Intracranial Hypertension

Excerpt

Intracranial hypertension is a condition characterized by elevated pressure within the skull. The increase in pressure can exert significant stress on the brain and other intracranial structures, potentially leading to a range of neurological symptoms and complications. Intracranial hypertension's clinical manifestations vary depending on the underlying cause, severity of pressure elevation, and individual patient factors. Common symptoms may include severe headaches, visual disturbances, nausea, vomiting, tinnitus, and, in severe cases, seizures or coma.

Diagnosing intracranial hypertension typically involves a combination of clinical evaluation, results of neuroimaging studies like computed tomography (CT) and magnetic resonance imaging (MRI), and intracranial pressure (ICP) measurement via invasive or noninvasive techniques. Early recognition and prompt management of this condition are essential to prevent potential complications, including permanent neurological damage and even death. Managing ICH typically involves addressing the underlying cause, optimizing cerebral perfusion, and sometimes surgical interventions to relieve pressure on the brain.

Cerebrospinal Fluid and Intracranial Pressure

The human skull has a fixed volume of approximately 1400 to 1700 mL. Intracranial content volume comprises 80% brain parenchyma, 10% cerebrospinal fluid, and 10% blood.

The choroid plexus is the main CSF producer and regulator, secreting around 20 mL per hour, averaging 450 mL per day. Arachnoid granulations reabsorb CSF and drain it into the venous system at similar rates. Normal cerebrospinal fluid (CSF) production varies by age, with typically high production during infancy that declines and stabilizes in childhood and adulthood. CSF pressures greater than 250 mm H20 in adults and 200 mm H20 in children generally signify increased ICP.

Intracranial volume is more or less constant once the sutures completely ossify. Intracranial tissue or fluid volume elevation can raise intracranial pressure, which can occur in the presence of intracranial masses, ventricular stenosis, and hematomas. A large part of treating intracranial hypertension involves mitigating the risk of increased ICP and making timely clinical decisions to prevent adverse consequences.