Myelopathy is the term used to describe the consequences of spinal cord compression. It characteristically occurs due to spinal cord compression in the neck (the cervical spine), although can occur more uncommonly in the thoracic spine (the portion of the spine within the rib cage). The causes for myelopathy are the same as described for brachialgia, namely a disc prolapse or more longstanding spondylotic changes in the spine. The reason for developing myelopathy rather than brachialgia (arm pain) is simply due to the anatomical location of the narrowing and resultant compression of the neurological structures. In myelopathy, the narrowing affects the main spinal canal with resultant compression on the spinal cord contained within. With brachialgia, the narrowing affects the exit channels for nerves emerging from the spinal cord, rather than the spinal cord itself. Not infrequently myelopathy and brachialgia can co-exist if a disc prolapse is compressing both the spinal cord and an exiting nerve root.
The symptoms from cervical myelopathy can initially be very subtle and, therefore, potentially overlooked. It is essentially a painless condition because pressure on the spinal cord produces loss of function rather than pain in the affected limbs. People with myelopathy will often describe a numb and clumsy feeling in their hands. They lose dexterity, particularly for fine tasks such as handwriting. They may also experience reduced grip strength and have a tendency to drop things. The altered sensation in the hands can be range from slight numbness to a more profound sense that the hands are completely numb, swollen and functionally of little use. The legs can be affected in a similar way. People may describe a numb, clumsy feeling in their legs as though they have lost a degree of control of leg function. This results in a gait which is shuffling and unsteady, often tripping easily and having to carefully watch where one is walking.
The treatment for myelopathy is almost invariably surgery, as without decompression of the spinal cord, the dysfunction is likely to progress. The principal aim of surgery is to halt this progression, and any recovery of neurological function is unpredictable.