Susac's syndrome: an update

Clinical Characterization and Prognostic Risk Factors of Susac Syndrome: A Retrospective Multicenter Study

BACKGROUND AND OBJECTIVES

Susac syndrome (SuS) is a rare disorder characterized by encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss, often accompanied by vertigo. Recent updates to diagnostic criteria and treatment guidelines have been made. This study examines clinical manifestations; disease activity; and risk factors of disability, dependency, and return to work in patients with SuS.

METHODS

A retrospective multicenter study was conducted on 20 consecutive patients with SuS with at least 2 years of follow-up. Clinical and paraclinical activities were assessed and rated according to the severity at onset and the end of follow-up. Cognitive function was assessed using the Montreal Cognitive Assessment while disability and dependence in daily activities were measured using the modified Rankin Scale. Employment status was graded.

RESULTS

The mean age at onset was 38.9 years, with a mean follow-up of 55.9 months. The female-to-male ratio was 1.86, and 45% of patients had the complete clinical triad. Severe cerebral involvement at onset was associated with a higher risk of cerebral exacerbations within the first year and with an increased long-term disability and dependency. Cognitive function improved in 75% of patients during follow-up. At disease onset, hearing loss excluding low frequencies occurred in 46.7%. Relapse of hearing loss was associated with greater impairment in daily activities. Male sex and elevated CSF protein levels were linked to poorer prognosis. Cerebral and inner ear exacerbations were most common in the first year while retinal exacerbations occurred more frequently, mainly within the first 2 years. Approximately 50% of patients resumed employment while 25% did not return to work.

DISCUSSION

Current treatment strategies for SuS do not fully prevent relapses. Severe brain manifestation at onset, male sex, and high CSF protein levels are risk factors of a worse prognosis of disability and dependence, indicating the need for intensive treatment. High-frequency hearing loss does not exclude SuS diagnosis.

Susac syndrome following COVID-19 vaccination: a case-based review

COVID-19 vaccine circulation approval was a turning point for the coronavirus pandemic. The current approved COVID-19 vaccines, including messenger ribonucleic acid (mRNA)-based and adenovirus vector-based vaccines, were shown to significantly reduce the disease mortality and severity, and its adverse reactions are mainly mild ones. However, few cases of autoimmune conditions, both flare-ups and new-onset, were described in association with these vaccines. Susac vasculitis (SaS) is a rare autoimmune disease characterized by the clinical triad of encephalopathy, visual disturbances, and sensorineural hearing loss. Its pathogenesis is still not fully understood but is believed to be related to autoimmune processes, including autoantibodies to anti-endothelial cells and cellular immune processes that lead to microvascular damage and, consequently, micro-occlusions of the cerebral, inner ear, and retinal vessels. It has been previously described following vaccination and, most recently, few cases following coronavirus vaccines. We here describe a case of a previously healthy 49-year-old man diagnosed with SaS 5 days following the first dose of the BNT162b2 COVID-19 vaccine.

Susac syndrome: A scoping review

Susac syndrome is a rare disease characterized by an inflammatory microangiopathy limited to the brain, eye, and ear vessels. It mainly affects young women. Although the pathophysiology is not fully elucidated, recent advances favour a primitive vasculitis affecting the cerebral, retinal and cochlear small vessels. Diagnosis relies on the recognition of the triad including: 1/subacute encephalopathy with unusual headache and pseudo-psychiatric features associated with multifocal ischemic white matter, grey matter nuclei and specifically corpus callosum lesions along with leptomeningeal enhancement on brain MRI, 2/ophthalmological involvement that may be pauci-symptomatic, with bilateral occlusions of the branches of the central artery of the retina at fundoscopy and arterial wall hyperfluorescence on fluorescein angiography, 3/cochleo-vestibular damage with neurosensorial hearing loss predominating on low frequencies. The full triad may not be present at diagnosis but should be sought repeatedly. Relapses are frequent during an active period lasting approximately 2 years. Eventually, the disease resolves but isolated retinal arterial wall hyperfluorescence without new occlusions may recur, which should not result in treatment intensification. First-line treatment mostly consists of high dose corticosteroids. In refractory patients or in case of relapse, immunomodulatory molecules such as intravenous immunoglobulins or immunosuppressive drugs such as mycophenolate mofetil, cyclophosphamide or rituximab should be started. Sequelae -mostly hearing loss and cognitive impairment- are usually mild but remain frequent in these young patients.

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.

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.

Use of ultra-wide field retinal imaging and optical coherence tomography angiography in the diagnosis of incomplete Susac syndrome

PURPOSE

To describe clinical findings through ultra-wide field (UWF) images and optical coherence tomography angiography (OCT-A), in Susac's syndrome (SS).

METHODS

SS patients were retrospectively analyzed in a single center. Clinical features, ultra-wide-field retinographies (UWF-PR), UWF fluorescein angiographies (UWF-FA), and optical coherence tomography angiography & en face (OCT-A/EF) were reviewed.

RESULTS

Twelve eyes from six patients with a mean follow-up of 35.66 months ± SD 36.88 were included. UWF-PR showed areas of retinal whitening and cotton-wool spots in all the eyes after acute attack. Segmentary mid peripheral arteriolitis could be observed in five eyes by UWF-FA in acute and convalescent stages. OCT-A revealed capillary density changes in all of the affected eyes. During the acute phase there was a well-preserved superficial capillary network, while deep retinal plexus showed a lower density in the affected areas. OCT-A/EF revealed deep retinal plexus drop-out and surrounding edematous retina in acute attacks, becoming atrophic over time. Conversely, superficial plexus was much less affected. Perifoveal reperfusion was seen in seven eyes after the acute attack.

CONCLUSIONS

UWF-PR/FA and OCT-A/EF might be helpful to stablish an early diagnosis and to monitor SS progression.

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.

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.

ULTRA-WIDE-FIELD FUNDUS IMAGING IN THE DIAGNOSIS AND FOLLOW-UP OF SUSAC SYNDROME

PURPOSE

To present the use of ultra-wide-field (UW) fundus imaging in the diagnosis and follow-up of a patient with Susac syndrome.

METHODS

Case report of a myopic patient presenting initially with rhegmatogenous retinal detachment. A significant portion of the retina was found to be avascular bilaterally at presentation. Surgery was performed with scleral buckle. Then, UW color and autofluorescent imaging and UW fluorescein angiography were obtained.

RESULTS

Successful retinal reattachment was obtained. Enlargement of the avascular area with neovascularization was observed at eight-month follow-up. In addition, the patient presented severe neurosensory hearing loss and clinical depression postoperatively. The results of UW fluorescein angiography revealed hyperfluorescent macular spots, arteriolar wall hyperfluorescence, leakage from retinal neovascularization, and confirmed the avascularity of two thirds of the retina, whereas the results of UW autofluorescence showed absence of the normal hypofluorescent retinal vessels outside the posterior pole. Findings of UW imaging in combination with systemic involvement led to the diagnosis of Susac syndrome. Appropriate treatment stopped the disease progress, ameliorated symptoms, and some of the occluded retinal vessels were reperfused.

CONCLUSION

In conclusion, UW fundus imaging is a valuable modality in the diagnosis and follow-up of patients with Susac syndrome. Early diagnosis and treatment is critical, particularly as it can lead to reperfusion of occluded retinal vessels.

Susac's Syndrome (Retinocochleocerebral Vasculopathy): Follow-up of a Pediatric Patient

Susac's syndrome (SS) is a triad of encephalopathy, branch retinal artery occlusion (BRAO), and sensorineural hearing loss as a result of microvascular occlusions of the brain, retina, and inner ear. It is also a disorder of autoimmune endotheliopathy. SS usually affects young women between the age of 20 and 40 years. SS can be misdiagnosed as multiple sclerosis (MS) or acute disseminated encephalomyelitis (ADEM) because of similar findings. A 15-year-old girl presented in June 2015 with vomiting and severe headache. Cerebral magnetic resonance imaging revealed multiple lesions in the corpus callosum. Cerebrospinal fluid findings gave normal results. The initial diagnosis was MS and steroid (1000 mg/day) was given. She started to describe hallucinations and became paraplegic. She then underwent plasmapheresis five times without response. Her electroencephalogram was diffusely slow with 2-3 Hz delta rhythm at the frontal regions. Audiological examination showed that she had sensorineural hearing loss in her left ear. Ophthalmologic evaluation revealed BRAO in both eyes. On the basis of these findings, she was diagnosed with SS and treated with intravenous immunoglobulin (IVIG) and aspirin. After monthly treatment with IVIG for 6 months, the patient has almost fully recovered. SS should be kept in mind in the differential diagnosis of MS and ADEM.

Susac's Syndrome: A Case with Unusual Cardiac Vestibular and Imaging Manifestations

Susac's syndrome (SS) is a disease of the microvasculature of the retina, brain, and inner ear. We describe a patient with unusual manifestations of SS with possible involvement of the brainstem, cardiac arrhythmia, and MRI findings lacking the characteristic lesions found in Susac's syndrome.

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.

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.

Central retinal artery occlusion and Susac syndrome: a case report

BACKGROUND

Susac syndrome is a rare disease attributed to microangiopathy involving the arterioles of the brain, retina, and cochlea. Understanding the pathogenesis is incomplete, but an immune-mediated process remains the leading hypothesis.

METHODS

Report of a single case of a previously healthy 22-year-old female patient showing the complete clinical triad.

RESULTS

Diagnosis of Susac syndrome in this patient was first questioned due to the atypical initial ophthalmologic presentation with central retinal artery occlusion. Multiple relapses occurred in the fellow eye during follow-up, showing the typical branch retinal artery occlusions, allowing definite diagnosis.

CONCLUSION

Susac syndrome should be considered in the differential diagnosis when facing (young) patients with central retinal artery occlusion, especially in the presence of unexplained encephalopathy and/or sensorineural hearing loss.

Vogt-Koyanagi-Harada syndrome

OBJECTIVES

The objectives of this study are to review our current knowledge of the aetiopathogenesis of Vogt-Koyanagi-Harada syndrome, including viral infection, genetic factors and immunomediated mechanisms, and to discuss pathogenesis and its relevance to pharmacotherapy.

SYSTEMATIC REVIEW METHODOLOGY

Relevant publications from 1965 to 2012 on the aetiopathogenesis and pharmacotherapy of VKHS were analysed.

RESULTS AND CONCLUSION

Vogt-Koyanagi-Harada syndrome (VKHS) is a rare multisystemic autoimmune disease that affects tissues containing melanin, including the eye, inner ear, meninges, and skin. The disease is characterised by bilateral uveitis associated with a varying constellation of auditory, neurological and cutaneous manifestations. The disease occurs more frequently among people with darker skin pigmentation. Asians, Native Americans, and Hispanics are most frequently affected. It predominates in patients aged between 20 and 50years, and females are affected more frequently, with a female:male ratio of 2:1. The classic clinical course is characterised by bilateral panuveitis, hypoacusis, and meningitis, in addition to cutaneous involvement with poliosis, vitiligo, and alopecia. Although the exact cause of VKH disease remains unknown, it is thought to be a T-cell-mediated autoimmune process directed against melanocytes. VKHS classically begins with vague systemic symptoms suggestive of a viral infection, although a clear association between a specific viral agent and the disease has not been established. Genetic factors may play an important role in the loss of self-tolerance in VKHS. The HLA-DRB1*0405 allele is the main susceptibility allele for VKHS. Early and aggressive systemic corticosteroids are still the primary initial therapy for VKHS. Ocular complications may require an intravitreous injection of corticosteroids. Despite proper treatment with steroids, a number of patients experience recurrent attacks or steroid-associated complications. Thus, non steroid immunomodulatory therapy (IMT) has become necessary for the treatment of VKHS.