PMC8769406_01
Preoperative images. T2-weighted sagittal (A) and axial (B) MRI show a dorsal indentation of the spinal cord at C7 and an intramedullary high-intense lesion at C5-C7. Sagittal (C) and axial (D) CT myelograms show an enlarged CSF space below C7 compressing the spinal cord on the back at C7. CSF: cerebrospinal fluid, CT: computed tomography, MRI: magnetic resonance imaging.
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F1
T2-weighted MRI showed a dorsal indentation of the cervical spinal cord at C7 and intramedullary high intensity at C5-C7 with widened dorsal CSF space but neither a suspected arachnoid band nor a cystic lesion (Figs. 1A and 1B), in addition to the cervical spinal canal stenosis. CT myelograms at 30 minutes after an injection of a contrast medium demonstrated an incomplete blockage of the CSF flow at C7 with no visible causes (Figs. 1C and 1D), leading to a definitive diagnosis of DAW taken together with MRI findings.
Intraoperative ultrasonograms (A, B) with the illustrations (C, D), and photos (E, F) around C7. Two membranes and an indentation of the spinal cord are observed on intraoperative ultrasonograms (A-D): both the cranial membrane (arrowhead) and the caudal membrane (arrow) are continuously fluttering, but the movement of the cranial membrane is smaller, suggesting that the cranial membrane is tighter than the caudal membrane. After cutting the arachnoid membrane rostrally to the cranial membrane (arrowhead) and flowing out the CSF, the cranial membrane remains bulging and pulsating: note the relationships between the cranial membrane and the small vessels on the cord (asterisk) (E, F). CSF: cerebrospinal fluid.
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F2
Intraoperative ultrasonography on the dura mater clearly showed that the spinal cord was compressed ventrally by the expanded CSF space, and that two membrane-like structures (cranial and caudal membranes) in the dorsal subarachnoid space were fluttering within the CSF flow at C7 (Figs. 2A-2D). When the arachnoid membrane was cut rostrally to the thick cranial membrane and CSF flowed out from there, the CSF space below the cranial membrane was not collapsed but was pulsating, and the caudal membrane was observed pulsating in the same way through the cranial membrane (Figs. 2E and 2F).
T2-weighted sagittal (A) and axial (B) MRI showing decompression and re-expansion of the spinal cord at C7, and a markedly reduced intramedullary high-intense lesion at C5-C7 at three months post-surgery. MRI: magnetic resonance imaging.
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F3
One-week and 3-month MRIs showed that both spinal cord compression and the intramedullary lesion were improved (Figs. 3A and 3B).