Evaluation of Cervical Vertebral Motion and Foraminal Changes During the Spurling Test Using Zero Echo Time MRI and CT Micromotion Analysis.

STUDY DESIGN: Clinical experimental diagnostic study.

OBJECTIVE: The objective of the study was to investigate cervical spine dynamics including changes of the cervical foramina in patients experiencing intermittent arm radiculopathy.

SUMMARY OF BACKGROUND DATA: Cervical foraminal stenosis is a frequent cause of radicular arm pain. The Spurling test, while specific, lacks the precision to identify symptomatic nerve roots. The relationship between vertebral motion, foraminal changes, and radiculopathy during a Spurling test remains underexplored.

METHODS: Ten patients with positive Spurling tests and MRI-confirmed one or two level cervical foraminal stenosis were scanned using the Dynamic MRI Compression System (DMRICS) enabling a simulated Spurling test inside the MRI gantry of a 3T MRI scanner with a dedicated neck coil. First, a relaxed image acquisition was undertaken followed by slowly applying the Spurling test until the patient reported aggravation of radiculopathy or discomfort, where the next image series was taken. Zero Echo Time (ZTE) MRI was employed to obtain CT-like images. The images were thereafter analyzed using the Sectra® CT-based Micromotion Analysis (CTMA) software for motion analysis.

RESULTS: The C4/C5 level exhibited the most significant movements both in translation and rotation, with less movements observed in C5-6 and C6-C7 levels. No uniform pattern emerged that differentiated suspected stenotic levels from non-suspected levels. Despite relatively small vertebral movements, 9/10 of patients reported arm pain during provocation, indicating extremely narrow margins of tolerance.

CONCLUSION: This study demonstrates the utility of ZTE MRI and CTMA in detecting subtle yet clinically relevant vertebral motions influencing the foramina in the cervical spine during the Spurling maneuver. These findings could lead to better understanding and potentially improved diagnostic strategies for cervical foraminal stenosis, although further research with a larger cohort is necessary to confirm these results.