Dynamic CSF MRI Findings in the Diagnosis and Follow-up of Arnold Chiari Type 1

Abstract

Aim:
 Chiari malformation is a spectrum of diseases that includes different subtypes, has a wide clinical presentation, and therefore has different follow-up and treatment methods. We aimed to compare clinical scoring systems and cerebrospinal fluid (CSF) dynamics obtained by magnetic resonance imaging (MRI) in Arnold Chiari Malformation Type-1 (CM-1) patients in the preoperative and postoperative periods.
 Material and Method:
 Twenty-one patients with a diagnosis of CM-1 who underwent CSF MRI between January 2016 and June 2020 were included. In addition, 21 healthy volunteers were evaluated. All the patients had undergone decompression surgery due to CM-1 related symptoms. The relationship between preoperative MRI findings and clinical findings of 21 patients was evaluated. Changes in clinical and imaging findings of 21 patients who underwent surgery were compared. 
 Results:
 Measurements were made just below the level of the cerebellar tonsil. CM-1 patients had higher preoperative peak positive velocity anteriorly (PPV: 6.26±2.72 vs 3.89±1.74 cm/s; p=0.001) and peak negative velocity anteriorly (PNV: -7.45±3.36 vs -3.61±2.65 cm/s; p=0.001) than healthy volunteers. Preoperative net flow in the posterior subarachnoid space of CM-1 patients was lower than in healthy volunteers (p=0.017).
 Aliasing of the reverse flow was seen in 13(62%) patients.
 PPV and PNV were decreased after surgery (PPV: 6.26±2.72 vs 4.73±1.94 cm/s, p=0.017; PNV: -7.45±3.36 vs -4.97±1.97, p=0.005). Net Flow was increased posteriorly (0.32 vs 2.21 ml/min; p=0.053).
 Postoperative response was inversely proportional to the degree of tonsillar herniation. As the Asgari score of the cases increases, the Peak Positive and Negative Velocity Anterior values also increase with a statistically significant correlation (p=0.003; p=0,032 respectively)
 Conclusions:
 Our findings suggest that the determination of flow dynamics and morphology using MR imaging correlates with clinical findings and may be a useful tool in determining the need and timing of surgery.