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Radiographics : a Review Publication of... Aug 2023Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to...
Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to provide a better understanding of the localization and extension of these diseases and summarize the clinical and imaging features of various conditions that cause dural and/or leptomeningeal enhancing lesions. These conditions include infectious meningitis (bacterial, tuberculous, viral, and fungal), autoimmune diseases (vasculitis, connective tissue diseases, autoimmune meningoencephalitis, Vogt-Koyanagi-Harada disease, neuro-Behçet syndrome, Susac syndrome, and sarcoidosis), primary and secondary tumors (meningioma, diffuse leptomeningeal glioneuronal tumor, melanocytic tumors, and lymphoma), tumorlike diseases (histiocytosis and immunoglobulin G4-related diseases), medication-induced diseases (immune-related adverse effects and posterior reversible encephalopathy syndrome), and other conditions (spontaneous intracranial hypotension, amyloidosis, and moyamoya disease). Although meningeal lesions may manifest with nonspecific imaging findings, correct diagnosis is important because the treatment strategy varies among these diseases. RSNA, 2023 and Quiz questions for this article are available through the Online Learning Center.
Topics: Humans; Posterior Leukoencephalopathy Syndrome; Meninges; Meningitis; Neuroimaging; Sarcoidosis; Meningeal Neoplasms; Magnetic Resonance Imaging
PubMed: 37535461
DOI: 10.1148/rg.230039 -
Journal of Neurology Dec 2023Susac syndrome (SuS) is a rare disease characterized by encephalopathy, hearing impairment and visual disturbances. Immunosuppressive treatments are used based on the... (Review)
Review
BACKGROUND
Susac syndrome (SuS) is a rare disease characterized by encephalopathy, hearing impairment and visual disturbances. Immunosuppressive treatments are used based on the hypothesis that an autoimmune endotheliopathy drives the disease. However, a solid evidence-based treatment approach is lacking. The aim of this review is to provide an overview of patient characteristics, disease course and treatment patterns related to successful outcome that have been reported in literature since 2013.
METHODS
Three reviewers conducted a systematic literature search in February 2022. The primary outcome was treatment used, derived from cases classified as probable or definite SuS, describing successful treatment outcome (i.e. no signs of disease activity for ≥ 1 month). Secondary outcomes were time-to-relapse and follow-up time. Published case reports and case series were included. Various clinical characteristics and treatment(s) were extracted and categorized into different phases of treatment.
RESULTS
A total of 810 records was identified. 120 articles met inclusion criteria and 161 cases were extracted. Of these, 151 cases were classified as probable or definite SuS and included in the final analysis. Number of combinations of treatments used per treatment phase were: 6 empirically, 35 after confirmed diagnosis, 43 for maintenance treatment, 22 after relapse, 18 during maintenance post-relapse. Median follow-up time was 12.3 months (0.5; 120) and median time to relapse was 4 months (1; 120).
CONCLUSION
This scoping review summarizes treatment approaches in patients with SuS, highlighting variability. International efforts to collect clinical, imaging and treatment data from patients with SuS in registries are needed, in order to provide less biased and long-term follow-up information on treatment response, predictors of relapse and patient outcomes. This may lead to more evidence-based therapeutic approaches.
Topics: Humans; Susac Syndrome; Brain Diseases; Vision Disorders; Treatment Outcome; Recurrence; Magnetic Resonance Imaging
PubMed: 37668702
DOI: 10.1007/s00415-023-11936-3 -
Clinical Neurology and Neurosurgery Oct 2023Susac syndrome is a rare autoimmune endotheliopathy involving the brain, retina, and inner ear. Olfactory dysfunction is a common early manifestation of several central...
OBJECTIVES
Susac syndrome is a rare autoimmune endotheliopathy involving the brain, retina, and inner ear. Olfactory dysfunction is a common early manifestation of several central nervous system diseases, including neurodegenerative diseases and autoimmune-mediated diseases such as Multiple Sclerosis. While the literature is abundant about the Susac syndrome classic triad of encephalopathy, branch retinal artery occlusion, and low-frequency sensorineural hearing loss, little is known about the extent of olfactory sense involvement.
METHODS
Using the Sniffin' Sticks test, this study evaluated olfactory function (identification and threshold) in ten recovering Susac syndrome patients under our clinic surveillance with a median of 3.1 (SD=1.53) years post-disease onset.
RESULTS
olfactory assessment by threshold and odor identification were within the normal range. No differences between recovering Susac syndrome patients to standard norms of odor identification and threshold were found.
CONCLUSIONS
Our findings do not support olfactory dysfunction in Susac syndrome and thereby, do not support olfactory assessment as a reliable biomarker for this condition.
PubMed: 37524045
DOI: 10.1016/j.clineuro.2023.107909 -
Journal of Neurology Dec 2023Susac syndrome is a likely autoimmune microangiopathy affecting the brain, retina and inner ear. Due to the rarity of this condition, diagnosis and treatment can be...
Susac syndrome is a likely autoimmune microangiopathy affecting the brain, retina and inner ear. Due to the rarity of this condition, diagnosis and treatment can be challenging. Diagnosis is based on the presence of the clinical triad of central nervous system dysfunction, branch retinal artery occlusions and sensorineural hearing loss. Typical MRI findings of callosal and peri-callosal lesions may assist in diagnosis. Clinical course can be monophasic, polycyclic or chronic continuous. It is important to look out for red flags to attain an accurate diagnosis and follow a therapeutic algorithm based on severity of the disease and response to treatment. Patients are treated with steroids and immunosuppressive agents with a variable response. Early aggressive treatment especially in severe cases, may help in preventing relapses and morbidity/disability. This study highlights important diagnostic features and proposes a treatment algorithm based on clinical experience from management of 16 patients from 2 neuroscience centres in the UK since 2007, who were followed up over a long period of 3-15 years.
Topics: Humans; Susac Syndrome; Follow-Up Studies; Brain; Retinal Artery Occlusion; Magnetic Resonance Imaging
PubMed: 37608221
DOI: 10.1007/s00415-023-11891-z -
Neurology(R) Neuroimmunology &... May 2024Susac syndrome (SuS) is an orphan microangiopathic disease characterized by a triad of encephalopathy, visual disturbances due to branch retinal artery occlusions, and... (Review)
Review
Susac syndrome (SuS) is an orphan microangiopathic disease characterized by a triad of encephalopathy, visual disturbances due to branch retinal artery occlusions, and sensorineuronal hearing loss. Our previous systematic review on all cases of SuS reported until 2012 allowed for a better understanding of clinical presentation and diagnostic findings. Based on these data, we suggested diagnostic criteria in 2016 to allow early diagnosis and treatment of SuS. In view of the accumulation of new SuS cases reported in the last 10 years and improved diagnostic tools, we here aimed at updating the demographic and clinical features of SuS and to review the updated ancillary tests being used for SuS diagnosis. Therefore, based on the 2016 criteria, we systematically collected and evaluated data on SuS published from January 2013 to March 2022.
Topics: Humans; Susac Syndrome; Magnetic Resonance Imaging; Brain Diseases; Vision Disorders; Diagnosis, Differential
PubMed: 38364193
DOI: 10.1212/NXI.0000000000200209 -
Journal of Neuro-ophthalmology : the... Dec 2023Susac syndrome is a vasculopathy, resulting in the classic triad of branch retinal artery occlusion (BRAO), inner ear ischemia, and brain ischemia. In this retrospective...
BACKGROUND
Susac syndrome is a vasculopathy, resulting in the classic triad of branch retinal artery occlusion (BRAO), inner ear ischemia, and brain ischemia. In this retrospective chart review, we characterize fluorescein angiography (FA) findings and other ancillary studies in Susac syndrome, including the appearance of persistent disease activity and the occurrence of new subclinical disease on FA.
METHODS
This multicenter, retrospective case series was institutional review board-approved and included patients with the complete triad of Susac syndrome evaluated with FA, contrasted MRI of the brain, and audiometry from 2010 to 2020. The medical records were reviewed for these ancillary tests, along with demographics, symptoms, visual acuity, visual field defects, and findings on fundoscopy. Clinical relapse was defined as any objective evidence of disease activity during the follow-up period after initial induction of clinical quiescence. The main outcome measure was the sensitivity of ancillary testing, including FA, MRI, and audiometry, to detect relapse.
RESULTS
Twenty of the 31 (64%) patients had the complete triad of brain, retinal, and vestibulocochlear involvement from Susac syndrome and were included. Median age at diagnosis was 43.5 years (range 21-63), and 14 (70%) were women. Hearing loss occurred in 20 (100%), encephalopathy in 13 (65%), vertigo in 15 (75%), and headaches in 19 (95%) throughout the course of follow-up. Median visual acuity at both onset and final visit was 20/20 in both eyes. Seventeen (85%) had BRAO at baseline, and 10 (50%) experienced subsequent BRAO during follow-up. FA revealed nonspecific leakage from previous arteriolar damage in 20 (100%), including in patients who were otherwise in remission. Of the 11 episodes of disease activity in which all testing modalities were performed, visual field testing/fundoscopy was abnormal in 4 (36.4%), MRI brain in 2 (18.2%), audiogram in 8 (72.7%), and FA in 9 (81.8%).
CONCLUSIONS
New leakage on FA is the most sensitive marker of active disease. Persistent leakage represents previous damage, whereas new areas of leakage suggest ongoing disease activity that requires consideration of modifying immunosuppressive therapy.
Topics: Humans; Female; Young Adult; Adult; Middle Aged; Male; Susac Syndrome; Fluorescein Angiography; Retrospective Studies; Retinal Artery Occlusion; Magnetic Resonance Imaging; Retina; Recurrence
PubMed: 37075250
DOI: 10.1097/WNO.0000000000001826 -
Frontiers in Immunology 2023CD8+ lymphocytes are adaptive immunity cells with the particular function to directly kill the target cell following antigen recognition in the context of MHC class I.... (Review)
Review
CD8+ lymphocytes are adaptive immunity cells with the particular function to directly kill the target cell following antigen recognition in the context of MHC class I. In addition, CD8+ T cells may release pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and a plethora of other cytokines and chemoattractants modulating immune and inflammatory responses. A role for CD8+ T cells has been suggested in aging and several diseases of the central nervous system (CNS), including Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, limbic encephalitis-induced temporal lobe epilepsy and Susac syndrome. Here we discuss the phenotypic and functional alterations of CD8+ T cell compartment during these conditions, highlighting similarities and differences between CNS disorders. Particularly, we describe the pathological changes in CD8+ T cell memory phenotypes emphasizing the role of senescence and exhaustion in promoting neuroinflammation and neurodegeneration. We also discuss the relevance of trafficking molecules such as selectins, mucins and integrins controlling the extravasation of CD8+ T cells into the CNS and promoting disease development. Finally, we discuss how CD8+ T cells may induce CNS tissue damage leading to neurodegeneration and suggest that targeting detrimental CD8+ T cells functions may have therapeutic effect in CNS disorders.
Topics: Humans; CD8-Positive T-Lymphocytes; Cytokines; Central Nervous System; Amyotrophic Lateral Sclerosis
PubMed: 37575227
DOI: 10.3389/fimmu.2023.1233870 -
Neurology(R) Neuroimmunology &... Jul 2023Alteration of the blood-brain barrier (BBB) at the interface between blood and CNS parenchyma is prominent in most neuroinflammatory diseases. In several neurologic...
BACKGROUND AND OBJECTIVES
Alteration of the blood-brain barrier (BBB) at the interface between blood and CNS parenchyma is prominent in most neuroinflammatory diseases. In several neurologic diseases, including cerebral malaria and Susac syndrome, a CD8 T cell-mediated targeting of endothelial cells of the BBB (BBB-ECs) has been implicated in pathogenesis.
METHODS
In this study, we used an experimental mouse model to evaluate the ability of a small-molecule perforin inhibitor to prevent neuroinflammation resulting from cytotoxic CD8 T cell-mediated damage of BBB-ECs.
RESULTS
Using an in vitro coculture system, we first identified perforin as an essential molecule for killing of BBB-ECs by CD8 T cells. We then found that short-term pharmacologic inhibition of perforin commencing after disease onset restored motor function and inhibited the neuropathology. Perforin inhibition resulted in preserved BBB-EC viability, maintenance of the BBB, and reduced CD8 T-cell accumulation in the brain and retina.
DISCUSSION
Therefore, perforin-dependent cytotoxicity plays a key role in the death of BBB-ECs inflicted by autoreactive CD8 T cells in a preclinical model and potentially represents a therapeutic target for CD8 T cell-mediated neuroinflammatory diseases, such as cerebral malaria and Susac syndrome.
Topics: Mice; Animals; Perforin; Neuroinflammatory Diseases; Malaria, Cerebral; Endothelial Cells; Susac Syndrome; Mice, Knockout; CD8-Positive T-Lymphocytes; Disease Models, Animal
PubMed: 37080596
DOI: 10.1212/NXI.0000000000200117 -
Archivos de La Sociedad Espanola de... May 2024A 40-year-old man who attended the emergency department with a scotoma in right eye. He mentioned hearing difficulties and headache for months and he had sensory and...
A 40-year-old man who attended the emergency department with a scotoma in right eye. He mentioned hearing difficulties and headache for months and he had sensory and motor deficits in the previous days. In the ophthalmic examination, the right eye had areas of arterial occlusion. MRI revealed hyperintense lesions. The patient was diagnosed with Susac syndrome. He was treated with systemic steroids, however, it was not enough to control the condition. Rituximab and intravenous immunoglobulins were added, which allowed the improvement of neurological symptoms, but the alteration of the visual field and the hearing defect did not recover. Early diagnosis of this pathology is essential, since delaying treatment can cause irreversible consequences. Sometimes it is difficult given the wide variety of symptoms and the course of the disease. Ocular manifestations may raise suspicion when the general symptoms are nonspecific.
PubMed: 38710368
DOI: 10.1016/j.oftale.2024.05.002 -
European Journal of Neurology Oct 2023Serum levels of neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) are promising neuro-axonal damage and astrocytic activation biomarkers....
BACKGROUND AND PURPOSE
Serum levels of neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) are promising neuro-axonal damage and astrocytic activation biomarkers. Susac syndrome (SS) is an increasingly recognized neurological condition and biomarkers that can help assess and monitor disease evolution are highly needed for the adequate management of these patients. sNfL and sGFAP levels were evaluated in patients with SS and their clinical relevance in the relapse and remission phase of the disease was assessed.
METHODS
As part of a multicentre study that enrolled patients diagnosed with SS from six international centres, sNfL and sGFAP levels were assessed in 22 SS patients (nine during a relapse and 13 in remission) and 59 age- and sex-matched healthy controls using SimoaTM assay Neurology 2-Plex B Kit.
RESULTS
Serum NfL levels were higher than those of healthy controls (p < 0.001) in SS patients and in both subgroups of patients in relapse and in remission (p < 0.001 for both), with significantly higher levels in relapse than in remission (p = 0.008). sNfL levels showed a negative correlation with time from the last relapse (r = -0.663; p = 0.001). sGFAP levels were slightly higher in the whole group of patients than in healthy controls (p = 0.046) and were more pronounced in relapse than in remission (p = 0.013).
CONCLUSION
In SS patients, both sNFL and sGFAP levels increased compared with healthy controls. Both biomarkers had higher levels during clinical relapse and much lower levels in remission. sNFL was shown to be time sensitive to clinical changes and can be useful to monitor neuro-axonal damage in SS.
Topics: Humans; Biomarkers; Glial Fibrillary Acidic Protein; Intermediate Filaments; Multiple Sclerosis; Neurofilament Proteins; Recurrence; Susac Syndrome
PubMed: 37335505
DOI: 10.1111/ene.15939