Betta fish convulsions/seizures

Question
I have a two and a half year old veiltail male betta who lives in a 2.5gal tank, uncycled, with 100% waterchanges every week. He had columnaris about a month back. It cleared up after two rounds of a med that contains Erythromycin and Chloramphenicol, using salt, lowered temperatures, and by aerating the water. I monitored him for a few weeks, and just a couple days ago I noticed that there was a small fungusy growth on his pectoral fin. However, this refused to go away with my antibacterial meds, so I figured it was a true fungus. I did a 100% waterchange on Wednesday December 17th and resolved to buy something to clear up the fungus. However, today, Friday December 19th he has developed a new symptom- he has begun having something that I could best describe as seizures. At 10am he had one, in which he went completely vertical (mouth 2in from the surface), his gills came out as though he were flaring, and he began trashing around as bubbles came out of his gills. Afterwards, he remained at the surface, gasping for breath, for a few hours. At 2:30pm he had another one, in which he did not go vertical but displayed every other symptom I just described. What causes this? What can I use to treat it?

Answer
Hi Bob,
This could be many things.  It could be internal, flukes, and it could be a reaction to the medication you gave him.  It could also be that his life is coming to an end.  I'm so sorry to tell you this.  I know how attached we are to our Bettas, and it is heartbreaking when they get sick, and pass away.   Although medication is good, sometimes it actually hurts the fish when trying to do our best to save him by giving him different medications too soon.  
Bubbles coming out of his gills could mean that the temperature of the water was heated up to fast.  If this is the case, you will have to stir up the water, and use forceful aeration.  Sometimes tiny bubbles come out of the gills, fins, or eyes.
If this is the case, make sure he has enough oxygen and check your PH.  When water temperature is heated quickly the PH may go down to acidic, and this is very bad for fish.  A downfall in the PH or a rise too rapidly could do lots of damage to your fish.
If you have ruled this out, and the water chemistry is fine, there is nothing you can do at the moment but treat him with kindness.
Let him rest in normal water, and if the situation gets worse, in a few days, try Malafix.  This is a natural product.  Use half the dosage, as a full dose could harm the betta.  You will need an eye dropper.  I will give you the dosage in case you need it.  Put 6 drops of Malafix in his water, stiring it well so it will mix in with all the water in the tank.  Everyday for 3 days, add 2 drops to his water.  On the fourth day, do a complete water change and follow the same steps.  
I hope he pulls through, keep his water very clean, make sure there are no gases in the water.
Hope this helps
Lynda