Superficial siderosis

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.

Superficial siderosis and intracranial hypotension syndrome following brachial plexus avulsion injury. A case of surgical treatment

Superficial siderosis (SS) is a slowly progressive neurodegenerative disorder caused by persistent or intermittent bleeding into the subarachnoid space. It leads to characteristic clinical and radiographic findings. Dural pathology is believed to be the most common identifiable etiology of SS. It has been suggested that dural tear may be the common pathology of both SS and intracranial hypotension syndrome. We present a patient with SS caused by posttraumatic duropathy that was associated with cerebrospinal fluid (CSF) hypotension headache. Patient was treated surgically with stabilization of neurological deficit and orthostatic headache improvement. It supports the speculated link between both entities and may confirm surgery being a reasonable approach in patients with SS.

Frequency, Extent, and Correlates of Superficial Siderosis and Ependymal Siderosis in Premature Infants with Germinal Matrix Hemorrhage: An SWI Study

BACKGROUND AND PURPOSE

Germinal matrix intraventricular hemorrhage is a common complication of prematurity. An underrecognized complication of germinal matrix intraventricular hemorrhage is superficial siderosis, and the clinical consequences of superficial siderosis are not well-known. We aimed to investigate the prevalence, anatomic distribution, and severity of superficial siderosis and ependymal siderosis in premature infants with germinal matrix intraventricular hemorrhage using SWI.

MATERIALS AND METHODS

In this retrospective study, we included 88 patients across all grades of germinal matrix intraventricular hemorrhage who underwent MR imaging at term-equivalent age. Images were evaluated for the presence, distribution, and severity of superficial siderosis and ependymal siderosis. Univariate and multivariate logistic regression analyses were performed to determine factors associated with superficial siderosis and ependymal siderosis. The agreement among T1, T2, and SWI sequences was examined.

RESULTS

Seventy-two patients had brain stem superficial siderosis, and 79 patients had ependymal siderosis. The presence, extent, and severity of superficial siderosis and ependymal siderosis were closely related to the grade of germinal matrix intraventricular hemorrhage and intraventricular hematoma volume. Brain stem superficial siderosis had a stronger correlation with intraventricular hemorrhage than with cerebellar hemorrhage. Compared with SWI, T1 and T2 sequences detected only small proportions of patients with superficial siderosis (12.5% and 6.9%, respectively).

CONCLUSIONS

The incidence of superficial siderosis and ependymal siderosis is very high in preterm infants with germinal matrix intraventricular hemorrhage when assessed by SWI at term-equivalent age. The presence and extent of superficial siderosis and ependymal siderosis are closely related to germinal matrix intraventricular hemorrhage grade and intraventricular hematoma volume. Additional prospective studies using SWI are needed to clearly determine the clinical consequences of germinal matrix intraventricular hemorrhage with superficial siderosis and ependymal siderosis.

Vestibular Dysfunction in Patients With Superficial Siderosis of the Central Nervous System

OBJECTIVE

To describe the vestibular function in patients with superficial siderosis of the central nervous system (SSCN).

STUDY DESIGN

Retrospective analysis.

SETTING

Tertiary referral center.

PATIENTS

Ten consecutive patients with SSCN. This study is the largest case series of SSCN in which detailed neuro-otological findings, including electronystagmography recording, video head impulse test (vHIT), and posturography, were described.

INTERVENTIONS

Audiological and neuro-otological examinations, including pure-tone audiometry, distortion product otoacoustic emissions, speech audiometry, auditory brainstem responses, electronystagmography recording, vHIT, and posturography.

MAIN OUTCOME MEASURES

Pure-tone average, DP level, maximum speech discrimination score, interpeak latency between auditory brainstem responses waves I and V, eye tracking test, examination of optokinetic nystagmus, caloric response, visual suppression, vestibulo-ocular reflex gains, total center of pressure path length, and Romberg's ratio.

RESULTS

Audiological examinations suggested that the sensorineural hearing loss was of a cochlear etiology in 3 ears, a retrocochlear etiology in 11 ears, and a combined cochlear and retrocochlear etiology in 6 ears. Neuro-otological examinations revealed that eight out of nine patients had cerebellar disorders, while all patients also had peripheral vestibular dysfunction.

CONCLUSION

In addition to cerebellar disorders, SSCN patients suffer from severe peripheral vestibular dysfunction, which can exacerbate the patient's imbalance. When otolaryngologists encounter patients with distinctly progressive sensorineural hearing loss and imbalance, they should include SSCN in the differential diagnosis and perform neuro-otological examinations, including an electronystagmography recording and vHIT and brain magnetic resonance imaging.

ACR Appropriateness Criteria® Ataxia

Ataxia can result from an abnormality in the cerebellum, spinal cord, peripheral nerves, and/or vestibular system. Pathology involving the brain, such as infarct or hydrocephalus, can also present with ataxia as part of the symptom constitution, or result in symptoms that mimic ataxia. Clinical evaluation by history and careful neurological examination is important to help with lesion localization, and helps determine where imaging should be focused. In the setting of trauma with the area of suspicion in the brain, a head CT without intravenous contrast is the preferred initial imaging choice. If vascular injury is suspected, CTA of the neck can be helpful. When the area of suspicion is in the spine, CT or MRI of the spine can be considered to assess for bony or soft-tissue injury, respectively. In the setting of ataxia unrelated to recent trauma, MRI is the preferred imaging modality, tailored to assess the brain or spine depending on the area of suspected pathology. The use of intravenous contrast is generally helpful. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Updating superficial siderosis of the central nervous system: bleeding of a dorsal osteophyte into the subarachnoid space from a perforating artery

Superficial siderosis of the central nervous system (SSCNS) is an uncommon and often unrecognized disorder that results from recurrent and persistent bleeding into the subarachnoid space. Currently, there is no effective treatment for SSCNS. The identification and surgical resolution of the cause of bleeding remains the most reliable method of treatment, but the cause of bleeding is often not apparent. The identified sources of recurrent bleeding have typically included neoplasms, vascular malformations, brachial plexus or nerve root injury or avulsion, and previous head and spinal surgery. An association between recurrent bleeding in the CNS and dural abnormalities in the spine has recently been suggested. Dural tears have been identified in relation to a protruding disc or osteophyte. Also in these patients, the exact mechanism of bleeding remains unknown because of a lack of objective surgical data, even in patients who undergo neurosurgical procedures.The present case concerns a 48-year-old man who presented with longstanding symptoms of mild hearing loss and mild gait ataxia. A diagnosis of SSCNS was made in light of the patient's history and the findings on physical examination, imaging, and laboratory testing. MRI and CT detected a small calcific osteophyte in the anterior epidural space of T8-9. The patient underwent surgical removal of the bone spur and dural tear repair. During the surgery, the authors detected a perforating artery, which was on the osteophyte, that was bleeding into the subarachnoid space. This case shows a possible mechanism of chronic bleeding from an osteophyte into the subarachnoid space. In the literature currently available, a perforating artery on an osteophyte bleeding into the subarachnoid space has never been described in SSCNS.

Bilateral Vestibular Weakness

Bilateral vestibular weakness (BVW) is a rare cause of imbalance. Patients with BVW complain of oscillopsia. In approximately half of the patients with BVW, the cause remains undetermined; in the remainder, the most common etiology by far is gentamicin ototoxicity, followed by much rarer entities such as autoimmune inner ear disease, meningitis, bilateral Ménière’s disease, bilateral vestibular neuritis, and bilateral vestibular schwannomas. While a number of bedside tests may raise the suspicion of BVW, the diagnosis should be confirmed by rotatory chair testing. Treatment of BVW is largely supportive. Medications with the unintended effect of vestibular suppression should be avoided.

Clival meningocele causing bilateral hearing loss in a child due to superficial siderosis of the central nervous system: case report

Superficial siderosis (SS) of the CNS is a rare and often unrecognized condition. Caused by hemosiderin deposition from chronic, repetitive hemorrhage in the subarachnoid space, it results in parenchymal damage in the subpial layers of the brain and spinal cord. T2-weighted MRI shows the characteristic hypointensity of hemosiderin deposition, classically occurring around the cerebellum, brainstem, and spinal cord. Patients present with progressive gait ataxia and sensorineural hearing impairment. Although there have been several studies, case reports, and review articles over the years, the clear pathophysiology of subarachnoid space hemorrhage remains to be elucidated. The proposed causes include prior intradural surgery, prior trauma, tumors, vascular abnormalities, nerve root avulsion, and dural abnormalities. Surgical repair of a dural defect associated with SS has been shown to be efficacious at preventing symptomatic progression. There have been several reports of dural defects within the spinal canal treated with surgery. Here, the authors present the first known case of a dural defect of the ventral skull base, namely a clival meningocele, presumed to be causing SS. In this case report, a 10-year-old girl with a history of head trauma at the age of 3 years was found to have a clival meningocele 3 years after her original trauma. On follow-up imaging, the patient was found to have radiographic growth of the meningocele along with evidence of SS of the CNS. The patient was treated conservatively until she began to have progressive hearing loss. It was presumed that the growing meningocele was the source of her SS. An endoscopic endonasal transclival approach with a multilayer dural reconstruction was performed to fix the dural defect and repair the meningocele in hopes of mitigating the progression of her symptoms. At her 12-month postoperative follow-up, she was doing well, with audiometry showing a slightly decreased hearing threshold in the left ear but improved speech discrimination bilaterally. Postoperative MRI showed a stable level of hemosiderin deposition and meningocele repair. Long-term follow-up will be necessary to evaluate for continued clinical stabilization or possible improvement.

Superficial Siderosis of the Central Nervous System due to Spinal Ependymoma

A 75-year-old woman presented with a 3-year history of progressive hearing loss, gait ataxia, and cognitive impairment. Brain magnetic resonance imaging (MRI) with a time gradient echo sequence showed deposition of hemosiderin along the surface of the cerebral cortex, brainstem, and cerebellum, as well as severe atrophy in the diffuse cerebral cortex and cerebellum. We established the diagnosis of superficial siderosis of the central nervous system on the grounds of former pathognomonic MRI findings. The thoraco-lumbar spine MRI demonstrated a myxopapillary ependymoma in the T11-L2 spinal canal that was considered to be the cause of a chronic subarachnoid hemorrhage, affecting the leptomeninges and subpial layers of the central nervous system.

Cerebral amyloid angiopathy: Review of clinico-radiological features and mimics

Cerebral amyloid angiopathy (CAA) is an important cause of lobar intracerebral haemorrhage (ICH) in the elderly, but has other clinico-radiological manifestations. In the last two decades, certain magnetic resonance imaging (MRI) sequences, namely gradient-recalled echo imaging and the newer and more sensitive susceptibility-weighted imaging, have been utilised to detect susceptibility-sensitive lesions such as cerebral microbleeds and cortical superficial siderosis. These can be utilised sensitively and specifically by the Modified Boston Criteria to make a diagnosis of CAA without the need for 'gold-standard' histopathology from biopsy. However, recently, other promising MRI biomarkers of CAA have been described which may further increase precision of radiological diagnosis, namely chronic white matter ischaemia, cerebral microinfarcts and lobar lacunes, cortical atrophy, and increased dilated perivascular spaces in the centrum semiovale. However, the radiological manifestations of CAA, as well as their clinical correlates, may have other aetiologies and mimics. It is important for the radiologist to be aware of these clinico-radiological features and mimics to accurately diagnose CAA. This is increasingly important in a patient demographic that has a high prevalence for use of antiplatelet and antithrombotic medications for other comorbidities which inherently carries an increased risk of ICH in patients with CAA.

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.

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.

Prevalence and Natural History of Superficial Siderosis: A Population-Based Study

BACKGROUND AND PURPOSE

Superficial siderosis (SS) is characterized by hemosiderin deposition in the superficial layers of the central nervous system and can be seen during postmortem examination or with iron-sensitive magnetic resonance imaging techniques. The distribution of SS may predict the probable underlying cause. This study aimed to report the prevalence and natural history of SS in a population-based study.

METHODS

Brain magnetic resonance imaging scans from the MCSA (Mayo Clinic Study of Aging), a population-based study of residents 50 to 89 years of age in Olmsted County, Minnesota, were reviewed. Participants with imaging consistent with SS were identified from 2011 through 2016. An inverse probability weighting approach was used to convert our observed frequencies to population prevalence of SS. Additional data abstracted included amyloid positron emission tomography, Apolipoprotein E genotype, coexisting cerebral microbleeds, and extent of SS.

RESULTS

A total of 1412 participants had eligible magnetic resonance imaging scans. Two participants had infratentorial SS, restricted to the posterior fossa. Thirteen participants had cortical SS involving the cerebral convexities (7 focal and 6 disseminated). Only 3 of the participants with cortical SS (23%) also had cerebral microbleeds. The population prevalence of SS was 0.21% (95% confidence interval, 0-0.45) in those 50 to 69 years old and 1.43% (confidence interval, 0.53-2.34) in those over 69 years old. Apolipoprotein E ε2 allele was more common in those with SS (57.1% versus 15.0%; P<0.001). Compared with participants without SS, those with SS were also more likely to have a positive amyloid positron emission tomographic scan (76.9% versus 29.8%; P<0.001).

CONCLUSIONS

SS may be encountered in the general elderly population. The association with increased amyloid burden and Apolipoprotein E ε2 genotype supports cerebral amyloid angiopathy as the most common mechanism. Longitudinal follow-up is needed to evaluate the risk of subsequent hemorrhage in cases of incidentally discovered SS.

Superficial siderosis of the central nervous system is a rare and possibly underdiagnosed disorder

Methods

Series of cases collected from Brazilian centers.

Results

We studied 13 cases of patients presenting with progressive histories of neurological dysfunction caused by SS-CNS. The most frequent clinical findings in these patients were progressive gait ataxia, hearing loss, hyperreflexia and cognitive dysfunction. The diagnoses of SS-CNS were made seven months to 30 years after the disease onset.

Conclusion

SS-CNS is a rare disease that may remain undiagnosed for long periods. Awareness of this condition is essential for the clinician.

[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.

Superficial Siderosis of the Central Nervous System Originating from the Thoracic Spine: A Case Report

Superficial siderosis of the central nervous system(SSCNS) is a rare disease characterized by hemosiderin deposition on the surface of the central nervous system. We report a case of SSCNS originating from the thoracic spine, presenting with neurological deficits including, sensorineuronal hearing loss, ataxia, and corticospinal and dorsal column tract signs. The patient underwent dural repair with an artificial dural patch. Clinical findings were elicited by neurological examination, imaging studies, and intraoperative findings, and these were addressed through literature review.

Superficial siderosis complicated by hydrocephalus: bleeding from the dura mater in the cerebrospinal fluid cavity after brain tumor surgery

BACKGROUND

In most patients with superficial siderosis of the central nervous system, the exact source of bleeding remains unknown and a treatment has not yet been established.

METHODS

We herein presented a case of superficial siderosis complicated by hydrocephalus 19 years after supratentorial brain tumor resection.

RESULTS

The bleeding source was identified as the dura mater in the intracranial cerebrospinal fluid cavity, and not a recurrent tumor.

CONCLUSION

Chronic intracranial bleeding from the dura mater was successfully arrested by replacement of the dura mater with the autologous fascia of the thigh, and hydrocephalus was treated with endoscopic surgery.

[Familial amyloid polyneuropathy involving a homozygous Val30Met mutation in the amyloidogenic transthyretin gene presenting with superficial siderosis: a case report]

A 76-year-old woman was admitted to our hospital because of transthyretin-related familial amyloid polyneuropathy (TTR-FAP). She had developed bilateral vitreous opacity at the age of 58 and paroxysmal atrial fibrillation at the age of 62. She suffered gait disturbance and dysesthesia of the limbs at the age of 68 and was diagnosed with FAP involving a homozygous Val30Met mutation in the amyloidogenic transthyretin (ATTR) gene after a genetic test. Her parents were cousins, and her aunt's medical history included pacemaker implantation and polyneuropathy. At the age of 74, the patient developed gait disturbance and dysesthesia of her extremities. A neurological examination revealed visual loss, hearing impairment, distal muscle weakness, dysesthesia, and decreased sensation in all modalities in her extremities. She could neither walk nor remain standing without support. Brain magnetic resonance imaging (MRI) revealed a low intensity lesion on the surface of the cerebellum on T2*-weighted images and susceptibility-weighted images. A low intensity pattern that was indicative of the classical type of superficial siderosis was detected. At the age of 76, when she was admitted to our hospital because of the deterioration of her gait disturbance and dysesthesia, brain MRI showed that the patient's cerebellar atrophy and hemosiderin deposition had worsened. Some reports suggest that FAP patients that are homozygous for the ATTR Val30Met mutation are more likely to develop central nervous involvement than those that are heterozygous for the mutation. Superficial siderosis may be responsible for the central nervous involvement.

Intracranial dural arteriovenous fistula as a cause for symptomatic superficial siderosis: A report of two cases and review of the literature

Background:

Superficial siderosis (SS) is the occult deposition of hemosiderin within the cerebral cortex due to repeat microhemorrhages within the central nervous system. The collection of hemosiderin within the pia and superficial cortical surface can lead to injury to the nervous tissue. The most common presentation is occult sensorineural hearing loss although many patients have been misdiagnosed with diseases such as multiple sclerosis and amyotrophic lateral sclerosis before being diagnosed with SS. Only one case report exists in the literature describing an intracranial dural arteriovenous fistula (dAVF) as the putative cause for SS.

Case Description:

We describe two cases of SS caused by a dAVF. Both patients had a supratentorial, cortical lesion supplied by the middle meningeal artery with venous drainage into the superior sagittal sinus. In both patients, symptoms improved after endovascular embolization. The similar anatomic relationship of both dAVFs reported presents an interesting question about the pathogenesis of SS. Similar to the pathologic changes seen in the formation of intracranial arterial aneurysms; it would be possible that changes in the blood vessel lining and wall might predispose a patient to chronic, microhemorrhage resulting in SS.

Conclusions:

We describe the second and third cases of a dAVF as the cause of SS, and the first cases of successful treatment of SS-associated dAVF with endovascular embolization. As noninvasive imaging techniques become more sensitive and easily obtained, one must consider their limitations in detecting occult intracranial vascular malformations such as dAVF as a possible etiology for SS.

Superficial siderosis of the central nervous system associated with incomplete dural closure following posterior fossa surgery: report of 3 cases

This report reviews a series of 3 patients who developed superficial siderosis following posterior fossa operations in which dural closure was incomplete. In all 3 patients, revision surgery and complete duraplasty was performed to halt the progression of superficial siderosis. Following surgery, 2 patients experienced resolution of their CSF xanthochromia while 1 patient had reduced CSF xanthochromia. In this paper the authors also review the etiology, pathophysiology, diagnosis, and treatment of this condition. The authors suggest that posterior fossa dural patency and pseudomeningocele are risk factors for the latent development of superficial siderosis and recommend that revision duraplasty be performed in patients with posterior fossa pseudomeningoceles and superficial siderosis to prevent progression of the disease.

Postoperative MR Imaging of Spontaneous Transdural Spinal Cord Herniation: Expected Findings and Complications

BACKGROUND AND PURPOSE

Spontaneous transdural spinal cord herniation is no longer a rare cause of myelopathy. The high frequency of diagnoses has led to an increase in the number of surgical procedures. The purpose of this study was to describe the spectrum of postoperative MR imaging findings concerning spontaneous transdural spinal cord herniation and to provide a practical imaging approach for differentiating expected changes and complications after an operation.

MATERIALS AND METHODS

We retrospectively reviewed MR images from 12 patients surgically treated for spontaneous transdural spinal cord herniation. Surgery comprised either dural defect enlargement or duraplasty procedures. Postoperative follow-ups included at least 3 (early, intermediate, late) MR imaging studies. MR images were analyzed with respect to 3 spinal compartments: intradural intramedullary, intradural extramedullary, and extradural. The meaning and reliability of changes detected on MR images were related to their radiologic and clinical evolution with time.

RESULTS

Spinal cord realignment has been stable since the early study, whereas spinal cord signal and thickness evolved during the following scans. Most extramedullary and extradural changes gradually reduced in later MR images. Three patients treated with dural defect enlargements experienced the onset of new neurologic symptoms. In those patients, late MR images showed extradural fluid collection and the development of pial siderosis.

CONCLUSIONS

Our findings demonstrate the spectrum of postoperative imaging findings in spontaneous transdural spinal cord herniation. Spinal cord thickness and signal intensity continued to evolve with time; most extramedullary postsurgical changes became stable. Changes observed in later images may be suggestive of complications.

Cortical superficial siderosis: detection and clinical significance in cerebral amyloid angiopathy and related conditions

Cortical superficial siderosis describes a distinct pattern of blood-breakdown product deposition limited to cortical sulci over the convexities of the cerebral hemispheres, sparing the brainstem, cerebellum and spinal cord. Although cortical superficial siderosis has many possible causes, it is emerging as a key feature of cerebral amyloid angiopathy, a common and important age-related cerebral small vessel disorder leading to intracerebral haemorrhage and dementia. In cerebral amyloid angiopathy cohorts, cortical superficial siderosis is associated with characteristic clinical symptoms, including transient focal neurological episodes; preliminary data also suggest an association with a high risk of future intracerebral haemorrhage, with potential implications for antithrombotic treatment decisions. Thus, cortical superficial siderosis is of relevance to neurologists working in neurovascular, memory and epilepsy clinics, and neurovascular emergency services, emphasizing the need for appropriate blood-sensitive magnetic resonance sequences to be routinely acquired in these clinical settings. In this review we focus on recent developments in neuroimaging and detection, aetiology, prevalence, pathophysiology and clinical significance of cortical superficial siderosis, with a particular emphasis on cerebral amyloid angiopathy. We also highlight important areas for future investigation and propose standards for evaluating cortical superficial siderosis in research studies.

Superficial siderosis of the central nervous system induced by a single-episode of traumatic subarachnoid hemorrhage: a study using MRI-enhanced gradient echo T2 star-weighted angiography

The purpose of this study was to examine whether a single episode of traumatic subarachnoid hemorrhage (tSAH) could cause superficial siderosis of the central nervous system (SS-CNS).This study was approved by the local ethics committee. Thirty-two patients with a history of a single episode of tSAH were enrolled in the study. An episode of tSAH was confirmed in patients based on a CT scan or a lumbar puncture, and a follow-up examination was conducted at least six weeks after the brain trauma. A follow-up MRI examination was performed, using enhanced gradient echo T2 star-weighted angiography (ESWAN) to detect hemosiderin deposition on the cortical surface. The extent to which hemosiderin deposition was associated with several clinical factors was investigated. Various degrees of hemosiderin deposition were detected in 31 of 32 (96.9%) single-episode tSAH patients. Analysis of contingency tables revealed an association between the regions of subarachnoid bleeding based on CT images and the regions of hemosiderin deposition based on ESWAN images (χ² = 17.73, P<0.05). SS-CNS was determined to be a common consequence after a single episode of tSAH. The extent of hemosiderin deposition is closely correlated with the initial bleeding sites and bleeding volume.

Superficial siderosis of the central nervous system: A case report

Superficial siderosis of the central nervous system (SSCNS) is a rare syndrome resulting from hemosiderin deposits in neuronal tissues close to the cerebrospinal fluid. SSCNS is characterized by sensorineural deafness, cerebellar ataxia and signs of pyramidal tract dysfunction. The present study describes a patient with SSCNS that did not suffer from hearing loss, which is the most common symptom of SSCNS. The patient was a 48-year-old male, presenting with dizziness, ataxia and slurred speech. The patient’s ataxia was characterized by dizziness, nystagmus, dysarthria, abnormal finger-nose pointing and heel-knee-shin tests and a positive Chaddock sign. The patient had suffered from a pontine hemorrhage two years prior to the study. Audiometric tests showed normal hearing during the hospital stay and at the two-month follow-up examination. The diagnosis of SSCNS was made based on magnetic resonance images, which showed areas of linear hypointensity on the surface of the pons with mild cerebellar atrophy. However, a long-term follow-up is required to monitor the hearing of the patient. Improved understanding of SSCNS is important for clinicians to identify SSCNS patients who present without typical clinical symptoms.

Superficial siderosis: bleeding from the bone marrow after laminectomy for spinal tumor removal

Superficial siderosis of the CNS is a rare disease characterized by the deposition of hemosiderin in the subpial layers of the CNS as the result of chronic subarachnoid bleeding. The arrest of bleeding is important for preventing the progression of this disease; however, the exact source of bleeding remains unknown in most cases because of a lack of objective surgical data. The authors of this report have described a unique case of superficial siderosis following cervical laminectomy and autograft fusion for the removal of a spinal schwannoma; the bleeding source was verified by intraoperative and histopathological findings. The patient exhibited no obvious neurological deficits, such as hearing loss or cerebellar ataxia, when the superficial siderosis was diagnosed, although there were the social impairments associated with schizophrenia. During repair surgery, the bleeding source was revealed as the bone marrow vasculature of the remaining vertebral arch, and not the fragile vessels at the dural defect or the residual tumor. Chronic bleeding was stopped before the onset of irreversible neurological deficits in this case. Bone marrow exposed to the intrathecal space may represent a chronic bleeding source in patients with superficial siderosis following CNS surgery including laminectomy or craniotomy. The following recommendations have been proposed for superficial siderosis of the CNS from both a preventative and a therapeutic perspective: 1) During CNS surgery, neurosurgeons should make every effort to prevent exposing bone marrow to the intrathecal space to avoid the risk of chronic subarachnoid bleeding. 2) In the case of a large dural defect and pseudomeningocele following CNS surgery, bone marrow around the dural defect should be considered as the bleeding source of superficial siderosis, and such cases should undergo revision surgery before the progression of this disease.

Superficial siderosis of the central nervous system secondary to spinal ependymoma

Superficial siderosis of the central nervous system is a syndrome caused by deposition of hemosiderin in the subpial layers of the central nervous system, occurring as a result of recurrent asymptomatic or symptomatic bleeding into the subarachnoid space. We report a rare case of superficial siderosis in a 33-year-old man who presented with sensorineural hearing loss. The diagnosis of superficial siderosis on MRI brain studies led to further investigations with detection of a spinal ependymoma at L1-L2, compressing the cauda equina. Gross total resection of the tumor arrested the progression of the neurological deterioration. Our report underlies the importance of early diagnosis and surgical management, with imaging examination of the full neuroaxis to identify the source of bleeding, to halt disease progression and improve prognosis.

[Clinical features of superficial siderosis]

Superficial siderosis (SS) of the central nervous system is a rare condition in which hemosiderin is deposited in the subpial layer of the brain and/or spinal cord. It is supposed that hemosiderin deposition is a result of recurrent or persistent hemorrhage in the subarachnoid space. The causes of hemorrhage are tumor, vascular abnormality, injury, dural defect, and others. The source of hemorrhage is not apparent despite of extensive examinations in about a half of the patients with SS. Patients with SS usually reveal slowly progressive and irreversible cerebellar ataxia and/or sensorineural hearing loss. MRI of T(2)WI or T(2)(*)WI demonstrates characteristic linear low intensity along surface of the brain and the spinal cord. There are two types of SS. One is a classical type, in which low intensity of MRI is diffuse and symmetrical. The other is a localized type. We attempted to make a clinical criteria of SS according to the world literature. Then, the criteria was applied to cases (53 cases of classical type and 7 cases of localized type) which are collected from Japanese nationwide questionnaires. The causes and symptoms of Japanese SS are similar with those of Western countries.

Superficial siderosis of the central nervous system caused by hemorrhagic intraventricular craniopharyngioma: case report and literature review

Superficial siderosis is a rare condition caused by hemosiderin deposits in the central nervous system (CNS) due to prolonged or recurrent low-grade bleeding into the cerebrospinal fluid (CSF). CNS tumor could be one of the sources of bleeding, both pre- and postoperatively. We report an extremely rare case of superficial siderosis associated with purely third ventricle craniopharyngioma, and review previously reported cases of superficial siderosis associated with CNS tumor. A 69-year-old man presented with headache, unsteady gait, blurred vision, and progressive hearing loss. Brain magnetic resonance (MR) imaging with gadolinium revealed a well enhanced, intraventricular mass in the anterior part of the third ventricle. T₂*-weighted gradient echo (GE) MR imaging revealed a hypointense rim around the brain particularly marked within the depth of the sulci. Superficial siderosis was diagnosed based on these findings. The tumor was diffusely hypointense on T₂*-weighted GE imaging, indicating intratumoral hemorrhage. The lateral ventricles were dilated, suggesting hydrocephalus. [¹⁸F]fluorodeoxyglucose positron emission tomography revealed increased uptake in the tumor. The whole brain surface appeared dark ocher at surgery. Histological examination showed the hemorrhagic tumor was papillary craniopharyngioma. His hearing loss progressed after removal of the tumor. T₂*-weighted GE MR imaging demonstrated not only superficial siderosis but also diffuse intratumoral hemorrhage in the tumor. Superficial siderosis and its related symptoms, including hearing loss, should be considered in patients with hemorrhagic tumor related to the CSF space. Purely third ventricle craniopharyngioma rarely has hemorrhagic character, which could cause superficial siderosis and progressive hearing loss.

Incidence of cerebral microbleeds in preclinical Alzheimer disease

OBJECTIVE

We sought to determine the incidence and associations of lobar microbleeds (LMBs) in a longitudinal cohort with (11)C-Pittsburgh compound B (PiB) PET imaging.

METHODS

One hundred seventy-four participants from the observational Australian Imaging, Biomarkers and Lifestyle Study of Ageing (97 with normal cognition [NC], 37 with mild cognitive impairment [MCI], and 40 with Alzheimer disease [AD] dementia) were assessed at 3 time points over 3 years with 3-tesla susceptibility-weighted MRI and (11)C-PiB PET. MRIs were inspected for microbleeds, siderosis, infarction, and white matter hyperintensity severity, blind to clinical and PiB findings. Neocortical PiB standardized uptake value ratio, normalized to cerebellar cortex, was dichotomized as positive or negative (PiB+/-, standardized uptake value ratio >1.5). Annualized LMB incidence was calculated, and logistic regression was used to determine the association of incident LMBs with PiB, APOE ε4+ status, and cerebrovascular disease.

RESULTS

LMBs were present in 18.6% of NC, 24.3% of MCI, and 40% of AD participants (p < 0.05 vs NC). LMB incidence was 0.2 ± 0.6 per year in NC participants, 0.2 ± 0.5 in MCI, and 0.7 ± 1.4 in AD (p < 0.03 vs NC) and was 6-fold higher in PiB+ than PiB-NC. Incident LMBs were associated with age, APOE ε4+, PiB+, and baseline LMBs. Incidence of multiple LMBs was also associated with lacunar infarction and white matter hyperintensity severity.

CONCLUSIONS

Older age, baseline LMBs, higher β-amyloid burden, and concomitant cerebrovascular disease may all confer higher risk of incident LMBs. This should be considered when designing protocols for amyloid-modifying clinical trials.