Related Experiment Video
Updated: May 13, 2026
In Vivo Morphometric Analysis of Human Cranial Nerves Using Magnetic Resonance Imaging in Menière's Disease Ears and Normal Hearing Ears
Published on: February 21, 2018
Contrast-Enhanced MRI-Based Grading of Nuchal Ligament Failure in Dropped Head Syndrome Caused by Isolated Neck
Kenji Endo1, Hirosuke Nishimura, Yasunobu Sawaji
1Department of Orthopedic Surgery, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan.
Study Design:
Retrospective observational cohort study.
Objective:
To establish a contrast-enhanced MRI-based grading system for imaging-defined nuchal ligament disruption in dropped head syndrome (DHS) caused by isolated neck extensor myopathy (INEM), and to evaluate its association with sagittal head alignment, cervical extension function, pain, and quality of life.
Methods:
A total of 130 patients with INEM-related DHS who underwent contrast-enhanced cervical MRI were retrospectively analyzed, along with 21 non-DHS controls. Nuchal ligament findings were classified into four grades (Grade 0-3) based on contrast enhancement patterns and ligament continuity. Clinical parameters included chin-brow vertical angle (CBVA), pain severity assessed using the Numerical Rating Scale (NRS), health-related quality of life assessed using EuroQol 5 Dimensions (EQ-5D), and the ability to actively achieve cervical extension in the prone all-fours position. Associations among MRI grades were evaluated using one-way analysis of variance and multivariable regression adjusted for age and sex.
Results:
All patients with INEM-related DHS demonstrated intraligamentous contrast enhancement, whereas non-DHS controls showed no such findings. CBVA differed significantly across MRI grades, with higher values observed in patients with advanced-grade disruption. However, when MRI grade was treated as an ordinal variable, a strictly linear association with CBVA was not observed. Active cervical extension was rare in patients with Grade ≥2 disruption. Pain severity did not differ among grades. In contrast, EQ-5D scores were significantly lower in higher grades and remained independently associated with MRI grade after adjustment for age and sex. Interobserver reliability was moderate (weighted κ=0.62).
Conclusions:
Contrast-enhanced MRI-based grading of imaging-defined nuchal ligament disruption provides a structural marker associated with sagittal head alignment and cervical extension dysfunction in INEM-related DHS. This classification may serve as a clinically useful adjunctive tool for severity assessment and stratification in selected patients.
Related Concept Videos
01:15Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
01:19Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...