Pet predicts outcomes for patients with cervical spinal cord compression

Cervical spinal stenosis is a condition in which the spinal canal narrows in the neck. While many patients lack symptoms, once symptoms appear, it usually indicates the presence of myelopathy. This compression can lead to progressive neurologic deficits, such as numbness, weakness or tingling in a leg, foot, arm or hand.

In the study "Hypermetabolism in ¹⁸F-FDG PET Predicts Favorable Outcome Following Decompressive Surgery in Patients with Degenerative Cervical Myelopathy," researchers aimed to assess the regional changes of glucose metabolism of the cervical spinal cord using ¹⁸F-FDG PET. "To date, experiences with ¹⁸F-FDG PET in symptomatic patients with degenerative cervical spine stenosis and consecutive compressive myelopathy are very limited," said Norbert Galldiks, MD, one of the lead researchers of the study."In the present study, we present the results of preoperative magnetic resoncance imaging and ¹⁸F-FDG PET imaging and postoperative follow-up imaging 12 months after decompressive surgery. Imaging findings were correlated with the clinical outcome."

Researchers observed two significantly different patterns of ¹⁸F-FDG uptake among the 20 study participants prior to surgery -- approximately half of the patients had increased ¹⁸F-FDG uptake at the site of spinal cord compression and were classified as myelopathy type 1, while the other half had inconspicuous ¹⁸F-FDG uptake and were classified as myelopathy type 2. Post-operatively, those with myelopathy type 1 had a marked decrease in ¹⁸F-FDG uptake, while myelopathy type 2 patients had only a moderate decline in uptake.

The overall outcome in myelopathy type 1 patients was favorable, and the patients showed significant improvement on their functional status assessment. In contrast, there was no significant clinical change in patients with inconspicuous ¹⁸F-FDG uptake.

"A hypermetabolism of the cervical spinal cord at the level of cervical spine stenosis as indicated by a locally increased ¹⁸F-FDG uptake seems to be a marker for a potentially reversible phase of a compression-induced cervical myelopathy," explained Galldiks. "The lesion of the spinal cord seems to be predominantly functional. Presence of this metabolic pattern reflects the time frame when decompressive surgery can lead to substantial clinical improvement. In order to stratify eligible patients for decompressive surgery, our findings may help to implement ¹⁸F-FDG PET investigations of the cervical spine in clinical routine."