LAUSR

Superficial siderosis of the central nervous system is considered a rare condition, observed on gradient echo T2*-weighted magnetic resonance imaging (MRI) as a typical signal hypointensity outlining the brain surface. ‘Classical’ superficial siderosis of the CNS, first described in 1908 [1], primarily affects the infratentorial regions and spinal cord, and typically presents with progressive sensorineural hearing impairment, cerebellar ataxia and pyramidal signs, although this form of superficial siderosis is assumed to be caused by chronic intermittent or continuous bleeding. Another type of brain siderosis restricted to the supratentorial compartment and the convexities of the cerebral hemispheres, which has gained recent interest is referred to as ‘cortical’ superficial siderosis (cSS) [2]. cSS has a different range of potential causes and clinical presentation to classical siderosis, but in older individuals is emerging as a key feature of cerebral amyloid angiopathy (CAA) [3, 4]. cSS is associated with characteristic clinical symptoms, including transient focal neurological episodes, and might be a marker of future intracerebral haemorrhage (ICH) risk in CAA patient [5, 6]. In the population-based Rotterdam Scan Study, using a 1.5Tesla (T) MRI, the overall incidence of SS was found to be 0.7%, all of whom had cortical microbleeds in their vicinity [7].