RESUMO
Midbrain cavernous malformations (MCMs) are rare and dangerous taken the important structures and tracts located in this segment of the brainstem. MCM treatment is still controversial, and surgical resection is basically indicated in cases of recurrent hemorrhage and progressive neurologic deterioration. The optimal moment to operate ruptured MCM is in the subacute stage. Once indicated for surgical resection, preoperative planning needs to be individualized. There are various ways to access midbrain lesions, depending on the extension and predominant location: lateral subtemporal, posterior transtentorial, interhemispheric transcallosal, and anterior temporopolar approaches, or some of the alternatives. The aim of this Video 1 case is to review the surrounding anatomic structures and demonstrate the advantages of the semisitting position and the viability of the supracerebellar infratentorial approach for a tegmental midbrain lesion.1-10 In this 2-dimensional video, we present an 18-year-old man with a 4-year history of diplopia and third nerve palsy, which worsened 10 days before admission. He underwent microsurgical total resection of this MCM via extreme lateral supracerebellar infratentorial approach in a semisitting position. At the end, the surgical site and surrounding structures were reviewed microscopically and endoscopically. The patient tolerated the surgery well, and the perioperative course was uneventful. His recovery was smooth but he maintained the previous oculomotor nerve palsy. We discuss important steps of the surgical approach, local neuroanatomy, and the microsurgical techniques for the resection of these challenging MCM. The goal is total resection of the MCM with the preservation of the developmental venous anomaly and the surrounding white fiber tracts.
RESUMO
Arachnoid cysts are responsible for 1% of expansive lesions in the central nervous system. Usually, they do not cause neurologic symptoms unless they have expansion or hemorrhage. Intracystic bleeding is caused by trauma or may be spontaneous. There are few cases in the literature of spontaneous hemorrhage of arachnoid cysts. This 2-dimensional video (Video 1) demonstrates the case of a 6-year-old boy who presented with headache and diplopia. At the physical examination, he exhibited right sixth nerve palsy. The complementary examinations revealed a left middle fossa arachnoid cyst classified as Galassi 2. An urgent procedure was planned to fenestrate the cyst. Informed written consent was obtained from the patient's family. Due to the team experience, endoscope-controlled microsurgery was performed. The patient experienced remission of the headache and the diplopia. A CT scan was performed on the first postoperative day and revealed a lamina of acute blood at the subdural space. It was an asymptomatic thin lamina of blood; we opted to watch and follow. One month later, a control MRI revealed a left frontoparietal subdural hematoma. Despite being asymptomatic, the hematoma was determined to have significant mass effect; thus, it was evacuated by a parietal burr-hole. After 1 month, another MRI showed resolution of the frontoparietal hematoma and significant reduction in the arachnoid cyst. There are few cases described of spontaneous rupture of arachnoid cyst; beyond that, we would like to illustrate a step-by-step procedure that is not widely available as a video article.