Superficial siderosis: a case report and review of the literature

A Case of Idiopathic Intracranial Hypertension Complicated with both Infratentorial and Supratentorial Cortical Superficial Siderosis: Novel Imaging Findings on Intravoxel Incoherent Motion Magnetic Resonance Imaging Offering Clues to Pathophysiology

The pathology of idiopathic intracranial hypertension (IIH), a disease characterized by papillary edema and increased intracranial pressure (IICP), is not yet understood; this disease significantly affects quality of life due to symptoms including vision loss, headache, and pulsatile tinnitus. By contrast, superficial siderosis (SS), a disorder in which hemosiderin is deposited on the surface of the cerebral cortex and cerebellum, potentially causes cerebellar ataxia or hearing loss. So far, no cases of IIH with infratentorial and supratentorial cortical SS have been reported. Herein, we report a case of a 31-year-old woman with obesity who developed this condition. The patient suddenly developed headache and dizziness, had difficulty walking, and subsequently became aware of diplopia. Fundus examination revealed bilateral optic nerve congestive papillae and right eye abducens disturbance. Head magnetic resonance imaging (MRI) showed prominent SS on the cerebellar surface and cerebral cortex. Lumbar puncture revealed IICP of 32 cmH2O, consistent with the diagnostic criteria for IIH, and treatment with oral acetazolamide was started; subsequently, the intracranial pressure decreased to 20 cmH2O. Her abduction disorder disappeared, and the swelling of the optic papilla improved. She was now able return to her life as a teacher without any sequelae. SS is caused by persistent slight hemorrhage into the subarachnoid space. In this case, both infratentorial and supratentorial cortical superficial SS was observed. Although cases of IIH complicated by SS are rare, it should be kept in mind that a causal relationship between IIH and SS was inferred from our case. Our findings also suggest that cerebrospinal fluid dynamic analysis using MRI is effective in diagnosing IIH and in determining the efficacy of treatment.

[Classical cortical superficial siderosis presenting as extensive higher brain dysfunction with hypoperfusion in the frontoparietal lobe on the 123I-IMP-SPECT: a case report]

A 72-year-old male developed neurological symptoms such as difficulty in charging his electronic money card and making his mobile-phone call ten months before admission. On admission, neurological examination revealed extensive higher brain dysfunction such as impairment in recent memory, executive function disorders, constructional disturbance, agraphia and acalculia. Brain MRI revealed a low intensity lesion on the surface of the cerebral cortex diffusely and symmetrically on T2*-weighted images. MRI images are consistent with superficial siderosis. However, the lack of hemosiderin deposition in the brain stem and cerebellar hemisphere was atypical of the classical type of superficial siderosis. 123I-IMP-SPECT revealed hypoperfusion dominantly in the left hemisphere, particularly in the left frontal and parietal lobes. According to the Boston criteria, the patient with the cerebral microbleeds and cortical superficial siderosis was diagnosed with probable CAA (cerebral amyloid angiopathy).

Closure of a dural defect as a cause of superficial siderosis: does early dural repair lead to a better outcome? Illustrative case

BACKGROUND

Superficial hemosiderosis (SS) of the central nervous system is a rare condition that is caused by chronic, repeated hemorrhage into the subarachnoid space. The subsequent deposition of hemosiderin in the brain and spinal cord causes neurological deterioration. In this report, the authors describe a repair procedure for SS associated with a dural defect in the thoracic spine.

OBSERVATIONS

A 75-year-old man presented with tinnitus symptoms that began about 1 year prior. Subsequently, his hearing loss progressed, and he gradually became unsteady on walking. Magnetic resonance imaging (MRI) of the head showed diffuse hemosiderin deposition on the surface of the cerebellum. Thoracic MRI showed ventral cerebrospinal fluid leakage of T2-7, and computed tomography myelography showed leakage of contrast medium that appeared to be a dural defect. Dural closure was successful, and MRI showed decreased fluid collection ventral to the dura. The patient's symptoms of wobbliness on walking and tinnitus improved dramatically from the postoperative period.

LESSONS

Dural abnormalities of the spine must always be considered as one of the causes of SS. Early dural closure is an effective means of preventing the progression of symptoms.

Superficial intraventricular surface siderosis brain

Superficial siderosis of the central nervous system is a chronic condition characterized by hemosiderin deposition in the brain and spinal cord. It's diagnosed by brain MRI. It can be caused by low-grade extravasation of blood into the subarachnoid space of the brain. There are 2 types of superficial siderosis cortical and infratentorial. Although asymptomatic in many cases; Cerebellar-predominant siderosis, a subtype of infratentorial, can affect hearing, gait, and even muscles. In this report, we present a case of a 51-year old female with complaints of hearing loss, unsteadiness in his lower limb, and spastic paresis. During MRI neuroimaging, we noticed findings of hypointensity areas within the brainstem and cerebellum, probably due to hemosiderin deposition. Based on the MRI findings, the patient was diagnosed with superficial siderosis. The patient was started on deferiprone and followed for the consecutive 18 months. Moderate improvement of the hearing loss and ataxia was noted while no change in muscle force. However, the repetitive MRI did not reveal any changes compared to the previous one.

Targeted detection and repair of a spinal dural defect associated with successful biochemical resolution of subarachnoid bleeding in classical infratentorial superficial siderosis

Background and importance  

Classical infratentorial superficial siderosis (iSS) is characterised by repeated insidious bleeding into the subarachnoid space, leading to haemosiderin deposition within the subpial layers of the brainstem, cerebellum and spinal cord, sometimes with supratentorial involvement. Although nearly always associated with a dural defect (usually from previous trauma or neurosurgery) there is little evidence to support definitive investigation and management strategies. Here, we present a novel investigation strategy to identify a dural defect and subsequent successful surgical repair with biochemical resolution of subarachnoid bleeding.

Clinical presentation

A 55-year-old gentleman presented with a 15-year progressive history of sensorineural deafness, followed by a slowly worsening gait ataxia. He had previously sustained cranio-spinal trauma. On examination there were features of myelopathy and ataxia. MRI demonstrated classical iSS, affecting cerebellum and cerebral cortices, with a cervicothoracic epidural CSF collection. Lumbar puncture (LP) revealed elevated ferritin 413 ng/mL and red cell count of 4160. Reverse CT myelography, a novel technique involving contrast injection into the collection, delineated a dural defect at the T9/T10 level that was not present on conventional myelography. Following surgical repair, repeat LP twelve months later demonstrated biochemical improvement (ferritin 18 ng/mL, red cells < 1). There was no further neurological deterioration in symptoms during eighteen months follow-up.

Conclusion

We show the value of a rational targeted investigation pathway in identifying a surgically reparable dural defect underlying classical iSS. We also provide proof of concept that surgical repair can facilitate biochemical resolution of subarachnoid bleeding and might prevent progression of neurological disability.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-022-06181-x.

Olfactory dysfunction is common in classical infratentorial superficial siderosis of the central nervous system

Background

Established features of classical infratentorial superficial siderosis (iSS) include hearing loss, impaired balance, myelopathy and, less commonly, cognitive compromise. Olfactory function may be affected but dedicated studies are lacking. This study aimed to assess the prevalence of olfactory dysfunction in iSS and correlate it with auditory and cognitive functions.

Methods

Ten participants with iSS completed the University of Pennsylvania Smell Identification Test (UPSIT). The scores were compared with population norms; regression analysis was performed to evaluate associations between the scores and hearing thresholds (3-frequency average, 3FA) or the number of cognitive domains impaired. Imaging was reviewed for haemosiderin distribution and to exclude other causes of olfactory and hearing dysfunction.

Results

Eight of ten participants were male; the mean (standard deviation, SD) age was 52.5 (14.5) years. Olfactory hypofunction was identified in all participants and in six (60%) was moderate or completely absent. The mean UPSIT score of 25.5 (7.8) was significantly worse than population norms (difference in means − 10.0; 95% CI − 15.6 to − 4.4). Linear regression identified an association between UPSIT and hearing thresholds (R = 0.75; p = 0.013). The score decreases by 0.157 units (95% CI − 0.31 to − 0.002; p = 0.048) per unit increase in 3FA, after adjusting for hearing loss risk factors. There was no statistically significant association between UPSIT and cognitive function (R = 0.383; p = 0.397).

Conclusion

We report a high prevalence of olfactory dysfunction in iSS, the severity of which correlated with hearing loss. Olfaction appears to be a core feature of the iSS clinical syndrome that should be assessed routinely.

Case Report: Dural Dissection With Ventral Spinal Fluid-Filled Collection in Superficial Siderosis: Insights Into the Pathology From Anterior-Approached Surgical Cases

Superficial siderosis (SS) of the central nervous system is a rare disease caused by chronic and repeated hemorrhages in the subarachnoid space. Recently, attention has been paid on the association of SS and dural defect with ventral fluid-filled collection in the spinal canal (VFCC). The pathophysiology of hemosiderin deposition in patients with SS and dural defects is still unclear. However, previous studies have suggested the possible mechanism: cerebrospinal fluid (CSF) leaks into the epidural space through the ventral dural defect, and repetitive bleeding occurs from the epidural vessels that circulate back to the subarachnoid space through the dural defect, leading to hemosiderin deposition on the surface of the brain, the central nerves, and the spinal cord. Previously, the surgical closure of dural defect via the posterior approach has been reported to be effective in arresting the continued subarachnoid bleeding and disease progression. Herein, we describe SS cases whose dural defects were repaired via the anterior approach. From the direct anterior approach to the ventral dural defect findings, we confirmed that the outer fibrous dura layer is intact, and the defect is localized in the inner thin layer. From the findings of this study, our proposed theory is that dural tear at the inner dural layer causes “dural dissection,” which is likely to occur between the outer fibrous layer and inner dural border cellular layer. Bleeding from the vessels between the inner and outer Line 39–40 dural layers seems to be the pathology of SS with dural defect.

Classical infratentorial superficial siderosis of the central nervous system: pathophysiology, clinical features and management

The term superficial siderosis (SS) is derived from the Greek word 'sideros', meaning iron. It includes two subtypes, distinguished by their anatomical distribution, causes and clinical features: 'classical' infratentorial SS (iSS, which sometimes also affects supratentorial regions) and cortical SS (cSS, which affects only supratentorial regions). This paper considers iSS, a potentially disabling disorder usually associated with very slow persistent or intermittent subarachnoid bleeding from a dural defect, and characterised by progressive hearing and vestibular impairment, ataxia, myelopathy and cognitive dysfunction. The causal dural defect-most often spinal but sometimes in the posterior fossa-typically follows trauma or neurosurgery occurring decades before diagnosis. Increasing recognition of iSS with paramagnetic-sensitive MRI is leading to an unmet clinical need. Given the diagnostic challenges and complex neurological impairments in iSS, we have developed a multidisciplinary approach involving key teams. We discuss pathophysiology, diagnosis and management of iSS, including a proposed clinical care pathway.

Diagnostic approach, therapeutic strategies, and surgical indications in intradural thoracic disc herniation associated with CSF leak, intracranial hypotension, and CNS superficial siderosis

Background and purpose

Intradural disc herniation (IDH) can manifest with radicular or medullary syndrome. In about 15% of cases, IDH may be responsible, through a dural laceration, for a CSF leak, determining spontaneous intracranial hypotension (SIH) and CNS superficial siderosis (CNSss). This paper attempts to present an overview on IDH as the cause for both CSF leak, and subsequent SIH, and CNSss, and to describe a peculiar clinical and neuroradiological scenario related to this condition.

Methods

A search on the PUBMED database was performed. Although the investigation did not rigorously follow the criteria for a systematic review (we consider only articles about thoracic IDH), nonetheless, the best quality evidence was pursued. Furthermore, an illustrative case was presented.

Results

A 69-year-old woman was referred to our hospital for slowly progressive gait disturbances and hearing impairment. Brain imaging revealed diffuse bilateral supratentorial and infratentorial superficial siderosis, mostly of the cerebellum, the eighth cranial nerves, and the brainstem. Spinal imaging disclosed a posterior disc herniation determining a dural tear at D6-D7. Lumbar puncture revealed low opening pressure and hemorrhagic CSF with siderophages. A posterior transdural herniectomy and dural sealing determined a stabilization of hearing and a significant improvement in both gait and balance.

Conclusions

The diagnostic workup of CNSss with suspected CNS leak demands whole neuraxis imaging, especially in cases presenting SIH or myelopathic symptoms. This may avoid delays in detection of IDH and spinal dural leaks. The different forms of treatment available depend on the type and severity of the clinical picture.

Quantitative clinical and radiological recovery in post-operative patients with superficial siderosis by an iron chelator

BACKGROUND

Superficial siderosis is a rare neurodegenerative disease caused by hemosiderin deposition on the brain surface. Although the efficacy of the iron chelator-deferiprone-in superficial siderosis has recently been documented, a comparative study of patients who underwent surgical ablation of their bleeding source and subsequently received treatment with or without deferiprone has not yet been conducted.

METHODS

Fifteen postoperative patients with superficial siderosis were recruited, and seven patients were administered deferiprone (combination therapy group). Quantitative changes in the hypointense signals on T2*-weighted magnetic resonance images were acquired; additionally, cerebellar ataxia was assessed (International Cooperative Ataxia Rating Scale score and Scale for the Assessment and Rating of Ataxia). Audiometry was performed and the results were compared with those of patients who did not receive deferiprone (surgical treatment group; controls).

RESULTS

Significant improvements in signal contrast ratios were noted in the lateral orbitofrontal gyrus, superior temporal lobe, insular lobe, brainstem, lingual gyrus, and cerebellar lobe in the combination therapy group. The scores of patients in the combination therapy group on the cerebellar ataxia scales significantly improved. The degree of signal improvement in the cerebellar lobe correlated with the improvement of cerebellar ataxia scores. Early deferiprone administration after disease onset and long-term administration were correlated with greater signal improvements on magnetic resonance imaging. No adverse effects were observed in the clinical or laboratory parameters.

CONCLUSIONS

Deferiprone administration significantly improved radiological and clinical outcomes in patients with postoperative superficial siderosis. Earlier and longer courses of deferiprone could result in better patient prognosis.

Superficial Siderosis With Verrucous Vegetation Around a Dural Defect Confirmed by Intraoperative Ultrasonography

Superficial siderosis (SS) of the central nervous system (CNS) is a rare disease caused by repeated hemorrhages in the subarachnoid space. We describe surgical treatment of an SS case in which a dural defect with verrucous vegetation in the spinal canal was detected by intraoperative ultrasonography (US). After laminectomy, intraoperative US imaging confirmed verrucous vegetation and epidural fluid collection around the ventral dural defect before incision of the posterior dura mater. As intraoperative US also showed a dural defect at the ventral and right sides of the spinal cord, the posterior dural incision was made in a manner that was slightly more right lateral than standard midline. The ventral dural defect was repaired by direct sutures. After repair, intraoperative US imaging confirmed dural hole closure, removal of vegetation and resolution of the collected fluid. Dural closure was successful and symptoms partially improved despite the patient’s long history of SS. Intraoperative US can help surgeons make decisions about precise dural incision before repair. Intraoperative US is useful for detecting the level of dural defect and verrucous vegetation before repair and confirming closure of the dural defect, successful removal of vegetation and resolution of fluid collection after repair.

Superficial Siderosis: A Clinical Review

Superficial siderosis of the central nervous system results from subpial hemosiderin deposition due to chronic low-grade bleeding into the subarachnoid space. The confluent and marginal subpial hemosiderin is best appreciated on iron-sensitive magnetic resonance imaging sequences. With widespread use of magnetic resonance imaging, the disorder is increasingly being recognized, including in asymptomatic individuals. Gait ataxia, often with hearing impairment is a common clinical presentation. A clinical history of subarachnoid hemorrhage is generally not present. A macrovascular pathology is generally not causative. The most common etiology is dural disease, often dural tears. Prior or less commonly ongoing symptoms of craniospinal hypovolemia may be present. Common etiologies for dural tears include disc disease and trauma, including surgical trauma. Patients with dural tears due to herniated and calcified discs often have a ventral intraspinal fluid collection due to cerebrospinal fluid leak. A precise identification of the dural tear relies on multimodality imaging. It has been speculated that chronic bleeding from fragile blood vessels around the dural tear may be the likely underlying mechanism. Surgical correction of the bleeding source is a logical therapeutic strategy. Clinical outcomes are variable, although neuroimaging evidence of successful dural tear repair is noted. The currently available data regarding use of deferiprone in patients with superficial siderosis is insufficient to recommend its routine use in patients. ANN NEUROL 2021;89:1068-1079.

Diskogenic Dural Defect Is the Reason for the Ventral Location of the Epidural Spinal Fluid Collection Seen in Superficial Siderosis

Purpose of Review

Superficial siderosis (SS) of the nervous system is often due to a dural pathology. This review focuses on recent developments related to the management of this subgroup of patients with SS.

Recent Findings

The presence of an epidural ventral spinal fluid collection in patients with SS is a clue to the presence of a diskogenic dural defect. The location of the defect is ascertained by a dynamic CT myelogram, which involves placing the patient in a prone position with hips elevated. This permits gravity-assisted preferential ventral localization of the contrast and active scanning during contrast injection facilitates a precise delineation of the initial point of contrast extravasation which localizes the defect.

Summary

Diskogenic dural defects are commonly the underlying etiology for SS in patients with a ventral spinal fluid collection. A dynamic CT myelogram facilitates detection and subsequent repair of these defects, which arrests the continued low-grade subarachnoid bleeding.

Superficial siderosis of the central nervous system with epilepsy originating from traumatic cervical injury: illustrative case

BACKGROUND

Superficial siderosis of the central nervous system (SSCNS) is a rare condition that results from hemosiderin deposition in the brain, brainstem, cerebellum, and spinal cord as a result of chronic, repeated, and recurrent subarachnoid hemorrhage. SSCNS that originates in the spinal cord is rarely reported, and epilepsy as a manifestation of such a case has not been reported before.

OBSERVATIONS

The authors reported a rare case of SSCNS with epilepsy originating from traumatic cervical injury and presented a literature review of all reported SSCNS cases that originated in the spine. The patient was a 29-year-old man with a 16-year history of progressive headache accompanied by seizures, ataxia, and sensorineural hearing loss. He had experienced a traumatic cervical injury at age 7. Magnetic resonance imaging revealed a characteristic hypointense rim around the pons and cervical spinal cord on susceptibility-weighted imaging scans. Cerebrospinal fluid examination during a headache episode confirmed subarachnoid hemorrhage and increased intracranial pressure. Surgical exploration revealed a C6 dural defect with bone spurs inserted into the dura mater. After the patient underwent dura mater repair and shunt implantation, his symptoms disappeared completely except for hearing loss.

LESSONS

This rare case indicated that symptomatic epilepsy followed by SSCNS can be eliminated by complete repair of the cervical dura mater.

Idiopathic superficial siderosis of the central nervous system

Background

Regardless of the cause of the superficial siderosis (SS) disease, which is bleeding, the source of bleeding cannot be found in some cases.

Case presentation

In this article, we report two cases with idiopathic SS. Case 1 presented with bilateral hearing loss, cognitive impairment, sleep disturbances, and tremors. Case 2 presented with sensory neural hearing loss, ataxia, and spastic paraparesis. In both cases, brain MRI indicated evidence of SS. CT myelogram and SPECT with labeled RBC couldn’t help finding the source of occult bleeding.

Conclusion

SS is a rare central nervous system disease caused by the deposition of hemosiderin in the brain and spinal cord, which results in the progression of neurological deficits. The cause of this hemorrhage is often subarachnoid haemorrhage, intracranial surgery, carcinoma, arteriovenous malformation, nerve root avulsion, and dural abnormality. The condition progresses slowly and, by the time diagnosis is confirmed, the damage is often irreversible. In our cases, brain MRI clarified the definitive diagnosis, but we could not find the source of bleeding. SS should be considered in cases with ataxia and hearing loss, even if no source of bleeding is found.

Unusual Presentation in Infratentorial Superficial Siderosis: Acute Intracranial Hypertension

Superficial siderosis (SS) of the nervous system is a rare acquired condition related to hemosiderin deposits in subpial layers of the brain, brainstem, cerebellum, cranial nerves, and spinal cord, leading to brain iron-mediated neurodegeneration. The cardinal neurological features are slowly progressive hearing loss, ataxia, and pyramidal signs. Here we describe an atypical case of infratentorial SS evolving with acute intracranial hypertension in the absence of typical chronic signs.

Treatment Response of Deferiprone in Infratentorial Superficial Siderosis: a Systematic Review

Superficial siderosis describes haemosiderin deposition on the surface of the brain. When present on infratentorial structures, it can cause ataxia, sensorineural hearing loss and pyramidal signs. There is no proven treatment and patients experience slow progression of symptoms. Iron-chelating agents have been suggested as a therapeutic option and deferiprone is suited as it crosses the blood-brain barrier. However, deferiprone is reported to have a 1–2% risk of agranulocytosis. We performed a systematic review on treatment of infratentorial superficial siderosis with deferiprone based on PRISMA guidelines. Studies were included if in English or an English language translation was available, were about human subjects and referred to patients with ataxia. Studies were excluded if they did not possess an English translation, included animal studies or did not have ataxia. Studies were excluded if they discussed cerebral amyloid angiopathy or siderosis of other regions. Eleven papers were included. We identified 69 patients. Seventeen patients (25%) discontinued the drug. The most encountered adverse effect was anaemia (21.7%). Neutropaenia was observed in 8.7% and agranulocytosis in 5.8% of patients. Clinically, response varied, and stability or improvement was seen across neurological domains in 6 studies while 5 showed a mixed response. On imaging, 13 (28.9%) patients improved, 24 (53.3%) stabilised and 8 (17.8%) deteriorated. A prospective international centralised register of patients should be developed to inform the design and conduct of a multicentre, placebo-controlled, randomised clinical trial to evaluate the efficacy of deferiprone. The evidence from this systematic review is that deferiprone is a promising intervention.

[Hemosiderosis of the central nervous system and its association with a pituitary macroadenoma: a case report]

Nous rapportons le cas clinique d´un patient de 58 ans qui présentait des céphalées depuis 3 mois dont les investigations paracliniques ont permis de poser le diagnostic d´hémosidérose du système nerveux centrale et son association rare avec un macro-adénome hypophysaire.

Spontaneous Intracranial Hypotension: Atypical Radiologic Appearances, Imaging Mimickers, and Clinical Look-Alikes

Spontaneous intracranial hypotension is a condition characterized by low CSF volume secondary to leakage through a dural defect with no identifiable cause. Patients classically present with orthostatic headaches, but this symptom is not specific to spontaneous intracranial hypotension, and initial misdiagnosis is common. The most prominent features of spontaneous intracranial hypotension on intracranial MR imaging include "brain sag" and diffuse pachymeningeal enhancement, but these characteristics can be seen in several other conditions. Understanding the clinical and imaging features of spontaneous intracranial hypotension and its mimickers will lead to more prompt and accurate diagnoses. Here we discuss conditions that mimic the radiologic and clinical presentation of spontaneous intracranial hypotension as well as other disorders that CSF leaks can imitate.

Transdural Thoracic Disk Herniation with Longitudinal Slitlike Dural Defect Causing Intracranial Hypotension: Report of 2 Cases

BACKGROUND

Intracranial hypotension (IH) has a widely variable clinical and radiologic presentation. Secondary IH may be caused by degenerative spine disorders and in particular by thoracic disk herniations (TDHs).

METHODS

We present 2 patients with a transdural TDH, a secondary IH, and superficial siderosis in 1.

RESULTS

Case 1 presented with headache, cognitive decline, staggering gait, bilateral subdural effusions, cerebral sagging, an extradural spinal cerebrospinal fluid (CSF) collection suggesting secondary IH, and a calcified TDH at T9-T10. Case 2 presented with intermittent pain at the craniocervical junction provoked exclusively by specific physical activities, superficial siderosis mainly in the posterior fossa, an extradural spinal CSF collection, and a calcified TDH at T7-T8 yet no intracranial signs of IH. In both cases, using strict thoracoscopic technique, we removed a transdural TDH and reconstructed an underlying longitudinal slitlike dural defect with smooth lining. Follow-up magnetic resonance imaging scans confirmed a dramatically improved situation without residual extradural intraspinal CSF collection or signs of IH.

CONCLUSIONS

This paper adds to the evidence that some cases of IH and even superficial siderosis are caused by transdural erosion of a TDH that may be otherwise asymptomatic. The dura may degenerate due to chronic compression, and a longitudinal slitlike dural defect with smooth lining may develop, causing continuous (Case 1) or intermittent (Case 2) intraspinal CSF leakage. To the best of our knowledge, such dural defects closely resembling the ones observed in idiopathic spinal cord herniation have never been demonstrated on intraoperative endoscopic video in IH patients.

Superficial Siderosis Associated with Long-Term Recurrence of Pilocytic Astrocytoma in an Elderly Person

BACKGROUND

Superficial siderosis is an irreversible disease in the central nervous system caused by the deposition of hemosiderin in the subpial tissue due to persistent bleeding in the subarachnoid space. The main symptoms include sensorineural hearing loss, cerebellar ataxia, and pyramidal tract disorder. Superficial siderosis is mainly idiopathic, but bleeding factors such as tumors or history of surgery often play an important role in its pathogenesis.

CASE DESCRIPTION

A 66-year-old man with a history of surgery for a cerebellar tumor 37 years ago complained of hearing loss. Magnetic resonance imaging showed recurrence of the tumor on T2-weighted images and hypointense areas along the cerebellar sulci on T2∗-weighted images. During the operation, microscopic bleeding was observed on the surface of the tumor. The pathologic diagnosis was pilocytic astrocytoma. A biopsy obtained during the first surgery revealed almost the same pathologic findings as those from a biopsy obtained during the second surgery, but the first specimen showed no hemosiderin deposition or active bleeding, which the second specimen did show.

CONCLUSIONS

Recurrent pilocytic astrocytoma with intratumoral hemorrhage was the suspected cause for superficial siderosis. The source of chronic bleeding was identified with intraoperative and pathologic findings. We describe the first report of superficial siderosis associated with a pilocytic astrocytoma that recurred 37 years after an initial tumor was excised.

Risks associated with oral deferiprone in the treatment of infratentorial superficial siderosis

Objective

Deferiprone is an iron chelator that has recently been used to treat patients with infratentorial superficial siderosis (iSS). It is considered to have a generally favourable safety profile but concerns have been raised due to the risk of agranulocytosis. We aimed to evaluate the safety and tolerability of oral deferiprone as a treatment for patients with iSS.

Methods

We present a case series of 10 consecutive patients presenting with classical iSS treated with deferiprone.

Results

Ten patients were followed up for a mean period of 2.3 years (range 0.5–5.5 years). Four patients (40%) were withdrawn from treatment because of treatment-related side effects. The reasons for treatment discontinuation were neutropenic sepsis (n = 3) and fatigue (n = 1). In 2 out of the 3 cases of neutropenic sepsis, patients initially developed neutropenia without sepsis. The mean time to neutropenic sepsis following deferiprone was 1.2 years (range 0.3–2.5) with mean neutrophil count of 0.4 (range 0.3–0.5). Six patients (60%) reported no change in neurological function while on treatment, and four patients (40%) reported that their condition deteriorated.

Conclusions

Deferiprone was poorly tolerated, with 40% of patients withdrawing from treatment, most commonly due to neutropenic sepsis, after an average of 2 years on treatment. This study increases the number of reported cases of agranulocytosis in patients with iSS treated with deferiprone. Clinicians treating iSS patients with deferiprone should be aware that this drug has a potentially life-threatening side effect of neutropenic sepsis, and should ensure that appropriate haematological monitoring is in place.

Haemoglobin scavenging in intracranial bleeding: biology and clinical implications

Haemoglobin is released into the CNS during the breakdown of red blood cells after intracranial bleeding. Extracellular free haemoglobin is directly neurotoxic. Haemoglobin scavenging mechanisms clear haemoglobin and reduce toxicity; these mechanisms include erythrophagocytosis, haptoglobin binding of haemoglobin, haemopexin binding of haem and haem oxygenase breakdown of haem. However, the capacity of these mechanisms is limited in the CNS, and they easily become overwhelmed. Targeting of haemoglobin toxicity and scavenging is, therefore, a rational therapeutic strategy. In this Review, we summarize the neurotoxic mechanisms of extracellular haemoglobin and the peculiarities of haemoglobin scavenging pathways in the brain. Evidence for a role of haemoglobin toxicity in neurological disorders is discussed, with a focus on subarachnoid haemorrhage and intracerebral haemorrhage, and emerging treatment strategies based on the molecular pathways involved are considered. By focusing on a fundamental biological commonality between diverse neurological conditions, we aim to encourage the application of knowledge of haemoglobin toxicity and scavenging across various conditions. We also hope that the principles highlighted will stimulate research to explore the potential of the pathways discussed. Finally, we present a consensus opinion on the research priorities that will help to bring about clinical benefits.

[Superficial siderosis of the central nervous system caused by myxopapillary ependymoma of conus medullaris and cauda equine: a case report and literature review]

Superficial siderosis of the central nervous system (SSCNS) is a rare disorder caused by hemosiderin deposits in the subpial layers of the brain and spinal cord due to prolonged or recurrent low-grade bleeding into the cerebrospinal fluid (CSF). Central nervous system tumor could be one of the sources of bleeding. Some problems exist at present regarding the diagnosis and treatment of SSCNS in China. On account of fewer cases, the insufficient awareness of the condition, and the lack of long-term follow-up data, enough attention has not been paid to etiological diagnosis. The speculative high rate of missed diagnoses of SSCNS indicates a great disparity in the treatment from the world's advanced level. Related data of clinical and basic research need to accumulate as soon as possible to promote the clinical diagnosis and treatment of the disease. The progressive neurological deficits are involved in the typical clinical manifestations of SSCNS with a triad of bilateral symmetrical sensorineural hearing loss, cerebellar ataxia and signs of corticospinal tract dysfunction. Nevertheless, there are few patients with the triad signs at the same time, which lead to a delayed diagnosis or misdiagnosis. Detection of this disease was commonly post-mortem until the advent of MRI with signal and location characteristics, which made diagnosis easier. Siderosis appears as a hypointense rim covering the surface of the cerebellum, the brain stem, the spinal cord, similar to a black pencil line, thin on SE-T2-weighted images, thick and conspicuous on GE-T2-weighted images or on susceptibility-weighted imaging (SWI). The only effective way of treating the disorder is to identify the source of bleeding and remove it. MR examination is useful for seeking a source of bleeding too. Therefore, once superficial siderosis is considered, lesions of the central nervous system must be searched using MRI of the brain and spine. We report here a 37-year-old male diagnosed of SSCNS with the classical clinical symptoms of cerebellar ataxia, sensorineural hearing loss and myelopathy. T2-weighed MRI showed characteristic marginal hypo-intensity around the central nervous system. Etiological explorations revealed a large conus medullaris / cauda equina ependymoma filling the lumbosacral spinal canal, a myxopapillary ependymoma (MPE) confirmed by surgical resection and histopathological examination. The related literature was reviewed to ascertain the mechanism of SSCNS secondary to MPE, and to discuss the pathogenesis, clinical features, diagnosis and treatment of SSCNS. This paper aims to improve the awareness of SSCNS and diagnostic level, and to lay stress on the etiological explorations that is beneficial to the development of exact treatment plan.

Superficial Siderosis of the Central Nervous System: Neurotological Findings Related to Magnetic Resonance Imaging

OBJECTIVE

To compare the neurotological results of five patients suffering from progressive hearing loss and ataxia due to superficial siderosis (SS) with the magnetic resonance imaging (MRI) findings.

STUDY DESIGN

Retrospective case review.

SETTING

Primary and hospital care center.

PARTICIPANTS

Five adult patients with neurotological symptoms of SS underwent MRI with acquisition of our temporal bone protocol including 3D-constructive interference in steady state (3D-CISS) and susceptibility-weighted imaging (SWI). All patients underwent a complete neurotological examination, the results of which were compared with the imaging findings.

MAIN OUTCOME MEASURES

Cochleovestibular deficits were present in all five patients as determined by uni- or bilateral bithermal caloric testing and/or video head impulse tests. Sacculocollic reflex was present with increased P1 and N1 latencies on both sides in all patients. MRI revealed an extensive hypointense SWI signal outlining the surface of the brain and the VIIIth cranial nerve in all five patients. Desynchronization of the brainstem auditory evoked potentials (BAEP) and partial or complete absence of the visual suppression of vestibulo-ocular reflex during the pendular rotatory test was particularly consistent with the lesions of the cochleovestibular nerves as well as the cerebellar atrophy seen on MRI.

CONCLUSION

The MRI results with SWI were related to neurotological findings in patients suffering from sensorineural deafness with ataxia due to SS. Our findings support the integration of the SWI and 3D-CISS sequences into the MRI protocol for all patients referred for evaluation of the extent of SS.

Clinical Significance of T2*gradient-recalled Echo/susceptibility-weighted Imaging Sequences in Evaluating Superficial Siderosis in the Setting of Intracerebral Tumors: Pilocytic Astrocytoma

Superficial siderosis is the slow accumulation of hemosiderin on the pial surfaces of the brain and spinal cord. The most common cause of intracranial superficial siderosis is secondary to subarachnoid hemorrhage. Rarely, superficial siderosis can also be caused by tumors. Superficial siderosis presents clinically as hearing loss and gait instability that progressively worsen. The diagnosis is primarily made by magnetic resonance imaging; however, susceptibility-weighted imaging (SWI) and T2* gradient echo (GRE) sequences demonstrate the highest sensitivity in detecting this condition. To the best of our knowledge, there has been only one previous case of superficial siderosis secondary to a pilocytic astrocytoma of the spine. However, we present a case of intracerebral pilocytic astrocytoma resulting in superficial siderosis, with emphasis on acquisition and use of T2*GRE/SWI sequences.

Bilateral Vestibulopathy in Superficial Siderosis

Background: Superficial siderosis (SS) is a rare condition in which hemosiderin, an iron storage complex, is deposited in neural tissues because of recurrent subarachnoid bleeding. Hemosiderin deposition in the vestibulocochlear nerve (CN VIII), brain, spinal cord and peripheral nerve can cause sensorineural hearing loss (SNHL) and postural imbalance, but much remains unknown about the vestibular manifestations of SS.

Objectives: To report the clinical course, cochleovestibular status, and patterns of vestibulopathy during follow-up of a relatively large case series, and to discuss the possible pathophysiological mechanism of vestibular deterioration.

Methods: Six patients diagnosed with SS by magnetic resonance imaging (MRI) were enrolled. Their medical records and radiological findings were retrospectively reviewed, particularly in terms of progression of the vestibulocochlear manifestations and the radiological characteristics.

Results: All six patients had SNHL. Five of them exhibited progressive hearing loss over years, which was asymmetric in four. On their most recent evaluations, patients showed cerebellar ataxia with combined central and peripheral vestibulopathy on both sides (n = 4), a bilateral peripheral vestibulopathy (n = 1) or isolated central vestibulopathy (n = 1). Notably, the former four patients showed an evolution of isolated central vestibulopathy into combined central and peripheral vestibulopathy. Hypo-intense lesions on T2 weighted MRIs were evident around the cerebellum in all patients, but such lesions were observed around the brainstem in five and the CN VIII in four. The cochlea-vestibular dysfunction generally progressed asymmetrically, but no left-right asymmetry was evident on MRI.

Conclusions: SS typically presents as bilaterally asymmetric, progressive cochleovestibular dysfunction with cerebellar ataxia. The pattern of vestibular dysfunction is usually combined central and peripheral vestibulopathy on both sides. Thus, precise identification of audiovestibular dysfunction and central signs is essential in SS, and patients with SS should undergo regular, comprehensive neurotological evaluation to optimize their treatments and prognosis.

Focused Neuro-Otological Review of Superficial Siderosis of the Central Nervous System

Background

Infratentorial siderosis (iSS) is a progressive degenerative disorder targeting primarily the cerebellum and cranial nerve eighth; therefore, progressive ataxia and its neuro-otological findings are common. Toxicity from hemosiderin involves selectively vulnerable neurons and glia in these posterior fossa structures. Other neurologic findings may be present, though our focus relates to the cochlea-vestibular cerebellar involvement. Radiographic evidence of siderosis may be the result of recurrent, albeit covert bleeding in the subarachnoid space, or the consequence of an overt post-traumatic or aneurysmal subarachnoid hemorrhage (SAH). The radiographic iSS appearance is identical regardless of the SAH cause. A recent study provides compelling evidence to search and correct possible hemorrhage sources in the spinal canal. The removal of residual existing hemosiderin deposits that may potentially cause clinical symptoms remains as a major therapeutic challenge.

Methods

We reviewed large data sources and identified salient papers that describe the pathogenesis, clinical and neurotologic manifestations, and the radiographic features of iSS.

Results

The epidemiology of iSS is unknown. In a recent series, clinically evident iSS was associated with recurrent SAH; by contrast, in a follow-up period ranging from weeks up to 11 years after a monophasic episode of SAH, radiographic siderosis was clinically silent. However, the post-aneurysmal or post-trauma SAH sample size in this single study was small and their observation period relatively short; moreover, the burden of intraneuronal hemosiderin is likely greater with recurrent SAH. There are a few reports of late iSS, several decades after traumatic SAH. A recent report found subjective hearing loss in aneurysmal SAH individuals with radiographic siderosis. Only in recent years, it is safe to perform magnetic resonance imaging (MRI) in post-aneurysmal SAH, because of the introduction of titanium, MRI-compatible aneurysm clips.

Conclusion

iSS can be associated with significant neurotologic and cerebellar morbidity; the recurrent SAH variant is frequently clinically symptomatic, has a shorter latency and greater neurotologic disability. In these cases, a thorough search and management of a covert source of bleeding may stop clinical progression. The frequency and clinical course of radiographic iSS after traumatic and post-aneurysmal SAH is largely unknown. Detection of radiographic iSS after trauma or aneurysm bleeding suggests that the slower clinical course could benefit from an effective intervention if it became available. The use of cochlear implants is a valid alternative with advanced hearing impairment.

Spinal endoscopy combined with selective CT myelography for dural closure of the spinal dural defect with superficial siderosis: technical note

The authors describe a new procedure to detect the tiny dural hole in patients with superficial siderosis (SS) and CSF leakage using a coronary angioscope system for spinal endoscopy and selective CT myelography using a spinal drainage tube. Under fluoroscopy, surgeons inserted the coronary angioscope into the spinal subarachnoid space, similar to the procedure of spinal drainage, and slowly advanced it to the cervical spine. The angioscope clearly showed the small dural hole and injured arachnoid membrane. One week later, the spinal drainage tube was inserted, and the tip of the drainage tube was located just below the level of the dural defect found by the spinal endoscopic examination. This selective CT myelography clarifies the location of the dural defect. During surgery, the small dural hole could be easily located, and it was securely sutured. It is sometimes difficult to detect the actual location of the small dural hole even with thin-slice MRI or dynamic CT myelography in patients with SS. The use of a coronary angioscope for the spinal endoscopy combined with selective CT myelography may provide an effective examination to assess dural closure of the spinal dural defect with SS in cases without obvious dural defects on conventional imaging.

Adult moyamoya disease associated with abundant phosphorylated tau accumulation in the brainstem: Report of a case with autopsy findings

We report the case of a 72-year-old Japanese woman with moyamoya disease (MMD). She experienced her first intracerebral hemorrhage (ICH) at the age of 32 years, and had nine ICHs and/or intraventricular hemorrhages during the following 40 years. Cerebral angiograms and vascular pathologies at autopsy confirmed that the patient suffered from MMD. Macroscopically, there were brown-colored changes in the subarachnoid space, mainly at the base of the brain and around the cerebellar hemispheres. Microscopically, hemosiderin deposits were observed mainly in the old hemorrhagic lesions and on the surface of the brainstem and cerebellum. Many AT8-immunoreactive neurons and neurites were observed in the pons and midbrain, mainly in the locus ceruleus and reticular formation in the midbrain. Several AT8-immunoreactive neurons and neurites were positive for Gallyas silver staining. A few tiny and short AT8-immunoreactive processes were observed in the molecular, Purkinje cell and granular layers of the cerebellum. There were a few phosphorylated tau accumulations in the cerebrum without senile plaques. Lewy pathologies and transactive response DNA-binding protein 43 kDa proteinopathy were not detected. We suspect that oxidative stress after repeated bleedings with long-term courses in the ventricles and subarachnoid space may accelerate phosphorylated tau accumulation in the brainstem. To our knowledge, this is the first report of MMD with tauopathy in the brainstem.

Two-year observational study of deferiprone in superficial siderosis

INTRODUCTION

Superficial siderosis is a rare, neurodegenerative disease caused by toxic accumulation of hemosiderin on the surface of the brain and the spinal cord, most commonly from chronic subarachnoid hemorrhage.

AIMS

The aim of this study was to assess the clinical and radiological outcomes of superficial siderosis patients using deferiprone, a cell permeant iron chelator. Subjects obtained pre- and post-treatment brain MRIs and weekly laboratory tests. Osirix software was used to develop a method of quantifying hemosiderin deposition. Three-dimensional whole brain images of gradient echo images were rendered and compared by dividing the mean T2 hyperintensity to the maximal cerebrospinal fluid signal.

RESULTS

A total of 38 subjects completed the study, of which clinical and radiological data were available for 30. The average age was 64 years (range 37-86), 53% were male, 94% were white. Nineteen subjects (63%) reported either no progression of disease or an improvement in at least one neurological domain, with 40% of patients reporting a stabilization in hearing function and 30% reporting stable or improved coordination and walking. By MRI, there was an overall mean increase in T2 hyperintensity of the whole brain of 1%-13% over the 2-year time period in half of patients, indicating a reduction hemosiderosis. There were no cases of agranulocytosis, and declines of white blood cells counts and neutrophils averaged <10%. Fatigue was the most common side effect.

CONCLUSION

This is the first long-term prospective study of superficial siderosis on the iron chelator, deferiprone. MRI quantification of hemosiderin appears to demonstrate a measurable reduction in half of patients and this correlated with a stabilized or improving disease course. A future placebo-controlled trial is necessary to determine whether deferiprone is an effective therapy for superficial siderosis.

Idiopathic infratentorial superficial siderosis of the central nervous system: case report and review of literature

The superficial siderosis (SS) of the central nervous system (CNS) is a rare condition characterized by a wide range of neurological manifestations directly linked to an acquired iron-mediated neurodegeneration. First described more than 100 years ago, only recently SS has been divided into two distinct entities, according to the distribution of iron deposition in the CNS: cortical superficial siderosis (cSS) and infratentorial superficial siderosis (iSS). Here we describe an adult case of iSS, with detailed clinical and radiological features. Moreover, we extensively review the literature of SS, particularly focusing on the pathogenesis, clinical-radiological classification, diagnostic algorithm and treatment options of this rare condition.

Aneurysmal wall imaging in a case of cortical superficial siderosis and multiple unruptured aneurysms

We report a case of interhemispheric and bifrontal cortical superficial siderosis in association with two intracranial aneurysms. The patient had no clinical history suggestive of aneurysm rupture, no feature of amyloid angiopathy or other apparent etiology for cortical siderosis. We performed high resolution brain MRI with dark blood T1 sequences before and after IV contrast injection. An anterior communicating aneurysm showed partial wall enhancement on the posterior wall whereas a left posterior communicating aneurysm did not. In the light of recent reports of the association of wall enhancement with unstable aneurysms, we considered wall enhancement to be a marker of inflammation and remodeling of the aneurysm wall, resulting in chronic hemorrhagic suffusion in the subarachnoid spaces. To our knowledge, this is the first report offering proof for a possible link between apparently unruptured aneurysms and cortical siderosis.

Case Report: A Comprehensive Neuropsychological Assessment of a Case of Superficial Siderosis

Objective

Superficial siderosis (SS) is a neurodegenerative condition due to the long-term effects of hemosiderin deposition on the surface of the brain, cerebellum, brainstem, and spinal cord. SS symptoms include sensorineural hearing loss, ataxia and upper motor neuron signs. SS was diagnostically evasive until magnetic resonance imaging (MRI) became available. As the detection of SS improved, case studies have become more prevalent. To our knowledge, however, this is the first report of SS detailing a comprehensive neuropsychological assessment.

Method

The current study presents a right-handed female in her early 60s, with a university level of education, who was diagnosed with SS.

Results

Her neuropsychological profile showed impairment across multiple domains, including memory and executive function, with consistent behavioral findings. The results from a comprehensive neuropsychological assessment include dementia and a cerebellar cognitive affective syndrome.

Conclusions

Neuropsychological evaluation of a patient with new cognitive impairment in combination with unexplained hearing loss, gait disorder, or myelopathy should lead to a referral for MRI that includes techniques sensitive for iron deposition, in order to rule out SS.

[A case of superficial siderosis ameliorated after closure of dural deficit detected by MRI-CISS (constructive interference in steady state) imaging]

A 64-year-old male developed headache, dizziness, and difficulty hearing, two years after an operation for chronic subdural hematoma due to head injury. These symptoms gradually worsened over the following 15 years. As he showed bloody cerebrospinal fluid (CSF) and marginal hypointensity on the surface of the brain and spinal cord on T₂/T₂*-weighted MRI, he was diagnosed with superficial siderosis (SS), although the source of the bleeding was unclear and anti-hemorrhagic drugs were ineffective. When he was admitted to our hospital, neurological examination disclosed horizontal gaze-evoked nystagmus, severe bilateral hearing loss, scanning speech, and limb and truncal ataxia. CISS (constructive interference in steady state) MRI detected a dural defect at the Th2-3 level on the anterior side of the spinal canal. On operation, a 2 mm × 6 mm size dural defect with blood clots was found at the Th2-3 level. After closure of the dural defect, bloody CSF became transparent, and his persistent headache, dizziness, and hearing impairment improved. Brain and whole spine MRI, especially CISS imaging, should be considered for detecting the source of bleeding in intractable cases of SS.

Rare association of secondary superficial siderosis caused by a fourth ventricle hemorrhagic ependymoma mimicking a cavernoma: Case report and literature review

Background:

The association of a hemorrhagic tumor with secondary superficial siderosis (SS) is a relatively rare although well described phenomenon.

Case Description:

We present the case report of a 35-year-old male with a history of drowsiness, hypoacusia, drop attacks, and multidirectional nystagmus during the last 2 months, who presented with acute obstructive hydrocephalus caused by a fourth ventricle mass displaying radiological signs of repeated intra and extratumoral hemorrhage with SS. He underwent gross surgical removal of the solid component of the tumor. Microscopic examination revealed an ependymoma with atypical features, including prominent angiomatous formations and internal chronic hemorrhages with hemosiderin deposits, resembling a cavernoma. The scarce tumoral component, which extended around these cavernous vessels, lacked the gross typical features of fibrillary stroma or perivascular pseudorosettes.

Conclusion:

To our knowledge, including the present case, there are 45 published reports of tumors associating secondary SS. Besides ependymoma, no other hemorrhagic lesion, tumoral or vascular, has been previously published associating a fourth ventricle location with secondary SS. The present case represents the fifth with this finding, and we strongly suggest ependymoma as a presumptive diagnosis when this rare association is encountered. In addition, this appears to be the first case reported in the scientific literature of a hemorrhagic fourth ventricle ependymoma mimicking both, radiologically and histologically, a cavernous malformation.