Dados do Trabalho

Título

Subarachnoid hemorrhage due to spontaneous rupture of an arachnoid cyst: case report

RESUMO

Presentation of the case:
A 37-year-old female patient seeks medical care at a private hospital in São Paulo. She was referring sudden, pulsating headache, with photophobia and phonophobia. The neurological examination was unremarkable. As the only previous medical history, she had deep venous thrombosis in 2014, since then she was irregularly using of Warfarin. She underwent CT and MRI of the skull which showed enlargement of the bilateral retrovermian and retrocerebellar cerebrospinal fluid space, with thin membranes/septations inside, and heterogeneous content, with deposition of hemoglobin degradation products. Such findings are consistent with a retrovermian arachnoid cyst with hemorrhagic content. No abnormalities were found in cervical abd intracranial arteries with angiotomography. The prothrombin time was normal and international normalized ratio (INR) was 1. The patient was discharged after 2 days of hospitalization with improvement in the headache.
Discussion:
Arachnoid cysts are collections of fluid located between the meningeal membranes. They are congenital and are formed due to a valve defect in the arachnoid membranes, which facilitate the passage of cerebrospinal fluid into its interior, leading to the formation of the collection. Most arachnoid cysts are an incidental finding. About 1 to 2% of the population has a subarachnoid cyst and symptoms can be seen when the cyst increases in size or bleeds inside the cyst. Thus, the case presented is a rare condition.
Final comments
The patient presented a headache with a warning sign – tunderclap headache – and was investigated aiming to rule out a subarachnoid hemorrhage which is frequently associated with aneurysm rupture. The neuroimaging findings disclosed a rare complication of the arachnoid cyst. The most important risk factor for arachnoid cyst hemorrhage is trauma. In the case described, there was no history of trauma. Another possibility would be the use of an anticoagulant; however, this association was ruled out with normal prothrombin time. The risk of intracystic hemorrhage in people using anticoagulants is unknown and so far there is no contraindication to their use in this population.

Palavras Chave

Subarachnoid hemorrhage; Stroke;