Someone mentioned Microglial Priming in another thread -
The inflammation from microglial priming will cause symptoms and there doesn't have to be a forceful impact for that to happen.

When trying to understand a complex problem, it helps to examine extremes. And if you look at more severe cases of PCS, they often involve multiple head hits. The impact forces weren't enough to cause severe symptoms, and anxiety alone wouldn't cause severe symptoms either.

For example, what about other people who complain of having trouble reading computer screens. It's not that they can't read, they just can't read very much. That's called neurofatigue and it's a sign of inflammation.

Same in my case. The symptoms have mostly been the same whether I was in bed or not - mild headache and dizziness (shaking sensation). What changes is the capacity for activity such as conversation (extreme neurofatigue). So basically there was so much inflammation that I couldn't get out of bed.

In this article about neuroinflammation and PCS symptoms, they conclude that a new term, Post-Inflammatory Brain Syndrome (PIBS), is necessary to describe Post Concussion symptoms - A review of the neuro- and systemic inflammatory responses in post concussion symptoms: Introduction of the “post-inflammatory brain syndrome” PIBS - ScienceDirect They also discuss microglia and how repeated mild impacts result in reduced cognitive function.