Phenotypes and Prognostic Factors of Syringomyelia in Single-Center Patients With Chiari I Malformation: Moniliform Type as a Special Configuration

Abstract

Objective: The specific association between morphometric characteristics of the syrinx and the prognosis of Chiari malformation type I (CM-I) with syringomyelia following surgical procedure seems to have not been fully elaborated. This study focused on the preoperative clinical and radiologic parameters in CM-I patients with syringomyelia to find out the relationship between the patients’ clinical status and the phenotypes of the syrinx with surgical outcome.Methods: A continuous series of pediatric and adult patients with CM-I and syringomyelia from a prospectively maintained database in a single center were included, and we explored the related factors affecting the prognosis following decompression surgery through retrospective analysis of clinical presentations, imaging characteristics, and the morphological features of syringomyelia, to provide a clinical reference for the treatment of syringomyelia.Results: There were 28 pediatric patients (13.8%), and 174 adults (86.2%) included in our study. The average Chicago Chiari Outcome Scale score was 14.56 ± 1.78. The overall prognosis after surgery was good in our series, among them 152 cases (75.25%) with a favorable prognosis, and syrinx was resolved effectively in 172 cases (85.15%). According to the univariate and multivariate analyses, the preoperative symptom duration, observation time, and with/without moniliform type were independent factors affecting the prognosis in adults. The most obvious difference between moniliform type and nonmoniliform type lies in the preoperative symptom duration, ventral subarachnoid space at the foramen magnum, and with/without straightened cervical physio-curve.Conclusion: Timely decompression surgery could achieve a better outcome in CM-I patients with syringomyelia. Moniliform syringomyelia may suggest a relatively better prognosis.

The Physiological Occlusion of the Central Canal May Be a Prerequisite for Syringomyelia Formation

“…Clinically, contrast-enhanced studies reveal increased CC signal in syringomyelia patients versus controls, suggesting excessive SAS CSF influx into the CC [ 28 ]. Additionally, surgical SAS decompression for obstruction (e.g., Chiari I malformation, arachnoiditis) often successfully resolves syringomyelia [ 29 , 30 ]. However, transverse SAS ligation failed to induce syringomyelia in rats.…”

“…In contrast to occlusion in humans, studies demonstrate patency of the CC in rats, which functions as a channel for CSF outflow. In rats, the CC directly receives CSF from the fourth ventricle and excretes it into the blood via the terminal filament and cauda equina [ 30 - 32 ]. The CC’s role in syringomyelia remains hypothetical due to a lack of methods to selectively occlude the CC without spinal cord injury in animals.…”

Individualized Functional Decompression Options for Adult Chiari Malformation With Syringomyelia and A Novel Scale for Syringomyelia Resolution: A Single-Center Experience

“…As adult CMI patients age, their surgical outcome scores consistently decline [ 31 ], and this decline may be attributed to decreased anterior CSF space with aging and makes decompression more challenging [ 32 ]. Thus, early decompression is recommended for symptomatic adult CMI patients [ 33 ]. According to the definition of CCOS, patients without pain symptoms definitely had more favorable improvement on the pain symptoms [ 12 ].…”

Single-cell transcriptomics reveals ependymal subtypes related to cytoskeleton dynamics as the core driver of syringomyelia pathological development

“… 16 Moreover, it is intriguing to see that in our prior clinical study on a series of patients with syringomyelia, the symptom duration of moniliform syringomyelia is shorter than that of the dilated type. 17 Most moniliform syrinx resolved quickly the following decompression, compared to dilated syringomyelia, and these patients with better prognosis. We hypothesized that the special syrinx phenotype in moniliform configuration might represent an early reversible state.…”