ABSTRACT
BACKGROUND: MRI has high sensitivity to thoracic myelopathy, which can assess the spinal cord injury by morphology and magnitude of cervical spinal cord compression. Additionally, it is a valuable tool for the prognosis evaluation of thoracic spinal stenosis. OBJECTIVE: To explore the value of quantitative MRI T2WI parameters in predicting surgical outcome of thoracic ossification of the ligamentum flavum, and to establish the prediction model of poor prognosis, so as to provide reference for prognosis evaluation. METHODS: From January 2010 to January 2019 at Cangzhou Central Hospital, clinical and imaging data of 87 cases of thoracic ossification of the ligamentum flavum treated by thoracic laminectomy were reviewed retrospectively. According to the JOA recovery rate at 6-month follow-up, the patients were divided into good recovery group (≥ 50%) and poor recovery group (< 50%). Age, sex, duration of disease, JOA score, Sato type of ossification, maximum spinal cord compression, cross-sectional area, distribution of hyperintense signal, signal intensity ratio, intramedullary signal size, local kyphosis, kyphosis correction, number of decompressed levels and incidence of cerebrospinal fluid were compared between two groups. Univariate analysis was used to analyze indicators with significant differences. Receiver operating characteristic curve was plotted to analyze prognosis. Areas under the curve and cut-off values were recorded. The independent predictors of poor recovery were estimated through multivariate logistic regression analysis and the prediction model was established. RESULTS AND CONCLUSION: (1) The duration of disease, JOA score, maximum spinal cord compression, cross-sectional area, signal intensity ratio and intramedullary signal size showed significant difference between good recovery and poor recovery groups (P < 0.05). (2) Receiver operating characteristic curve analysis showed that the area under the curve of the duration of disease, JOA score, maximum spinal cord compression, cross-sectional area, signal intensity ratio and intramedullary signal size was 0.670, 0.733, 0.647, 0.715, 0.753 and 0.765 respectively. The cut-off value was duration of 13 months, score 4, 29.8%, 0.25 cm2, 1.593 and 13.64 mm respectively. The duration of disease and maximum spinal cord compression had low discrimination power (the area under the curve < 0.7) in predicting poor recovery, whereas the JOA score, cross-sectional area, signal intensity ratio and intramedullary signal size had moderate discrimination power (the area under the curve 0.7-0.9). The area under the curve indicates good ability of signal intensity ratio and intramedullary signal size in combination (the area under the curve=0.791). (3) Logistic multivariate regression analysis showed that JOA score, cross-sectional area and combination of signal intensity ratio and intramedullary signal size were independent risk factors of poor recovery. A predicting model was built according to the result of the logistic regression analysis. It was shown that the area under the curve of this model was 0.890, which was significantly higher than that of the JOA score, cross-sectional area and combination of signal intensity ratio and intramedullary signal size (P < 0.05). (4) Combination of signal intensity ratio and intramedullary signal size had higher predictive ability than other MRI parameters. JOA score, together with quantitative MRI T2WI parameters may have a better predictive value for the risk of poor recovery in patients with thoracic ossification of the ligamentum flavum.
ABSTRACT
STUDY DESIGN: This was a retrospective study. PURPOSE: The purpose of this study was to study the relationship between prevalence of pyramidal signs and the severity of cervical myelopathy. The study is focused on patients having increased signal intensity in T2-weighted magnetic resonance imaging. OVERVIEW OF LITERATURE: Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction in elderly population. It is the consequence of spondylotic changes leading to cervical cord injury with resulting clinical deficits. Diagnosis in such patients is made based on clinical and radiographic features. A patient must have both symptoms and signs consistent with cervical cord injury as well as radiographic evidence of damage to spondylotic cord. METHODS: Forty-six patients with complaint of cervical spondylotic myelopathy with increased signal intensity in T2-weighted magnetic resonance imaging were included in the study. The neurological finding of the patients was reviewed for the presence of pyramidal signs. The prevalence of each pyramidal sign was calculated and correlated to severity of cervical myelopathy. The motor function scores of the upper and lower extremities for cervical myelopathy set by the Japanese Orthopedic Association (motor Japanese Orthopaedic Association score, m-JOA) scores were used to assess severity of myelopathy. RESULTS: The most prevalent signs were hyperreflexia (89.1%), Hoffmann reflex (80.4%), Babiniski sign (56.5%), and ankle clonus (39.1%). Babiniski sign, ankle clonus, and Hoffmann reflex showed significant association with the lower m-JOA score. CONCLUSIONS: In patients with cervical myelopathy, hyperreflexia exhibited highest sensitivity whereas ankle clonus demonstrated lowest sensitivity. The prevalence of the pyramidal signs is correlated with increasing severity of myelopathy.