Scoping review of cochlear implantation in Susac's 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).

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.