Decompressive craniectomy is a neurosurgical treatment comprising temporary removal of a large part of the cranium to increase intracranial space and compliance in patients with severe intracranial pressure (ICP) elevation or impending intracranial herniation. Decompressive craniectomy effectively lowers ICP, decreases mortality and increase favourable functional outcome, although many patients remain dependent on care. The high morbidity is partly caused by complications related to disturbed ICP and cerebrospinal fluid (CSF) flow. To improve understanding of the pathophysiology in these patients with large cranial defects and to gain knowledge about intracranial physiology in general, we studied long-term ICP following decompressive craniectomy. We found that ICP gradually decreased during the first month and then stabilised at low (negative) values, both in the supine and sitting position, meaning that the “circadian” postural ICP changes were absent in this state. Furthermore, intracranial PWA was severely diminished reducing the effect of intracranial pulsatility as a driver of intracranial fluid movements (e.g. CSF or glymphatic flow). Following cranioplasty, normal intracranial physiology regarding ICP, postural ICP changes and intracranial PWA was restored in all patients. These findings complement existing vidence showing improved cerebral blood flow and metabolism after cranioplasty. Normalisation of ICP and CSF flow might be involved in the neurological and cognitive improvement observed after cranioplasty and our findings underline the importance of a rigid cranium for normal intracranial physiology in humans.
Place of employment
Date and place of defense
February 22nd 2019, Department of Clinical Medicine (Mærsk Tower), University of Copenhagen
Professor Marianne Juhler, MD, PhD, DMSc (main)
Associate Professor Kåre Fugleholm, MD, PhD, DMSc
Jesper Kelsen, MD, PhD
Morten Andresen, MD, PhD