Stir hyperintensity @ C5-C6 in the cord and at C4-C5. Can you explain?

I think it's time to see an expert neurosurgeon who fixes problems at Mayo or another large teaching hospital with a super MRI machine. Have your PCP refer you. You did not mention when the surgery was, your age or what the new symptoms are. This might be very serious.

sure, firechif.
spondylolisthesis is when one vertebra slips forward over the next. It can reduce the space in the tiny joints where the nerves exit the spine. And produces pain when the medial branch nerve gets pinched on the way out. Your slip is mild.
Stir is an MRI sequence used to better detect edema or nerve damage, especially helpful to reduce "signal noise" when a person has metal implants
Hyperintensity at C5-C6 in the cord and at C4-C5 image either fluid in that space or nerve damage. If the surgery wasn't long ago, it may just be swelling from the procedure. It may be from the disc between the vertebra that disc spaces section indicates is mild/mild to moderate.
I include this link for the image differentiating foraminal stenosis from central stenosis https://mayfieldclinic.com/pe-decompression.htm
There are minimally invasive procedures that can yield relief.
I think it's wise to sort the language before seeing your provider.
I don't have a medical background.

@gently
I have to ask if you got this information through doing a Google search?

firechif (@firechif
Thanks for posting this. I agree that a Neurosurgeon is who you need to talk with to get specific answers. I would like it if you would post the information that was asked about your age and when surgery was done. I am going through something similar and I’m holding off surgery on my cervical discs for as long as possible because of learning that one surgical surgery will put stress on the rest of the vertebrae and will usually lead to more spinal surgeries down the line— at about 2 to 3 years following the first surgery.

@dit09,
I googled the image to indicate the place difference between central and foraminal nerve impingement, because I couldn't seem to articulate it clearly.
I have this wonderful textbook called The Cervical Spine given to me by Tony Yeung a spine surgeon in Phoenix, AZ years ago.
I prefer the NIH PubMed data base, focusing on later publications.
You can, of course, google all of it. You probably know that google AI has questionable sources. I have heard that some AI application will eliminate certain sources, but you can always tap on the source. But then, later, you have to remember where you read something, so I tend to avoid google AI.