A Combination of Magnetic Resonance Imaging Techniques to Localize the Dural Defect in a Case of Superficial Siderosis—A Case Report

• Main Authors: Hiroyuki Katoh, Shuhei Shibukawa, Keiko Yamaguchi, Akihiko Hiyama, Tomohiko Horie, Masato Sato, Masahiko Watanabe
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Medicines
• Subjects: superficial siderosis; spinal extradural arachnoid cyst; duropathy; magnetic resonance imaging
• Online Access: https://www.mdpi.com/2305-6320/7/6/36

<b>Background:</b> Superficial siderosis is a progressively disabling disease caused by recurrent subarachnoid hemorrhage with accumulation of hemosiderin in the surface of the central nervous system. Although a wide variety of conditions may cause superficial siderosis, approximately half of the cases are reported to be associated with a defect in the ventral spinal dura mater, in which case treatment entails surgical repair of the defect. Here, we report a case of superficial siderosis and report on our method to pinpoint the dural defect using a combination of magnetic resonance imaging (MRI) techniques. <b>Methods and Results:</b> A 74-year-old female presented suffering from hearing loss and progressive ataxia over a duration of seven years. A T2-weighted MRI study revealed hypointensity in the superficial areas of the central nervous system, leading to the diagnosis of superficial siderosis, and the presence of a fluid-filled collection in the anterior spinal canal of C7 to T10 suggested that a dural defect was the cause of the repeated hemorrhage. A balanced turbo field echo (BTFE) MRI sequence revealed possible dural defects at T1–T2 and T5–T6, and a dynamic improved motion-sensitized driven-equilibrium steady-state free precession (dynamic iMSDE SSFP) sequence revealed an irregular flow of cerebrospinal fluid through the dura at the T5–T6 level. The dural defect was confirmed and sutured through a minimal T5–T6 laminectomy without neurological consequences, and the patient reported mild improvement in gait one year after surgery. <b>Conclusions:</b> A combination of MRI sequences provided the necessary information to confidently perform minimal surgery to repair the dural defect. We recommend coupling a balanced steady-state free precession (SSFP) sequence to provide high resolution, high contrast images of anatomical structures and a dynamic iMSDE SSFP sequence to confirm cerebrospinal fluid motion through the defect.