Use of disease assessment tools to increase the value of case reports on Susac syndrome: two case reports.

BACKGROUND: Susac syndrome is an immune-mediated, ischemia-producing, occlusive microvascular endotheliopathy that threatens the brain, retina, and inner ear. There is a need for disease assessment tools that can help clinicians and patients to more easily, accurately, and uniformly track the clinical course and outcome of Susac syndrome. Ideally, such tools should simultaneously facilitate the clinical care and study of Susac syndrome and improve the value of future case reports. To meet this need, two novel clinical assessment tools were developed: the Susac Symptoms Form and the Susac Disease Damage Score. The former is a comprehensive self-report form that is completed by patients/families to serially document the clinical status of a patient. The latter documents the extent of damage perceived by individual patients/families and their physicians. Both forms were initially trialed with two particularly representative and instructive patients. The results of this trial are shared in this report. CASE PRESENTATION: Patient 1 is a 21-year-old Caucasian female who presented with an acute onset of headache, paresthesias, cognitive dysfunction, and emotional lability. Patient 2 is a 14-year-old Caucasian female who presented with an acute onset of headache, cognitive dysfunction, urinary incontinence, ataxia, and personality change. Both patients fulfilled criteria for a definite diagnosis of Susac syndrome: both eventually developed brain, retinal, and inner ear involvement, and both had typical "snowball lesions" on magnetic resonance imaging. The Susac Symptoms Form documented initial improvement in both patients, was sufficiently sensitive in detecting a subsequent relapse in the second patient, and succinctly documented the long-term clinical course in both patients. The Disease Damage Score documented minimal disease damage in the first patient and more significant damage in the second. CONCLUSIONS: The Susac Symptoms Form and the Disease Damage Score are useful disease assessment tools, both for clinical care and research purposes. Their use could enhance the value of future case reports on Susac syndrome and could improve opportunities to learn from a series of such reports.

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 complicating a SARS-CoV-2 infection.

In 2020 the world was captivated by the COVID-19 pandemic. Current scientific evidence suggests an interaction of SARS-CoV-2 and the human immune system. Multiple cases were reported of patients with COVID-19 presenting with encephalopathy, confusion or agitation, stroke, and other neurologic symptoms. We present a case of a 40-year-old man diagnosed with Susac syndrome after COVID-19, presenting with acute sensorineural hearing loss, encephalopathy, a splenial "snowball-like" lesion, and branch retinal artery occlusions with distal arterial wall hyperintensity. Although the pathophysiology of Susac syndrome remains unclear, this case is in line with the ongoing debate about the influence of SARS-CoV-2 on the human immune system. Corticosteroid treatment was initiated, followed by two treatments with rituximab, with clinical improvement of the symptomatology. Maintenance treatment currently consists of mycophenolic acid (MPA). Future research will need to focus on the underlying mechanisms for COVID-19-associated (autoimmune) complications.