Please explain the significance of my recent MRI findings on my cervical spine. I have a history of spinal stenosis in the lower back. I recently had an MRI on my cervical spine showing significant to severe foraminal and thecal sac narrowing at multiple

About 20% of people. With lumbar spinal stenosis will have coexisting cervical spinal stenosis. Spinal stenosis is a narrowing of a bony canal structure such as the central spine canal or the exiting nerve holes known as neuroforamen which when severe enough by imaging studies will be deemed spinal stenosis.
It . It sounds like you have a similar process occurring in both your lumbar and cervical spine. Spinal (thecal sac) and foraminal stenosis (narrowing) can produce inflammation in the nerves. This could lead to pain in the neck, shoulder or arm. Many people have such narrowing and do not have symptoms; however some people will have significant symptoms which would also include numbness, weakness and tingling. You surgeon will evaluate you and try to determine if your symptoms are related to your MRI findings.