I couldn't tell you if that is a chiari or not. I have Chiari Malformation Type 1. I've had the surgery. I also have syringomyelia. My regular doctor told me when I was twelve and had a severe onset of symptoms that everything was fine. The radioligist said everything was fine. 7 years later I saw a neurologist and finally someone figured out what was wrong with me. And they helped alleviate the symptoms.

See a neurologist.

Also, for me, straining and rushes of adrenaline/blood flow made it worse. Like, 100 times worse. If you think you might have a chiari, lay off the heavy lifting and sprinting. Also, try to chill out. Stress can't help this. Relax as best as you can and take pain killers sparingly if you need them. Really, for me, I just couldn't yell, strain, lift heavy things, sprint, or have strong adrenaline rushes and I'd be mostly okay.