PMC9553696_01
MRI of the brain showing features of intracranial hypotension. (a) FLAIR: bilateral subdural hygromas (white arrows) and slit-like ventricle (white arrowhead). (b, c) Post-contrast: reduced pre-pontine space (asterisk) and diffuse pachymeningeal enhancement (yellow arrow).
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Contrast-enhanced MRI of the brain showed typical features of SIH (Figures 1(a)-1(c)): diffuse pachymeningeal enhancement, distension of the cerebral venous sinuses, bilateral subdural hygromas, reduced pre-pontine space, and slit-like ventricles. Contrast-enhanced MRI of the cervical spine showed supporting imaging features of intracranial hypotension, including a small thecal sac and prominent epidural veins in the cervical spine (Figure 2); no epidural CSF fluid collection was visualized.
Contrast-enhanced MRI of the cervical spine, axial view. T2-weighted image: prominent epidural veins (blue arrows).
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Contrast-enhanced MRI of the brain showed typical features of SIH (Figures 1(a)-1(c)): diffuse pachymeningeal enhancement, distension of the cerebral venous sinuses, bilateral subdural hygromas, reduced pre-pontine space, and slit-like ventricles. Contrast-enhanced MRI of the cervical spine showed supporting imaging features of intracranial hypotension, including a small thecal sac and prominent epidural veins in the cervical spine (Figure 2); no epidural CSF fluid collection was visualized.
(a) Radionuclide (Tc-99 DTPA) cisternogram at 3-hour interval showed Tc-99 DTPA tracking out at the right of the upper cervical/thoracic vertebrae (white arrow). (b) SPECT at 2-hour time interval, axial view, showed focal extrathecal tracer accumulating at the right anterolateral aspect of the C7/T1 level (white arrow).
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Within this time, the site of CSF leak was identified (and the study did not have to be prolonged up to 24 hours): his cisternogram showed tracer tracking out to the right of the upper cervical/lower thoracic vertebrae as early as 1.5 hours (Figure 3(a)). Supplementary single-photon emission computed tomography (SPECT) of the cervical and thoracic spine at the 2-hour interval showed focal extrathecal tracer accumulation at the right anterolateral aspect of the C7/T1 level, likely representing CSF tracking out from the right C7/T1 neural foramen (Figure 3(b)).
Posterior-approach cervical epidural blood patch under fluoroscopy.
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At the right paramedian cervical region, 25 mL of autologous blood was injected into the epidural space at the C7/T1 level of the spine from the posterior approach, under fluoroscopy guidance (Figure 4).
CT-guided injection. Axial section showing the tip of the 22G spinal needle at the right C7/T1 foramen. The contrast was injected to confirm flow centrally (yellow arrowhead).
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The choice of the anterior transthyroid approach afforded the greatest precision to target the CSF leak site, and a 22G spinal needle was inserted via the transforaminal route followed by injection of a total of 7 mL of autologous blood around the C7/T1 epidural space under CT guidance (Figure 5).