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Acta Neurochirurgica. Supplement

Sophie Kelly, Steven M Bishop, Ari Ercole
OBJECTIVES: The pressure-reactivity index (PRx) is defined in terms of the moving correlation coefficient between intracranial pressure (ICP) and mean arterial pressure (MAP) and is a measure of cerebral autoregulation ability. Plots of PRx against cerebral perfusion pressure (CPP) show a U-shaped behaviour: the minimum reflecting optimal cerebral autoregulation (CPPopt). However U-shaped behaviour may also occur by chance. To date there has been no evaluation of the statistical properties of these signals...
2018: Acta Neurochirurgica. Supplement
Kyriaki Kostoglou, Ronald Schondorf, Julie Benoit, Saharnaz Balegh, Georgios D Mitsis
OBJECTIVE: In this study we aimed to predict the time to syncope occurrence (TSO) in patients with vasovagal syncope (VVS), solely based on measurements recorded during the supine position of the head-up tilt (HUT) testing protocol. METHODS: We extracted various time and frequency domain features related to morphological aspects of arterial blood pressure (ABP) and the electrocardiogram (ECG) raw signals as well as to dynamic interactions between beat-to-beat ABP, heart rate, and cerebral blood flow velocity...
2018: Acta Neurochirurgica. Supplement
Denis E Bragin, Gloria L Statom, Edwin M Nemoto
OBJECTIVE: In previous work we showed that high intracranial pressure (ICP) in the rat brain induces a transition from capillary (CAP) to pathological microvascular shunt (MVS) flow, resulting in brain hypoxia, edema, and blood-brain barrier (BBB) damage. This transition was correlated with a loss of cerebral blood flow (CBF) autoregulation undetected by static autoregulatory curves but identified by induced dynamic ICP (iPRx) and cerebrovascular (iCVRx) reactivity. We hypothesized that loss of CBF autoregulation as correlated with MVS flow would be identified by iPRx and iCVRx in traumatic brain injury (TBI) with elevated ICP...
2018: Acta Neurochirurgica. Supplement
Alexander D Wright, Jonathan D Smirl, Kelsey Bryk, Paul van Donkelaar
OBJECTIVE: To determine whether acute sports-related concussion (SRC) exerts differential effects on cerebral autoregulatory properties during systole versus diastole. MATERIALS AND METHODS: One hundred and thirty-six contact-sport athletes tested preseason; 14 sustained a concussion and completed follow-up testing at 72 hours, 2 weeks, and 1 month post-injury. Five minutes of repetitive squat-stand maneuvers induced blood pressure (BP) oscillations at both 0.05 and 0...
2018: Acta Neurochirurgica. Supplement
Bianca Pineda, Colin Kosinski, Nam Kim, Shabbar Danish, William Craelius
OBJECTIVE:  Following brain injury, unstable cerebral hemodynamics can be characterized by abnormal rises in intracranial pressure (ICP). This behavior has been quantified by the RAP index: the correlation (R) between ICP pulse amplitude (A) and mean (P). While RAP could be a valuable indicator of autoregulatory processes, its prognostic ability is not well established and its validity has been questioned due to potential errors in measurement. Here, we test (1) whether RAP is a consistent measure of intracranial hemodynamics and (2) whether RAP has prognostic value in predicting hemodynamic instability following brain injury...
2018: Acta Neurochirurgica. Supplement
Marine Flechet, Geert Meyfroidt, Ian Piper, Giuseppe Citerio, Iain Chambers, Patricia A Jones, Tsz-Yan Milly Lo, Per Enblad, Pelle Nilsson, Bart Feyen, Philippe Jorens, Andrew Maas, Martin U Schuhmann, Rob Donald, Laura Moss, Greet Van den Berghe, Bart Depreitere, Fabian Güiza
OBJECTIVE:   The aim of this study is to assess visually the impact of duration and intensity of cerebrovascular autoregulation insults on 6-month neurological outcome in severe traumatic brain injury. MATERIAL AND METHODS:   Retrospective analysis of prospectively collected minute-by-minute intracranial pressure (ICP) and mean arterial blood pressure data of 259 adult and 99 paediatric traumatic brain injury (TBI) patients from multiple European centres. The relationship of the 6-month Glasgow Outcome Scale with cerebrovascular autoregulation insults (defined as the low-frequency autoregulation index above a certain threshold during a certain time) was visualized in a colour-coded plot...
2018: Acta Neurochirurgica. Supplement
Samuel Patrick Klein, Dominike Bruyninckx, Ina Callebaut, Bart Depreitere
OBJECTIVE: We investigated the effect of cerebrospinal fluid (CSF) drainage on the intracranial pressure (ICP) signal measured in the parenchyma and the ventricle as well as the effect on the pressure reactivity index (PRx) calculated from both signals. METHODS:  Ten patients were included in this prospective study. All patients received a parenchymal ICP sensor and an external ventricular drain (EVD) for CSF drainage. ICP signals (ICP-p and ICP-evd) were captured...
2018: Acta Neurochirurgica. Supplement
Konstantin Hockel, Martin U Schuhmann
OBJECTIVE: A drawback in the use of an external ventricular drain (EVD) originates in the fact that draining cerebrospinal fluid (CSF) (open system) and intracranial pressure (ICP) monitoring can be done at the same time but is considered to be unreliable regarding the ICP trace. Furthermore, with the more widespread use of autoregulation monitoring using blood pressure and ICP signals, the question arises of whether an ICP signal from an open EVD can be used for this purpose. Using an EVD system with an integrated parenchymal ICP probe we compared the different traces of an ICP signal and their derived parameters under opened and closed CSF drainage...
2018: Acta Neurochirurgica. Supplement
Flora A Kennedy McConnell, Stephen J Payne
OBJECTIVE: Ischemic stroke is a leading cause of death and disability. Autoregulation and collateral blood flow through the circle of Willis both play a role in preventing tissue infarction. A steady-state model of the cerebral arterial network was used to investigate the interaction of these mechanisms when autoregulation is impaired ipsilateral to an occluded artery. MATERIALS AND METHODS: Twelve structural variants of the circle of Willis were modelled with left internal carotid artery occlusion and coupled with (1) a passive model of the cerebral vascular bed, (2) a steady-state model of an autoregulating cerebral vascular bed, and (3) a model in which the contralateral hemisphere autoregulates and the ipsilateral hemisphere does not...
2018: Acta Neurochirurgica. Supplement
Solventa Krakauskaite, Corey Thibeault, James LaVangie, Mateo Scheidt, Leo Martinez, Danielle Seth-Hunter, Amanda Wu, Michael O'Brien, Fabien Scalzo, Seth J Wilk, Robert B Hamilton
OBJECTIVE: To determine normal ranges for traditional transcranial Doppler (TCD) measurements for two age groups (14-19 and 20-29 years) and compare to existing literature results. The development of a normal range for TCD measurements will be required for the development of diagnostic and prognostic tests in the future. MATERIALS AND METHODS: We performed TCD on the middle cerebral artery on 147 healthy subjects aged 18.9 years (SD = 2.1) and calculated mean cerebral blood flow velocity (mCBFV) and pulsatility index (PI)...
2018: Acta Neurochirurgica. Supplement
Jonathan D Smirl, Alexander D Wright, Philip N Ainslie, Yu-Chieh Tzeng, Paul van Donkelaar
OBJECTIVE: Cerebral pressure-flow dynamics are typically reported between mean arterial pressure and mean cerebral blood velocity. However, by reporting only mean responses, potential differential regulatory properties associated with systole and diastole may have been overlooked. MATERIALS AND METHODS: Twenty young adults (16 male, age: 26.7 ± 6.6 years, BMI: 24.9 ± 3.0 kg/m2 ) were recruited for this study. Middle cerebral artery velocity was indexed via transcranial Doppler...
2018: Acta Neurochirurgica. Supplement
Simon Garnotel, Stéphanie Salmon, Olivier Balédent
OBJECTIVE: Cerebrospinal fluid (CSF) stroke volume in the aqueduct is widely used to evaluate CSF dynamics disorders. In a healthy population, aqueduct stroke volume represents around 10% of the spinal stroke volume while intracranial subarachnoid space stroke volume represents 90%. The amplitude of the CSF oscillations through the different compartments of the cerebrospinal system is a function of the geometry and the compliances of each compartment, but we suspect that it could also be impacted be the cardiac cycle frequency...
2018: Acta Neurochirurgica. Supplement
A Lokossou, O Balédent, S Garnotel, G Page, L Balardy, Z Czosnyka, P Payoux, E A Schmidt
OBJECTIVE: The amplitude of intracranial pressure (ICP) can be measured by ICP monitoring. Phase-contrast magnetic resonance imaging (PCMRI) can quantify blood and cerebrospinal fluid (CSF) flows. The aim of this work was to investigate intracranial compliance at rest by combining baseline ICP monitoring and PCMRI in hydrocephalus patients. MATERIALS AND METHODS: ICP monitoring was performed before infusion testing to quantify ΔICP_rest at the basal condition in 33 suspected hydrocephalus patients (74 years)...
2018: Acta Neurochirurgica. Supplement
Andreas Spiegelberg, Matthias Krause, Juergen Meixensberger, Burkhardt Seifert, Vartan Kurtcuoglu
OBJECTIVE: We aimed to test whether there is an association of slow vasogenic wave (SVW) occurrence with positive response to external lumbar drainage (ELD) and ventriculoperitoneal shunting and to design a method for the recognition and quantification of SVWs in the intracranial pressure (ICP) signal. MATERIALS AND METHODS: We constructed SVW templates using normalized sine waves. We calculated the cross-correlation between the respective SVW template and the ICP signal...
2018: Acta Neurochirurgica. Supplement
Cyrille Capel, Marc Baroncini, Catherine Gondry-Jouet, Roger Bouzerar, Marek Czosnyka, Zofia Czosnyka, Olivier Balédent
OBJECTIVES: Cerebrospinal fluid (CSF) and blood flows have a strong relationship during a cardiac cycle. Idiopathic intracranial hypertension (IIH) is a pathology that seems to present hemodynamic and hydrodynamic disturbance. The aim of this study was to establish CSF and blood interaction in IIH. MATERIAL AND METHODS: We retrospectively studied cerebral hydrodynamic and hemodynamic flows by phase-contrast MRI (PCMRI) in 13 IIH subjects (according Dandy's criteria) and 16 controls...
2018: Acta Neurochirurgica. Supplement
Zofia Czosnyka, Dong-Joo Kim, Olivier Balédent, Eric A Schmidt, Peter Smielewski, Marek Czosnyka
OBJECTIVE: The phase-contrast MRI technique permits the non-invasive assessment of CSF movements in cerebrospinal fluid cavities of the central nervous system. Of particular interest is pulsatile cerebrospinal fluid (CSF) flow through the aqueduct cerebri. It is allegedly increased in hydrocephalus, having potential diagnostic value, although not all scientific reports contain unequivocally positive conclusions. METHODS: For the mathematical simulation of CSF flow, we used a computational model of cerebrospinal blood/fluid circulation designed by a former student as his PhD project...
2018: Acta Neurochirurgica. Supplement
Eva Nabbanja, Marek Czosnyka, Nicole C Keong, Matthew Garnett, John D Pickard, Despina Afroditi Lalou, Zofia Czosnyka
OBJECTIVE: The term "hydrocephalus" encompasses a range of disorders characterised by clinical symptoms, abnormal brain imaging and derangement of cerebrospinal fluid (CSF) dynamics. The ability to elucidate which patients would benefit from CSF diversion (a shunt or third ventriculostomy) is often unclear. Similar difficulties are encountered in shunted patients to predict the scope for improvement by shunt re-adjustment or revision. MATERIALS AND METHODS: We compared retrospective pre-shunting infusion test results performed in 310 adult patients diagnosed with normal pressure hydrocephalus (NPH) and their improvement after shunting...
2018: Acta Neurochirurgica. Supplement
Marc Baroncini, Olivier Balédent, Celine Ebrahimi Ardi, Valerie Deken Delannoy, Gregory Kuchcinski, Alain Duhamel, Gustavo Soto Ares, Jean-Paul Lejeune, Jérôme Hodel
OBJECTIVE: In the case of ventriculomegaly in the elderly, it is often difficult to differentiate between communicating chronic hydrocephalus (CCH) and brain atrophy. The aim of this study is to describe the MRI criteria of CCH, defined by a symptomatic patient with ventriculomegaly and that improved after shunt placement. MATERIALS AND METHODS: Magnetic resonance imaging was prospectively evaluated in 90 patients with ventriculomegaly. Patients were classified into three groups: patients without clinical signs of CCH (control, n = 47), patients with CCH treated by shunt placement with clinical improvement (responders, n = 36), and patients with CCH treated using a shunt without clinical improvement (nonresponders, n = 7)...
2018: Acta Neurochirurgica. Supplement
Noam Alperin, Ahmet M Bagci
OBJECTIVE: Most of the astronauts onboard the International Space Station (ISS) develop visual impairment and ocular structural changes that are not fully reversible upon return to earth. Current understanding assumes that the so-called visual impairments/intracranial pressure (VIIP) syndrome is caused by cephalad vascular fluid shift. This study assesses the roles of cerebrospinal fluid (CSF) and intracranial pressure (ICP) in VIIP. MATERIALS AND METHODS: Seventeen astronauts, 9 who flew a short-duration mission on the space shuttle (14...
2018: Acta Neurochirurgica. Supplement
J Donnelly, M Czosnyka, H Adams, C Robba, L A Steiner, D Cardim, B Cabella, X Liu, A Ercole, P J Hutchinson, D K Menon, M J H Aries, P Smielewski
OBJECTIVES: Retrospective data from patients with severe traumatic brain injury (TBI) indicate that deviation from the continuously calculated pressure reactivity-based "optimal" cerebral perfusion pressure (CPPopt) is associated with worse patient outcome. The objective of this study was to assess the relationship between prospectively collected CPPopt data and patient outcome after TBI. METHODS: We prospectively collected intracranial pressure (ICP) monitoring data from 231 patients with severe TBI at Addenbrooke's Hospital, UK...
2018: Acta Neurochirurgica. Supplement
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