CASE 14767 Published on 15.06.2017

Superficial siderosis

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Pardo, Camilo MD; Donato, Angel MD; Huapaya, Janice MD; Figueroa, Ramon E. MD FACR

(1)Fundacion Universitaria Sanitas, Bogota, Colombia.
(2)Augusta University. Augusta, GA. USA
Email:donatoangel@yahoo.com
Patient

14 years, male

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR
Clinical History
14-year-old male patient with history of Chiari I decompression and syringohydromyelia with new onset bilateral sensorineural hearing loss.
Imaging Findings
MRI shows superior vermian volume loss with extensive susceptibility signal loss outlining the cerebellar folia surface in keeping with superficial siderosis, most pronounced on susceptibility-weighted imaging. There is also a severe pattern of superficial siderosis throughout the supratentorial compartment.
Discussion
Superficial siderosis (SS) is the result of deposits of haemosiderin along the flexible layers of the meninges, spinal cord and cranial nerves, especially the VIII. [1]

SS has asymmetric male:female ratio of approximately 3:1, most frequently seen between ages of 50 to 60 years. SS results from chronic haemorrhage byproduct deposits in the pia-arachnoid. Its aetiology could be idiopathic or seen in patients with traumatic brain or spinal cord injury, previous CNS tumour, history of neurosurgical interventions, amyloid angiopathy and subarachnoid haemorrhage from aneurysms or arteriovenous malformations [1, 2].

The characteristic symptoms are: sensorineural hearing loss, which is usually bilateral, ataxia, cerebellar dysarthria and pyramidal symptoms. If the disease is advanced, it could be associated with dementia, bladder incontinence, sensory deficits and symptoms derived from damage to the cranial nerves. Fluid from lumbar puncture is usually haemorrhagic or xanthochromic [3, 4]

Haemosiderin-induced vestibulocochlear nerve damage leads to sensorineural hearing loss due to its long cisternal course, making it more susceptible to toxic damage by iron compounds.

MRI is the image of choice for the diagnosis of SS. CT is not sensitive or specific for the diagnosis of this pathology [5]. The pia mater and ependymal surfaces are coated by haemosiderin, particularly along the brainstem and cerebellum, which may be associated with cerebellar atrophy.
Siderosis results in low T1 signal, low T2 signal, low GRE signal and accentuated blooming signal loss on SWI series. If clinically suspected but no lesion is identified intracranially, then imaging of the entire spinal canal is indicated [5].

Unfortunately, there is no treatment to reverse the damage caused by haemosiderin deposition at the central nervous system level. Several treatments with iron chelates such as desferroxamine show no conclusive results. [6]
Differential Diagnosis List
Superficial siderosis
Normal leptomeningeal melanin
Meningoangiomatosis
Neurocutaneous melanosis
MR sequence artefacts
Final Diagnosis
Superficial siderosis
Case information
URL: https://eurorad.org/case/14767
DOI: 10.1594/EURORAD/CASE.14767
ISSN: 1563-4086
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