Cervical Muscle Composition in Degenerative Dropped Head Syndrome: A Propensity Score Matching Study.

Area of Science:

• Orthopedics and Spine Surgery
• Neurology
• Radiology

Background:

• Dropped Head Syndrome (DHS) is characterized by severe weakness of cervical paraspinal muscles, leading to a chin-on-chest deformity.
• This condition impairs head lifting against gravity, forward gaze, and daily activities.

Purpose of the Study:

• To compare cervical muscle composition in patients with non-neuromuscular Dropped Head Syndrome (DHS) due to degenerative cervical spine disease.
• To compare these patients to individuals without DHS who underwent anterior cervical discectomy and fusion (ACDF).

Main Methods:

• A retrospective, cross-sectional study design was employed.
• Propensity score matching (age, sex, BMI) was used to compare three groups: DHS patients, non-DHS patients with 1-2 level ACDF, and non-DHS patients with 3+ level ACDF.
• Cervical muscles (C3-C7) were segmented on T2 MRI, and percent fat infiltration (FI) was measured using validated software.

Main Results:

• Patients with DHS exhibited significantly higher fat infiltration in anterior, posterolateral, posteromedial, scalenus, and trapezius muscle groups compared to ACDF groups.
• Higher FI was noted in the sternocleidomastoid muscle group at C4 in DHS patients versus ACDF groups.
• These findings indicate significant muscular decompensation in DHS patients.

Conclusions:

• This study is the first to quantify cervical muscle fat infiltration in DHS patients without neurodegenerative/neuromuscular disease.
• DHS patients demonstrate significant muscular decompensation, with pronounced atrophy in extensor and anterior muscles.
• Further research is warranted to explore these muscle-related findings in DHS patients with neurodegenerative conditions.