gms | German Medical Science

Objective: Pathological CSF dynamics in the cranio cervical junction are thought to account for pathophysiology in Chiari Type I Malformations. Distinctive flow patterns have been visualized by four dimensional MRI phase contrast flow imaging. However, it remains unclear how these recognizable patterns alter after operative treatment (posterior fossa decompression). This work aims on analyzing the changes in perioperative MR CSF flow studies.

Methods: Surgical decompression of the craniocervical junction was performed on a mixed collective of pediatric and adult patients with symptomatic Chiari Type I Malformations. Four dimensional MRI phase contrast flow imaging was added to the conventional MRI protocol and performed before and sequentially after surgery. CSF dynamics were analyzed and the results were compared to the clinical course.

Results: A total number of ten patients were included into the prospective observational study:eightfemales, two males; 3-73 years of age; eight posterior fossa decompressions without duraplasty, two posterior fossa decompressions with duraplasty.Three preoperative flow patterns were observed: heterogenous flow, vortex formation and anterolateral flow jets. These phenomenons sequentially subsided, as were the clinical symptoms.

Conclusion: Four dimensional MR phase contrast flow imaging visualizes improved CSF flow dynamics after posterior fossa decompression. This compares to the improvement of the patients’ symptoms. Further studies with larger patient numbers are needed to better correlate imaging findings with clinical outcomes.