SUPERFICIAL SIDEROSIS OF THE CENTRAL NERVOUS SYSTEM SECONDARY TO DEGENERATIVE DISC DISEASE

TÜRK MANYETİK REZONANS DERNEĞİ 27. YILLIK BİLİMSEL TOPLANTISI, Ankara, Türkiye, 11 - 13 Mayıs 2023, ss.175-176

Yayın Türü: Bildiri / Özet Bildiri
Basıldığı Şehir: Ankara
Basıldığı Ülke: Türkiye
Sayfa Sayıları: ss.175-176
İstanbul Üniversitesi Adresli: Evet

Özet

Selahattin Durmaz, Sinan Seyrek, Mehmet Barburoglu Department of Radiology, Istanbul University, Istanbul School of Medicine, İstanbul

Introduction and Purposes: Superficial siderosis (SS) of the central nervous system (CNS) is a slowly progressive neurodegenerative disorder that occurs secondary to subpial hemosiderin deposition in the brain and spinal cord due to chronic recurrent low-volume bleeding into the subarachnoid space (1). Hearing impairment (%95) and pyramidal symptoms (%76) are the typical clinical presentations of this entity (2). Dural pathologies are known as the most common etiological factors. While less common neoplasms and vascular malformations can also be encountered (3). The purpose of this case presentation is to review imaging findings of SS of the CNS and increase the awareness and level of knowledge about this entity.

Case presentation: A 57-year-old male was admitted to our hospital with bilateral deafness and upper extremity weakness that has been existing for 18 months and worsened in the last 6 months. Physical examination revealed bilateral hearing loss and gait ataxia. The motor system examination was unremarkable. On the basis of clinical and physical examination findings contrast contrast-enhanced cranial and spinal MRI examination was performed. The T2-WI revealed linear hypointensity along the bilateral cerebral cortical sulci and cerebellar folia, around the pons, midbrain, bilateral intracranial segments of vestibulocochlear and facial cranial nerves, and along the surface of the spinal cord suggestive of hemosiderin deposition (Figure 1,2,3). Accompanying cerebellar atrophy findings were also observed (Figure 2). Furthermore: spinal MRI and CT depicted cerebrospinal fluid (CSF) collection in the anterior epidural distance between C7-T9 levels (Figure 4A, 4B), narrowed intervertebral disc space at C6-C7 and osteophyte formation at the posterior edges of the vertebral body (Figure 4C). Based on imaging findings and clinical presentation, the diagnosis of SS of the CNS secondary to a dural tear caused by osteophyte formations was considered in the first place. The patient underwent surgery. Neurosurgeons detected and repaired the dural tear at C6-C7 levels during the surgery.

Discussion and Conclusions: As mentioned previously, the most commonly encountered etiology of SS of the CNS is dural pathologies. Among the dural pathologies, dural tears secondary to disc pathologies (protrusion, osteophyte), trauma, and intradural surgery comprise the majority of the cases (4). MRI, particularly iron-sensitive sequences(ISS), are highly sensitive in detecting subpial hemosiderin deposition. Hence, SS of the CNS has increasingly been detected even in asymptomatic patients (2). Besides that CT myelography, MR angiography, and cerebrospinal angiography can also be used during the diagnostic workup. Despite comprehensive screening, the origin of chronic subarachnoid bleeding may not be detected in %50 of patients (3). Hemosiderin tends to accumulate in the cerebellum, olfactory nerve, vestibulocochlear nerve, brain stem, Sylvian cortex, and spinal cord and cause reactive gliosis and neuron damage with demyelination (1). Atrophy and gliosis findings tend to be more prominent in the posterior fossa structures. As in our case, a linear, confluent hypointensity along the cerebral and cerebellar cortex, around the medulla oblongata and spinal cord on T2-weighted images and ISS should bring to mind the diagnosis of SS of the CNS. The presence of ventral intraspinal CSF collection, calcified disc, and/or osteophyte formation is often associated with the dural tear (4).

Keywords: Superficial siderosis, magnetic resonance imaging, CSF leak, intervertebral disc degeneration

References

1. Rodriguez FR, Srinivasan A. Superficial siderosis of the CNS. AJR Am J Roentgenol. 2011 Jul;197(1):W149-52. doi: 10.2214/AJR.09.7215.

2. Khalatbari K. Case 141: superficial siderosis. Radiology. 2009 Jan;250(1):292- 7. doi: 10.1148/radiol.2501051201.

3. Kumar N. Neuroimaging in superficial siderosis: an in-depth look. AJNR Am J Neuroradiol. 2010 Jan;31(1):5-14. doi: 10.3174/ajnr.A1628. Epub 2009 Sep 3.

4. Kumar N. Superficial Siderosis: A Clinical Review. Ann Neurol. 2021 Jun;89(6):1068-1079. doi: 10.1002/ana.26083. Epub 2021 Apr 28