PMC9996024_01
Axial MRI contrast-enhanced T1 images: similar sections at the moment of diagnosis (A-C), and, respectively, 5 months later (D-F). Initially, the MRI revealed diffuse, relatively uniform thickening and enhancement of the pachymeninges and tentorium, without pathological enhancement [(A, B):yellow arrows] and an enlarged pituitary gland with a cranially convex superior border [(C):yellow arrow]. Also, the dural venous sinuses and cortical veins were initially slightly engorged. Five months later the images showed normalization of the pachymeninges (D, E) and a reduction of the craniocaudal diameter of the hypophysis (F).
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F1
Considering the sensitivity to changes in position, a characteristic element of SIH, a contrast-enhanced MRI of the brain was also performed (Figures 1A-C). The MRI revealed diffuse, relatively uniform thickening and enhancement of pachymeninges, without pathological leptomeningeal enhancement (Figures 1A, B), an enlarged pituitary gland with a cranially convex superior border (Figure 1C) and slightly engorged dural venous sinuses and cortical veins, all findings suggestive of intracranial hypotension syndrome. The brain MRI also showed marked improvement, with the disappearance of the thickening of the pachymeninges (Figures 1D, E) and with a slightly reduced size of the pituitary gland (Figure 1F).
(A-C) Sagittal, axial, and coronal computed tomography, and (D-F) MRI images at approximately the same anatomical plane of section. (D-F) Voluminous meningoceles visible on the MRI images. (B) The posterior dysraphism is clearly visible on the CT transversal section. (C) The fracture line is best visualized in the coronal plane (small and large yellow arrows), with a bone fragment protruding into the sacral canal on the left side [(A-F):large yellow arrows]. (D, E) The bone fragment clearly imprints the left sacral meningocele and appears to pierce it (F).
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F2
There was a wide posterior S3-S4 dysraphism, and bilateral S3 bulky meningocele (32/22/22.5 mm on the right side and 27/16/21 mm on the left side) occupied the sacral canal (Figures 2D, E) exerting significant mass effect with pressure atrophy of the S3, S4 bodies and of posterior vertebral elements. The anterior sacral wall seemed fractured at the S4 level, with a small left anterolateral bone fragment that appeared to protrude internally (Figure 2F). Considering the malformed osseous aspects, the suspected sacral fracture and limited MRI resolution in regard to bone, a computed tomography of the spine was also performed, confirming the S4 fracture extending between both anterior holes with a displaced bony fragment (5/2 mm) protruding into the sacral canal (Figures 2A-C).
(A, B, D, E) 3D reconstruction of the sacrum from the CT scan images. (C, F) A spinal canal mold from the CSF signal on the MRI images. The left S2 radicular cyst is visible above the meningoceles. (A) Posterior view showing the dysraphism at the level of the bone. [(A):small arrowheads] The fracture line is partially visible. [(B):small arrowheads] Posterior oblique view of the pelvic surface of the sacrum showing the transverse fracture at S4 and [(B):black arrow] the bone fragment that protrudes into the spinal canal. (C) The spinal canal ends with two large meningoceles at the S3 level. (D) Interior view of the sacral canal from the midline, the black arrow points to the protruding bone fragment. [(E):small arrowheads] Interior view of the posterior wall of the sacral canal, showing the line of fracture and [(E):black arrow] the protruding fragment. (F) Oblique posterior view showing the imprint of the fractured bone fragment on the left meningocele.
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F4
Probably incidentally, two periradicular arachnoid cysts were present on the left S2 and S4 roots (Figure 4).
PMC9996024_02
(A) Coronal MRI contrast-enhanced T1 image revealing slight diffuse thickening of the cerebellar tentorium and pericerebral pachymeninges, especially bilateral paramedian parietal [(A):yellow arrows]. (B) Sagittal MRI contrast-enhanced T1 showing an enlarged pituitary gland with superior border cranially convex [(B):yellow arrow]. (C) Sagittal spine MRI showing a posterior cervicothoracic epidural collection with fluid signal, extended craniocaudal from the C4 to T10, with a maximum thickness of about 5 mm in the thoracic region. The thoracic spinal cord is anteriorly displaced but not compressed. (D) Transversal MRI section of the thoracic spine (T6) showing the posterior epidural collection that displaces the spinal content anteriorly [(D):yellow arrow].
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F3
Next, we ordered a contrast-enhanced MRI of the brain, which revealed mild diffuse cortical vein engorgement visible on SWI, minimal diffuse thickening of the cerebellar tentorium and pericerebral pachymeninges (especially bilateral paramedian parietal) (Figure 3A), and an enlarged pituitary gland with superior border cranially convex (Figure 3B), all of which suggested intracranial hypotension.