I heard a bit of his program as well, and I thought why is he still on?  He obviously was struggling at times and didn't seem to be able to concentrate.  Jerry didn't seem overly concerned however since he said this had happened quite a few times before and over many years.   Although he said it wasn't going away this time. Good that he wasn't in pain at least.  

The comment that he was "stuck on air" and no one to replace him for two hours was not accurate.  Various people could fill in on air for him quickly like Mike Bendixen, or John Moore and Ryan Doyle in fact was put in quickly. With all of the home set up's for hosts this makes it even easier. 

Hope Jerry is alright and he gets better soon and they find the cause of these silent migraines...

This reminds me of a similar situation from the mid 80s...  it happened at CING 108 when the the studios/offices were still on the South Service Road in Burlington. 

The Saturday afternoon host was on air, and was operating as well. The doors to the facility were also locked. 

Just after 3pm, the host missed a couple of cues, late rolls, some dead air. Then he started to slur his speech, and became very incoherent.

Luckily, a quick thinking listener realized what was happening, and called Halton Emergency services. Police, Fire, and Ambulance quickly attended, and gained access to the building (I think by this time, some other staff had also arrived at the studio).

The on air host was experiencing a medical event related to diabetes.  That quick thinking listener was most likely a nurse or doctor.

 

Agar returned for an update at 11:30, and said he was feeling better and was headed to a doctor. He related how during that weird 20 minutes, he couldn't remember who anyone was and had a kind of brain fog. He managed to recognize Ryan Doyle's moniker, though, and seemed relieved when he took over. 

Given that and what I heard, I doubt he would have been able to finish the show. 

Agar addressed his sudden illness on his show Tuesday, saying this problem stretches back at least 25 years, when he was working at another station in the U.S. and suddenly couldn't read his computer screen. He related that on Friday, he lost the ability to even remember certain words, phrases or people's names, and that he couldn't recall anything, even seconds after his producer told him what it was. 

He said she told him she was calling manager Mike Bendixen to try and replace him - and he had no idea who he was. He had a newspaper column to write and wanted to call in and cancel - but couldn't remember who to contact.

He called it frustrating and difficult and he was fortunate to be home, so he could get immediate help. His wife thought he was having a stroke and indeed, it did sound like that on air at times. 

In the end, it went away about two hours later and while he visited his doctor, he never did have to go to the ER - although he will be seeing a neurologist in the near future. 

All in all, a very scary yet inarguably fascinating moment in radio you fortunately don't hear very often.