User Tools

Site Tools


intracranial_hypertension

Intracranial hypertension

Intracranial hypertension, commonly abbreviated IH, IICP or raised intracranial pressure (ICP), is elevation of the pressure in the cranium greater than 20 cmH2O.

ICP is normally 7–15 mm Hg; at 20–25 mm Hg, the upper limit of normal, treatment to reduce ICP may be needed.

Cerebral venous sinus stenosis has been reported in up to 90% of patients with IIH.

Repeat studies after normalization of the intracranial pressure demonstrated normalization of this finding.

The cerebral sinus narrowing might be a consequence of the increased intracranial pressure. However, venous sinus narrowing/thrombosis could cause increased intracranial pressure as well. This situation could represent the chicken or egg debate as to which occurs first 1).

Types

Idiopathic intracranial hypertension

Patients suffering from uncontrollable intracranial hypertension due to posttraumatic brain swelling.

see Intracranial Hypertension in Children.

Diagnosis

An MRI or CT scan of the head can usually determine the cause of increased intracranial pressure and confirm the diagnosis.

Intracranial pressure may be measured during a spinal tap (lumbar puncture). It can also be measured directly by using a device that is drilled through the skull or a tube (catheter) that is inserted into a hollow area in the brain called the ventricle.

see Intracranial pressure monitoring.

see Non invasive intracranial pressure monitoring.


The diagnosis of raised intracranial pressure (ICP) is important in many critically ill patients. The optic nerve sheath is contiguous with the subarachnoid space; thus, an increase in ICP results in a corresponding increase in the optic nerve sheath diameter.

Ocular sonography shows good diagnostic test accuracy for detecting raised ICP compared to CT: specifically, high sensitivity for ruling out raised ICP in a low-risk group and high specificity for ruling in raised ICP in a high-risk group. This noninvasive point-of-care method could lead to rapid interventions for raised ICP, assist centers without CT, and monitor patients during transport or as part of a protocol to reduce CT use 2).

see Optic nerve sheath diameter ultrasonography.

Outcome

Raised intracranial pressure (ICP) is associated with worse outcomes after acute brain injury, and clinical guidelines advocate early treatment of intracranial hypertension.

Complications

Autonomic impairment after acute traumatic brain injury has been associated independently with both increased morbidity and mortality. Links between autonomic impairment and increased intracranial pressure or impaired cerebral autoregulation have been described as well. However, relationships between autonomic impairment, intracranial pressure, impaired cerebral autoregulation, and outcome remain poorly explored.

If intracranial pressure gets too high, it can lead to deadly brain herniation, in which parts of the brain are squeezed past structures in the skull.

Treatment

ICP-lowering therapies are usually administered in a stepwise manner, starting with safer first-line interventions, while reserving higher-risk options for patients with intractable intracranial hypertension.

Hyperosmolar therapy has been the keystone of medical interventions used to control intracranial hypertension.

see Decompressive craniectomy.

In a review, LeRoux will examine the implications of the Benchmark Evidence from South American Trials: Treatment of Intracranial Pressure (BEST TRIP) trial, evidence for an influence of ICP care on outcome, and a need for greater understanding of the pathophysiology than just ICP through multimodal monitoring (MMM) to enhance the outcome.

ICP-based monitoring and treatment alone may not be enough to enhance TBI outcome, but ICP and cerebral perfusion pressure therapy remain important in TBI care. Although high-quality evidence for MMM is limited, it should be more widely adapted to better understand the complex pathophysiology after TBI, better target care, and identify new therapeutic opportunities 3).

see Prophylactic Hypothermia for severe traumatic brain injury.

1)
Shaw GY, Million SK. Benign intracranial hypertension: a diagnostic dilemma. Case Rep Otolaryngol. 2012;2012:814696.
2)
Ohle R, McIsaac SM, Woo MY, Perry JJ. Sonography of the Optic Nerve Sheath Diameter for Detection of Raised Intracranial Pressure Compared to Computed Tomography: A Systematic Review and Meta-analysis. J Ultrasound Med. 2015 Jul;34(7):1285-94. doi: 10.7863/ultra.34.7.1285. Review. PubMed PMID: 26112632.
3)
Le Roux P. Intracranial pressure after the BEST TRIP trial: a call for more monitoring. Curr Opin Crit Care. 2014 Apr;20(2):141-7. doi: 10.1097/MCC.0000000000000078. Review. PubMed PMID: 24584171.
intracranial_hypertension.txt · Last modified: 2017/08/15 19:24 by administrador