Cervical spondylotic myelopathy (CSM) is the most common acquired cause of spinal cord dysfunction in people aged >55 years.1 It is a slowly progressive disorder usually caused by spinal cord compression and ischemia due to age-related changes in the spine and is characterized by neck pain, radicular arm pain, paresthesia, weakness, lower extremity hyperreflexia, and gait and balance abnormalities and may also present with bowel and bladder dysfunction. The majority of cases progress in a stepwise manner, but about 5% of cases decline rapidly, and the prognosis of nonoperative treatment is poor once the patient is truly myelopathic. The objective of surgery is to decompress the spinal cord before permanent damage has set in.2-4
Several studies have attempted to describe the prognostic significance of duration of symptoms in surgical decompression of CSM. Some studies have found that there is no association with outcomes,5-7 but most of the studies have concluded that there is an association. Several of these studies specify that duration of symptoms is significant beyond particular time points, typically of 12 months8-12 or 24 months.13,14 At least 2 review studies have found low evidence for the influence of symptom duration on postoperative outcomes.15,16
Age has also been cited as an important prognostic factor in surgical decompression of CSM by some of these same studies. Only a few studies have concluded that age itself does not affect outcomes.17-19 However, most of the studies conclude that advanced age is a significant factor. Most of these cite a cutoff of 60 years of age,14,20 65 years of age,21 or 70 years of age,10 but at least 1 study has cited a cutoff as young as 40 years of age,9 and at least 1 other has cited 50 years of age.8
Most of the available literature has evaluated the effects of age and duration of symptoms separately. However, at least 2 studies have discussed the interplay between these variables, and both found that outcomes are associated with duration of symptoms only in the elderly, defined as above either 65 or 70 years of age.5,19 This study is an attempt to clarify this relationship.
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