Brain herniation in a patient with apparently normal intracranial pressure: a case report

Introduction Intracranial pressure monitoring is commonly implemented in patients with neurologic injury and at high risk of developing intracranial hypertension, to detect changes in intracranial pressure in a timely manner. This enables early and potentially life-saving treatment of intracranial hypertension. Case presentation An intraparenchymal pressure probe was placed in the hemisphere contralateral to a large basal ganglia hemorrhage in a 75-year-old Caucasian man who was mechanically ventilated and sedated because of depressed consciousness. Intracranial pressures were continuously recorded and never exceeded 17 mmHg. After sedation had been stopped, our patient showed clinical signs of transtentorial brain herniation, despite apparently normal intracranial pressures (less than 10 mmHg). Computed tomography revealed that the size of the intracerebral hematoma had increased together with significant unilateral brain edema and transtentorial herniation. The contralateral hemisphere where the intraparenchymal pressure probe was placed appeared normal. Our patient underwent emergency decompressive craniotomy and was tracheotomized early, but did not completely recover. Conclusions Intraparenchymal pressure probes placed in the hemisphere contralateral to an intracerebral hematoma may dramatically underestimate intracranial pressure despite apparently normal values, even in the case of transtentorial brain herniation

Intracranial Pressure and Multimodal Monitoring

Secondary brain injury results from ischemia, tissue hypoxia, and a cascade of ongoing metabolic events. Neuromonitoring has evolved over the last two decades with the goal of preventing, detecting, and attenuating the damage from these secondary events. Typical monitored parameters include intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Advanced multimodal monitoring includes monitoring of cerebral blood flow (CBF), brain tissue oxygenation (transcranial oximetry, jugular bulb oximetry, brain tissue oxygen tension), and brain metabolism (intracerebral microdialysis). In this chapter, we will review basic principles of brain physiology and the complex and dynamic interactions between these parameters. In the future, neuromonitoring will be supported by advanced signal processing and analysis that will enable clinicians to synthesize information and form hypotheses that best explain the current situation. Such an integrated system will translate data into actionable information and provide situational awareness