This is a false claim about taking antidepressants (which tramadol is not, it’s an opioid painkiller) just once can cause permanent brain damage. This claim has been repeated all over the internet for 20 something years, and they are just as false then as they are now. It’s fear mongering, plain and simple.
Taking 700 mg of tramadol that one time does not cause any of the symptoms you describe, let alone permanent brain damage. Tramadol does increase your threshold of seizures, and does not play nice with other drugs or itself, for that matter. Unless you had a seizure taking that much tramadol at once, and don’t remember having one, your problems are not caused from a single dose of 700 mg of tramadol. Your beliefs are being falsely reinforced by misinformation found on the internet. A seizure absolutely can cause permanent brain damage, but you would probably remember having one if you did.
We get posts like these every few years, and they are all just trying to continue the spread misinformation about antidepressants (tramadol in this case) causing permanent brain damage after just one time taking them. That’s fear mongering, like anti-vaxxers are with COVID. You are repeating a completely debunked conspiracy theory, and continuing the exact same false information that reads like all of the other false claims on the internet verbatim.