MRI findings in Susac's syndrome

Diagnostic and therapeutic complexity of Susac syndrome

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.

Uncommon and Miscellaneous Inflammatory Disorders of the Brain and Spine

Inflammatory disorders of the brain and spine have a highly variable MRI appearance, often demonstrating significant overlap in imaging features. The resulting diagnostic dilemma is particularly challenging when considering the more uncommon neuroinflammatory entities. Diligent examination of the salient clinical presentation and signal alteration on imaging examination is necessary when considering neuroinflammation as a diagnostic possibility and may aid in raising suspicion for a particular neuroinflammatory entity. This article reviews a selection of uncommon and miscellaneous inflammatory disorders of the brain and spine to raise awareness of the clinical and imaging features that may assist in this challenging diagnostic task.

Challenges in Diagnosis and Therapeutic Strategies in Late-Onset Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and degenerative demyelinating disease of the central nervous system of unknown etiology, which affects individuals in their early adulthood. However, nearly 5-10% of people with MS can be diagnosed at ages above 50 years old, referred to as late-onset multiple sclerosis (LOMS). Some studies have reported a distinctive presentation, clinical course, and prognosis for LOMS, implicating a different diagnostic and therapeutic approach for this population. Furthermore, similar manifestations between LOMS and other age-related conditions may lead to potential misdiagnosis and diagnostic delays, and a higher burden of multimorbidity associated with aging can further complicate the clinical picture. This review aims to explore the clinical characteristics, the disease course, and the differential diagnosis of LOMS and addresses therapeutic considerations for this population.

Cognitive outcomes in Susac syndrome: A 2-year neuropsychological follow-up study

BACKGROUND AND PURPOSE

Susac syndrome (SuS) is a rare, autoimmune, neurological disease characterized by a clinical triad of branch retinal artery occlusion, sensorineural hearing loss and encephalopathy. Neuropsychological functioning in SuS is little researched and the prevalence, nature, and evolution over time of cognitive deficits in SuS remain unclear. This study aimed to better understand the long-term neuropsychological outcomes of patients with SuS.

METHODS

Thirteen patients with SuS (mean [SD] age 39.5 [11.1] years) were enrolled at the Ghent University Hospital by their treating neurologist. The cognitive functioning and emotional well-being of each patient was evaluated by means of a thorough neuropsychological test battery at baseline and after 2 years. Follow-up testing after 2 years was performed in 11 patients (mean [SD] age 42.2 [11.5] years).

RESULTS

Patients showed normal neuropsychological test results at a group level, both at baseline and follow-up testing. Significant improvements over time were found for information processing speed, verbal recognition, and semantic and phonological fluency. Individual test results showed interindividual variability at baseline, with most impairments being in attention, executive functioning and language, which improved after a 2-year period. In addition, patients reported significantly lower mental and physical well-being, both at baseline and follow-up testing.

CONCLUSIONS

Our results suggest that neuropsychological dysfunction in SuS is limited at a group level and improves over time. Nonetheless, individual test results reveal interindividual variability, making cognitive screening essential. Furthermore, a high psycho-emotional burden of the disease was reported, for which screening and follow-up are necessary.

Ophthalmological Outcomes in Patients with Susac Syndrome

BACKGROUND

To report ophthalmological outcomes and treatment regimen in patients with Susac syndrome.

METHODS

This is a retrospective analysis of patients with Susac syndrome treated between November 2015 and March 2023. Multimodal imaging findings, ophthalmic examination data, information on neurological and sensorineural involvement, and therapeutic regimen were reviewed. Visual acuity was recorded as the logarithm of the minimum angle of resolution (logMAR). Ophthalmological manifestations and disease severity were assessed using the previously described clinical activity score (CAS).

RESULTS

Ten patients with Susac syndrome m : f = 5 : 5 were identified. The mean follow-up time was 31.2 ± 23.3 months (range 1 to 78 months). The mean age was 41.4 ± 13.8 years (range 21 to 59 years). At baseline, corrected distance visual acuity (CDVA) was 0.03 ± 0.08 logMAR. At the last follow-up, CDVA improved to 0.00 ± 0.03 logMAR (p = 0.029). Three of 20 eyes showed an improvement of 5 letters, while no loss of visual acuity was recorded during the follow-up time. Baseline CAS was 10.65 ± 12.69, and CAS at the last follow-up was 5.15 ± 5.49 (p = 0.068). Except for one patient, all were initially treated with intravenous (i. v.) steroids and subsequent oral tapering. Depending on the treatment response, cyclophosphamide (n = 4), i. v. immunoglobulins (IVIGs) (n = 4), anti-CD20 antibodies (n = 3), or plasmapheresis (n = 1) were applied. All patients under treatment for more than 1 month (n = 9) showed improvement in CAS and CDVA.

CONCLUSION

Susac syndrome is a rare autoimmune vascular endotheliopathy. Treatment of Susac syndrome appears to result in improving CAS and CDVA. The majority of patients, in addition to the systemic steroids, required systemic immunosuppressive agents. Interdisciplinary communication is crucial to reduce the time to diagnosis and initiation of therapy in patients with Susac syndrome.

Case report: Susac syndrome-two ends of the spectrum, single center case reports and review of the literature

Susac syndrome is a rare and enigmatic complex neurological disorder primarily affecting small blood vessels in the brain, retina, and inner ear. Diagnosing Susac syndrome may be extremely challenging not only due to its rarity, but also due to the variability of its clinical presentation. This paper describes two vastly different cases-one with mild symptoms and good response to therapy, the other with severe, complicated course, relapses and long-term sequelae despite multiple therapeutic interventions. Building upon the available guidelines, we highlight the utility of black blood MRI in this disease and provide a comprehensive review of available clinical experience in clinical presentation, diagnosis and therapy of this disease. Despite its rarity, the awareness of Susac syndrome may be of uttermost importance since it ultimately is a treatable condition. If diagnosed in a timely manner, early intervention can substantially improve the outcomes of our patients.

Central intra-lesional iron deposits as a possible novel imaging marker at 7 Tesla MRI in Susac Syndrome - an exploratory study

BACKGROUND

Susac syndrome (SuS) is a rare autoimmune disease that leads to hearing impairment, visual field deficits, and encephalopathy due to an occlusion of precapillary arterioles in the brain, retina, and inner ear. Given the potentially disastrous outcome and difficulties in distinguishing SuS from its differential diagnoses, such as multiple sclerosis (MS), our exploratory study aimed at identifying potential new SuS-specific neuroimaging markers.

METHODS

Seven patients with a definite diagnosis of SuS underwent magnetic resonance imaging (MRI) at 7 Tesla (7T), including T2* weighted and quantitative susceptibility mapping (QSM) sequences. T2 weighted hyperintense lesions were analyzed with regard to number, volume, localization, central vein sign, T1 hypointensity, and focal iron deposits in the center of SuS lesions ("iron dots"). Seven T MRI datasets from the same institute, comprising 75 patients with, among others, MS, served as controls.

RESULTS

The "iron dot" sign was present in 71.4% (5/7) of the SuS patients, compared to 0% in our control cohort. Thus, sensitivity was 71.4% and specificity 100%. A central vein sign was only incidentally detected.

CONCLUSION

We are the first to demonstrate this type of "iron dot" lesions on highly resolving 7T T2*w and QSM images in vivo as a promising neuroimaging marker of SuS, corroborating previous histopathological ex vivo findings.

Inflammatory lesions of the brainstem: Keys for the diagnosis by MRI

OBJECTIVE

To describe the magnetic resonance imaging (MRI) findings for the most common inflammatory and immune-mediated diseases that involve the brainstem.

CONCLUSION

Inflammatory lesions involving the brainstem are associated with a wide range of autoimmune, infectious, and paraneoplastic syndromes, making the differential diagnosis complex. Being familiar with these entities, their clinical characteristics, and their manifestations on MRI, especially the number of lesions, their shape and extension, and their appearance in different sequences, is useful for orienting the radiological diagnosis.

Diffuse Cerebral Edema With Uncal Herniation Leading to Brain Death in Patient With Fulminant Susac syndrome: Rare Complication of Rare Disease

Susac Syndrome was first described as an inflammatory microangiopathy of the brain and retina. Since then, multiple articles have been published in attempts to improve the understanding of this rare disease. Clinically Susac Syndrome is known to present with triad of encephalopathy, sensorineural hearing loss and branch of retinal artery occlusion (BRAO), along with characteristic "snowball" or "spoke" appearing white matter lesions of the corpus callosum. It has been characterized by vast heterogeneity in terms of its presenting symptoms, severity, and clinical course. Although subset of patients present with severe forms of Susac Syndrome and can develop prominent residual neurologic deficits, it has been reported to be mostly non-life-threatening and only few fatal cases have been described in the literature. Based on the available case reports with fatal outcome, mortality has been related to the systemic complications either during acute disease flare or during chronic-progressive phase. We describe a case of fulminant Susac Syndrome complicated by the sudden and rapid progression of diffuse cerebral edema leading to brain herniation and ultimate brain death, in order to increase awareness of this rare and catastrophic complication.

Overlap between ophthalmology and psychiatry - A narrative review focused on congenital and inherited conditions

A number of congenital and inherited diseases present with both ocular and psychiatric features. The genetic inheritance and phenotypic variants play a key role in disease severity. Early recognition of the signs and symptoms of those disorders is critical to earlier intervention and improved prognosis. Typically, the associations between these two medical subspecialties of ophthalmology and psychiatry are poorly understood by most practitioners so we hope to provide a narrative review to improve the identification and management of these disorders. We conducted a comprehensive review of the literature detailing the diseases with ophthalmic and psychiatric overlap that were more widely represented in the literature. Herein, we describe the clinical features, pathophysiology, molecular biology, diagnostic tests, and the most recent approaches for the treatment of these diseases. Recent studies have combined technologies for ocular and brain imaging such as optical coherence tomography (OCT) and functional imaging with genetic testing to identify the genetic basis for eye-brain connections. Additional work is needed to further explore these potential biomarkers. Overall, accurate, efficient, widely distributed and non-invasive tests that can help with early recognition of these diseases will improve the management of these patients using a multidisciplinary approach.

Susac syndrome: neurological update (clinical features, long-term observational follow-up and management of sixteen patients)

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.

Clinical Reasoning: A 24-Year-Old Pregnant Woman With Headache and Behavioral Change Progressing to Coma

The broad differential diagnosis associated with progressive subacute encephalopathy can be intimidating, especially in a young, pregnant woman. In this case, a 24-year-old woman at 21 weeks of gestation presented with persistent, drug-resistant fronto-parietal headache, with subsequent progressive development of psychomotor lentification and inappropriate behavior. Physical examination was normal, as were routine laboratory parameters and CT findings, and these symptoms were initially interpreted in the context of chronic depression. Later, the patient developed generalized dystonia and fever, with rapid clinical deterioration, depression of consciousness and, eventually, progression to coma. This case emphasizes the complexity and challenges involved in the diagnostic approach to a patient with progressive subacute encephalopathy framed by worsening CNS symptoms. It highlights the clinical considerations and complementary investigation of various etiologies, in a step-by-step approach, ultimately leading to the final diagnosis. Early recognition and appropriate treatment of these conditions can lead to more favorable outcomes, particularly in gestating patients, where prompt intervention is crucial, and where critical decisions may have to be made regarding pregnancy and the safety of treatment options.

Case report: 3D intracranial vessel wall MRI in Susac syndrome: potential relevance for diagnosis and therapeutic management

Background

Susac syndrome (SS) is a rare immune-mediated vasculitis affecting retina, inner ear and brain. Assessment of central nervous system (CNS) involvement is currently based on standard brain magnetic resonance imaging (MRI) sequences. Accuracy of three dimensional (3D)-vessel wall imaging (VWI) was compared to standard sequences and contrast-enhanced-3D T2-fluid attenuated inversion recovery (CE-FLAIR) to assess CNS disease activity in two cases of definite SS.

Methods

Brain MRI scan and retinal fluorescein angiogram (RFA) were performed at disease onset and at 1, 3, and 6 months after induction therapy start. CE-FLAIR and VWI based on 3D black-blood proton density weighted (PDW) with and without gadolinium were added to standard sequences on a 3 Tesla MRI scanner.

Results

Contrast enhanced-VWI (CE-VWI) detected an abnormal diffuse leptomeningeal enhancement (LME) in both cases at onset and during follow-up. Pathological enhancement on CE-VWI persisted at 6-month brain MRI, despite absence of new lesions and disappearance of LME on CE-FLAIR. Follow-up RFA revealed new arterial wall hyperfluorescence in both cases.

Conclusions

VWI may represent a useful tool for diagnosing and monitoring CNS disease activity in SS patients, as confirmed by concordance with RFA, leading treatment's choice and timing. Moreover, CE-VWI seemed at least as sensitive as CE-FLAIR in detecting LME, possibly being superior to the latter in posterior fossa. LME remission might be not accurate in predicting suppression of CNS inflammation in SS.

Advances in Management of the Stroke Etiology One-Percenters

PURPOSE OF REVIEW

Uncommon causes of stroke merit specific attention; when clinicians have less common etiologies of stoke in mind, the diagnosis may come more easily. This is key, as optimal management will in many cases differs significantly from "standard" care.

RECENT FINDINGS

Randomized controlled trials (RCT) on the best medical therapy in the treatment of cervical artery dissection (CeAD) have demonstrated low rates of ischemia with both antiplatelet and vitamin K antagonism. RCT evidence supports the use of anticoagulation with vitamin K antagonism in "high-risk" patients with antiphospholipid antibody syndrome (APLAS), and there is new evidence supporting the utilization of direct oral anticoagulation in malignancy-associated thrombosis. Migraine with aura has been more conclusively linked not only with increased risk of ischemic and hemorrhagic stroke, but also with cardiovascular mortality. Recent literature has surprisingly not provided support the utilization of L-arginine in the treatment of patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); however, there is evidence at this time that support use of enzyme replacement in patients with Fabry disease. Additional triggers for reversible cerebral vasoconstriction syndrome (RCVS) have been identified, such as capsaicin. Imaging of cerebral blood vessel walls utilizing contrast-enhanced MRA is an emerging modality that may ultimately prove to be very useful in the evaluation of patients with uncommon causes of stroke. A plethora of associations between cerebrovascular disease and COVID-19 have been described. Where pertinent, authors provide additional tips and guidance. Less commonly encountered conditions with updates in diagnosis, and management along with clinical tips are reviewed.

Atypical clinical and novel radiological findings in Susac syndrome: Experience from a large monocentric cohort

Susac syndrome (SuS) is a rare immune-mediated endotheliopathy that affects the brain, retina and inner ear and is characterised by the variable clinical triad of encephalopathy, visual and vestibulocochlear dysfunction. Here, we present clinical and paraclinical data of 19 SuS patients followed at Ghent University Hospital and highlight some atypical clinical and novel radiological findings. Our findings suggest that spinal involvement expands the clinical phenotype of SuS. We further introduce dark blood sequences as a more sensitive technique to detect radiological disease activity in SuS. Our data add to the current understanding of the diagnosis, monitoring and treatment of SuS.

Fulminant Susac syndrome-a rare cause of coma: The history of the fatal course in a young man

Susac syndrome is a rare microangiopathy of indeterminate etiology, presumably autoimmune, characterized by a triad of encephalopathy, sensorineural hearing loss, and branch retinal artery occlusions occurring predominantly in women. The onset and progression patterns are multiple, mainly of three modes. Fulminant evolution is exceptional, rarely reported across literature. We report through this case a Susac syndrome in a young man in whom evolution was fatal. Magnetic resonance imaging is essential to raise the diagnosis and for follow-up, with almost pathognomonic findings, all the more useful as the clinical triad is usually incomplete and as the encephalopathy is the most limiting of the symptoms.

Imaging of Central Nervous System Autoimmune, Paraneoplastic, and Neuro-rheumatologic Disorders

OBJECTIVE

This article provides an overview of the imaging modalities used in the evaluation of central nervous system (CNS) autoimmune, paraneoplastic, and neuro-rheumatologic disorders. An approach is outlined for interpreting imaging findings in this context, synthesizing a differential diagnosis based on certain imaging patterns, and choosing further imaging for specific diseases.

LATEST DEVELOPMENTS

The rapid discovery of new neuronal and glial autoantibodies has revolutionized the autoimmune neurology field and has elucidated imaging patterns characteristic of certain antibody-associated diseases. Many CNS inflammatory diseases, however, lack a definitive biomarker. Clinicians should recognize neuroimaging patterns suggestive of inflammatory disorders, as well as the limitations of imaging. CT, MRI, and positron emission tomography (PET) modalities all play a role in diagnosing autoimmune, paraneoplastic, and neuro-rheumatologic disorders. Additional imaging modalities such as conventional angiography and ultrasonography can be helpful for further evaluation in select situations.

ESSENTIAL POINTS

Knowledge of imaging modalities, both structural and functional, is critical in identifying CNS inflammatory diseases quickly and can help avoid invasive testing such as brain biopsy in certain clinical scenarios. Recognizing imaging patterns suggestive of CNS inflammatory diseases can also facilitate the early initiation of appropriate treatments to diminish morbidity and future disability.

A Case Report: Splenium of the Corpus Callosum Infarct Associated With COVID-19

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has been recently associated with infarction of the central splenium of the corpus callosum. These are described as cytotoxic lesions, and imaging rarely reveals enhancement. They have not been described in the body or head of the corpus callosum. Few diseases affect the corpus callosum, but the most common include multiple sclerosis, aquaporin-4 disease, and Susac syndrome. There is also emerging literature on Mild Encephalopathy with Reversible Splenial lesions associated with central and not basal lesions. The reason for the location of these lesions in acute COVID-19 infection is unknown.

CASE REPORT

A 22-year-old female presented to the ED for altered mental status after being found down. A brief history review indicated that the patient had been altered for 2-3 days before being found naked and covered in her own feces and urine by her family after they had not heard from her. As she lived alone, a clear history of the events preceding her admission remains unclear. On initial assessment, the patient was found to be somnolent and nonverbal, though she could follow simple commands. On admission, testing for SARS CoV-2 RNA PCR was positive. Patient was admitted to the hospital for further work up to determine the cause of the altered mental status.

CONCLUSION

We present a new case of a young woman who developed a central splenium lesion during acute COVID-19 infection and explain the predilection for the callosum in these patients, as well as literature to show that COVID-19 was most likely the cause.

Case Report of Spinal Cord Involvement in Susac Syndrome Masquerading as a Multiple Sclerosis Mimic

We present a unique case of a 59-year-old woman with atypical Susac syndrome and prominent involvement of the spinal cord. She initially presented with progressive headaches, lower extremity weakness and hearing loss. Her MRI brain showed multiple enhancing lesions and her MRI spine showed a T8 enhancing lesion as well as a C2 cord infarct. She was treated with IV methylprednisolone with initial stabilization. However, she developed worsening encephalopathy and lower extremity weakness. Her repeat MRI brain showed new bilateral enhancing lesions and subacute infarcts. Given the increased burden of new lesions, she underwent a brain biopsy, which showed perivascular chronic inflammation within a small vessel distribution. Additionally, fluorescein angiography revealed bilateral branch retinal arterial occlusion (BRAO) and an audiogram demonstrated bilateral sensorineural hearing loss. She was diagnosed with Susac syndrome and treated with IV cyclophosphamide with improvement in her clinical exam. Spinal cord involvement is extremely rare for Susac syndrome, which commonly manifests as the classic triad of encephalopathy, BRAO and hearing loss. Her presentation with myelopathy highlights the importance of considering atypical presentations of well-established syndromes for optimal diagnosis and management.

Susac Syndrome: an uncommon cause of impaired vision

A 35-year-old Caucasian woman presented an abrupt onset of bilateral impaired vision, and arrived to our attention two weeks later. She had a previous episode of mild dizziness. She underwent a fluorescein angiography showing branch retinal artery occlusions and a brain magnetic resonance imaging (MRI) revealing several supraand infratentorial FLAIR-hyperintense white matter lesions, two with contrast enhancement. Thrombophilic, autoimmune and infective (including Human Immunodeficiency Virus, Borrelia burgdorferi, Hepatitis B Virus, Hepatitis C Virus, Herpes Simplex Virus 1-2, Varicella Zoster Virus) screening was negative. Cerebrospinal fluid analysis showed intrathecal IgG synthesis. We suspected a Primary Central Nervous System Vasculitis, and intravenous steroids were started. Three months later a second brain MRI showed seven new lesions without contrast enhancement, and she revealed a cognitive impairment and bilateral hearing loss. Reviewing the clinical history and MRI, she fulfilled diagnostic criteria for Susac syndrome. She had two cycles of cyclophosphamide, and recovered in 6 months and then remained stable with metotrexate.

[Unusual forms of inflammatory diseases of the central nervous system]

BACKGROUND

White matter lesions of the central nervous system (CNS) are frequently encountered on magnetic resonance imaging (MRI) exams. If the morphologic findings, clinical symptoms and laboratory results are not typical for one of the more common inflammatory CNS diseases, the diagnosis may become challenging, which also means that interesting and sometime emotional discussions may arise.

OBJECTIVE

While frequent causes of inflammatory CNS diseases were already discussed in a previous article, we now focus on more seldom forms and place attention on morphologic characteristics which may help to find the correct diagnosis.

Diagnosis, differential diagnosis and misdiagnosis of Susac syndrome

Background and purpose

Susac syndrome (SuS) is an inflammatory condition of the brain, eye and ear. Diagnosis can be challenging, and misdiagnosis is common.

Methods

This is a retrospective review of the medical records of 32 adult patients from an Australasian cohort of SuS patients.

Results

An alternative diagnosis prior to SuS was made in 30 patients (94%) with seven patients receiving two or more diagnoses. The median time to diagnosis of SuS was 3 months (range 0.5–100 months). The commonest misdiagnoses were migraine in 10 patients (31%), cerebral vasculitis in six (19%), multiple sclerosis in five (16%) and stroke in five (16%). Twenty‐two patients were treated for alternative diagnoses, 10 of whom had further clinical manifestations prior to SuS diagnosis. At presentation seven patients (22%) met criteria for definite SuS, 19 (59%) for probable SuS and six (19%) for possible SuS. Six patients (19%) presented with brain–eye–ear involvement, 14 with brain–ear (44%), six with brain–eye (19%) and six (19%) with only brain involvement. In patients with the complete triad of symptoms the median delay to diagnosis was 3 months (range 1–9 months) compared to 5.25 months (range 0.5–100 months) for patients with encephalopathy and ocular symptoms at presentation.

Conclusions

Susac syndrome patients are frequently misdiagnosed at initial presentation, despite many having symptoms or radiological features that are red flags for the diagnosis. Delayed diagnosis can lead to patient morbidity. The varied ways in which SuS can present, and clinician failure to consider or recognize SuS, appear to be the main factors leading to misdiagnosis.

Susac syndrome with a unique involvement of the thoracic spinal cord

A woman in her late 20s presented with headaches and subacute encephalopathy. MRIs showed multiple punctate subcortical and periventricular white matter hyperintensities with diffusion restriction, infratentorial lesions, leptomeningeal enhancement of the cervical spinal cord, brainstem and cerebellum and two areas of high-signal abnormality at T4 and T6 raising suspicion for multiple sclerosis or acute disseminated encephalomyelitis.Further studies and evolution of her symptoms during her hospital stay confirmed the clinical triad of encephalopathy, branch retinal artery occlusions and hearing loss pathognomonic for Susac's syndrome.While cervical spinal cord and cauda equina involvement have been reported in Susac's syndrome previously, no thoracic spinal cord involvement has been reported.We report the novel MRI finding of thoracic spinal cord involvement in Susac's syndrome. In order to avoid misdiagnosis, neurologists and neuroradiologists should be aware that any part of the spinal cord can be involved in Susac's syndrome.

Leptomeningeal enhancement in multiple sclerosis and other neurological diseases: A systematic review and Meta-Analysis

BACKGROUND

The lack of systematic evidence on leptomeningeal enhancement (LME) on MRI in neurological diseases, including multiple sclerosis (MS), hampers its interpretation in clinical routine and research settings.

PURPOSE

To perform a systematic review and meta-analysis of MRI LME in MS and other neurological diseases.

MATERIALS AND METHODS

In a comprehensive literature search in Medline, Scopus, and Embase, out of 2292 publications, 459 records assessing LME in neurological diseases were eligible for qualitative synthesis. Of these, 135 were included in a random-effects model meta-analysis with subgroup analyses for MS.

RESULTS

Of eligible publications, 161 investigated LME in neoplastic neurological (n = 2392), 91 in neuroinfectious (n = 1890), and 75 in primary neuroinflammatory diseases (n = 4038). The LME-proportions for these disease classes were 0.47 [95%-CI: 0.37-0.57], 0.59 [95%-CI: 0.47-0.69], and 0.26 [95%-CI: 0.20-0.35], respectively. In a subgroup analysis comprising 1605 MS cases, LME proportion was 0.30 [95%-CI 0.21-0.42] with lower proportions in relapsing-remitting (0.19 [95%-CI 0.13-0.27]) compared to progressive MS (0.39 [95%-CI 0.30-0.49], p = 0.002) and higher proportions in studies imaging at 7 T (0.79 [95%-CI 0.64-0.89]) compared to lower field strengths (0.21 [95%-CI 0.15-0.29], p < 0.001). LME in MS was associated with longer disease duration (mean difference 2.2 years [95%-CI 0.2-4.2], p = 0.03), higher Expanded Disability Status Scale (mean difference 0.6 points [95%-CI 0.2-1.0], p = 0.006), higher T1 (mean difference 1.6 ml [95%-CI 0.1-3.0], p = 0.04) and T2 lesion load (mean difference 5.9 ml [95%-CI 3.2-8.6], p < 0.001), and lower cortical volume (mean difference -21.3 ml [95%-CI -34.7--7.9], p = 0.002).

CONCLUSIONS

Our study provides high-grade evidence for the substantial presence of LME in MS and a comprehensive panel of other neurological diseases. Our data could facilitate differential diagnosis of LME in clinical settings. Additionally, our meta-analysis corroborates that LME is associated with key clinical and imaging features of MS. PROSPERO No: CRD42021235026.

Marburg Multiple Sclerosis Variant: Complete Remission with Very Early Administration of Mitoxantrone-A Case Report

Marburg variant is a severe and fulminant pseudotumor form of multiple sclerosis (MS) with high morbidity and mortality rates. Because of its scarcity, it remains incompletely characterized and physicians' experiences will influence the treatment. We report the inflammatory explosive case of a 31-year-old woman presenting with rapid neurological degradation of histology proven Marburg's disease, successfully treated with early administration of Mitoxantrone (MITX). To our knowledge, it is the first case describing complete remission after MITX in a biopsy-proven condition.

Susac syndrome with cognitive impairment - case report of 31-year-old woman

Introduction: Susac syndrome (SuS) is a rare immune-mediated disease caused by occlusions of microvessels in the brain, retina and inner ear. It is characterized by the clinical triad of encephalopathy, visual disturbances and hearing loss. The diagnosis of SuS is based mainly on the clinical symptoms and the supporting tests in which characteristic changes occur in the MRI.

Case report: Here, we present a case of a patient with possible SuS with psychiatric symptoms. A 31-year-old woman was admitted to the Department of Psychiatry due to deteriorating mental health for several weeks manifested as a negative mood and suicidal thoughts. During hospitalization, a neurological consultation was conducted, in which the patient was identified as conscious, psychomotor sluggish, with impaired verbal contact and persistent hearing and vision impairment. Cross-sectional assessment of cognitive functions revealed that the patient had a generalized syndrome of neuropsychological deficits, which confirms the diagnosis of dementia.

Discussion: This case summary provides an example of a woman diagnosed with SuS manifested as a cognitive impairment with associated vision and hearing deterioration. It is worth emphasizing the fact that such presentation of the triad of at disease onset is rare. The characteristics of the organic changes in the brain described in the MRI probably explain the symptoms described in that case. The prognosis of SuS depends on early diagnosis and treatment.

Conclusions: A diagnosis of SuS should always be considered in the presence of nonspecific neuropsychiatric symptoms and progressive multifocal neurological symptoms, hearing loss, and visual impairment. An important fact is that the typical triad of SuS symptoms in most cases does not occur simultaneously, which makes the diagnostic process very difficult and may lead to misdiagnosis.

Construction of an MRI-based decision tree to differentiate autoimmune and autoinflammatory inner ear disease from chronic otitis media with sensorineural hearing loss

Autoimmune and autoinflammatory inner ear diseases (AIED/AID) are characterized by the symptom of sensorineural hearing loss (SNHL). To date, standardized diagnostic tools for AIED/AID are lacking, and clinically differentiating AIED/AID from chronic otitis media (COM) with SNHL is challenging. This retrospective study aimed to construct a magnetic resonance imaging (MRI)-based decision tree using classification and regression tree (CART) analysis to distinguish AIED/AID from COM. In total, 67 patients were enrolled between January 2004 and October 2019, comprising AIED/AID (n = 18), COM (n = 24), and control groups (n = 25). All patients underwent 3 T temporal bone MRI, including post-contrast T1-weighted images (postT1WI) and post-contrast FLAIR images (postFLAIR). Two radiologists evaluated the presence of otomastoid effusion and inner ear contrast-enhancement on MRI. A CART decision tree model was constructed using MRI features to differentiate AIED/AID from COM and control groups, and diagnostic performance was analyzed. High-intensity bilateral effusion (61.1%) and inner ear enhancement (postFLAIR, 93.8%; postT1WI, 61.1%) were the most common findings in the AIED/AID group. We constructed two CART decision tree models; the first used effusion amount as the first partitioning node and postT1WI-inner ear enhancement as the second node, whereas the second comprised two partitioning nodes with the degree of postFLAIR-enhancement of the inner ear. The first and second models enabled distinction of AIED/AID from COM with high specificity (100% and 94.3%, respectively). The amount of effusion and the degree of inner ear enhancement on MRI may facilitate the distinction between AIED/AID and COM with SNHL using decision tree models, thereby contributing to early diagnosis and intervention.

RECURRENT BRANCH RETINAL ARTERY OCCLUSION FROM SUSAC SYNDROME: CASE REPORT AND REVIEW OF LITERATURE

PURPOSE

We report a patient with branch retinal artery occlusion predominant Susac syndrome and review the literature on current diagnostic modalities and therapeutic approaches for this rare condition.

METHODS

Case report.

RESULTS

A 23-year-old white male presented with a 5-month history of a scotoma in his right eye vision, headaches, and intermittent paresthesias of the lower extremities. Ophthalmic examination was normal with the exception of a hypopigmented small retinal area inferonasal to the fovea in the right eye. Optical coherence tomography demonstrated inner retinal atrophy and optical coherence tomography angiography showed deep capillary layer vessel dropout in both eyes. Ultra-wide-field fluorescein angiography revealed bilateral arteriolar wall hyperfluorescence. Corpus callosal lesions were present on magnetic resonance imaging. Lumbar puncture demonstrated elevated protein. Audiogram was normal. A diagnosis of Susac syndrome was made. The patient initially received oral steroids followed by intravenous steroids and mycophenolate mofetil because of new branch retinal artery occlusions. Thirteen months after initial presentation, the vision was stable at 20/20 in both eyes.

CONCLUSION

It is a diagnostic challenge when recurrent branch retinal artery occlusion secondary to Susac syndrome presents without the classic symptoms. Optical coherence tomography angiography and subtle magnetic resonance imaging findings aided in early recognition of the diagnosis in our patient. Ultra-wide-field fluorescein angiography was an important tool in disease monitoring. Aggressive management with intravenous corticosteroids and initiation of immunosuppression resulted in long-term preservation of vision and improvement in visual field.

Fundamental mechanistic insights from rare but paradigmatic neuroimmunological diseases

The pathophysiology of complex neuroimmunological diseases, such as multiple sclerosis and autoimmune encephalitis, remains puzzling - various mechanisms that are difficult to dissect seem to contribute, hampering the understanding of the processes involved. Some rare neuroimmunological diseases are easier to study because their presentation and pathogenesis are more homogeneous. The investigation of these diseases can provide fundamental insights into neuroimmunological pathomechanisms that can in turn be applied to more complex diseases. In this Review, we summarize key mechanistic insights into three such rare but paradigmatic neuroimmunological diseases - Susac syndrome, Rasmussen encephalitis and narcolepsy type 1 - and consider the implications of these insights for the study of other neuroimmunological diseases. In these diseases, the combination of findings in humans, different modalities of investigation and animal models has enabled the triangulation of evidence to validate and consolidate the pathomechanistic features and to develop diagnostic and therapeutic strategies; this approach has provided insights that are directly relevant to other neuroimmunological diseases and applicable in other contexts. We also outline how next-generation technologies and refined animal models can further improve our understanding of pathomechanisms, including cell-specific and antigen-specific CNS immune responses, thereby paving the way for the development of targeted therapeutic approaches.

A rare presentation of Susac syndrome: Report of three pediatric cases

Susac syndrome is a rare disorder that is clinically characterized by encephalopathy, retinopathy and hearing loss. Most of the reported cases in the literature are adult patients, pediatric presentation is extremely rare. Here we present three pediatric patients aged between 10-15; diagnosed as Susac syndrome. They all had thalamic involvement in addition to typical callosal lesions. All of the three patients had a monophasic course and good treatment response.

Leptomeningeal enhancement on post-contrast FLAIR images for early diagnosis of Susac syndrome

BACKGROUND

Leptomeningeal enhancement (LME) is a key feature of Susac syndrome (SuS) but is only occasionally depicted on post-contrast T1-weighted images (T1-WI).

OBJECTIVE

As post-contrast fluid-attenuated inversion recovery (FLAIR) may be more sensitive, our aim was to assess LME in SuS on this sequence.

METHODS

From 2010 to 2020, 20 patients with definite SuS diagnosis were retrospectively enrolled in this multicentre study. Two radiologists independently assessed the number of LME on post-contrast FLAIR and T1-WI acquisitions performed before any treatment. A chi-square test was used to compare both sequences and the interrater agreement was calculated.

RESULTS

Thirty-five magnetic resonance imagings (MRIs) were performed before treatment, including 19 post-contrast FLAIR images in 17 patients and 25 post-contrast T1-WI in 19 patients. In terms of patients, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (17/17 (100%) vs. 15/19 (79%), p < 0.05). In terms of sequences, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (19/19 (100%) vs. 16/25 (64%), p < 0.005). LME was disseminated at both supratentorial (19/19) and infratentorial (18/19) levels on post-contrast FLAIR, contrary to post-contrast T1-WI (3/25 and 9/25, respectively). Interrater agreement was excellent for post-contrast FLAIR (κ = 0.95) but only moderate for post-contrast T1-WI (κ = 0.61).

CONCLUSION

LME was always observed and easily visible on post-contrast FLAIR images prior to SuS treatment. In association with other MRI features, it is highly indicative of SuS.

Headache in Susac's Syndrome

PURPOSE OF REVIEW

Provide an overview of the current diagnosis, pathophysiology, and treatment of Susac's syndrome (SuS), with special emphasis on summarizing what is currently known about headache as a symptom of disease activity.

RECENT FINDINGS

The most recent literature in SuS has focused on furthering the understanding of the underlying pathology and efficacy of treatments for SuS. The importance of early recognition to facilitate timely treatment and avoid long-term disability has been highlighted. Headache, the most common symptom experienced by patients with SuS, can occur up to 6 months in advance of other symptoms, and exacerbations of headache can herald increased disease activity. Susac's syndrome (SuS) is a rare disorder classically characterized by triad of encephalopathy, branch retinal artery occlusion (BRAO), and sensory neuronal hearing loss (SNHL). The full triad is uncommon at initial presentation, which can confound efforts to make timely diagnosis and treatment decisions. Headache is the most common symptom in SuS, is often an early feature, and can help separate SuS from other diagnoses in the differential. However, the features and management of the headache associated with SuS have not been systematically defined in the literature.

Corpus callosum lesions are not inextricably linked to CNS symptoms in reported cases of susac syndrome

OBJECTIVE

To evaluate whether corpus callosum (CC) lesions are inextricably linked to CNS symptoms of Susac Syndrome (SuS) by reviewing published cases to find instances where: 1) CC lesions occur without CNS symptoms, and 2) whether patients with CNS symptoms lack CC lesions.

METHODS

100 reported cases of SuS were identified in PubMed. Clinical symptoms, para-clinical testing and MRI data were collected both at presentation and for any available follow-up and analyzed. Cases were reviewed to evaluate how they met European diagnostic criteria for SuS (EuSaC) both at first presentation and at most recent evaluation after followup, if available.

RESULTS

Limited disease is a common finding in the 100 recently published cases and 56/100 cases did not meet EuSaC probable or definite criteria at first evaluation. CC lesions were not inextricably linked with encephalopathy, as 8 cases presented with CC lesions without CNS symptoms and 6 cases had encephalopathy without CC lesions. In five patients with both eye and ear involvement, isolated CC lesions or CNS symptoms could enhance diagnostic certainty. This may reduce specificity, but would increase sensitivity, ultimately benefitting patient care.

CONCLUSION

Patients with early SuS rarely meet diagnostic criteria at presentation. Future diagnostic criteria could make use of unlinked CC lesions or CNS symptoms.

Susac's Syndrome: An Updated Review

Susac's syndrome is a rare immune-mediated endotheliopathy that mainly affects young women. It is characterised by the presence of encephalopathy, retinal vaso-occlusive disease and hearing loss. Diagnosis is based on the clinical presentation, brain magnetic resonance imaging, retinal fluorescein angiography, and audiometry. Treatment consists of immunosuppressive therapy. This review focuses on recent developments in the diagnosis and management of the condition.

Susac Syndrome and Pregnancy

Susac syndrome (SuS) is a rare poorly characterised disorder that affects the brain, retina, and cochlea. Here, we present a case of a 31-year-old pregnant female with a new diagnosis of SuS that was successfully managed to 36 weeks of gestation with minimal disease burden to both the mother and newborn. She was treated initially using intravenous methylprednisolone followed by oral prednisone, and intravenous immunoglobulin (IVIg). We stress the importance of a multidisciplinary approach, involving both neurology and maternal-fetal medicine, and provide guidance in navigating the various options for immunosuppressive therapy during pregnancy.

Vestibular function assessment of Susac syndrome patients by the video head impulse test and cervical vestibular-evoked myogenic potentials

BACKGROUND

Susac syndrome (retino-cochleo-cerebral vasculopathy, SuS) is an autoimmune endotheliopathy characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. In contrast to data regarding auditory function, data measuring vestibular function is sparse and the cervical vestibular-evoked myogenic potentials (cVEMPs).

OBJECTIVE

To determine whether the video head impulse test (vHIT) can serve as a confirmatory assessment of vestibulocochlear dysfunction in cases of suspected SuS.

METHODS

Seven patients diagnosed with SuS underwent pure tone audiometry, a word recognition test, cVEMPs and the vHIT.

RESULTS

Five patients were diagnosed with definite SuS, and two with probable SuS. Two patients were asymptomatic for hearing loss or tinnitus, and no sensorineural hearing loss was detected by audiograms. Four patients complained of tinnitus, and three patients reported experiencing vertigo. Three patients had abnormal cVEMPs results. All seven patients' vHIT results were normal, except for patient #2, who was one of the three who complained of vertigo. The calculated gain of her left anterior semicircular canal was 0.5, without saccades.

CONCLUSIONS

This is the first study to describe the results of the vHIT and cVEMPs among a group of patients with SuS. The results suggest that the vHIT should not be the only exam used to assess the function of the vestibular system of SuS patients.

Vestibular function assessment of Susac syndrome patients by the video head impulse test and cervical vestibular-evoked myogenic potentials

BACKGROUND

Susac syndrome (retino-cochleo-cerebral vasculopathy, SuS) is an autoimmune endotheliopathy characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. In contrast to data regarding auditory function, data measuring vestibular function is sparse.

OBJECTIVE

To determine whether the video head impulse test (vHIT) can serve as a confirmatory assessment of vestibulocochlear dysfunction in cases of suspected SuS.

METHODS

Seven patients diagnosed with SuS underwent pure tone audiometry, a word recognition test, cervical vestibular-evoked myogenic potentials (cVEMPs), and the v-HIT.

RESULTS

Five patients were diagnosed with definite SuS, and two with probable SuS. Two patients were asymptomatic for hearing loss or tinnitus, and no sensorineural hearing loss was detected by audiograms. Four patients complained of tinnitus, and three patients reported experiencing vertigo. Three patients had abnormal cVEMPs results. All seven patients' vHIT results were normal, except for patient #2, who was one of the three who complained of vertigo. The calculated gain of her left anterior semicircular canal was 0.5, without saccades.

CONCLUSIONS

This is the first study to describe the results of the vHIT and cVEMPs among a group of patients with SuS. The results suggest that the vHIT should not be the only exam used to assess the function of the vestibular system of SuS patients.

Neuro-ophthalmic manifestations of Susac syndrome

PURPOSE OF REVIEW

This review discusses general features and organ-specific presentations of Susac syndrome as well as diagnosis and treatment.

RECENT FINDINGS

Latest literature regarding demographics, new diagnostic modalities such as optical coherence tomography and treatment options for Susac syndrome are discussed in detail in this review, summarizing the most recent updated information.

SUMMARY

Susac syndrome is a rare, underdiagnosed, and often misdiagnosed disease that can lead to severe complications such as deafness, vision loss, dementia, and death. It involves the central nervous system and may mimic other neurological and neuro-ophthalmological diseases.

Susac syndrome (Retino-cochleo-cerebral vasculitis), the ophthalmologist in the role of the whistleblower

BACKGROUND/PURPOSE

Susac syndrome is a rare microangiopathy of suspected autoimmune origin affecting arteries of the retina, the cochlea and the brain. The aim of the study was to give a review of the disease entity and determine the proportion of cases and their characteristics in a uveitis referral centre.

PATIENTS AND METHODS

Charts of patients with the diagnosis of Susac syndrome seen in the Uveitis Clinic of the Centre for Ophthalmic Specialised Care (COS), Lausanne, Switzerland were reviewed retrospectively to determine the frequency of such cases in a uveitis referral centre. Clinical symptoms and signs, functional data, imaging signs and evolution were analysed in the 3 COS cases and one case shared with the Uveitis Clinic of the Department of Ophthalmology, University of Innsbruck, Austria. Characteristic signs were searched possibly allowing a prompt diagnosis.

RESULTS

During the period from 1994 to 2019 (24 years, 2045 patients), 3 charts with the diagnosis of Susac syndrome were found (0.15%). The whole collective, including the additional case, comprised three women aged 28, 32 and 63 at presentation and one man, aged 42. None of the 3 cases that were referred were diagnosed beforehand. The characteristic item found in all 4 cases was the abrupt arterial stop or segmental interruption of arteries and increased staining of arterial wall on angiography more clearly shown on indocyanine green angiography that can potentially be proposed as a crucial diagnostic element. All 4 cases responded to dual steroidal and non-steroidal immunosuppression. Under treatment, all four patients did not show any further evolution.

CONCLUSION

Susac syndrome is a multilocation arteritis of the head that can involve the eye, ear and brain often first diagnosed by the ophthalmologist. The diagnosis is rapidly reached in uveitis referral centres but seems to be missed otherwise, A helpful angiographic sign to be searched is an abrupt or segmental arterial stop and increased staining of the arterial wall more clearly seen on indocyanine green angiography. Patients often present first to the ophthalmologist who should be acting as a whistleblower to avoid severe involvement of the brain.

Ultra-high-field 7-T MRI in multiple sclerosis and other demyelinating diseases: from pathology to clinical practice

Magnetic resonance imaging (MRI) is essential for the early diagnosis of multiple sclerosis (MS), for investigating the disease pathophysiology, and for discriminating MS from other neurological diseases. Ultra-high-field strength (7-T) MRI provides a new tool for studying MS and other demyelinating diseases both in research and in clinical settings. We present an overview of 7-T MRI application in MS focusing on increased sensitivity and specificity for lesion detection and characterisation in the brain and spinal cord, central vein sign identification, and leptomeningeal enhancement detection. We also discuss the role of 7-T MRI in improving our understanding of MS pathophysiology with the aid of metabolic imaging. In addition, we present 7-T MRI applications in other demyelinating diseases. 7-T MRI allows better detection of the anatomical, pathological, and functional features of MS, thus improving our understanding of MS pathology in vivo. 7-T MRI also represents a potential tool for earlier and more accurate diagnosis.