Intracranial emergencies in neurosurgical oncology: pathophysiology and clinical management

Abstract

AbstractIntracranial tumors pose a challenge in neurosurgery, especially when patients present emergently or require emergency surgery. Tackling an acute change in the patient’s mental status is the primary reason for seeking an emergency surgery in the setting of an intracranial tumor. In addressing tumor-related complications, the aim of surgery is to relieve elevated intracranial pressure (ICP), confirm a diagnosis, improve or stabilize function, and extend the patient’s life by preventing herniation.Tumors and peritumoral edema form a space-occupying lesion that causes mass effect on nearby structures and elevates ICP. Surgical management involves (1) external ventricular drain (EVD) placement to monitor ICP, lower the volume of cerebrospinal fluid (CSF), and temporarily treat intracranial hypertension, (2) resection of the space-occupying mass responsible for the rise in ICP, and (3) in some patients, decompressive craniectomy (DC). Patients with brain tumors may also present with hydrocephalus due to the tumor’s obstructing CSF flow or disrupting CSF absorption. Tumors also cause tumor-associated epilepsy (TAE) and status epilepticus (TASE). TASE is a life-threatening condition characterized by an abnormally prolonged generalized seizure (or a chain of multiple seizures) without recovery of consciousness to baseline. Time is of the essence when managing TAE and TASE, and surgical resection of the tumor-associated epileptogenic focus can be curative. Brain tumors and their treatment can also provoke ischemic stroke, intratumoral hemorrhage, and cerebral venous sinus thrombosis depending on their location. Hemorrhagic infarction of pituitary adenomas leading to rapid expansion of the sellar region and acute pituitary gland dysfunction is known as pituitary apoplexy. Here, optimizing the patient’s hemodynamic status and treating adrenal insufficiency are crucial upon presentation. Emergency surgical resection plays an important role in saving nearby neurovascular entities when conservative treatment proves inadequate. Finally, infections of the central nervous system (CNS) occur as a result of immunologic compromise caused by the tumor itself or by its treatment.In conclusion, in severe and rapidly progressing cases in which the patient presents with altered mental status and neurologic deficits, an emergency neurosurgical procedure is indicated for removal of the cause(s) of the excess ICP, protection of brain function, and monitoring of ICP.