case_images: PMC10991849_01
case_images: Initial imaging. (A) Initial [day 4 (D4)] MRI (axial diffusion b2000 sequence): bilateral thalamic ischemia. (B) Initial (D4) MRI (3D arterial time-of-flight image): no arterial amputation favoring ischemic stroke. (C) Initial (D4) MRI (sagittal view of a T2-weighted sequence): evidence of posterior sagging of the brain and brainstem, with closure of the angle between the protuberance and the diencephalon, verticalization of the cerebellar tent, herniation of the cerebellar amygdala, favoring the SIH diagnosis. The angle between the vein of Galen and the right sinus was measured at 52  (angle marked in red). (D) D17 MRI (axial T1-weighted sequence): significant and diffuse pachymeningeal enhancement after contrast agent injection and markedly distended dural venous sinuses, favoring the SIH diagnosis. (E) D0 CT-scan (no contrast agent). Evidence of a 13-mm-thick heterogenous subdural collection in the right convexity with significant midline deviation. (F) D0 CT-scan: No uncal herniation, favoring no intracranial hypertension (SDH, subacute subdural hematoma; SIH, spontaneous intracranial hypotension; D0: day of neurosurgical evacuation of the SDH).
case_images: fneur-15-1308462-g001.jpg
case_images: PMC10991849_01_fneur-15-1308462-g001.jpg
case_images: fig1
case_images: Immediate brain MRI highlighted bilateral thalamic diffusion and FLAIR hypersignals, with apparent diffusion coefficient hyposignals, associated with thin, chronic, right convexity SDH (Figure 1A). Arterial 3D time-of-flight sequences did not show arterial amputations consistent with ischemic stroke (Figure 1B), and no cerebral venous (sinus) thrombosis was evidenced. An urgent brain CT scan revealed an acute bleed inside the chronic right-convexity SDH (13 mm total thickness) causing a subfalcine herniation without associated uncal herniation (Figures 1E,F). A review of the MRI (Figures 1C,D) and the ICP measurements confirmed the diagnosis of severe SIH. Because of the persistence of the patient's lack of communication and low ICP (continuously <=5 mmHg), two dynamic myelography examinations were performed on D25 and D48 to search for a dural tear that could have been surgically repaired (Supplementary Figures 1A,B). Figures 1C,D). Finally, in view of the bilateral thalamic ischemia and the sharp angle between the vein of Galen and the straight sinus on a D35 phlebography-CT scan (measured at 12 , Supplementary Figures 1E,F), digital subtraction angiography-phlebography was performed on D55 to search for an obstacle to the venous drainage.
case_images: Timeline of diagnostic and therapeutic procedures.
case_images: fneur-15-1308462-g002.jpg
case_images: PMC10991849_01_fneur-15-1308462-g002.jpg
case_images: fig2
case_images: Figure 2 shows a timeline of diagnostic and therapeutic procedures.
case_images: LITP and ICP curves during the three saline epidural patches (identical scales). Each procedure included an initial measurement of LITP at L3-L4. The epidural patch treatment involved three 20-ml syringe injections into the epidural space at L2-L3 (marked by arrows and annotated S1, S2, S3). (A) First epidural patch (D13). Three epidural injections of 20-mL volume led to a moderate increase in LITP (max 25 mmHg), with no increase in ICP (curve not recorded). (B) Second epidural patch (D20). Three epidural injections of 20-mL volume led to a transient but significant increase in LITP (max 75 mmHg), with an increase in ICP only during the third injection (max 45 mmHg). (C) Third epidural patch (D36). Three epidural injections of 20-mL volume resulted in a major and strictly parallel increase in LITP and ICP during all three injections (max 85 mmHg). Thus, the three epidural patches led to a progressive increase in LITP and ICP as well as transmission from LITP to ICP. This phenomenon probably indicates that the intraspinal and intracranial compliances became lower, even if the pressures themselves remained low (apart from their transient increase during the injections). Hence, volume deficit of the intraspinal compartment was probably filled by the first epidural injections and the dural tear was treated (LITP, lumbar intrathecal pressure; ICP, intracranial pressure).
case_images: fneur-15-1308462-g003.jpg
case_images: PMC10991849_01_fneur-15-1308462-g003.jpg
case_images: fig3
case_images: The EPs consisted of three 20-ml syringe injections into the epidural space at L2-L3 while measuring LITP and ICP (Figure 3).