The characteristics of posttraumatic syringomyelia.

STUDY DESIGN: Retrospective cross-sectional study.

OBJECTIVES: To investigate the characteristics of posttraumatic symptomatic syringomyelia after spinal cord injury (SCI).

SETTING: Swiss Paraplegic Centre, Nottwil, Switzerland.

METHODS: The patient database was screened for patients diagnosed with posttraumatic syringomyelia. Syrinx characteristics were determined on T2-weighted magnetic resonance images. Binary logistic regression analysis was used to investigate the effects of age, injury level, injury severity and syrinx location on early syrinx formation, syrinx length and syrinx extending cranial to the lesion.

RESULTS: The data of 138 patients were analyzed. The majority of the patients (78.3%) suffered from motor and sensory complete SCI (American Spinal Injury Association Impairment Scale (AIS) A). Syringomyelia was diagnosed a median 15.0 years after SCI at a median age of 42 years. The cervical spine was involved in >57% of the patients, and syringomyelia extended over a median seven vertebral levels. Complete SCI (P=0.035) and age (P=0.001) were significant predictors of early syrinx formation. Syringomyelia occurred significantly earlier in older (>30 years) patients (P⩽0.002) and those with complete SCI (P=0.027) compared with younger patients (⩽30 years) and those with incomplete SCI (AIS B-D), respectively. Age, injury level, injury severity (AIS A) and syrinx location did not have any significant (P>0.9) effect on syrinx extending cranially or syrinx length.

CONCLUSIONS: Posttraumatic syringomyelia mainly occurs in patients with complete SCI (AIS A) and involves the cervical spine in 6 of the 10 patients. Patients with complete SCI and those age >30 years have an increased risk of syrinx formation within 5 years after injury.