Mullin, Jeffrey P.

OBJECTIVE The aim of this study was to determine predictors of the minimum clinically important difference (MCID) in the Neck Disability Index (NDI) following cervical spinal deformity surgery. METHODS A retrospective review was performed of a prospective, multicenter adult cervical spinal deformity database. All patients had baseline and 1-year NDI scores. Patients met MCID with an improvement of NDI by 7 points between baseline and 1 year, as previously established. Baseline demographics, comorbidities, and both baseline and 1-year spinopelvic parameters were evaluated for statistical significance in a univariate logistic regression analysis. Significant variables, in addition to baseline NDI, were analyzed in a multivariable logistic regression model by backward selection with Akaike information criterion minimization. RESULTS A total of 122 patients were included with a median age of 62 (IQR 56, 69) years; 62% of patients were female. Of the 122 patients, 72 (59%) achieved NDI MCID at 1 year. Predictors of achieving MCID on univariate analysis included a lower Charlson Comorbidity Index (CCI) total score (OR 0.70, p = 0.03), depression as a comorbidity (OR 2.9, p = 0.02), lower C2 tilt at the 1-year follow-up (OR 0.92, p = 0.02), and a greater difference between 1-year postoperative C2–7 sagittal vertical axis (SVA) and preoperative C2–7 SVA (OR 0.98, p = 0.0495). On multivariable logistic regression analysis, predictors of achieving MCID included a lower CCI (OR 0.62, p = 0.03), depression as a comorbidity (OR 3.1, p = 0.059), a greater change in C2–7 SVA at the 1-year follow-up compared with baseline (OR 0.97, p = 0.055), and baseline NDI (OR 1.02, p = 0.24) with an area under the curve of 0.74. CONCLUSIONS The best-fit multivariable model included higher baseline NDI, a greater change in C2–7 SVA, patient-reported baseline depression, and lower CCI as important factors in predicting NDI MCID.

Heterotopic gray matter has been implicated in epilepsy; however, not much is known regarding heterotopia beyond epilepsy. Here, the authors describe 2 pediatric patients with deep heterotopias contiguous with basal ganglia structures. These heterotopias appear to have manifested as movement disorders. One patient presented with a left-sided myoclonus and choreiform movements associated with a right caudate heterotopia; she experienced vast improvement after resection of periventricular heterotopia. The other patient presented with progressive dystonia and a ballistic movement disorder. Initial bilateral globus pallidus internus stimulation resulted in successful treatment of the dystonia; however, her movement disorder worsened. After an extensive workup, including STATISCOM (statistical ictal SPECT coregistered to MR imaging), the patient underwent cortical stimulation with improvement in her movement disorder. To the best of our knowledge, these cases are the first reported instances of heterotopic gray matter associated with movement disorders. Both patients experienced significant improvements following resection of their heterotopias.