Abstract
Dropped head syndrome (DHS), also known as camptocephalia is characterized by chin-on-chest deformity due to the progressive weakening of cervical paraspinal muscles. The assessment and management of DHS remains controversial since most of clinical series consist of a relatively small sample size.
Previously, lateral cervical direct X-ray has been used for the analysis of sagittal alignment in DHS patients. Afterward, global spinal alignment has been considered for the evaluation. 1 Konishi et al. take it a step forward and raise an important question about the influence of cervical flexion deformity on global sagittal spinal alignment in patients with DHS. 2 Cervical flexion affects T1 slope and T5-8 angle in normal individuals while this does not exist in DHS patients since the reciprocal change of cervicothoracic segment is lost in camptocephalia. 3 Besides, the correlation between the C2-C7 angle and C0-C2 angle is disappeared in DHS patients. This important information helps us to understand the symptomatology of this complex disorder as neck pain is the chief complaint. Regarding the T1-T4 angle, it stays stable during cervical flexion in DHS patients when it compares with the control group because of the bilateral strut effect of shoulder girdle to the upper thoracic spine. This finding underlined extending of fusion to upper thoracic segments between T1-4 in the surgical treatment of DHS patients. 4 This provides a stable distal foundation to the posterior fusion construct and may reduce the risk of complications such as distal junctional problems.
This study has several acknowledged limitations, including small sample size, the lack of similarity on age of control groups, and also absence of subgroup analysis according to sagittal vertical axis (SVA) (−) and SVA (+). Another important limitation is considering the degree or severity of flexion in the DHS. Some of the patients may already have a mild deformity whereas the others may have severe DHS. Consequently, this heterogeneity can affect the results. This should be investigated as a dependent variable in future studies.
The current article, I believe, maintains a research effort to explain details of the burden of sagittal alignment in DHS patients by analyzing various radiological parameters. This effort will help us to understand the etiopathogenesis and management of this complex disorder more effectively.
