Introduction: Surgical decompression is a treatment option used for syringomyelia caused by compression
at the cranio-cervical junction. However, there is limited evidence detailing the
exact time course for radiographic resolution of a syrinx after decompression.
Methods: A 28-year-old female presented with progressive myelopathy. She was found to have
basilar impression secondary to atlanto-occipital assimilation as well as an extensive
cervicothoracic syrinx. A two-staged approach was planned: a posterior occipito-cervical
fusion followed by an anterior transcervical odontoidectomy using intraoperative magnetic
resonance imaging (MRI). During the anterior procedure an intraoperative pre- and
post-decompression MRI was obtained with the patient fixed in the same position to
allow for a comparison of equivalent MRI slices. A 3-month postop MRI was also obtained
for comparison. The width of the syrinx was measured in the sagittal plane at the
C4-T1 levels.
Results: A sequential decrease in the width of the syrinx was seen at the C4 (5.9mm, 3.4mm,
0mm), C5 (6.3mm, 4.7mm, 3.7mm), and C6 (5.5mm, 4.4mm, 3.6mm) when comparing pre-decompression,
post-decompression, and 3-month follow-up. A transient increase post decompression
followed by overall decrease at the 3-month interval was seen at C7 (6.0mm, 7.0mm,
3.8mm) and T1 (6.5mm, 7.0mm, 4.6mm). Intraoperative MRI revealed that the syrinx diminished
immediately after odontoidectomy. Three month postoperative MRI revealed that the
syrinx continued to diminish in size. The immediate radiographic reduction of the
syrinx after decompression in this case provides further support for treating syringomyelia
with surgical decompression and reveals that treatment may result in immediate effects.
Conclusion: Surgical decompression resulted in immediate radiographic changes in the associated
cervico-thoracic syrinx. These findings suggest that syringomyelia resolution may
begin immediately post decompression.
Table: Anterior-posterior diameter of syrinx
|
Intra-Op before decompression (mm) |
Intra-Op after decompression (mm) |
3 mo post-Op (mm) |
| C4 |
5.9 |
3.4 |
0 |
| C5 |
6.3 |
4.7 |
3.7 |
| C6 |
5.5 |
4.4 |
2.6 |
| C7 |
6.0 |
7.0 |
3.8 |
| T1 |
6.5 |
7.0 |
4.6 |
Fig. 1 Intraoperative Sagital T2WI MRI before (left) and after (right) decompression, demonstrating
intraoperative changes in syrinx size.
