Anti-endothelial serum antibodies in a patient with Susac's syndrome

Circulating Anti-Endothelial Cell Antibodies in Patients with Geographic Atrophy Related to Dry Age-Related Macular Degeneration

Background and Objectives: Age-related macular degeneration (AMD) is one of the leading causes of central vision loss among elderly patients, and its dry form accounts for the majority of cases. Although several causes and mechanisms for the development and progression of AMD have previously been identified, the pathogenesis of this complex disease is still not entirely understood. As inflammation and immune system involvement are strongly suggested to play a central role in promoting the degenerative process and stimulating the onset of complications, we aimed to analyze the frequency of serum anti-retinal (ARAs) and anti-endothelial cell antibodies (AECAs) in patients with dry AMD and to determine their relationship with the clinical features of the disease, notably the area of geographic atrophy (GA). Materials and Methods: This study included 41 patients with advanced-stage dry AMD and 50 healthy controls without AMD, matched for gender and age. ARAs were detected by indirect immunofluorescence using monkey retina as an antigen substrate, and the presence of AECAs was determined using cultivated human umbilical vein endothelial cells and primate skeletal muscle. Results: ARAs were detected in 36 (87.8%) AMD patients (titers ranged from 1:20 to 1:320) and in 16 (39.0%) (titers ranged from 1:10 to 1:40) controls (p = 0.0000). Twenty of the forty-one patients (48.8%) were positive for AECAs, while in the control group, AECAs were present only in five sera (10.0%). The titers of AECAs in AMD patients ranged from 1:100 to 1:1000, and in the control group, the AECA titers were 1:100 (p = 0.0001). There were no significant correlations between the presence of AECAs and disease activity. Conclusions: This study demonstrates a higher prevalence of circulating AECAs in patients with dry AMD; however, no correlation was found between the serum levels of these autoantibodies and the area of GA.

Therapeutic plasma exchange in refractory Susac's syndrome: A brief report

Susac's syndrome (SuS) is an autoimmune endotheliopathy that typically presents with the clinical triad of encephalopathy, hearing loss, and branch retinal artery occlusion. It has a wide range of possible presentations, and its pathogenesis remains uncertain. Fulminant and refractory cases are difficult to treat, and no standard treatment protocol has been established. However, therapeutic plasma exchange (TPE) has been described as an adjunctive therapy in several SuS cases. Herein we present a case of a 63-year-old male with debilitating encephalopathy and recent hearing and vision loss, who responded favorably to TPE. Given this and other published reports of plasma exchange therapy for SuS, treatment protocols should consider TPE in early stages of disease.

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.

A young soldier with Susac syndrome: a case report

Background

Susac syndrome is a rare disease with multisystem manifestations. While the exact pathogenesis is not known, it has been proposed to be an autoimmune endotheliopathy affecting the microvasculature of the brain, retina, and inner ear. The disease is characterized by a triad of encephalopathy, vision loss, and hearing loss. However, patients may not have the triad at initial presentation and present with only a single finding.

Case presentation

A 25-year-old male resident of Panu Akil presented to Combined Military Hospital Lahore with complaints of dizziness and vertigo associated with severe migraine like headaches. He experienced sudden painless loss of vision in his right eye and was admitted to the medical intensive care unit. On examination, he had right-beating nystagmus and diplopia along with scintillating scotoma. After his admission, contrast-enhanced magnetic resonance imaging (MRI) was done which showed numerous enhancing bilateral white matter internal capsule micro-infarcts indicating typical “string of pearls” sign and a snowball lesion on the corpus callosum. His fundus fluorescein angiography (FFA) did not exhibit any branched retinal artery occlusions (BRAO). Fundoscopy showed the presence of drusen spots. His pure tone audiometry was unremarkable. Based on the highly characteristic findings present on the MRI, a diagnosis of Susac syndrome was made. He was started on injection methylprednisolone 1 gm IV in 500 ml normal saline over 1 h once a day for 5 days and then once a week for 8 weeks. He was also started on tablet mycophenolate mofetil 500 mg once daily for 7 days. Patient showed marked clinical improvement afterwards.

Conclusions

Susac syndrome is a rare multisystem illness with an often insidious presentation. Patients can be misdiagnosed due to the nonspecific nature of the early complaints present in the disease. High index of suspicion is required for timely diagnosis and adequate management. Although no specific guidelines exist, management consists mainly of immunosuppressants.

Susac's syndrome - A new ocular finding and disease outcome

BACKGROUND

Susac's syndrome, a rare autoimmune vasculo-occlusive disease, may pose a diagnostic challenge and result in a devastating ocular and systemic outcome. Our study identifies a new retinal finding and evaluates disease outcome. We aimed to assess clinical and imaging findings, systemic manifestations and disease outcome in patients with ocular Susac's syndrome under immunosuppressive/immunomodulation therapies.

METHODS

Retrospective tertiary center study including patients with a diagnosis of Susac's syndrome with >12 months follow up. Medical record review including ocular, neurological and auditory clinical and imaging findings, and treatment modalities. Main outcome measures were clinical manifestations and disease outcome.

RESULTS

Seven patients (14 eyes) with a mean age of 34.1 years were included. Mean follow-up was 31.9 months (12.4-72.4). All had bilateral ocular disease. Retinal microaneurysms, a new ocular finding, were demonstrated in 5 patients and persisted at the final visit. In 5 eyes, they further extended during follow-up. All were treated with immunosuppressive drugs and 5/7 additional immunomodulation therapy. At last examination, best corrected visual acuity was >20/40 in all eyes, 1/10 eyes had visual field deterioration, no eye had active ocular disease, all patients achieved neurological stability, and 1 patient had auditory deterioration.

CONCLUSION

Retinal microaneurysms, a new ocular finding in Susac's syndrome, were present in most of our patients, indicating ischemic retinal damage. Immunosuppressive and immunomodulation therapies seem to be highly effective in the control of disease activity.

Assessment of the microvasculature in poppers maculopathy

Purpose

To investigate a possible microvascular component of poppers maculopathy (PMP) using optical coherence tomography angiography (OCTA).

Methods

Twelve patients suffering from poppers maculopathy were included. Health records, optical coherence tomography (OCT), and OCTA data was gathered and compared to a healthy control group (HC). PMP lesion type was determined by manifestation in OCT. OCTA-based evaluation of retinal vascular plexus and choriocapillaris (CC) was executed. Vessel density (VD) and vessel length density (VLD) in superficial and deep capillary plexus (SCP, DCP), as well as flow deficits (FD), within the foveal avascular zone (FAZ) in CC were assessed.

Results

Median age of PMP patients was 40 (min 24; max 64) years, all male. Eleven patients presented with ellipsoid zone-type lesions; one patient showed a vitelliform-type lesion. No qualitative microvascular changes between PMP patients and HC were identified. Quantitative values for VD and VLD of SCP and DCP did not differ in between the two groups. The analysis of FDs in CC showed no deviation from PMP patients to HC.

Conclusions

No vascular anomalies in qualitative and quantitative analysis in OCTA were detected in PMP patients. The constitution of the CC within FAZ of PMP patients does not differ from HC when assessed as FD.

A Novel Quantitative Assessment Method of Disease Activity in Susac's Syndrome Based on Ultra-Wide Field Imaging

PURPOSE

Susac's syndrome (ScS) is a rare, potentially life-threatening auto-immune disease. Ophthalmic imaging can depict characteristic branch retinal arteriolar occlusions (BRAO) and arterial wall hyperfluorescences that form one of the three diagnostic pillars of this condition. We aim to demonstrate that ophthalmological ultrawide-field (UWF) imaging allows for a qualitative and quantitative assessment in ScS, with application in diagnostics, monitoring of treatment response, and titration of therapy.

METHODS

In seven ScS patients (♀:♂ = 2:5), with a median age of 36 years, range 18 to 57 years, serial ultrawide-field fluoresceine angiography (UWF-FA) studies were performed, with adjunctive wide-field optical coherence tomography angiography analyses (WF-OCTA) in five patients. Mean follow-up was 12.5 months, range 1 to 46 months.

RESULTS

In all seven patients, BRAO and arterial wall hyperfluorescences were present in UWF-FA and calculated as a quantitative score of disease activity in fluorescein angiography (DA-FA) during follow-up visits. Treatment response was accessible in follow-up imaging as partial reperfusion of retinal vessels, resolution of arterial wall hyperfluorescences and consequently, in reduction of DA-FA score. While qualitative analysis of WF-OCTA provided further information about retinal micro-perfusion, quantitative analysis did not demonstrate a vectored treatment response as it was accessible in FA.

CONCLUSION

DA-FA score, as a comprehensive disease activity parameter in ScS has potential to facilitate optimal communication between subspecialties and thereby treatment success.

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.

EVALUATION OF TUMOR NECROSIS FACTOR INHIBITOR THERAPY IN SUSAC SYNDROME

PURPOSE

To evaluate the effect of tumor necrosis factor (TNF) inhibitor therapy on ocular relapses in patients with Susac syndrome.

METHODS

Multicenter retrospective cohort study of patients diagnosed with Susac syndrome according to classical clinical criteria. We evaluated the disease activity before and after introduction of anti-TNF therapy and its value as a steroid-sparing agent.

RESULTS

Five patients were included. All were initially treated with a combination of corticosteroids and classical immunosuppressive drugs. Infliximab was started in three patients, and adalimumab was started in two patients. Patients had on average 5 ocular relapses during a mean follow-up time of 2.59 years before introducing a TNF inhibitor, corresponding with on average 1.93 relapses per year. After the introduction of an anti-TNF agent, this number was reduced by factor 5.51 to an average of 0.35 relapses per year for a mean follow-up of 2.86 years (P = 0.10). Before anti-TNF introduction ocular relapses occurred at a mean daily dose of 34 mg of prednisone, whereas with anti-TNF treatment, corticosteroid administration could be completely stopped in four patients with one patient still needing 5 mg daily (P = 0.10). Infliximab and adalimumab generally were well tolerated, and no serious adverse events were reported.

CONCLUSION

Although not statistically significant, our results suggest that anti-TNF therapy can be a valuable option for the treatment of ocular Susac syndrome and may especially be considered in those patients unresponsive to more conventional immunosuppressive treatment.

Susac syndrome and pregnancy: a review of published cases and considerations for patient management

Susac syndrome (SuS) is a rare autoimmune endotheliopathy leading to hearing loss, branch retinal artery occlusions and encephalopathy. Young females are more frequently affected than males, making counselling for family planning an important issue. We reviewed published cases on SuS during pregnancy or in the postpartum period, and selected 27 reports describing the details of 33 patients with SuS. Treatment options and implications for pregnancy and breastfeeding are discussed. We propose new areas for research and suggest a management strategy.

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.

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.

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.

Increased incidence of Susac syndrome: a case series study

BACKGROUND

Susac syndrome (SuS) is a rare condition characterized by a clinical triad of sensorineural hearing loss, branch artery occlusion and encephalopathy. This study reports an increased incidence of SuS in Israel. We describe the clinical characteristics of these patients, diagnostic procedures and the use and subsequent outcomes of newly published treatment guidelines.

METHODS

This is a single center retrospective study. Patients who were diagnosed with SuS between July 2017 and August 2018 were enrolled in this study.

RESULTS

Seven patients were diagnosed with SuS according to the diagnostic criteria in a time period of 13 months. The annual incidence was recently evaluated in Austria to be 0.024/100000, therefore, our case series represent at least a 5.4- fold increase in the annual incidence of SuS expected in Israel and a 7-fold increase in the annual incidence expected in our medical center. Mean time from the onset of the symptoms to diagnosis was three weeks and follow-up time was twenty four months. Recent exposure to cytomegalovirus was serologically evident in three patients and one patient had high titer of anti-streptolysin antibody. All patients underwent brain MRI, fluorescein angiography and audiometry. All patients were treated according to the newly recommended guidelines. All patients achieved clinical and radiological stability.

CONCLUSIONS

We report of an increased incidence of SuS in Israel. Infectious serological findings may imply a post infectious mechanism. The use of the recommended diagnostic procedures reduced the time to diagnosis. Newly published treatment guidelines led to favorable clinical outcomes.

Diagnostic Criteria and Treatment Algorithm for Susac Syndrome

BACKGROUND

Susac syndrome (SS) classically presents with the clinical triad of retinal artery occlusion, sensorineural hearing loss, and encephalopathy and the neuroimaging triad of white matter lesions, deep gray matter lesions, and leptomeningeal disease. However, patients can present with an incomplete clinical or neuroimaging triads making diagnosis difficult in certain situations. A standard treatment paradigm also is lacking in this illness. It is important for neuro-ophthalmologists to recognize clinical and radiographic findings that are pathognomonic for this syndrome and have a basic understanding of the available treatment options.

EVIDENCE ACQUISITION

Review of medical literature.

RESULTS

A definite diagnosis of SS is made when the clinical triad or the neuroimaging triad is present. There are numerous reports of 2 other imaging findings in this condition: arteriolar wall hyperfluorescence (AWH) on fluorescein angiography in retinal arterioles remote from retinal ischemia and central callosal lesions on MRI. Both of these imaging findings are diagnostic of SS. Gass plaques in retinal arterioles are almost always seen in the acute phase of the illness but are not pathognomonic for SS. The most common medications used in this syndrome are corticosteroids and intravenous immunoglobulin. A number of other medications have been used including mycopheolate, rituximab, azathioprine, and cyclophosphamide.

CONCLUSIONS

In the absence of the clinical triad or magnetic resonance imaging triad for SS, AWH remote from retinal vascular injury and central callosal lesions are confirmatory of the diagnosis because they have never been described in any other condition. The presence of Gass plaques in retinal arterioles should strongly suggest the diagnosis. Despite the lack of clinical trial data, patients with SS must be treated promptly and aggressively. In more fulminant cases, addition of mycophenolate mofetil or rituximab is required, followed by cyclophosphamide when disease is refractory to other medications.

CD8+ T cell-mediated endotheliopathy is a targetable mechanism of neuro-inflammation in Susac syndrome

Neuroinflammation is often associated with blood-brain-barrier dysfunction, which contributes to neurological tissue damage. Here, we reveal the pathophysiology of Susac syndrome (SuS), an enigmatic neuroinflammatory disease with central nervous system (CNS) endotheliopathy. By investigating immune cells from the blood, cerebrospinal fluid, and CNS of SuS patients, we demonstrate oligoclonal expansion of terminally differentiated activated cytotoxic CD8+ T cells (CTLs). Neuropathological data derived from both SuS patients and a newly-developed transgenic mouse model recapitulating the disease indicate that CTLs adhere to CNS microvessels in distinct areas and polarize granzyme B, which most likely results in the observed endothelial cell injury and microhemorrhages. Blocking T-cell adhesion by anti-α4 integrin-intervention ameliorates the disease in the preclinical model. Similarly, disease severity decreases in four SuS patients treated with natalizumab along with other therapy. Our study identifies CD8+ T-cell-mediated endotheliopathy as a key disease mechanism in SuS and highlights therapeutic opportunities.

Autoimmune vertigo: an update on vestibular disorders associated with autoimmune mechanisms

The role of the immune system in mediating cochleovestibular pathologies has received increasing attention in recent years. Autoimmune vertigo may be an invalidating condition and may worsen the quality of life of affected patients, especially in the cases of delayed diagnosis. Since the etiopathogenesis is still not clear, also the treatment is not yet completely delineated. According to the clinical presentation, autoimmune vertigo can present as an isolated disorder or in association with systemic autoimmune diseases. The main feature in autoimmune vertigo is the presence of an abnormal immune response, in either absence or presence of systemic autoimmune disease, directed against delicate components of the inner ear. This may determine a functional or anatomical alteration, with an inflammatory reaction often devastating for hearing and balance. Being the exact pathogenesis unknown, the diagnosis of autoimmune vertigo is based either on clinical criteria or on a positive response to steroids. The earlier the diagnosis is made, the sooner the therapy can be installed, giving a chance to the recovery of inner ear damages. Corticosteroids represent the most effective and universally accepted treatment, even if other immunomodulatory drugs are now having a more extensive use. HIGHLIGHTS: Vertigo is relatively frequent in autoimmune diseases; however, it is often misdiagnosed or attributed to central nervous system alterations rather to specific inner ear involvement. Vertigo and other audiovestibular symptoms may be the first manifestation of an autoimmune disease and if correctly addressed could significantly contribute to early diagnosis of the underlying autoimmune disease. Early diagnosis of immune-related vertigo can lead to prompt initiation of targeted therapy with elevate chances of preventing irreversible damages to the inner ear. The presence of alternating phases of well-being and disabling symptoms in patients with vertigo should always been considered, as they could suggest an underlying autoimmune condition.

Otologic manifestations of Susac syndrome

Susac syndrome, a rare autoimmune disorder first described as a classic triad (encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss) in 1979 by renowned physician John O. Susac, has been an advancing area of clinical interest and scientific research over the last several decades. This comprehensive review aims to succinctly highlight the breadth and detail of this enigmatic disease, with a primary focus on otologic manifestations. Topics discussed include epidemiology, pathophysiology, clinical manifestations, differential diagnoses, classification schema, laboratory investigations, characteristic audiometric findings, high-yield radiographic imaging, temporal bone histopathology, treatment strategies and overall prognosis.

INTRAVITREAL TRIAMCINOLONE IN SUSAC SYNDROME

PURPOSE

To report the use of intravitreal triamcinolone for Susac Syndrome in one patient.

METHODS

Case report.

RESULTS

A 23-year-old woman presented with presented with sudden visual loss in the left eye with associated neurologic symptoms. Ophthalmic examination and fluorescein angiography showed multiple areas of branch retinal artery occlusion, bilaterally. Magnetic resonance imaging showed dot-like, diffusion-restricted lesions in the corpus callosum, and audiometry showed low-frequency sensory hearing loss, compatible with Susac Syndrome. The patient received a single intravitreal injection of triamcinolone (4 mg) in the left eye. One week later, before beginning systemic corticosteroids, all signs and symptoms resolved in the left eye only.

CONCLUSION

In cases of delayed systemic corticosteroid therapy, intravitreal triamcinolone resolves the ocular manifestations of Susac Syndrome.

Anatomical and functional correlation in Susac syndrome: multimodal imaging assessment

Background

Susac’s syndrome (SuS) is an uncommon disease characterized by retinal microangiopathy that may be assessed more accurately with optical coherence tomography angiography (OCTA), a new imaging technique which provides a retinal microvasculature map. The purpose of this case report is to describe the multimodal imaging findings of SuS correlating OCTA with functional tests.

Case presentation

Retrospective review of one case with clinical and imaging evidence of SuS. Color fundus photograph, fluorescein angiography (FA), OCTA, microperimetry (MP) and visual field (VF) tests were analyzed at the time of presentation and at 1- and 6-month visit following initiation of treatment. The study patient underwent standard treatment for SuS. The patient age was 31 year-old and the baseline visual acuity was 20/60 and 20/20 in the right and left eyes, respectively. At presentation, FA showed branch retinal arterial occlusion within the macular area of the right eye and vascular leakage in the periphery of the left eye. OCTA demonstrated areas of superficial and deep retinal vascular plexuses hypoperfusion in both eyes. The OCTA segmentations in the outer retina and choriocapillaris were normal. The low VF and MP sensitivity signals precisely corresponded to the topography of decreased vascular perfusion seen on the OCTA density map in both eyes. Six months after specific SuS therapy, retinal vascular perfusion showed partial improvement in both eyes.

Conclusion

OCTA may demonstrate superficial and deep retinal vascular non-perfusion without choriocapillary vasculature changes in SuS. This anatomical information given by OCTA corresponded to points of low sensitivity on functional tests represented by VF and MP.

Potential benefits of early aggressive immunotherapy in Susac syndrome

Susac syndrome is a rare vasculopathy of unknown aetiology, affecting prominently young women and electively targeting brain (encephalopathy), retina (visual field defects), and cochlea (hearing loss), of which optimal treatment has yet to be established. We report clinical, CSF and MRI features together with the long-term outcome in a monocentric series of eight consecutive patients with unusual sex ratio (5 male; 3 female), to define the best diagnostic/therapeutic strategy. Six patients presented with the classical clinical triad within less than 6 months after symptoms onset; two did not suffer from sensorineural hearing loss. All but one received a treatment combining high doses of methylprednisolone and cyclophosphamide intravenously. The first two patients had very delayed diagnosis (6-4 months) resulting in severe cognitive sequelae. The third one had only mildly delayed diagnosis (2 months) with subsequent behaviour impairment and severe right hypoacousia. All three were unable to return to work. The last five patients who had early diagnosis and undelayed aggressive treatment were able to resume their professional activities.

Serum anti-endothelial cell antibodies in patients with age-related macular degeneration treated with intravitreal bevacizumab

PURPOSE

To analyse the prevalence and changes in circulating anti-endothelial cell antibodies (AECA) during anti-vascular endothelial growth factor (anti-VEGF) therapy.

METHODS

Ninety-eight patients with exudative age-related macular degeneration (AMD) were treated with intravitreal bevacizumab. Fifty sex- and age-matched healthy subjects were used as controls. Serum AECA were detected using indirect immunofluorescence on primate skeletal muscle and cultivated human umbilical vein endothelial cells (HUVEC). These investigations were repeated at 4-week intervals within 8 months of follow-up.

RESULTS

At baseline examination, 30 of the 98 patients (30.6%) were positive for AECA. The titres of AECA ranged from 1:10 to 1:320. In the control group, AECA were present in only nine sera (18%) with titres ranging between 1:20 and 1:80 (p = 0.0000). The greatest rates of reduction of AECA titres were observed during the 'loading' phase of therapy. During the 'maintenance' phase, the rates of changes in serum AECA levels were less significant and remained constant. In follow-up period in 13 patients (13.3%), serum AECA were detected de novo in titres of 1:10 to 1:80. Statistical analysis did not show any significant correlation between the presence of AECA and activity of the disease.

CONCLUSIONS

There is growing evidence that AMD is an immune-mediated disease, and thus it cannot be excluded that AECA may be involved in its pathogenesis and progression. We also speculate that AECA develop in response to retinal damage and anti-VEGF therapy.

RETINAL LESION EVOLUTION IN SUSAC SYNDROME

PURPOSE

To describe retinal lesion development in Susac syndrome during acute, postacute, and late phases of the disease.

METHODS

Cross-sectional study of four patients with Susac syndrome and longitudinal short-interval case study of one additional patient. Retinal changes were analyzed with high-resolution spectral domain optical coherence tomography and retinal fluorescein angiography.

RESULTS

Retinal Susac syndrome lesions comprise four different lesion sections, which can be distinguished in acute and postacute phases of the disease: a primary section at the site of branch retinal artery occlusion, which spans more layers than supplied by the affected vessel; hypoxic sections from superficial and deep capillary networks; and an axonal damage section with degenerating axons from perished ganglion cells in the main and hypoxic sections. In the later stages, main and hypoxic lesion sections can no longer be distinguished, and both show degeneration from outer plexiform to retinal nerve fiber layers.

CONCLUSION

The dynamics of lesion development and morphologically distinct lesion sections suggest more complex mechanisms of lesion evolution beyond an isolated endothelial immune reaction and subsequent hypoxic tissue damage. The characteristic lesion morphology assists in differentiating the diagnosis of acute visual loss in neuroinflammatory disease. Specificity of the identified changes has to be determined in future studies also including patients with other retinal vascular diseases.

[Ultrahigh field MRI in context of neurological diseases]

Ultrahigh field magnetic resonance imaging (UHF-MRI) has recently gained substantial scientific interest. At field strengths of 7 Tesla (T) and higher UHF-MRI provides unprecedented spatial resolution due to an increased signal-to-noise ratio (SNR). The UHF-MRI method has been successfully applied in various neurological disorders. In neuroinflammatory diseases UHF-MRI has already provided a detailed insight into individual pathological disease processes and elucidated differential diagnoses of several disease entities, e.g. multiple sclerosis (MS), neuromyelitis optica (NMO) and Susac's syndrome. The excellent depiction of normal blood vessels, vessel abnormalities and infarct morphology by UHF-MRI can be utilized in vascular diseases. Detailed imaging of the hippocampus in Alzheimer's disease and the substantia nigra in Parkinson's disease as well as sensitivity to iron depositions could be valuable in neurodegenerative diseases. Current UHF-MRI studies still suffer from small sample sizes, selection bias or propensity to image artefacts. In addition, the increasing clinical relevance of 3T-MRI has not been sufficiently appreciated in previous studies. Although UHF-MRI is only available at a small number of medical research centers it could provide a high-end diagnostic tool for healthcare optimization in the foreseeable future. The potential of UHF-MRI still has to be carefully validated by profound prospective research to define its place in future medicine.

Recurrence of Susac Syndrome following 23 Years of Remission

Susac syndrome is an autoimmune microangiopathy affecting the brain, retina and inner ear (cochlea and semicircular canals), leading to encephalopathy, branch retinal artery occlusions (BRAOs) and asymmetric neurosensory hearing loss, respectively. The natural history and long-term prognosis are variable as the disease has been shown to be monophasic and self-limiting, polycyclic or chronic continuous. We describe a 35-year-old woman who presented with a sudden hearing loss in the left ear in the 37th week of her second pregnancy. She subsequently developed BRAO in the right eye 2.5 months after having given birth. MRI findings included round lesions in the corpus callosum which are pathognomonic for Susac syndrome. Previous patient records documented encephalopathy, sudden deafness of the right ear and visual field defects in the left eye at the age of 12, followed by permanent hearing and visual defects. We expand on the variability in the course of Susac syndrome as recurrence may occur after as long as 23 years. Cases of monophasic self-limiting Susac syndrome may in fact turn polycyclic with an interval of more than 2 decades between the bouts of the disease. In these cases, suspecting the development of exacerbation early is important in order to start the treatment promptly.

Susac's syndrome--pathogenesis, clinical variants and treatment approaches

Susac's syndrome is a rare disease that is characterised by the clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. It was first described as a distinctive syndrome by Susac in 1979. There have been 304 reported individual patients with Susac's syndrome. Etiopathogenesis is not clear, although it is now thought that it is an immune-mediated endotheliopathy that affects the microvasculature of the brain, retina, and inner ear. Antiendothelial cell antibodies (AECAs) play an important role in mediating the endothelial cell injury with consequent deposition of thrombotic material in the lumen of the small vessel. In biopsies of the brain, microinfarcts with atrophy of the white and grey matter could be detected. These microinfarcts are caused by a microangiopathic process with arteriolar wall proliferation, lymphocytic infiltration and basal lamina thickening. At clinical onset, the most common manifestation was central nervous system symptoms, followed by visual symptoms and hearing disturbances. Diagnosis is based on Magnetic Resonance Imaging (MRI), retinal fluorescein angiography, and audiometry; these are considered crucial tests to enable diagnosis. Antiendothelial cell antibodies (AECAs) are also of diagnostic relevance. Based on the hypothesis of being an autoimmune disease, treatment has to be immunosuppressive. In addition, anticoagulation measures, antiplatelet agents and antivasospastic agents should be considered. The majority of patients did not initially present with the complete triad of symptoms. An appropriate approach would be to perform a search for absent components of the triad if the clinical presentation is suggestive of Susac's syndrome. Improved understanding of the presentation of Susac's syndrome will prevent misdiagnosis and ensure that patients receive the best possible care.

Clinical, paraclinical and serological findings in Susac syndrome: an international multicenter study

Background

Susac syndrome (SuS) is a rare disorder thought to be caused by autoimmune-mediated occlusions of microvessels in the brain, retina and inner ear leading to central nervous system (CNS) dysfunction, visual disturbances due to branch retinal artery occlusions (BRAO), and hearing deficits. Recently, a role for anti-endothelial cell antibodies (AECA) in SuS has been proposed.

Objectives

To report the clinical and paraclinical findings in the largest single series of patients so far and to investigate the frequency, titers, and clinical relevance of AECA in SuS.

Patients and methods

A total of 107 serum samples from 20 patients with definite SuS, 5 with abortive forms of SuS (all with BRAO), and 70 controls were tested for AECA by immunohistochemistry employing primate brain tissue sections.

Results

IgG-AECA >1:100 were detected in 25% (5/20) of patients with definite SuS and in 4.3% (3/70) of the controls. Median titers were significantly higher in SuS (1:3200, range 1:100 to 1:17500) than in controls (1:100, range 1:10 to 1:320); IgG-AECA titers >1:320 were exclusively present in patients with SuS; three controls had very low titers (1:10). Follow-up samples (n = 4) from a seropositive SuS patient obtained over a period of 29 months remained positive at high titers. In all seropositive cases, AECA belonged to the complement-activating IgG1 subclass. All but one of the IgG-AECA-positive samples were positive also for IgA-AECA and 45% for IgM-AECA. SuS took a severe and relapsing course in most patients and was associated with bilateral visual and hearing impairment, a broad panel of neurological and neuropsychological symptoms, and brain atrophy in the majority of cases. Seropositive and seronegative patients did not differ with regard to any of the clinical or paraclinical parameters analyzed.

Conclusions

SuS took a severe and protracted course in the present cohort, resulting in significant impairment. Our finding of high-titer IgG1 and IgM AECA in some patients suggest that humoral autoimmunity targeting the microvasculature may play a role in the pathogenesis of SuS, at least in a subset of patients. Further studies are warranted to define the exact target structures of AECA in SuS.

Detection of branch retinal artery occlusions in Susac's syndrome

Background

We report an interesting case of asymptomatic retinal involvement in an encephalopathic patient enabling early identification of Susac’s syndrome.

Case presentation

A 39-year-old Caucasian lady with hearing loss and encephalopathy was referred for ophthalmic assessment, including screening for branch retinal artery occlusions characteristic of Susac’s syndrome. Clinical features included severe headaches, right-sided hypoacusis, dysphasia and poor memory. Routine blood tests were normal. MRI brain showed numerous hyperintense lesions mainly in corpus callosum. Although she was visually asymptomatic, dilated funduscopy detected bilateral multiple peripheral branch retinal artery occlusions which were confirmed on fluorescein angiography. She was subsequently started on intravenous steroids and pulsed cyclophosphamide which improved her symptoms within 48 hours. Full recovery was made with no new arterial occlusions on four months follow-up.

Conclusion

The case further establishes the crucial role of a detailed ophthalmic examination supported by fluorescein angiography in the assessment of these patients, who are at risk of being misdiagnosed and undertreated.

Diagnosis and classification of Susac syndrome

Susac syndrome (SS) is an autoimmune disease characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and neuro-sensorial hearing loss; it is due to a microangiopathy affecting the precapillary arterioles of the brain, retina and inner ear. SS is characterized by typical radiological features on magnetic resonance imaging (MRI) which, together with clinical symptoms, may permit a diagnosis. Branch retinal artery occlusions (BRAOs) are best evaluated using fluorescein angiography (FA) which may show the typical multifocal fluorescence. SS is an autoimmune endotheliopathy that requires treatment with immunosuppressive agents: steroids, azathioprine, mycophenolate mofetil, methotrexate, cyclophosphamide and intravenous immunoglobulin, usually in combination. Plasma exchange is also useful. In addition, antiplatelet agents may be a useful adjunct. Correct immunosuppressive therapy results in significant clinical and radiological improvement. An early diagnosis and treatment are important to delay the disease progression and prevent permanent disability.

A case of Susac syndrome with cervical spinal cord involvement on MRI

We describe a typical case presentation of Susac syndrome with a novel MRI finding of cervical spinal cord involvement. A 25-year-old, 14-week gestation white woman presented with two episodes of encephalopathy, responsive to steroids, with abnormal brain magnetic resonance imaging (MRI) concerning for Susac syndrome. Further studies confirmed the clinical triad of encephalopathy, branch retinal artery occlusions and hearing loss pathognomonic for Susac syndrome. Cervical spine MRI demonstrated two focal areas of high-signal abnormality at C2 and C3. We provide a brief review of Susac syndrome, data regarding pregnancy in this rare syndrome, and discuss how this unique observation may assist in the medical management of such cases and contribute to the understanding of the underlying pathophysiology.

Encephalopathic Susac's Syndrome associated with livedo racemosa in a young woman before the completion of family planning

Background

Susac’s Syndrome (SS) consists of the triad of encephalopathy, branch retinal artery occlusions (BRAO) and hearing loss (HL). Histopathologically, SS is characterised by a microangiopathy, and some observations suggest that an immune-mediated damage of endothelial cells might play a role. These findings also implicate a similarity between SS and other autoimmune diseases, most notably juvenile dermatomyositis (JDM). However, SS and JDM are commonly thought to affect distinct and non-overlapping sets of organs, and it is currently not clear how these specificities arise. Moreover, in the absence of clinical trials, some authors suggest that therapeutic approaches in SS should rely on the model of other autoimmune diseases such as JDM.

Case presentation

Here, we report a case of SS in a 32-year-old pregnant woman. She initially was admitted to the hospital with subacute severe encephalopathy and multifocal neurologic signs. As cranial magnetic resonance imaging (MRI) revealed multifocal white matter lesions including the corpus callosum, erroneously a diagnosis of multiple sclerosis (MS) was made, and intravenous methylprednisolone (IVMP) therapy was initiated. A few days later, an exanthema appeared on the trunk and extremities, which was diagnosed as livedo racemosa (LR). Several weeks later, the patient was readmitted to the clinic with an obscuration of her left visual hemifield and a bilateral HL. Ophthalmologic examination revealed extensive ischemic damage to both retinae. Now the correct diagnosis of SS was established, based on the above triad of clinical symptoms in conjunction with typical MRI and fundoscopic findings. When SS was diagnosed, the standard therapy with intravenous cyclophosphamide (IVCTX) was not instituted because of a significant risk of permanent infertility. Instead, sustained control of disease activity could be achieved with a therapeutic regime combining prednisolone, intravenous immunoglobulins (IVIG), mycophenylate mofetil (MM), and methotrexate (MTX).

Conclusions

An association with LR has only been described in very few cases of SS before and further underlines the pathogenetic relationship between SS and other autoimmune diseases such as JDM. In young women with SS and the desire for a child the combination of MM and MTX may represent a reasonable alternative to IVCTX.

Antibodies target microvessels in neuromyelitis optica and multiple sclerosis patients

OBJECTIVE

This study investigated the presence of serum antibodies targeting microvessels in Chinese patients with multiple sclerosis (MS) and neuromyelitis optica (NMO).

METHODS

Serum samples were collected from 50 patients with NMO, 10 with longitudinally extensive transverse myelitis (LETM), 4 with recurrent optic neuritis, 42 with MS and 27 controls. Serum antibodies binding to microvessels were measured by indirect immunofluorescence (IIF) assay of tissue sections from the brain, stomach and pancreas, and human umbilical vein endothelial cells (HUVEC). Aquaporin-4 (AQP4) antibodies were detected using a cell-based assay.

RESULTS

Indirect immunofluorescence assay of tissue sections from 42 samples (30.4%, 42/138) were positive for microvessel antibodies, where microvessel antibody positivity was 38% (19/50) in patients with NMO, 57.1% (8/14) in high-risk NMO (hrNMO), 26.2% (11/42) in MS, and 14.8% (4/27) in controls. Based on HUVEC analysis, 14 patients with NMO (28%, 14/50), 5 with hrNMO (35.7%, 5/14), 15 with MS (35.7%, 15/42), and 5 controls (18.5%, 5/27) had (AECA). Sixteen patients (32%, 16/50) with NMO, four with hrNMO (28.6%, 4/14), two with MS (4·8%, 2/42), and 0% of controls were positive for antinuclear antibodies (ANA). In MS patients, seropositive AECA MS patients had higher numbers of relapse events and increased spinal lesions than seronegative MS patients (P < 0.05).

CONCLUSIONS

Serum microvessel antibodies were present in patients with NMO and MS and the role of microvessel antibodies in diseases may be heterogeneous. This study suggests that AECA may have some significance in MS patients.

Susac's Syndrome in a 27-Year-Old Female

A 27-year-old woman was referred by the neurologist for ophthalmic examination. She had a history of headache, visual loss in her right eye, four-limb paresthesia, and behavioral changes over the previous 10 months. The patient complained of tinnitus and hearing loss for two weeks. The patient was initially diagnosed with multiple sclerosis, but auditory and retinal involvement (small branch retinal artery occlusion in fluorescein angiography) raised the possibility of Susac's syndrome.

Patterns of retinal damage facilitate differential diagnosis between Susac syndrome and MS

Susac syndrome, a rare but probably underdiagnosed combination of encephalopathy, hearing loss, and visual deficits due to branch retinal artery occlusion of unknown aetiology has to be considered as differential diagnosis in various conditions. Particularly, differentiation from multiple sclerosis is often challenging since both clinical presentation and diagnostic findings may overlap. Optical coherence tomography is a powerful and easy to perform diagnostic tool to analyse the morphological integrity of retinal structures and is increasingly established to depict characteristic patterns of retinal pathology in multiple sclerosis. Against this background we hypothesised that differential patterns of retinal pathology facilitate a reliable differentiation between Susac syndrome and multiple sclerosis. In this multicenter cross-sectional observational study optical coherence tomography was performed in nine patients with a definite diagnosis of Susac syndrome. Data were compared with age-, sex-, and disease duration-matched relapsing remitting multiple sclerosis patients with and without a history of optic neuritis, and with healthy controls. Using generalised estimating equation models, Susac patients showed a significant reduction in either or both retinal nerve fibre layer thickness and total macular volume in comparison to both healthy controls and relapsing remitting multiple sclerosis patients. However, in contrast to the multiple sclerosis patients this reduction was not distributed over the entire scanning area but showed a distinct sectorial loss especially in the macular measurements. We therefore conclude that patients with Susac syndrome show distinct abnormalities in optical coherence tomography in comparison to multiple sclerosis patients. These findings recommend optical coherence tomography as a promising tool for differentiating Susac syndrome from MS.

A brief review of Susac syndrome

Susac syndrome was named after J.O. Susac who first described the syndrome in 1979. It is characterized by the clinical triad of encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. It mainly occurs in young women. This underdiagnosed disease needs to be considered in the differential diagnosis of a broad variety of disorders. In Susac syndrome, autoimmune processes leading to damage and inflammation-related occlusion of the microvessels in brain, retina, and inner ear are thought to play a causal role. The diagnosis is based primarily on the clinical presentation, the documentation of branch retinal artery occlusion by fluorescence angiography, and characteristic findings on cerebral MRI, that help in distinguishing Susac syndrome from other inflammatory entities, like multiple sclerosis. Antiendothelial cell antibodies could be detected in some patients. Patients are successfully treated with immunosuppression, however, the best regimen still needs to be defined. As a result of the rarity of the disease, controlled therapeutic trials are missing so far. In this review, we want to demonstrate the clinical features, natural history, treatment, and clinical course of Susac syndrome, illustrated by a typical case history.