Send a picture please. Also take a picture of a branch that is near the dead ones but still green. Use a hand lens to enlarge if possible. . Also any description of when this started and how fast or slow it progressed would be helpful. There are several needle fungi that can cause brown needles. It is often one of two different types—Cytospora Canker and Rhizosphaera Needle Cast. Trees with Rhizosphaera needle cast are usually affected first on the inside of the tree, working out, and at the bottom of the tree, working up. This disease is most apparent on older needles on the tree. If you see scattered branches with areas on the bark leaking abundant white, sticky resin on dead branches then they have Cytospora canker. It could also be mite damage. Mites are tiny spider-like creatures that suck the sap from spruce needles, so that when viewed under magnification the needles appear speckled with yellow flecks. You can scout for mites by shaking a symptomatic branch over a white sheet of paper and then looking for tiny, moving dots (mites). The following site has more information. http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/spruce-tree-diseases/

Thanks for getting back to me. I have noticed the balding of the branches for several years now. It seems to start from the inside of the tree, working out, and at the bottom of the tree, working up, So I'm thinking it is Rhizosphaera needle cast. I have attached some pics and would appreciate your opinion.

These pictures do not give enough info to confirm the disease. You need to see the black dots along the living needles to confirm this disease. Here is another website to show what you are looking for. See: https://hort.uwex.edu/articles/rhizosphaera-needle-cast/