Is there an aftermath of cervical spine stenosis?

Yes. If it is left untreated you can be left with permanent injury to the nerves and or spinal cord. Once treated you are at risk for development of adjacent level degeneration either above and/or below the level of any fusion.
Yes. Aftermath from surgery is that adjacent levels in the neck can degenerate at an accelerated rate due to added stress. Aftermath without surgery is that progressive weakness and neurological decline can ensue causing permanent problems. If it's present and significant, see a neurosurgeon to have it repaired as soon as possible before an accident happens with permanent problems.