Study Design: Prospective observational cross- sectional study

Purpose: Degenerative Cervical Myelopathy (DCM) is a common spinal disorder with subtle, non-specific symptoms that can hinder awareness, causing delayed diagnosis and lasting disabilities. This study aimed to identify early somatosensory deficits in mild DCM to promote early detection and prevent delayed diagnosis.

Methods: Chinese DCM subjects aged 45 or 90 above were assessed with the modified Japanese- Orthopaedic-Association Scoring System for cervical myelopathy (mJOA) and somatosensory functions, including superficial pain, temperature, discriminative touch, vibration, and proprioception. The prevalence and correlation between somatosensory deficits and disease severity were analyzed.

Results: Among the 436 DCM cohort, 20% were asymptomatic, and proprioceptive deficit had the highest prevalence among the symptomatic DCM subjects (54%; odds ratio: 7, p=0.002), even among individuals with very mild symptoms across disease severity. A substantial association with disease severity was confirmed in proprioceptive and vibratory deficits. Proprioceptive deficit exhibited the strongest correlation with mJOA (r = -0.51, p < 0.001) concerning disease progression. It was observed in milder DCM cases compared to other sensory modalities, with a cutoff mJOA of 15.3 and an Area- Under-the-Curve of 0.84.

Conclusion: This study is the first comprehensive sensory testing to reveal the trend of somatosensory deficits in DCM, occurring from ‘mild’ to ‘moderate’ and ‘severe’ DCM. Spinal cord disturbances can evolve from an isolated proprioceptive deficit to complex impairments. Notably, proprioceptive deficit was the most common somatosensory symptom, ranging from mild to severe DCM. These findings highlight the importance of assessing proprioception in suspected cases of DCM to enable early detection for further investigations.