RESUMEN
This case report is a multimodal analysis of a pregnant patient with branch retinal artery occlusion (BRAO) associated to patent foramen ovale (PFO). A 28-year-old woman presented at the clinic 20 h after an acute, painless black spot appearance in the inferior temporal visual field of the right eye (OD). At that time, she was 18 weeks pregnant and had no report of complications in her previous pregnancy. Best-corrected visual acuity was 1.0 in both eyes. Color fundus photo, perimetry, and OCT angiography were required. The results clearly showed an embolus in the superior nasal retinal arteriole, associated with a pallor in the distal retina. Patient was referred to a cardiologist and a transcranial Doppler with contrast indicated a right-to-left intracardiac shunt, confirmed by the presence of a PFO at the transesophageal echocardiography. Thrombophilic conditions were excluded. Enoxaparin 1 mg/kg was started and kept until the delivery. Now, a PFO surgical closure is on schedule. This case highlights the noteworthiness of considering PFO as a source of embolism for BRAO in young patients, the capability of OCTA as a dye-free method for use in pregnancy and emphasizes the importance of systemic evaluation in patients with BRAO.
RESUMEN
Susac syndrome is a disorder thought to be mediated by an autoimmune response towards endothelial cells, leading to a characteristic clinical triad of encephalopathy, visual disturbances due to branch arterial occlusions and sensorineural hearing impairment. Although it is a rare disease, three reasons make it important. First, given its variable presentation, Susac syndrome is underdiagnosed. Second, it is considered an important differential diagnosis in different neurological, psychiatric, ophthalmological and hearing disorders, and consequently is frequently misdiagnosed. Third, in many cases, Susac syndrome is diagnosed and treated late, with significant irreversible sequelae including dementia, blindness and hearing loss. Neuropathology findings derived from both Susac syndrome patient tissue and novel transgenic mouse models indicate cytotoxic CD8+ T cells adhere to microvessels, inducing endothelial cell swelling, vascular narrowing and occlusion, causing microinfarcts. Anti-endothelial cell antibodies are present in serum in 25% of Susac syndrome patients, but it is unclear whether they are aetiologically related to the disease, or an epiphenomenon. The clinical triad comprising encephalopathy, branch arterial occlusions, and sensorineural hearing impairment is considered pathognomonic, although great variability is found in presentation and natural course of disease. At first evaluation, only 13-30% of patients exhibit the full clinical triad, making diagnosis difficult. Retinal fluorescein angiography, optic coherence tomography, MRI and tonal audiometry are helpful methods for diagnosing and monitoring disease activity during treatment. By contrast, there are no reliable objective immune markers to monitor disease activity. Immunosuppression is the current treatment, with high-dose corticosteroid therapy as the mainstay, but additional therapies such as intravenous immunoglobulins, cyclophosphamide, rituximab and mycophenolate mofetil are often necessary, because the disease can be devastating, causing irreversible organ damage. Unfortunately, low rates of disease, variability in presentation and paucity of objective biomarkers make prospective controlled clinical trials for Susac syndrome treatment difficult. Current immunosuppressive treatments are therefore based on empirical evidence, mainly from retrospective case series and expert opinion. In this review, we draw attention to the need to take consider Susac syndrome in the differential diagnosis of different neurological, psychiatric, ophthalmological and hearing disorders. Furthermore, we summarize our current knowledge of this syndrome, in reference to its pathophysiology, diagnosis and management, emphasizing the need for prospective and controlled studies that allow a better therapeutic approach.