Differential diagnosis of degenerative cervical myelopathy considered in patients spine surgeons referred to neurologists: a retrospective cohort study.

BACKGROUND: When patients suspected of degenerative cervical myelopathy present with atypical neurological findings, the spine surgeons generally referred the patients to neurologists preoperatively to distinguish it from non-compressive neurological diseases. This study aimed to elucidate the diseases that should be differentiated from degenerative cervical myelopathy and the differentiation points. METHODS: We conducted a retrospective cohort study, and extracted consecutive patients who were suspected of degenerative cervical myelopathy with spinal cord compression and consulted a spine surgeon but were referred to a neurologist from 2011 to 2021 because of atypical findings. The main reason for consultation with a neurologist and the definitive diagnosis were investigated. RESULTS: Sixty-eight patients were included (60 men and 8 women; median age [interquartile range], 72 [63–76]). The main reasons for consultation with a neurologist were lack of sensory disturbance in 43 patients, lack of upper extremity symptoms and/or atypical gait impairment in 13, and symptoms in the unilateral upper and lower extremities in 3, and others. Definitive diagnoses were degenerative cervical myelopathy in 40 patients, non-compressive neurological diseases in 26, and others in 2. Non-compressive neurological diseases included parkinsonian syndromes in 9 patients, amyotrophic lateral sclerosis in 3, cerebrovascular disease in 3, and others. Regarding paresis of upper extremity in patients with lack of sensory disturbance, bilateral extensive type and no abnormality in upper extremity were related to non-compressive neurological diseases. In patients with lack of upper extremity symptoms and/or atypical gait impairment, 8 of 10 patients with non-spastic gait were diagnosed with non-compressive neurological diseases, and 5 of them with parkinsonian syndromes. CONCLUSIONS: Non-compressive neurological disease should be considered in patients with a lack of sensory disturbance who present with bilateral extensive paresis or no neurological abnormality in the upper extremity. Parkinsonian syndromes should be considered as differential diagnosis for patients presenting with non-spastic abnormal gait.