Superficial cerebral siderosis as stroke-mimic

Abstract

Superficial siderosis of the central nervous system results from hemosiderin deposition in the subpial layers of the brain and spinal cord [1]. A clinical history of subarachnoid hemorrhage is often absent, and in most cases patients present with slowly progressive gait ataxia and sensorineural hearing impairment [1]. We describe a patient diagnosed with superficial cortical siderosis presenting with sudden occurrence of aphasia and facial palsy mimicking a cerebrovascular event. A 87-year-old man presented with expressive aphasia and hemisensory loss involving right hand and face. No headache was reported. His previous medical history was notable for high blood pressure treated with valsartan 80 mg/day. Neurological examination revealed a mild expressive aphasia with right central facial palsy. A CT head without contrast showed a rim of cortical hyperdensity on the left-side central sulcus (Fig. 1a). T2weighted and gradient-echo magnetic resonance imaging (MRI) showed a T2 hypointensity along the cortical sulci of both sides, indicative of hemosiderin deposition (Fig. 1b). Diffusion-weighted MRI, performed when neurological deficits were still present, showed no sign of recent ischemia and MR-angiography did not show evidence of a vascular malformation or aneurysm. Spin-echo and gradient-echo sequences failed to reveal any source for bleeding such as amyloid angiopathy or cavernomas, and no evidence of hemosiderin deposition in posterior fossa was found. Since the presence of aphasia pointed to a cortical disturbance, a CSF examination was not performed; however, a cervical spine MR with contrast did not show any vascular abnormality. Laboratory examinations, duplex ultrasound imaging and EEG revealed no abnormalities. Within 2 days the aphasia and facial palsy recovered. A diagnosis of superficial cerebral siderosis was made and the patient discharged. Superficial siderosis of the central nervous system is characterized by hemosiderin deposition in those parts of the central nervous system adjacent to cerebrospinal fluid, with following discoloration of the leptomeninges and adjacent parenchyma. The most involved sites are the superior vermis, cerebellar folia, basal frontal lobe, temporal cortex, brainstem, spinal cord, and cranial nerves I and VIII [1]. The clinical features are related to the site of hemosiderin deposition, and in most cases patients present with slowly progressive cerebellar ataxia (often with dysarthria), often associated with hearing loss (sometimes with vestibular failure), which may be accompanied by tinnitus [2]. However, also pyramidal and sensory signs are common and may relate to brainstem or spinal cord involvement. Sensory symptoms or a sensory level are rarely present [1]. Hemosiderin deposition around the brain, brainstem and spinal cord results in the characteristic hypointensity seen on T2-weighted MRI. Gradient-echo T2-weighted images F. Brigo (&) Section of Clinical Neurology, Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy e-mail: dr.francescobrigo@gmail.com