy has only a few emerging leaves. My neighbor is worried. I'm worried too, mostly for her mental health. This lady is very attached to that tree and will mourn grievously if it dies. I suspect, but really don't know, that it might need a serious pruning, now rather than later. Any opinions?

A frost we had a few weeks ago got to it for sure, although there wasn't much visible spring growth at the time. But much of the emerging greenery got fried by that frost -- it just didn't seem like enough damage to make the entire tree stop producing leaves and blooms.

I know wisteria is a wildly invasive plant, scorned by true gardeners. But with care you can prevent it from spreading.