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

Spontaneous Non-Aneurysmal Convexity Subarachnoid Hemorrhage: A Scoping Review of Different Etiologies beyond Cerebral Amyloid Angiopathy

Spontaneous convexity subarachnoid hemorrhage (cSAH) is a vascular disease different from aneurysmal SAH in neuroimaging pattern, causes, and prognosis. Several causes might be considered in individual patients, with a limited value of the patient's age for discriminating among these causes. Cerebral amyloid angiopathy (CAA) is the most prevalent cause in people > 60 years, but reversible cerebral vasoconstriction syndrome (RCVS) has to be considered in young people. CAA gained attention in the last years, but the most known manifestation of cSAH in this context is constituted by transient focal neurological episodes (TFNEs). CAA might have an inflammatory side (CAA-related inflammation), whose diagnosis is relevant due to the efficacy of immunosuppression in resolving essudation. Other causes are hemodynamic stenosis or occlusion in extracranial and intracranial arteries, infective endocarditis (with or without intracranial infectious aneurysms), primary central nervous system angiitis, cerebral venous thrombosis, and rarer diseases. The diagnostic work-up is fundamental for an etiological diagnosis and includes neuroimaging techniques, nuclear medicine techniques, and lumbar puncture. The correct diagnosis is the first step for choosing the most effective and appropriate treatment.

The Relationship Between Aortic Arch Calcification and Recurrent Stroke in Patients With Embolic Stroke of Undetermined Source-A Case-Control Study

Background

Aortic arch calcification (AoAC) is associated with plaque development and cardiovascular events. We aimed to estimate the predictive value of AoAC for stroke recurrence in patients with embolic stroke of undetermined source (ESUS).

Methods

Consecutive patients with ESUS who were admitted to our center between October 2019 and October 2020 and who had a 1-year follow-up of stroke recurrence were retrospectively reviewed. According to our AoAC grading scale (AGS), AoAC was classified into four grades based on chest computed tomography (CT) findings: no visible calcification (grade 0), spotty calcification (grade 1), lamellar calcification (grade 2), and circular calcification (grade 3).

Results

Of the 158 patients with ESUS (age, 62.1 ± 14.5 years; 120 men) enrolled, 24 (15.2%) had recurrent stroke within a 1-year follow-up. The Cox regression analysis showed that stroke history [hazard ratio (HR), 4.625; 95% confidence interval (CI), 1.828–11.700, p = 0.001] and AoAC (HR, 2.672; 95% CI, 1.129–6.319; p = 0.025) predicted recurrent stroke. AGS grade 1 was associated with a significantly higher risk of stroke recurrence than AGS grade 0 (HR, 5.033; 95% CI, 1.858–13.635, p = 0.001) and AGS grade 2 plus 3 (HR, 3.388; 95% CI, 1.124–10.206, p = 0.030). In patients with AoAC, receiver operating characteristic (ROC) analysis showed that AGS had a good value in predicting stroke recurrence in patients with ESUS, with an area under curve (AUC) of 0.735 (95% CI = 0.601–0.869, p = 0.005).

Conclusions

Aortic arch calcification, especially spotty calcification, had a good predictive value for stroke recurrence in patients with ESUS.

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.

Acute convexity subarachnoid hemorrhage (cSAH) in infectious endocarditis (IE): imaging features and follow-up

AIM

To assess: (1) the prevalence of convexity subarachnoid hemorrhage (cSAH) in infective endocarditis (IE); (2) its relationship with IE features; (3) the associated lesions; (4) whether cSAH is a predictor of future hemorrhage; (5) whether cSAH could cause cortical superficial siderosis (cSS).

METHODS

We retrospectively evaluated the MRI data in 240 IE-patients: At baseline, the location of cSAH and associated lesions; at follow-up, the occurrence of new lesions and of cSS. Patients with and without cSAH were compared.

RESULTS

There were 21 cSAH-IE patients without (Group 1a) and 10 with intracranial infectious aneurysms (IIAs) (Group 1b). cSAH was revealed by headache (16.1%), confusion (9.7%), acute meningeal syndrome (3.2%) and was incidental in 71%. In most cases, the cSAH was: in the frontal (61.3%) and the parietal lobe (16.1%), unifocal, and mainly localized within a single sulcus (80.7%), appearing as a thick intrasulcal dark line on T2* in 70% of IIA patients. Valvular vegetations (87.1%, p < 0.0001), vegetations length ≥ 15 mm (58.1%, p < 0.0001) and mitral valve involvement (61.3%; p = 0.05) were significantly associated. There was no significant difference between the two groups in terms of pathogen distribution, valve characteristics and clinical expression. Associated lesions were: CMBs (77.4%), DWILs (51.6%), brain hemorrhages (16.1%) brain micro-abscesses (3.2%) meningitis (3.2%), visceral emboli (45.2%). At follow-up: no SAH recurrence or neurological event. cSS disappeared in 7/12 cases.

CONCLUSION

cSAH in IE is mostly an incidental finding but may be the telltale sign of an IIA. cSAH is not a marker of poor prognosis in non-IIA patients.

A case of aneurysmal subarchnoid haemorrhage and superficial siderosis complicated by prospagnosia, simultagnosia and alexia without agraphia

A 42-year-old lady presented with acute aneurysmal subarachnoid haemorrhage and developed difficulty recognising faces (prosopagnosia), inability to process visual information in busy environments (simultagnosia) and difficulty to read (alexia). She was subsequently found to have superficial siderosis on MRI.

The aetiologies of the unilateral oculomotor nerve palsy: a review of the literature

Oculomotor nerve palsy (ONP) is an important and common clinical diagnosis. Its main features are diplopia and ptosis. Its aetiologies are various and complex. A number of different conditions have been reported to cause ONP, such as diabetes mellitus, aneurysm, tumours, painful ophthalmoplegia, pituitary lesions, cavernous sinus lesions, central nervous system infections, and subarachnoid haemorrhage. A patients needs to undergo several tests in order to establish the correct underlying pathology. In this review, we have summarized the aetiologies of the unilateral ONP, and discussed their relative clinical features, pathogenesis, diagnostic criteria, treatment options, and prognosis. We searched PubMed for papers related to ONP and its aetiologies, and selected the publications, which seemed appropriate.

Superficial siderosis misdiagnosed as idiopathic bilateral neurosensorial deafness

Superficial siderosis (SS) is a rare condition resulting from different sources of bleeding into the subpial space. The most common symptoms are: hypoacusia, ataxia, incontinence, dementia and parkinsonism. Since several neurodegenerative disorders may present with same clinical features, SS is often misdiagnosed. Here we present a case of SS misdiagnosed as idiopathic bilateral neurosensorial deafness.

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.

Superficial siderosis of central nervous system with unknown cause: report of 2 cases and review of the literature

Objective: To report 2 cases of superficial siderosis of central nervous system (SS-CNS) and a review of the literature. Methods: We have analyzed the clinical data and relevant features of two patients with SS-CNS who were presented with ataxia and slurred speech. Both patients undertook blood tests, lumbar puncture, head CT (computer tomography) scans, and brain and spinal cord magnetic resonance (MR) scans. In addition, the first patient also undewent enhanced susceptibility-weighted angiography (ESWAN) and the second patient undertook susceptibility weighted imaging (SWI) scan. We searched PubMed with the keywords superficial siderosis and superficial siderosis of central nervous system, and selected publications that seemed appropriate. Results: A neurological examination revealed bilateral sensorineural hearing impairment in both the patients. Their past history was not significant to identify hemorrhage. Brain MR scans demonstrated typical hypointensity rimming at the brain surface on T2 weighted images. The patients were diagnosed with SS-CNS. Conclusion: SS-CNS should be highly suspected in patients with progressive sensorineural hearing loss, ataxia, and signs of pyramidal tracts, and MR scans of brain and whole spinal cord should be undertaken to confirm the diagnosis. Advanced MRI techniques such as SWI and ESWAN are helpful in making the diagnosis of SS-CNS. The cause of hemorrhage is not identified in most cases.

Cortical superficial siderosis and first-ever cerebral hemorrhage in cerebral amyloid angiopathy

OBJECTIVE

To investigate whether cortical superficial siderosis (cSS) is associated with increased risk of future first-ever symptomatic lobar intracerebral hemorrhage (ICH) in patients with cerebral amyloid angiopathy (CAA) presenting with neurologic symptoms and without ICH.

METHODS

Consecutive patients meeting modified Boston criteria for probable CAA in the absence of ICH from a single-center cohort were analyzed. cSS and other small vessel disease MRI markers were assessed according to recent consensus recommendations. Patients were followed prospectively for future incident symptomatic lobar ICH. Prespecified Cox proportional hazard models were used to investigate cSS and first-ever lobar ICH risk adjusting for potential confounders.

RESULTS

The cohort included 236 patients with probable CAA without lobar ICH at baseline. cSS prevalence was 34%. During a median follow-up of 3.26 years (interquartile range 1.42-5.50 years), 27 of 236 patients (11.4%) experienced a first-ever symptomatic lobar ICH. cSS was a predictor of time until first ICH (p = 0.0007, log-rank test). The risk of symptomatic ICH at 5 years of follow-up was 19% (95% confidence interval [CI] 11%-32%) for patients with cSS at baseline vs 6% (95% CI 3%-12%) for patients without cSS. In multivariable Cox regression models, cSS presence was the only independent predictor of increased symptomatic ICH risk during follow-up (HR 4.04; 95% CI 1.73-9.44, p = 0.001), after adjusting for age, lobar cerebral microbleeds burden, and white matter hyperintensities.

CONCLUSIONS

cSS is consistently associated with an increased risk of future lobar ICH in CAA with potentially important clinical implications for patient care decisions such as antithrombotic use.

An autopsy case of cortical superficial siderosis with persistent abnormal behavior

In recent years, MRI has revealed cortical superficial siderosis (cSS), which exhibits hemosiderin deposition in only the cortical surface. However, the associations between the histological findings and clinical symptoms of cSS remain unclear. We herein report an autopsy case of a 75-year-old Japanese man with cSS with persistent abnormal behavior according to cognitive impairment, hallucination and delusion. At 73 years of age, the patient presented with unusual behavior that indicated auditory hallucination and delusion. One year later, he was admitted to the hospital for malignant lymphoma. On admission, cognitive impairment was detected by a screening test. Soon after hospitalization, he presented with active delirium including visual hallucination and delusion. The patient's excited behavior was improved by the administration of a major tranquilizer. However, the abnormal behavior and cognitive impairment persisted. At 75 years of age, he died of heart failure. A neuropathological investigation revealed hemosiderin depositions in the superficial layer of the cortex in the medial and lateral frontal lobe, the lateral temporal lobe, the parietal lobe, and the medial and lateral occipital lobe. Neuritic plaques and diffuse plaques were extensively observed, which corresponded to Braak stage C and CERAD B, although NFTs were observed that corresponded to Braak stage II. Cortical amyloid angiopathy was not observed in any regions. Ischemic change of brain was also mild. Our report suggests that localized deposition of hemosiderin in the cortex might affect the manifestation of cognitive impairments and hallucination. Further clinicopathological studies are needed to clarify the clinical manifestations of patients with cSS.

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.

Frequency and appearance of hemosiderin depositions after aneurysmal subarachnoid hemorrhage treated by endovascular therapy

INTRODUCTION

It is still unclear how often subarachnoid hemorrhage (SAH) leads to chronic hemosiderin depositions. In this study, we aimed to determine the frequency of chronic hemosiderin depositions after aneurysmal SAH in patients who did not undergo surgery. Furthermore, we analyzed typical MRI patterns of chronic SAH and sought to obtain information on the temporal course of MRI signal changes.

METHODS

We retrospectively analyzed 90 patients who had undergone endovascular treatment for acute aneurysmal SAH. In all patients, initial CT studies and at least one T2*-weighted MRI obtained 6 months or later after SAH were analyzed for the presence and anatomical distribution of SAH or chronic hemosiderin depositions. In total, 185 T2*-weighted MRI studies obtained between 2 days and 148 months after SAH were evaluated (mean follow-up 30.2 months).

RESULTS

On MRI studies obtained later than 6 months after SAH, subpial hemosiderin depositions were found in 50 patients (55.5%). Most frequent localizations were the parenchyma adjacent to the frontal and parietal sulci and the insular cisterns. While the appearance of hemosiderin depositions was dynamic within the first 3 months, no changes were found during subsequent follow-up. MR signal changes were not only conclusive with subarachnoid hemosiderin depositions but in many cases also resembled those that have been associated with cortical hemosiderosis.

CONCLUSIONS

T2*-weighted MRI is an effective means of diagnosing prior SAH. Our study suggests that chronic hemosiderin depositions can be found in a considerable number of patients after a single event of subarachnoid hemorrhage.