Comparison of pulsatile and static pressures within the intracranial and lumbar compartments in patients with Chiari malformation type 1: a prospective observational study
- 325 Downloads
In Chiari malformation type 1 (CMI), the obstruction of cerebrospinal fluid (CSF) flow through the foramen magnum is believed to cause alterations of intracranial pressure (ICP) pulsations. Foramen magnum decompression (FMD) is therefore considered a treatment of choice. However, the pathophysiology of CMI is poorly understood and it remains unknown how ICP alterations relate to symptoms and radiological findings. This study was undertaken to measure pulsatile pressure and its gradient between intracranial and lumbar compartments, and to determine its relationship to clinical and radiological findings.
In patients with symptomatic CMI, we simultaneously measured ICP and lumbar CSF pressure, with particular focus on analysis of pulsatile pressure. Ventricular CSF volume (VV), intracranial volume (ICV) and posterior cranial fossa volume (PCFV) were calculated using volumetry software.
In 26 patients (median 35 years), we found clearly abnormal or borderline values of pulsatile ICP in 18/26 patients (69 %; median 4.5 mmHg) and abnormal pulsatile pressure gradient in 17/24 patients (71 %; median 2.6 mmHg). The correlation between pulsatile ICP and the pulsatile pressure gradient was significantly positive (p < 0.001). We found no significant correlation between pulsatile or static pressure and extent of tonsillar ectopy, VV, ICV or PCFV. The pulsatile pressure gradient was significantly higher in patients with syringomyelia (p = 0.02).
In this cohort, the pulsatile ICP was elevated in 69 %. The intracranial-lumbar pulsatile pressure gradient was abnormal in 71 % and significantly higher in patients with syringomyelia. The elevated pulsatile ICP significantly correlated with pulsatile pressure gradient; no similar correlation was found for static ICP. We interpret the results as providing evidence of impaired intracranial compliance as an important pathophysiological mechanism in CMI.
KeywordsChiari malformation type I Cerebrospinal fluid dynamics Foramen magnum Syringomyelia Intracranial pressure
Conflicts of Interest
R. Frič discloses no conflicts of interests. The software used for analysis of the ICP recordings (Sensometrics Software) is manufactured by a software company (dPCom AS, Oslo, Norway) in which P.K. Eide has a financial interest.
- 9.Eide PK, Bentsen G, Sorteberg AG, Marthinsen PB, Stubhaug A, Sorteberg W (2011) A randomized and blinded single-center trial comparing the effect of intracranial pressure and intracranial pressure wave amplitude-guided intensive care management on early clinical state and 12-month outcome in patients with aneurysmal subarachnoid hemorrhage. Neurosurgery 69:1105–1115PubMedGoogle Scholar
- 18.Gardner WJ, Angel J (1959) The mechanism of syringomyelia and its surgical correction. Clin Neurosurg 6:131–140Google Scholar
- 26.Krayenbuhl H (1975) Evaluation of the different surgical approaches in the treatment of syringomyelia. Clin Neurology Neurosurg 77:111–128Google Scholar
- 35.Poca MA, Sahuquillo J, Ibanez J, Amoros S, Arikan F, Rubio E (2002) Intracranial hypertension after surgery in patients with Chiari I malformation and normal or moderate increase in ventricular size. Acta Neurochir Suppl (Wien) 81:35–38Google Scholar
- 36.Poca MA, Sahuquillo J, Topczewski T, Lastra R, Font ML, Corral E (2006) Posture-induced changes in intracranial pressure: a comparative study in patients with and without a cerebrospinal fluid block at the craniovertebral junction. Neurosurgery 58:899–906, discussion 899-906 CrossRefPubMedGoogle Scholar