Two Sisters with Leukoencephalopathy, Hearing Loss and Retinopathy: A Familial Case of Susac's Syndrome?

Aims: Susac’s syndrome is a rare clinical entity characterized by encephalopathy, sensorineural hearing loss and retinopathy caused by immune-mediated arteriole occlusion in the brain, retina and inner ear. No familial cases have been reported. We describe here the cases of two sisters who were seen at our Department for subacute neurological symptoms suggestive of a multifocal central nervous system disorder associated to hearing impairment and clinical or subclinical involvement of visual function.
Presentation of Cases: The first case presented with a two-years history of progressive paraparesis, gait ataxia and cognitive dysfunction started at age 46; she also suffered from epileptic seizures since childhood and bilateral visual loss occurred between age 37 and 38. Her sister, aged 44, had a long-standing history of headache followed by sudden-onset bilateral hearing loss at age 35, which did not recover, and an acute episode of right-sided face paresthesias nine years later. Brain MRI showed multiple T2-hyperintense supratentorial lesions involving the corpus callosum in both sisters, with “snowball” appearance in the older one. Serum anti-endothelial cell antibodies assay was positive in the youngest patient.
Discussion and Conclusion: After exclusion of other possible options, a diagnosis of Susac's syndrome looked probable for both sisters. Further studies investigating the pathogenesis and the genetic background of the disease are needed.