Is having a cervical spinal stenosis a valid reason to apply for disability?

Depends. Cervical spinal stenosis can be a valid reason to apply for disability if it is severe and causes disabling symptoms--like severe pain or weakness of the arms. The validity of it being a disabling diagnosis is stronger if all treatment options have been tried and failed.
Depends. Depends on how physically impaired your are & if that would qualify as a disability . Just having this image finding does not mean there is impairment unless it is causing clinical findings of myleopathy especially weakness or dexterity / balance issues or radicular pain with associated weakness or significant pain restricting you or requiring medication to control symptoms that then impairs.

Related Questions

How can I help prevent cervical spinal stenosis?

You can't. The size of the canal is inherited. The secondary degenerative leading to further narrowing is also linked to genetics. You may be able to reduce this by healthy living (regular exercise, no tobacco use, etc), but overall you have little influence on this condition. Read more...
Don't smoke. If you have the congenital type, then that is just bad luck. Over time, our spines age & degenerative changes can lead to a narrowing of the spinal canal to a degree that compromises the nerve tissue & this is then called spinal stenosis. By not smoking, you avoid accelerating these changes & by avoiding neck trauma you can help minimize these degenerative changes that may lead to stenosis. Read more...

When is it time to have surgery with Cervical Spinal Stenosis?

Easy question. It's YOUR call. The best way to handle this (surgery for low back/sciatica pain works the same) is to keep following conservative measures (meds, aquatherapy/PT, thermal therapy, etc.) until as Popeye says, "I caint takes it no more!" Pain, numbness/tingling will drive you to the point where you'll be PLEADING for the surgeon. Then, it's time. Weakness/atrophy in Upper Extremities? - Do it NOW. Read more...