Journal of Craniovertebral Junction and Spine (Jan 2021)

Pulsatile cerebrospinal fluid dynamics in Chiari I malformation syringomyelia: Predictive value in posterior fossa decompression and insights into the syringogenesis

  • Sabino Luzzi,
  • Alice Giotta Lucifero,
  • Yasmeen Elsawaf,
  • Samer K Elbabaa,
  • Mattia Del Maestro,
  • Gabriele Savioli,
  • Renato Galzio,
  • Cristian Gragnaniello

DOI
https://doi.org/10.4103/jcvjs.JCVJS_42_20
Journal volume & issue
Vol. 12, no. 1
pp. 15 – 25

Abstract

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Background: Pathophysiological mechanisms underlying the syringomyelia associated with Chiari I malformation (CM-1) are still not completely understood, and reliable predictors of the outcome of posterior fossa decompression (PFD) are lacking accordingly. The reported prospective case-series study aimed to prove the existence of a pulsatile, biphasic systolic–diastolic cerebrospinal fluid (CSF) dynamics inside the syrinx associated with CM-1 and to assess its predictive value of patients' outcome after PFD. Insights into the syringogenesis are also reported. Methods: Fourteen patients with symptomatic CM-1 syringomyelia underwent to a preoperative neuroimaging study protocol involving conventional T1/T2 and cardiac-gated cine phase-contrast magnetic resonance imaging sequences. Peak systolic and diastolic velocities were acquired at four regions of interest (ROIs): syrinx, ventral, and dorsal cervical subarachnoid space and foramen magnum region. Data were reported as mean ± standard deviation. After PFD, the patients underwent a scheduled follow-up lasting 3 years. One-way analysis of variance with Bonferroni Post hoc test of multiple comparisons was performed P was <0.001. Results: All symptoms but atrophy and spasticity improved. PFD caused a significant velocity changing of each ROI. Syrinx and premedullary cistern velocities were found to be decreased within the 1st month after PFD (<0.001). A caudad and cephalad CSF jet flow was found inside the syrinx during systole and diastole, respectively. Conclusion: Syrinx and premedullary cistern velocities are related to an early improvement of symptoms in patients with CM-1 syringomyelia who underwent PFD. The existence of a biphasic pulsatile systolic–diastolic CSF pattern inside the syrinx validates the “transmedullary” theory about the syringogenesis.

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