I realize I am replying to a very old post, but since the original poster wasn't able to get treatment for his or her bird and wasn't able to have a necropsy done, I thought I'd share my experience in order to set OP's mind at ease a bit. First, my belated condolences on Henri's loss - it's terribly traumatic for the owner (and companion bird) to watch a feathered friend depart.

My sweet, beloved Marie was only three years old when this happened to her. I'd taken her and her mate, Lilo, outside to enjoy the unseasonably warm and sunny weather last March, when the wind unexpectedly picked up, and a gust blew directly in my birds' faces. I examined the birds briefly to make sure they were all right, about to take them in, but a neighbor came up and began chatting away, so I lingered a moment. Suddenly, Marie extended her wings and opened her mouth, squawking intermittently - I was afraid that in her alarm at the wind gust, she'd leapt up and hit her head on the bars of the cage, or perhaps that she was simply dangerously alarmed. I hurriedly took the birds inside and removed them from the cage. Lilo flew back to their home cage without incident, but Marie flew haphazardly into a piece of furniture. I scooped her up and held her - by this time her left side was twitching violently, and the poor precious was grasping at anything she could with her beak amid terrified squawks. I immediately took her to the emergency vet service, who mercifully treat exotics after hours.

The vet immediately took her into the back and gave her a shot of Valium. That did the trick instantly, and when they summoned me back into the treatment room, I had a glimmer of hope as I held my poor little sweetheart, who was now quite still and calm and sleeping peacefully. I was told that if she responded to the Valium and stopped seizing, she might recover. I went home for an hour or two, primarily because I suppose some part of me feared the worst, and I wanted her to have the comfort of her adoring mate. It was late when I arrived with Lilo, but they allowed us to sit with Marie - now in a glass box with towels for her to rest on - for several hours before they shooed me out. By now the full extent of Marie's illness was apparent - even with the Valium, she twitched constantly, every so often having a full blown seizure where her neck would stretch and twist, her head tucked under. I placed Lilo's little travel cage against the glass, and when Marie briefly woke to find us there, bless her dear little heart, she eagerly dragged herself over the towels to the glass, where she pressed herself as close to Lilo as she could go. I have a heartbreaking photo of her there, leaning against the glass, with Lilo looking at me in alarm as if to say, 'Isn't she going to be all right???!'

After a moment's repose - or perhaps farewell to me - she struggled along the glass, trying to get closer to where Lilo was perched, before she began seizing uncontrollably. I called in the vet, who began breaking it to me that they couldn't keep dosing her with Valium (in fact, I don't think they gave her another shot of it). She hadn't eaten in hours, and she wasn't stable enough for either bloodwork or tube feeding. Part of me wishes I'd asked her to euthanize my Marie right then - it might have saved her a few hours of suffering. But I still had hope, because the vets hadn't given up hope, and I allowed them to take both Marie and Lilo - for companionship - back into the back while I went home to get a few hours' sleep.

I called first thing in the morning and was told they were tube feeding Marie but that she was still seizing. Truth to tell, I don't think the feeding happened because at necropsy, her crop was completely empty. But I don't blame the vet - she was already too far gone. By the time I was up and dressed and ready to return to the vet hospital, I received a call telling me she was gone. I was so sorry that I wasn't there at the end, though I know having Lilo there must have been a comfort to her.

The necropsy was negative for heavy metal toxicity - a concern, since she had been chewing avidly on the bars of the cage to the point that the enamel was stripped off. Her brain, heart and lungs were also normal. Her liver apparently was very small and hardened, however. All were sent off for analysis. The results were inconclusive, because either a pesticide (unlikely) or low blood sugar caused by liver failure could have caused the seizures. Because she would not have had access to any neurotoxic pesticides, the vet concluded that it was the atrophied liver that was the culprit. I have no idea what caused it.

In any event, there is likely nothing any vet could have done for the original poster's budgie, other than to ease her suffering by putting her to sleep.