LAUSR

Susac Syndrome (SuS) is an immune-mediated microvascular endotheliopathy that affects capillaries and precapillary arterioles in the brain, retina and inner ear. The immunopathogenesis is not well established, but histopathologic findings have suggested a similar mechanism to that seen in juvenile dermatomyositis (JDM), which is an immune-mediated occlusive microvascular endotheliopathy that causes microinfarctions in a different triad of tissues (muscle, skin, and gastrointestinal tract) [1–2]. SuS is characterized by the clinical triad of visual disturbances, hypoacusia, and diffuse encephalopathy. The most reported clinical manifestations are uni or bilateral visual field defects, hypoacusia, headache, confusion, memory disturbances, behavioral changes, ataxia, bladder dysfunction, vertigo, and dysarthria. In classical cases, Brain Magnetic Resonance Imaging (MRI) reveals “snowball” lesions in the corpus callosum (CC) due to central fibers microinfarctions [3]. Other typical callosal lesions include hypointense T1 sequelae CC lesions (“holes”) and sagittal T2 FLAIR upper CC fibers damage (“icicles”) and linear infarctions (“spokes”). Also, internal capsule infarctions in a “string of pearls” pattern, nonspecific white matter lesions and leptomeningeal gadolinium enhancement can be present. Additional complementary diagnostic tests important to confirm SuSdiagnosis are retinal fluorescein angiography (FA) and tonal audiometry (TA): branch retinal artery occlusions (BRAO) and/or vessel wall hyperfluorescence can be present in FA and uni or bilateral hearing loss can be found in TA. There have been reported a small number of patients with dermatological compromise in SuS [3] but, under the best of our knowledge, none with gastrointestinal affection. We report the first case of a patient with SuS and idiopathic ischemic colitis and analyze the possible pathophysiological mechanisms that could be involved in this association. A 52-years-old previously healthy male developed scotoma in the right eye. One week later he was admitted in the hospital because confusion, irritability, disinhibition, left-sided deafness, vertigo, constipation and urine incontinence. MRI showed white matter microinfarctions, compromising CC central fibers. Serologic test as antinuclear antibodies, Anti-dsDNA, anti-neutrophil cytoplasmic antibody, latex test and citrulline antibodies were negative. The polymerase chain reaction for herpes virus family, VDRL test, hepatitis B surface antibody and antigen, hepatitis C antibodies and human immunodeficiency virus serology were all negative. Cerebrospinal fluid analysis showed 1 lymphocyte, elevated proteins concentration (170mg/dl) and an IgG index slightly elevated. FA revealed BRAO and vessel wall hyperfluorescence. TA showed unilateral low frequency sensorineural hearing loss,