Uncovertebral joints, also known as joints of Luschka, are formed when the uncinate processes on the inferior aspect of a cervical vertebra articulate with the superior surface of the vertebra above. This arrangement is a feature of the cervical spine, typically from C3 to C7. These joints provide lateral stability and help guide and limit certain movements, especially flexion and extension while restricting lateral flexion. They are not the facet (zygapophyseal) joints, which occur between the superior and inferior articular processes and sit more posteriorly; they are not intervertebral discs, which lie between the vertebral bodies; and they are not costovertebral joints, which connect ribs to vertebrae. With aging, these joints can develop osteophytes and degenerative changes that may impinge nearby neural structures.

Degenerative changes in the spine accumulate where loading and motion are greatest, and the lumbosacral junction bears the heaviest load. L5-S1 transfers the body's weight to the pelvis and experiences substantial flexion–extension and shear forces, so the disc there degenerates most severely first. This leads to disc height loss, facet joint osteoarthritis, and possible nerve compression at that level. As degeneration progresses, the altered mechanics place more stress on the levels above, causing the disease to ascend the lumbar spine. The thoracic region is shielded by the rib cage and has less motion, and while the cervical spine can develop OA/DDD, the most severe level overall is the L5–S1 junction with upward progression.

As OA/DDD progresses, discs lose water and structural integrity, so disc height diminishes. The nucleus pulposus becomes desiccated and loses proteoglycans, reducing its osmotic swelling pressure and ability to maintain height. Over time, annulus degeneration, endplate changes, and osteophyte formation accompany these changes, all contributing to a thinner disc space. Imaging typically shows reduced disc height as these degenerative processes advance, rather than the disc becoming taller, staying the same, or fluctuating without decrease.

Vascular dementia is caused by cerebrovascular disease, so its risk increases with age and with prior vascular events like strokes. Because age is a major driver and some vascular risk factors are more prevalent in men, the demographic most commonly affected is men who are over 70. Younger groups (under 60 or children) and even older women have lower overall incidence, even though risk climbs with age for everyone. So the combination of male sex and age above 70 captures the group most commonly affected.