title: [Subarachnoid hemorrhage associated to subhyaloid hemorrhage: "Terson syndrome"].
abstract: BACKGROUND
  The combination of subarachnoid hemorrhage (SAH) and subhyaloid hemorrhage is known as 'Terson syndrome'. Retinal hemorrhage is commonly observed clinically in the optic fundi of patients with SAH, however, subhyaloid hemorrhage of the globe in the setting of SAH has been rarely on CT of the brain. Several mechanisms of subhyaloid hemorrhage have been proposed: a. A sudden increase in intracranial pressure (ICP) forces blood from the subarachnoid space directly into the preretinal space. b. A sudden rise in ICP is thought to decrease venous return to the cavernous sinus from the veins draining the globe. The increased retinal venous pressure results in stasis followed by vessel rupture. c. A sudden rise in ICP obstructs both the retinochoroidal anastomoses and the central retinal vein due to a rapid effusion of CSF through the communication of the subarachnoid space with the optic nerve sheat. This produces an acute decrease in venous drainage from the retina and results in stasis and hemorrhage.
  
  
  METHODS
  A 35 year old man, with a history of a non controlled arterial hypertension, dilated cardiopathy and 'agitation episodes'. He had a spontaneous intracranial hemorrhage, consistent in a parenchymal hematoma ruptured into ventricles and subarachnoid space. The CT showed through optic nerve sheath this hemorrhage extended to subhyaloid space. The patient came in coma 'dépassé' and brain death.
  
  
  CONCLUSIONS
  We report a case of Terson syndrome demonstrated by CT. This CT allow see the blood from the subarachnoid space erupt directly into the preretinal space through optic nerve sheath, confirming one the proposed mechanism for this syndrome.
authors.affiliation: Servicio de Radiodiagnóstico, Ciudad Sanitaria y Universitaria de Bellvitge, Barcelona, España.
authors.forename: C H
authors.initials: CH
authors.lastname: Castaño-Duque
authors.forename: L C
authors.initials: LC
authors.lastname: Pons-Irazazabal
authors.forename: J L
authors.initials: JL
authors.lastname: López-Moreno
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology; D003128:Coma / Q000175:diagnosis / Q000209:etiology; D015600:Glasgow Coma Scale; D006406:Hematoma / Q000473:pathology; D006801:Humans; D007427:Intracranial Pressure; D008297:Male; D012166:Retinal Hemorrhage / Q000150:complications* / Q000175:diagnosis; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000175:diagnosis; D013577:Syndrome; D014057:Tomography, X-Ray Computed