You note chronic neck pain with radiation into shoulders. Your report states: “Marrow signal is notable for degenerative endplate changes within the C4 level, progressed from the prior exam…There is severe right and moderate to severe left neural foraminal narrowing”.
Also; “There is worsening junctional zone spondylosis at C4-C5, where there is a new retrolisthesis and there are degenerative changes”
It does not appear that your Chiari type I is significantly symptomatic so I would believe that C4-5 is causing a majority of symptoms. The way to test this is to get bilateral SNRBs at C4-5 and keep a pain diary. If your symptoms temporarily are eliminated, this is good evidence that a surgical intervention (ACDF or ADR) would be quite helpful.