Clinical Outcomes Following Surgical Management of Coexisting Parkinson Disease and Cervical Spondylotic Myelopathy

Abstract

Background: Distinguishing the causes of weakness and gait instability in patients with Parkinson disease (PD) and cervical spondylotic myelopathy (CSM) is a diagnostic and therapeutic challenge due to symptomatic similarities. No study has reported outcomes following decompression in patients with PD and CSM.

Objective: To report outcomes following cervical decompression for patients with coexisting PD and CSM.

Methods: A retrospective matched cohort study of all patients with PD and CSM undergoing cervical decompression at a tertiary-care center between January 1996 and December 2014 was conducted. PD patients were matched to patients with CSM alone by age, gender, American Society of Anesthesiologists classification, and operative parameters. Myelopathy was assessed by Nurick and modified Japanese Orthopaedic Association (mJOA) scales. The effect of PD on mJOA was modeled using multivariable regression.

Results: Twenty-one matched pairs were included. PD patients experienced poorer improvement in Nurick (0.0 vs -1.0, P < .01) and mJOA (0.9 vs 2.5, P < .01) composite scores. However, no significant changes in absolute improvement in the upper extremity motor, upper extremity sensory, or sphincter mJOA components were observed. Multivariable regression identified PD as a significant predictor of decreased improvement in mJOA (β = -0.89, P < .01) and failure to achieve a minimal clinically important difference in change in mJOA (OR 0.18, P = .03).

Conclusion: This study is the first to characterize outcomes following cervical decompression in patients with PD and CSM. PD patients experienced symptomatic improvement but less overall improvement in myelopathy compared to controls. However, PD patients demonstrated improvement in upper extremity motor, upper extremity sensory, and sphincter symptoms no worse than control patients.

Keywords: Cervical spondylotic myelopathy; Minimal clinically important difference; Modified Japanese Orthopaedic Association score; Multivariable regression; Nurick score; Parkinson's disease.