Intracranial volume versus static and pulsatile intracranial pressure values in children with craniosynostosis

A clinical evaluation of variation in paediatric intracranial pressure waveforms

Introduction

Intracranial pressure (ICP) monitoring is commonly used in investigating the aetiology of chronic paediatric neurological conditions. A series of high-amplitude spikes has been observed in overnight ICP recordings of some children, many of whom have hydrocephalus or craniosynostosis.

Research question

This clinical evaluation aimed to define the spike pattern, describe the patient group in which it is most likely to occur, and conduct high-resolution waveform analysis.

Material and methods

ICP waveforms from 40 patients aged 0-5 years (inclusive), recorded between 2017 and 2021 at the Royal Hospital for Children Glasgow, were retrospectively analysed. The pattern was defined through visual inspection of regions of interest by two reviewers. Patients were stratified using demographic and clinical data. R software was used to perform regression and high-resolution waveform analyses.

Results

The spike pattern was defined as the presence of 2 consecutive spikes with an amplitude of at least 8 mmHg, with a gap of at least 30 min between spikes. In the adjusted Poisson regression, age was significantly associated with the number of spikes (IRR 0.8, 95% CI 0.70 to 0.92, p-value 0.001).

Discussion and conclusion

Younger age was significantly associated with an increased number of spikes in this cohort. Investigation of clinical consequences of the spikes is warranted.

Moderne Behandlung von Kraniosynostosen

Hintergrund

Bei 13–48 % aller Lebendgeborenen treten Auffälligkeiten der Schädelform auf. Meistens ist ein lagerungsbedingter Plagiozephalus ursächlich. Bei vorzeitigem Verschluss von Schädelnähten resultieren pathognomische Deformitäten durch das kompensatorische Wachstum der umgebenden Schädelknochen. Es muss zwischen Einzelnahtsynostosen und Kraniosynostosen im Rahmen syndromaler Erkrankungen unterschieden werden.

Ziel

Diese Arbeit soll einen Überblick über Diagnostik, konservative und chirurgische Therapie von Kraniosynostosen geben.

Methoden

Narratives Review.

Ergebnis

Bei Verdacht auf eine Kraniosynostose erfolgt zunächst die klinische Beurteilung und Einschätzung durch erfahrene Untersucher. Die pathognomische Schädelform ergibt die Arbeitsdiagnose. Bestätigt wird diese durch Verfahren wie 3D-Stereofotografie und Sonographie. In komplexen Fällen können CT oder MRT notwendig sein.

Die Indikation für eine Therapie ergibt sich aus ästhetischen Gesichtspunkten und der Vorbeugung psychosozialer Folgen. Bei syndromalen Formen besteht diese insbesondere zur Vermeidung möglicher Folgen eines erhöhten Hirndrucks.

Besteht die Indikation zur Operation muss zwischen endoskopischer und offener Technik unterschieden werden. Unterschiede bestehen hier hinsichtlich Invasivität und möglichem Korrekturausmaß. Im Anschluss an die operative Behandlung schließt sich häufig eine Helmtherapie an, um das bestmögliche Ergebnis zu erreichen. Die anschließende Follow-up-Periode erstreckt sich mindestens bis zum 12. Lebensjahr. Insgesamt sollte die Behandlung im Team mit Neurochirurgen, Mund‑, Kiefer‑, Gesichtschirurgen, Kinderärzten, Augenärzten und Humangenetikern stattfinden.

Evaluation of diurnal and postural intracranial pressure employing telemetric monitoring in idiopathic intracranial hypertension

OBJECTIVES

Intracranial pressure (ICP) has been thought to vary diurnally. This study evaluates diurnal ICP measurements and quantifies changes in ICP occurring with changes in body posture in active idiopathic intracranial hypertension (IIH).

METHODS

This prospective observational study utilized telemetric ICP monitoring in people with active IIH. Participants had the Raumedic p-Tel ICP intraparenchymal device (Raumedic, Hembrechts, Germany) surgically inserted. Changes in ICP in the supine position were evaluated. Then, the ICP was measured in the standing, sitting, supine, left lateral decubitus positions and with coughing and bending. Ultimately, changes in ICP over the course of 24 h were recorded. ISRCTN registration number 12678718.

RESULTS

15 women were included, mean (standard deviation) age 29.5 (9.5) years, body mass index 38.1 (6.2) kg/m², and baseline mean ICP of 21.2 (4.8) mmHg (equivalent to 28.8 (6.5) cmCSF). Mean ICP rose with the duration in the supine position 1.2 (3.3) mmHg over 5-minutes (p = 0.175), 3.5 (2.8) mmHg over 30-minutes (p = 0.0002) and by a further 2.1 (2.2) mmHg over 3 h (p = 0.042). Mean ICP decreased by 51% when moving from the supine position to standing (21.2 (4.8) mmHg to 10.3 (3.7) mmHg respectively, p = 0.0001). Mean ICP increased by 13% moving from supine to the left lateral decubitus position (21.2 (4.8) mmHg to 24.0 (3.8) mmHg, p = 0.028). There was no significant difference in ICP measurements at any point during the daytime, or between 5-minute standing or supine recordings and prolonged ambulatory daytime and end of night supine recordings respectively. ICP, following an initial drop, increased progressively in conjunction with lying supine position from 23:00 h to 07:00 h by 34% (5.2 (1.9) mmHg, p = 0.026).

CONCLUSION

This analysis demonstrated that ICP does not appear to have a diurnal variation in IIH, but varies by position and duration in the supine position. ICP rose at night whilst the patient was continuously supine. Furthermore, brief standing and supine ICP measures in the day predicted daytime prolonged ambulatory measures and end of night peak ICP respectively. This knowledge gives reassurance that ICP can be accurately measured and compared at any time of day in an ambulant IIH patient. These are useful findings to inform clinical measurements and in the interpretation of ICP analyses in IIH.

TRIAL REGISTRATION

ISTCRN (12678718).

Evaluating Cranial Growth in Japanese Infants Using a Three-dimensional Scanner: Relationship between Growth-related Parameters and Deformational Plagiocephaly

In this study, we aimed to evaluate the longitudinal changes in the cranial shape of healthy Japanese infants using a three-dimensional scanner and construct a normal values database for the growth process. Preterm infants (gestational age < 37 weeks), infants with neonatal asphyxia (5-minute Apgar score of <7), and patients who started helmet therapy for deformational plagiocephaly were excluded from this study. The first scan was performed at approximately 1 month of age, followed by two scans conducted at 3 and 6 months of age. The parameters considered were as follows: cranial length, width, height, circumference, volume, cranial vault asymmetry index, and cephalic index. A cranial vault asymmetry index >5% was defined as deformational plagiocephaly. Changes in each parameter were examined using repeated-measures analysis of variance classified by sex and deformational plagiocephaly status. The rate of increase in each parameter was also examined. In total, 88 infants (45 boys and 43 girls) were included in this study. All growth-related parameters were noted to increase linearly with time. Sex differences were observed in all parameters except cranial length. Deformational plagiocephaly was found to have no effect on growth-related parameters. Cranial volume increased by 60% from 1 to 6 months of age. The growth almost uniformly influenced the rate of increase in volume in each coordinate axis direction. Overall, the mean trends in three-dimensional parameters in infants up to 6 months of age were obtained using a three-dimensional scanner. These trends could be used as a guide by medical professionals involved in cranioplasty.

Sleep, cerebrospinal fluid, and the glymphatic system: A systematic review

Current theories of the glymphatic system (GS) hypothesize that it relies on cerebrospinal fluid (CSF) circulation to disseminate growth factors and remove metabolic waste from the brain with increased CSF production and circulation during sleep; thereby, linking sleep disturbance with elements of CSF circulation and GS exchange. However, our growing knowledge of the relations between sleep, CSF, and the GS are plagued by variability in sleep and CSF measures across a wide array of pathologies. Hence, this review aims to summarize the dynamic relationships between sleep, CSF-, and GS-related features in samples of typically developing individuals and those with autoimmune/inflammatory, neurodegenerative, neurodevelopmental, sleep-related, neurotraumatic, neuropsychiatric, and skull atypicalities. One hundred and ninety articles (total n = 19,129 participants) were identified and reviewed for pathology, CSF circulation and related metrics, GS function, and sleep. Numerous associations were documented between sleep problems and CSF metabolite concentrations (e.g., amyloid-beta, orexin, tau proteins) and increased CSF volumes or pressure. However, these relations were not universal, with marked differences across pathologies. It is clear that elements of CSF circulation/composition and GS exchange represent pathways influenced by sleep; however, carefully designed studies and advances in GS measurement are needed to delineate the nuanced relationships.

Intraoperative Measurement of Intracranial Pressure During Cranial Vault Remodeling in Children with Craniosynostosis

Purpose  In this study, we analyzed the utility of intracranial pressure (ICP) monitoring intraoperatively for deciding height reduction and need for cerebrospinal fluid (CSF) diversion during cranial vault remodeling in children with multisutural craniosynostosis (CS).

Methods  This is a retrospective observational study of children who underwent surgery for CS and ICP monitoring during surgery. The ICP was monitored using an external ventricular drainage catheter. The ICP monitoring was continued during the entire procedure.

Results  A total of 28 (19 boys) children with the involvement of two or more sutures underwent ICP monitoring during surgery. The commonest pattern of suture involvement was bicoronal seen in 16 (57.1%) children followed by pancraniosynostoses in eight (28.6%) cases. The mean opening ICP was 23 mm Hg, which dropped to 10.9 mm Hg after craniotomy. The ICP increased transiently to 19.5 mm Hg after height reduction, and the mean ICP at closure was 16.2 mm Hg. The ICP recordings helped in undoing the height reduction in two children and ventriculoperitoneal shunt after surgery in two children.

Conclusions  Intraoperative monitoring of ICP helps in deciding the type of cranial vault remodeling and the need for CSF diversion after surgery.

The role of pulsatile and static intracranial pressure measurements in the management of children with craniosynostosis-an institutional experience from 49 patients

BACKGROUND

Although measurement of intracranial pressure (ICP) has occasionally been utilized in children with craniosynostosis (CSS), data on parameters of pulsatile ICP in CSS are still lacking, and the role of pulsatile ICP measurements in the management of CSS is not well established.

METHODS

From our department's database, we retrieved the data from children in whom the measurement of static and pulsatile ICP was a part of the diagnostic work-up in different clinical situations related to CSS. Both clinical and ICP data were retrospectively reviewed and analyzed.

RESULTS

We identified 49 children with CSS, median age 4.4 years (range 0.2-18.9), in whom a total of 67 diagnostic ICP measurements were undertaken between 2002 and 2014. The CSS was syndromal in 23 cases. The rationale for ICP measurement was a question of indication for cranial vault expansion surgery (CVES) in 12 patients (Group 1), of its timing in 10 patients (Group 2), of suspected abnormally elevated ICP or hydrocephalus in 11 patients (Group 3), of indication for repeated CVES in 13 patients (Group 4), or shunt dysfunction in three patients (Group 5). The average mean ICP for the whole cohort was 15.1 ± 5.5 mmHg and mean wave amplitude (MWA) 5.3 ± 2.2 mmHg. There was no significant difference in ICP parameters when compared between Groups 1-5. Fundoscopy revealed papilledema in five out of 32 children (15.6%). There were significantly higher parameters of pulsatile ICP (MWA) in patients with papilledema, but no statistically significant difference in parameters of static ICP.

CONCLUSIONS

In this cohort of pediatric patients with CSS presenting with various diagnostic challenges, we found the diagnostic measurement of static and pulsatile ICP useful in selecting the optimal treatment modality and timing of surgery. Papilledema was associated with elevated pulsatile ICP, a parameter that in previous studies has been shown to correlate with impaired intracranial compliance.

Reference values for intracranial pressure and lumbar cerebrospinal fluid pressure: a systematic review

BACKGROUND

Although widely used in the evaluation of the diseased, normal intracranial pressure and lumbar cerebrospinal fluid pressure remain sparsely documented. Intracranial pressure is different from lumbar cerebrospinal fluid pressure. In addition, intracranial pressure differs considerably according to the body position of the patient. Despite this, the current reference values do not distinguish between intracranial and lumbar cerebrospinal fluid pressures, and body position-dependent reference values do not exist. In this study, we aim to establish these reference values.

METHOD

A systematic search was conducted in MEDLINE, EMBASE, CENTRAL, and Web of Sciences. Methodological quality was assessed using an amended version of the Joanna Briggs Quality Appraisal Checklist. Intracranial pressure and lumbar cerebrospinal fluid pressure were independently evaluated and subdivided into body positions. Quantitative data were presented with mean ± SD, and 90% reference intervals.

RESULTS

Thirty-six studies were included. Nine studies reported values for intracranial pressure, while 27 reported values for the lumbar cerebrospinal fluid pressure. Reference values for intracranial pressure were -  5.9 to 8.3 mmHg in the upright position and 0.9 to 16.3 mmHg in the supine position. Reference values for lumbar cerebrospinal fluid pressure were 7.2 to 16.8 mmHg and 5.7 to 15.5 mmHg in the lateral recumbent position and supine position, respectively.

CONCLUSIONS

This systematic review is the first to provide position-dependent reference values for intracranial pressure and lumbar cerebrospinal fluid pressure. Clinically applicable reference values for normal lumbar cerebrospinal fluid pressure were established, and are in accordance with previously used reference values. For intracranial pressure, this study strongly emphasizes the scarcity of normal pressure measures, and highlights the need for further research on the matter.