You could have some kind of malformation or inflammation from your injury causing a build up of cerebral fluid, so when you move it's able to rush past into the spine and make the funky fluid noises. In perfectly healthy people, the flow is controlled by a sort of tonsil, and during movement or laughing/coughing it is able to escape into the spine as well. In people who have a malformation from birth, it can cause all kinds of physical developmental issues like lopsided muscle reactions, scoliosis and such. It also gets worse and worse, not better.

I'm not a doctor, just had a close family member with a malformation there which was corrected with surgery. You should really see a specialist!

Interesting. What sort of specialist knows about that?

In my family members case, an orthopaedic surgeon diagnosed the issue, but a neuro surgeon was required to confirm the diagnosis and eventually perform the surgery.

The issue they had is known as a Chiari Malformation.

https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Educat...

Thanks for the info

When I have a migraine, and the excedrin (migraine medication) begins to kick in, I also notice this exact sensation/"sound", like a draining, as a pressure in my skull begins to be relieved.

Obviously this is purely anecdotal and not scientific at all, but it's fun to speculate. I like concepts that are intuitive, and this one seems pretty intuitive to me.

Can't comment on the whooshing issue. But, I got hit hard in the head by a frisbee and had concussion like symptoms.

Both my neck and visual system got thrown off by it it turns out. I went to someone who does therapy for that, and with work on my neck + eye tracking the symptoms went away. Mental fatigue was a big symptom.

However, I did not have fatigue due to a particular angle, so that sounds different. But, I suspect you might have the issues I had as an additional factor.

Yeah that's something I'd see as many doctors and specialists as it takes to find an answer for.

What you're describing sounds similar to a Craniocervical Instability (CCI).[1] It can be confused with Chronic Fatigue Syndrome. I learned about the condition through Jeff Wood's blog posts.[2]

1: https://en.wikipedia.org/wiki/Craniocervical_instability

2: https://www.mechanicalbasis.org/