Management of Intracranial Hypertension

Diagnosis and Evaluation

• The American Academy of Neurology recommends evaluating intracranial hypertension through urgent neuroimaging, lumbar puncture when safe, and managed using a stepwise approach including positioning, osmotic therapy, CSF drainage, and surgical interventions when necessary 1
• MRI brain with contrast is the preferred first-line imaging within 24 hours, and if MRI is unavailable, urgent CT brain followed by MRI should be performed 1
• CT or MR venography is mandatory to exclude cerebral sinus thrombosis 1
• Normal ICP is <10 mmHg or <20 cmH2O, and pathologically elevated ICP is ≥25 cmH2O in adults 1
• Clinical assessment, rather than CT scan, should be the primary method to determine if a lumbar puncture is safe to perform in patients with suspected increased intracranial pressure (ICP), with neuroimaging such as CT or MRI performed as soon as possible, and MRI preferred when available for its detailed information about brain parenchyma 2, 3

Management Principles

• The three main principles of management are: treat the underlying disease, protect vision, and minimize headache morbidity 1
• For patients with BMI >30 kg/m², weight loss is the only disease-modifying therapy, and referral to a structured weight management program is recommended 1
• Decompressive craniectomy may be considered for refractory intracranial hypertension 1
• For idiopathic intracranial hypertension with visual loss, CSF diversion procedures are preferred 1

Monitoring and Treatment

• Options for monitoring include intraventricular catheter and intraparenchymal pressure monitor 4
• For rapid visual decline within 4 weeks of diagnosis, consider serial lumbar punctures as a temporizing measure, and implement longer-term measures such as CSF diversion or optic nerve sheath fenestration 1
• Maintaining ICP below 20-25 mmHg and cerebral perfusion pressure (CPP) above 50-70 mmHg (optimal range 60-90 mmHg) is recommended, with evidence suggesting that maintaining CPP above 70 mmHg may further improve neurological outcomes, as supported by the American Heart Association and American College of Cardiology 5, 6, 7
• Supporting systemic blood pressure to maintain adequate CPP (>60-70 mmHg) is essential, while avoiding overaggressive treatment of hypertension, which may decrease CPP 7
• Mannitol is recommended as the first-line agent for acute ICP elevation, with a dosage of 0.5-1 g/kg IV bolus over 30-60 minutes, and may be repeated once or twice as needed if serum osmolality is less than 320 mOsm/L, as suggested by the American College of Cardiology 6, 7
• Hypertonic saline can also be used as an osmotic agent in refractory cases, with careful monitoring of electrolytes and renal function 8, 9
• The effects of carbon dioxide on cerebral blood flow are as follows:

• Maintaining normocapnia (PaCO₂ 35-40 mmHg) is crucial, and short-term hyperventilation (PaCO₂ 25-30 mmHg) may be used for acute, life-threatening ICP elevations, but caution is advised as prolonged hyperventilation can cause cerebral vasoconstriction and ischemia, as recommended by the American Thoracic Society 6, 4

Special Considerations

• A multidisciplinary approach involving obstetricians is recommended for pregnant patients with intracranial hypertension, with careful risk-benefit assessment for headache medications during pregnancy 1
• Acute brain injury management involves a multidisciplinary approach to prevent further brain damage and promote optimal recovery, as recommended by the American Heart Association and American College of Cardiology 5, 6, 7
• Elevating the head of bed by 20-30° improves venous drainage, according to the American Heart Association 10
• Mild restriction of fluids is recommended, as per the American Heart Association guidelines 10
• Avoiding hypo-osmolar fluids, such as 5% dextrose, is advised as they may worsen cerebral edema, according to the American Heart Association 10
• Correcting electrolyte abnormalities is essential, as suggested by the British Medical Association 11
• Monitoring for Cushing's triad, pupillary changes, abnormal posturing, focal neurological deficits, and respiratory abnormalities is recommended as indicators of increased intracranial pressure, particularly in patients with brainstem compression 11
• Decreased consciousness, progressing to stupor and coma, can be a late sign of increased intracranial pressure, and early recognition is crucial for timely intervention 11
• Lumbar puncture should be performed as soon as possible after hospital admission unless contraindicated, with reassessment every 24 hours if initially contraindicated, and careful consideration for elderly patients who may present atypically 2, 3
• Frequent neurological evaluation is necessary to detect signs of herniation, and to monitor for complications of intracranial hypertension management, including herniation, secondary ischemia, hydroelectrolytic disturbances, and renal insufficiency due to osmotic therapy 6, 12
• Ventricular drainage is recommended for treating hydrocephalus, and CSF drainage is an effective method for reducing ICP, particularly in hydrocephalus, with options including intermittent drainage via intraventricular catheter, continuous external ventricular drainage, and lumbar drainage (if no risk of herniation), as suggested by the American Heart Association and American College of Cardiology 5, 7, 6
• Surgical evacuation for hematomas causing mass effect, antibiotics for infectious causes, and steroids may be beneficial for cerebral edema due to tumors, but are not recommended for traumatic brain injury or spontaneous ICH, as recommended by the American College of Cardiology 7
• The relationship between PEEP and ICP is as follows:

• Positive end-expiratory pressure (PEEP) levels can increase intracranial pressure, particularly in patients with severe lung injury or during the vasospasm period, and should be used with caution 13
• The key principles of treatment are as follows:

• Controlling seizures with appropriate antiepileptic therapy is crucial in managing intracranial pressure, as recommended by the American Heart Association 7
• The use of intravenous sedation and analgesia is recommended to minimize pain and ICP increases while allowing neurological assessment, as suggested by the American College of Cardiology 7
• Maintaining normothermia and treating fever aggressively is recommended to improve outcomes in patients with intracranial hypertension, as suggested by the American Heart Association 7
• In children with sickle cell anemia, acute headache is more frequently associated with acute central nervous system events than in the general pediatric population 14