Otologic manifestations of Susac syndrome

Phenotyping vestibulocochlear manifestations in Susac syndrome: a cohort study

PURPOSE

To characterize vestibulocochlear involvement in patients with Susac syndrome (SuS), a rare immune-mediated endotheliopathy of cerebral, retinal and inner ear microvasculature causing a triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss.

METHODS

The electronic patient files of 21 patients with SuS are reviewed for data on demography, clinical presentation, disease course and audiovestibular testing.

RESULTS

All 21 patients experienced some form of audiovestibular complaints during the disease course, with vertigo and instability being most frequently reported, followed by hearing loss, tinnitus and aural fullness. These audiovestibular symptoms did not always coincide. Fifteen patients had objectified predominant low- to midfrequency sensorineural hearing loss and 8 out of 18 patients showed abnormalities on vestibular testing, most frequently vestibular evoked myogenic potential-abnormalities, indicating otolith dysfunction. Treatment protocols consisted of uniformly extensive immunosuppressive therapy and hearing loss remained mostly mild.

CONCLUSION

Audiovestibular involvement is very common in patients with SuS. Characteristic findings include a "reverse-slope" configuration on audiological testing and otolith dysfunction on vestibular testing. Aggressive immunosuppression may prevent severe audiovestibular dysfunction. Symptoms as aural fullness and otolith dysfunction may indicate an underlying hydrops. Further investigations are necessary to elucidate the histopathological mechanisms underlying these preferentially involved cochleovestibular areas. Early recognition and treatment of SuS are important to stabilize or decrease disease activity and might also have beneficial effects on inner ear outcome. THE SUBMITTED MANUSCRIPT REPORTS DATA DERIVED FROM CLINICAL OBSERVATIONS IN HUMANS: Consent for the research was provided by the Ethics Committee of Ghent University hospital (application number 2019/1443, registration date 31/12/2021, principal investigator Guy Laureys).

Successful treatment of a complete Susac syndrome in a 16-year-old boy: A case report

Key Clinical Message

We reported a pediatric case of SuS with a complete diagnosis triad. Although the optimal treatment of SS is unclear, prompt diagnosis and treatment can result in almost a complete recovery.

Abstract

Susac's syndrome (SuS) is a rare, autoimmune disorder known as a typical triad of sensorineural hearing impairment, central nervous system involvement, and multiple branch retinal artery occlusions (BRAOs). It is usually misdiagnosed or underdiagnosed because its symptoms may vary at the presentation time. Diagnosis can be established based on neuroimaging, ophthalmic examination, and audiometry, which match the clinical symptoms. SuS is very limited and rare in childhood and can be easily misdiagnosed with multiple sclerosis or acute disseminated encephalomyelitis. We report a 16-year-old boy patient with a completed SuS triad including BRAO in fluorescent angiography (FA), mild to moderate sensory neural hearing loss (SNHL), "Snowball lesions," and "pearl of string" signs in magnetic resonance imaging (MRI). Successful treatment was achieved with methylprednisolone, rituximab, azathioprine, cyclophosphamide, and plasmapheresis. SuS is a rare disorder, which rarely presents with a full triad and all the manifestations may not be present at the onset of the disease, leading to misdiagnosis or underdiagnosis. Our case is exceptional because he was in a pediatric age and presented with a complete triad of SuS which adds to the rarity of this disease. Although optimal treatment of SuS is unclear, our treatment regimen resulted in almost a complete recovery.

Fatal Presentation of Susac Syndrome in a Congenitally Deaf Patient With a Cochlear Implant

OBJECTIVE

To report a fatal case of Susac syndrome in a congenitally deaf patient with a cochlear implant and a history of migraines, emphasizing the diagnostic challenges in patients with preexisting conditions.

PATIENT

A 33-year-old male with congenital hearing loss, a cochlear implant, and chronic migraines who presented with mild subacute auditory disturbance and headaches that later progressed to severe encephalopathy.

INTERVENTION

Explantation of a non-magnetic resonance imaging (MRI) compatible cochlear implant followed by MRI, fundoscopy, and the administration of immunosuppressive medications.

MAIN OUTCOME MEASURES

Diagnosis was confirmed by characteristic MRI appearance and the presence of a hemi-retinal artery occlusion.

RESULTS

After weeks of immunosuppressive treatment, the patient died of a global cerebral ischemic event of unknown origin.

CONCLUSIONS

For patients with preexisting sensorineural hearing loss and cochlear implants, Susac syndrome poses a diagnostic challenge. Auditory disturbances in the absence of cochlear implant failure should prompt further evaluation for visual disturbances and encephalopathy. MRI and fundoscopy should be performed to detect other features of the disease.

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.

Cervical and Ocular Vestibular Evoked Myogenic Potential Recovery in Susac Syndrome: A Case Report

Purpose:

Susac syndrome (SS) is a rare autoimmune disorder that affects the brain and the retina and causes unilateral or bilateral sensorineural hearing loss. Although vestibular dysfunction is reported in SS, limited information is available underlying the vestibular pathophysiology.

Method:

The diagnosis of SS was established based on symptoms and diagnostic tools such as magnetic resonance imaging and fundus fluorescein angiography. The audiovestibular evaluation was done on the seventh day of admission (Session 1) into the emergency unit, whereas the second and third evaluations were done at 3-month (Session 2) and 8-month (Session 3) follow-ups after discharge, respectively. The audiovestibular test battery consisted of routine audiological tests, auditory brainstem response, and vestibular evoked myogenic potentials (VEMPs; both cervical and ocular).

Results:

We found unilateral sensorineural hearing loss and absent cervical VEMPs(cVEMPs) when testing the left ear during Session 1. In the following sessions, the unilateral hearing loss did not recover; however, cVEMPs were present bilaterally. The ocular VEMPs showed an increase in amplitude during Sessions 2 and 3.

Conclusions:

SS can selectively disrupt auditory and vestibular structures. It may present with unique findings of audiovestibular tests. A detailed audiovestibular evaluation may be essential in patients with SS.

Supplemental Material:

https://doi.org/10.23641/asha.21513843

WIDEFIELD FLUORESCEIN ANGIOGRAPHY IN THE DIAGNOSIS OF SUSAC SYNDROME

PURPOSE

To present the clinical manifestations and results of key diagnostic investigations in patients with Susac syndrome, with special emphasis on the principal role of fluorescein angiography (FA) of the peripheral retina.

METHODS

A retrospective analysis of medical records (collected 2000-2019) of 20 patients (15 women and five men), aged 20 to 51 years (mean age: 31.6 years) with complete or incomplete Susac syndrome diagnosed by an ophthalmic examination and widefield fluorescein angiography (WF-FA) by Spectralis and Optos Tx200.

RESULTS

Fluorescein angiography abnormalities included vascular changes in the posterior pole in 64.7% and in the peripheral retina in 82.4%. Widefield FA abnormalities in the peripheral retina alone were seen in 35.3% and in the posterior pole, but without peripheral vascular involvement, in 17.6%. Secondary leakage from veins was noted in 58.8%.

CONCLUSION

Widefield FA of the peripheral retina has a key role in cases of suspected Susac syndrome as it confirms the diagnosis and assesses disease activity. In addition to the characteristic findings, late-phase FA revealed leakage from veins which is not a typical sign. Patients experiencing migraine headaches may benefit from increasing awareness of neurologists and otologists who more promptly referred patients with suspected Susac syndrome for ophthalmologic evaluation and WF-FA of the peripheral retina.

Scoping review of cochlear implantation in Susac's syndrome

OBJECTIVE

Scoping review of published literature to establish clinical characteristics and audiologic outcomes in patients diagnosed with Susac's Syndrome(SS) who have undergone cochlear implantation (CI).

DATA SOURCES

All published studies of CI in SS and contribution of two of our own patients who have not been reported previously.

METHODS

A comprehensive search of MEDLINE (via PubMed) was carried out in March 2020 using the following keywords and related entry terms: Susac's Syndrome, Cochlear Implantation.

RESULTS

Our search identified a total of five case reports of CI in SS. With the addition of our two patients reported here, we analyzed characteristics and outcomes in seven patients. Mean age at implantation was 30 years old (range 19-46), with six women and one man implanted. Mean time from onset of hearing loss to implantation was 17 months (range three months to four years). Best reported postoperative speech understanding was reported via different metrics, with six of seven patients achieving open set speech scores of 90% or better, and one subject performing at 68%. Vestibular symptoms were present preoperatively in four of seven patients (57%), with vestibular testing reported in two patients, and showing vestibulopathy in one patient. No complications were reported following cochlear implantation.

CONCLUSION

Cochlear implantation is a viable option for hearing rehabilitation in patients with SS, with levels of attainment of open set speech comparable to other populations of CI candidates.

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.

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.

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.

The Role of Anti-Endothelial Cell Autoantibodies and Immune Response in Acute Low-Tone Hearing Loss

OBJECTIVE

Immunity is associated with acute low tone hearing loss. However, the exact pathophysiology of immunity-mediated acute low tone hearing loss remains unknown. In this study, we evaluated the presence, therapeutic effectiveness, and immunopathological mechanisms of anti-endothelial cell autoantibodies (AECEs) in patients with acute low-frequency hearing loss.

MATERIAL AND METHODS

Forty-nine patients who were treated as inpatients having acute low-frequency hearing loss and additional symptoms, such as ear fullness, tinnitus, dizziness, or hyperacusis, were enrolled in this study. Serum samples from these patients were collected for laboratory serum autoimmunity detection, including AECAs, antinuclear antibodies, immunoglobulin, and circular immune complex. Therapeutic responses to combination therapy in short-term outcome and serum cytokine levels were compared between AECA-positive and AECA-negative patients.

RESULTS

Anti-endothelial cell autoantibodies-positive patients tended to show significantly less response to standard therapy compared with AECAs controls (P < .05). Moreover, some serum cytokine levels elevated in both AECAs- and AECAs+ groups. Positive ratio of interleukin-8 and concentrations of macrophage inflammatory protein-1α were found higher in AECAs+ groups (P < .05).

CONCLUSION

The results supported that AECAs might wield influence on the short-term outcome of acute low-tone hearing loss (ALHL) treatment. Furthermore, AECA-mediated acute low-frequency hearing loss possibly involved dysregulation of inflammation process and release of cytokines.