Reduced Field-of-View Diffusion Tensor Imaging of the Spinal Cord Shows Motor Dysfunction of the Lower Extremities in Patients With Cervical Compression Myelopathy

Spine 2018;43:89–96

Study Design. A cross-sectional study.

Objective. The aim of this study was to quantify spinal cord dysfunction at the tract level in patients with cervical compressive myelopathy (CCM) using reduced field-of-view (rFOV) diffusion tensor imaging (DTI).

Summary of Background Data. Although magnetic resonance imaging (MRI) is the standard used for radiological evaluation of CCM, information acquired by MRI does not necessarily reflect the severity of spinal cord disorder. There is a growing interest in developing imaging methods to quantify spinal cord dysfunction. To acquire high-resolution DTI, a new scheme using rFOV has been proposed.

Methods. We enrolled 10 healthy volunteers and 20 patients with CCM in this study. The participants were studied using a 3.0-T MRI system. For DTI acquisitions, diffusion-weighted spinecho rFOV single-shot echo-planar imaging was used. Regions of interest (ROI) for the lateral column (LC) and posterior column (PC) tracts were determined on the basis of a map of fractional anisotropy (FA) of the spinal cord and FA values were measured. The FA of patients with CCM was compared with that of healthy controls and correlated with Japanese Orthopaedic Association (JOA) score.

Results. In LC and PC tracts, FA values in patients with CCM were significantly lower than in healthy volunteers. Total JOA scores correlated moderately with FA in LC and PC tracts. JOA subscores for motor dysfunction of the lower extremities correlated strongly with FA in LC and PC tracts.

Conclusion. It is feasible to evaluate the cervical spinal cord at the tract level using rFOV DTI. Although FA values at the maximum compression level were not well correlated with total JOA scores, they were strongly correlated with JOA subscores for motor dysfunction of the lower extremities. Our findings suggest that FA reflects white matter dysfunction below the maximum compression level and FA can be used as an imaging biomarker of spinal cord dysfunction.

Key words: . Level of Evidence: 4

Transvertebral anterior key hole foraminotomy without fusion for the cervicothoracic junction

Acta Neurochir (2012) 154:1797–1802

Various surgical procedures have been used to repair disc herniations and osteophytes at the cervicothoracic junction. Among these procedures, transvertebral anterior foraminotomy without fusion is a relatively less invasive, safe and useful method, although the majority of spinal surgeons remain unfamiliar with this method. We describe the surgical procedure for a transvertebral anterior keyhole foraminotomy without fusion at the cervicothoracic junction, and we assess the middle-term clinical and radiological outcomes.

Methods Of 118 patients undergoing this surgery in our institute between 2007 and 2010, five (4.2 %) had C8 radiculopathy causing C7/T1 disc herniations or osteophytes. We studied five patients who underwent trans-C7 vertebral keyhole foraminotomy without fusion. We retrospectively examined clinical data, pre- and postoperative neurological status.

Results In all cases, surgical decompression was successfully achieved without difficulty when accessing the pathology. No complications related to the surgical procedure were reported. The follow-up period was 12– 28 (mean 20) months. In all patients, the visual analogue scale (VAS) due to radicular pain immediately decreased after the operation and did not increase thereafter. The mean VAS decreased from 7.8 (4.5–9.6) to 1.0 (0–2.1). The Cobb angle at C2-T1 in a neutral position improved from −12.6 (−2.8 to −24.7) degrees to −6.9 (4.2 to −25.4). The postoperative C7/T1 disc height decreased from 5.4 to 4.9 mm, indicating minimal loss.

Conclusions This procedure allows for direct access to the pathology and is less invasive. In this study, we clarified that this technique yields excellent radiological and clinical outcomes.