DCM-72 (dexterity, cutaneous, and muscle-72): A composite scoring system for objective assessment of upper limb dysfunction in patients with degenerative cervical myelopathy

Background Context

Degenerative cervical myelopathy (DCM) is characterized by spinal cord compression, which can present with limb weakness and numbness, loss of fine motor skills, gait disturbance, and bladder dysfunction. The modified Japanese Orthopedic Association (mJOA) and Graded Redefined Assessment of Strength, Sensibility, and Prehension Version Myelopathy (GRASSP-M) scores evaluate distinct aspects to assess the severity of upper and lower extremity dysfunction. Our study aims to develop an integrative, multidimensional Dexterity, Cutaneous, and Muscle (DCM-72) scoring system to provide a more comprehensive and objective evaluation of upper extremity functional impairment.

Methods

Within this prospective, 2 center study, a total of 123 participants, comprising of 94 subjects with confirmed DCM and 29 controls with cervical radiculopathy were enrolled. A composite DCM-72 score was developed incorporating several upper extremity functional assessments with 24 total points allocated to each of the 3 components: dexterity, sensation, and muscle strength. Descriptive statistics were used with a p≤0.05 indicating statistical significance.

Results

The mean age of the participants is 60.2±12.1 years, with a female-to-male ratio of 1:1.2. The average DCM-72 scores for the dominant and nondominant upper extremities are 28.0±6.0 and 27.3±6.5. Analysis of variance with posthoc analysis identified significant differences between mild-severe and moderate-severe cases as stratified by mJOA subclassification. The proposed composite DCM-72 severity score ranges are defined as: 68.5-72 (normal), 64.3-68.4 (mild), 56.7-62.3 (moderate), and <56.7 (severe).

Conclusion

The DCM-72 score effectively stratifies upper extremity dysfunction in patients with DCM through a set of well-established quantitative assessments offering objective performance evaluations as compared to existing scoring systems. DCM-72 can further assist clinicians to monitor outcome trajectories to support decision-making and prognostication and further serves as a candidate tool to improve sensitivity for interventional trial testing.