case_images: PMC11026624_01
case_images: (A) Pure tone audiometry (PTA) test results showing low-frequency sensorineural hearing loss in both ears. (B) Results of a PTA test performed 2 weeks after the initiation of steroid therapy. (C) Distortion product otoacoustic emissions were not detected at low frequencies. (D) The patient's electrocochleography test results. (E) Timeline of the case.
case_images: fneur-15-1394534-g001.jpg
case_images: PMC11026624_01_fneur-15-1394534-g001.jpg
case_images: fig1
case_images: Pure tone audiometry testing indicated a moderate decline in low-frequency thresholds, with a maximum hearing loss of 45 dB (250 Hz) and 35 dB (250 Hz) in the left and right ear, respectively (Figure 1A). Distortion product otoacoustic emissions were absent at low frequencies (Figure 1C). Hz) and 30 dB (250 Hz) in the right and left ear, respectively (Figure 1B). However, due to unresolved tinnitus and fluctuating ear fullness, the patient received additional intratympanic steroid injections. Electrocochleography tests (Figure 1D) and brain and spine MRI scans were performed to look for endolymphatic hydrops. The timeline of the episodes and interventions for this case is presented in Figure 1E.
case_images: (A) Axial post-contrast medium T1-weighted magnetic resonance (MR) image showing diffuse smooth thickening of the cerebral convexity dura (white arrows) and bilateral subdural liquid collection (yellow arrows). (B) Coronal T1-weighted MR image with contrast demonstrating diffuse dural enhancement (white arrows) with bilateral subdural liquid collection (yellow arrows). (C) Sagittal post-contrast medium T1-weighted MR image showing dural enhancement of the pituitary (yellow arrow). The presence of diffuse smooth dural thickening (white arrows), which extends into the spine, indicates spontaneous intracranial hypotension, demonstrating prominent sagittal sinus (arrowheads) and transverse sinus (black arrowhead). (D-G) Intrathecal Gd-magnetic resonance myelography images revealing cerebrospinal fluid leakage at multiple levels (C4-5, C5-6, C6-7, and C7-T1 on right side, C4-5 on left side, and T1-2 on both sides) in the coronal (D) and axial views (E). (F,G) Cerebrospinal fluid leakage is also observed at the T10-11 and T11-12 levels on both sides. (H) Axial T2-weighted magnetic resonance (MR) image showing a normal internal auditory canal in both ears. The HYDROPS MR image was generated by subtracting the positive perilymph signal from the positive perilymph image. The dotted circles indicate the cochlea (I) and vestibular apparatus (J). The endolymphatic hydrops is detectable as a black area inside the perilymphatic space filled with the gadodiamide.
case_images: fneur-15-1394534-g002.jpg
case_images: PMC11026624_01_fneur-15-1394534-g002.jpg
case_images: fig2
case_images: MRI scan of the brain revealed subdural fluid collection along the bilateral convexity and thickened dural enhancement around the pituitary gland, which were evidence of a small subdural hemorrhage and intracranial hypotension (Figures 2A-C). MR myelography of the entire spine showed significant leakage at multiple levels of the retrospinal region (right C4-5, C5-6, and C6-7 and bilateral T1-2, T10-11, and T11-12) (Figures 2D-G). The patient was treated with intravenous fluids and absolute bed rest, followed by an epidural blood patch (EPB) administered by a C-arm fluoroscopically-guided injection of 10 mL of autologous blood into the C7-T1 epidural space. To enhance the contrast for visualizing the inner ear, and since the gadolinium-based contrast agent was given as a single intravenous dose (0.2 mL/kg body weight, 4 h before MRI), a HYDROPS MR image was obtained by subtracting the T2-weighted 3D inversion recovery image (positive endolymphatic image) from the 3D fluid-attenuated inversion recovery image (positive perilymphatic image), thus improving the interface between the three spaces in a single image (Figures 2H-J). The summating potential/action potential ratios were 0.095 in the right ear and 0.185 in the left ear, and the HYDROPS MR image showed significant endolymphatic hydrops in the cochlea (Figure 2I) and vestibules (Figure 2J) of both ears.