Article Figures & Data
Figures
- FIG 1.
A, Details of cryoablation and thermal monitoring. B, Details of spinal cord monitoring.
- FIG 2.
Temperature curves of the representative case with the lowest epidural temperature of 4 °C (case 6).
- FIG 3.
A, Scatterplots illustrate the relationship between the left and right CMAPs at 2.5, 5, 7.5, and 10 minutes after the start of cryoablation and the corresponding epidural temperatures. B, Scatterplots illustrate the relationship between the SCEPs at 2.5, 5, 7.5, and 10 minutes after the start of cryoablation and an average of the corresponding left and right epidural temperatures.
- FIG 4.
Change of the CMAP and SCEP waveform in representative cases with the lowest epidural temperature of 18 °C (case 3) (A) and –8 °C (case 11) (B). A, The CMAP and SCEP waveforms decreased as the epidural temperature dropped. However, the waveforms recovered with rewarming of the epidural temperature. B, The CMAP and SCEP waveforms decreased as the epidural temperature dropped. The waveform of the CMAP did not completely recover after rewarming of the epidural temperature.
- FIG 5.
The pathologic findings of the spinal cord in H&E staining. A, The pathologic specimen of the spinal cord in the representative case with the lowest epidural temperature of −8 °C (case 11) illustrates the cryogenic change in the left lateral and anterior columns (2× magnification). B, In lesions of cryogenic change, there is the proliferation of glial cells, neuronal vacuolation (spongiosis), and dilated myelin sheaths that contain hypereosinophilic swollen axons (spheroids) (60× magnification). C and D, The pathologic specimens of the spinal cord in cases 7 (C) and 8 (D). In these 2 cases with the lowest epidural temperatures of 1 °C (case 7) and 0 °C (case 8), the pathologic evaluation shows cryogenic spinal cord injuries, though spinal cord monitoring after epidural rewarming and the postprocedural motor function were normal. The specimens of the spinal cord in cases 7 (C) and 8 (D) illustrate the cryogenic changes in the left lateral and anterior columns (2× magnification).
Tables
Modified Tarlov scale
Grade 0 Complete paraplegia with no hind extremity function I Minor joint movements II Major joint movements III Animal can stand IV Animal can walk V Animal can climb a 20° inclined plane
