Study design: A prospective study.
Objective: To examine the prevalence and clinical manifestations of segmental motor paralysis after cervical laminoplasty and to investigate the presence of intramedullary high-signal intensity area (HIA) on postoperative T2-weighted magnetic resonance imaging (MRI).
Summary of background data: Almost all previous studies had been retrospectively conducted, and MRIs of all subjects, including a control population, have never been investigated.
Methods: In the 79 patients of the prospective group, the sole examiner evaluated muscle strengths daily for perioperative 3 weeks and MRI scans were performed before and after surgery. Medical records of the 79 consecutive patients before this study were also investigated (control group).
Results: Ten patients from the prospective group developed segmental motor paralysis (proximal in 5, distal in 2, and diffuse in 3), whereas paralysis occurred in only 4 patients from the control group (proximal in 3 and diffuse in 1). On postoperative MRI, a linear HIA corresponded to the paralyzed segment more frequently than a focal or no HIA.
Conclusion: In the prospective cases, distal or diffuse paralysis was found more frequently than in the retrospective control group. Linear HIAs were significantly more likely to present in the paralyzed segments.