Origin of Syrinx Fluid in Syringomyelia: A Physiological Study

Abstract

Background: The origin of syrinx fluid is controversial.

Objective: To elucidate the mechanisms of syringomyelia associated with cerebrospinal fluid pathway obstruction and with intramedullary tumors, contrast transport from the spinal subarachnoid space (SAS) to syrinx was evaluated in syringomyelia patients.

Methods: We prospectively studied patients with syringomyelia: 22 with Chiari I malformation and 16 with SAS obstruction-related syringomyelia before and 1 wk after surgery, and 9 with tumor-related syringomyelia before surgery only. Computed tomography-myelography quantified dye transport into the syrinx before and 0.5, 2, 4, 6, 8, 10, and 22 h after contrast injection by measuring contrast density in Hounsfield units (HU).

Results: Before surgery, more contrast passed into the syrinx in Chiari I malformation-related syringomyelia and spinal obstruction-related syringomyelia than in tumor-related syringomyelia, as measured by (1) maximum syrinx HU, (2) area under the syrinx concentration-time curve (HU AUC), (3) ratio of syrinx HU to subarachnoid cerebrospinal fluid (CSF; SAS) HU, and (4) AUC syrinx/AUC SAS. More contrast (AUC) accumulated in the syrinx and subarachnoid space before than after surgery.

Conclusion: Transparenchymal bulk flow of CSF from the subarachnoid space to syrinx occurs in Chiari I malformation-related syringomyelia and spinal obstruction-related syringomyelia. Before surgery, more subarachnoid contrast entered syringes associated with CSF pathway obstruction than with tumor, consistent with syrinx fluid originating from the subarachnoid space in Chiari I malformation and spinal obstruction-related syringomyelia and not from the subarachnoid space in tumor-related syringomyelia. Decompressive surgery opened subarachnoid CSF pathways and reduced contrast entry into syringes associated with CSF pathway obstruction.

Figures

FIGURE 1.

FIGURE 2.

FIGURE 3.

T1-weighted MRI scan of the cervical spine after intravenous gadolinium contrast administration in a middle-aged man with von Hippel-Lindau disease demonstrates a syrinx on midsagittal (A, white arrowhead) and axial (B, white arrowhead) images adjacent to an enhancing intramedullary hemangioblastoma (C, black arrow). Serial CT imaging was performed, before D and after E through K intrathecal installation of contrast. Contrast dye is seen around the spinal cord in the subarachnoid space, F through J but not in the syrinx.

FIGURE 4.

Graphical representation of group results. A, The baseline HU of the syrinx before intrathecal contrast injection was similar among groups. The maximum HU in the syrinx after intrathecal contrast injection minus the baseline values is shown for each group, including the values after surgery for the Chiari and spinal syringomyelia groups. Two points are off the graph (–40.5 in the spinal baseline group, 399 in the spinal group before surgery). B, The area of HU under the concentration-time curve (AUC) in the syrinx was greater in the Chiari and spinal groups than the tumor group and was greater before compared to after surgery. One point is off the graph, 3412 in the Chiari group before surgery. C, The ratios of the AUC between the syrinx and subarachnoid CSF were greater in the Chiari and spinal groups compared to the tumor group, but returned to values like the tumor group after surgical decompression of the subarachnoid CSF obstruction. D, Mean maximum HU in the spinal subarachnoid CSF before surgery was greater in the Chiari and spinal group than the tumor group before surgery and was reduced by surgery in the Chiari, but not the spinal group. Each circle represents 1 patient. The long horizontal lines indicate the mean for each group. The shorter horizontal lines indicate 1 SD above and below the mean.

Jeff kept painting, refining his style and techniques. He donated art to charity fundraisers, like the Medical Missions Foundation Gala in 2007. He began receiving commissions from people who had seen his art or heard his story; from his ophthalmologist, from his favorite eye glasses company, from a local apartment complex, on it went. At age 17, Jeff sold $140 000 in art and generated another $200 000 for charity through canvas donations. In 2010, he was named global ambassador for the Make-A-Wish® Foundation (he continued to donate to their fundraising auctions, giving back to those who granted his wish). In 2011, Prudential gave Jeff one of the 10 national Prudential Spirit of Community Awards. In 2012, Jeff was selected as the United States Small Business Administration's Region VII Young Entrepreneur of the Year. Image: Arriving in Murano © Jeffrey Owen Hanson LLC. Used with permission, all rights reserved.