The diagnostic value of optic disc evaluation in acute elevated intracranial pressure

Extended reality quantification of pupil reactivity as a non-invasive assessment for the pathogenesis of spaceflight associated neuro-ocular syndrome: A technology validation study for astronaut health

The National Aeronautics and Space Administration (NASA) has rigorously documented a group of neuro-ophthalmic findings in astronauts during and after long-duration spaceflight known as spaceflight associated neuro-ocular syndrome (SANS). For astronaut safety and mission effectiveness, understanding SANS and countermeasure development are of utmost importance. Although the pathogenesis of SANS is not well defined, a leading hypothesis is that SANS might relate to a sub-clinical increased intracranial pressure (ICP) from cephalad fluid shifts in microgravity. However, no direct ICP measurements are available during spaceflight. To further understand the role of ICP in SANS, pupillometry can serve as a promising non-invasive biomarker for spaceflight environment as ICP is correlated with the pupil variables under illumination. Extended reality (XR) can help to address certain limitations in current methods for efficient pupil testing during spaceflight. We designed a protocol to quantify parameters of pupil reactivity in XR with an equivalent time duration of illumination on each eye compared to pre-existing, non-XR methods. Throughout the assessment, the pupil diameter data was collected using HTC Vive Pro-VR headset, thanks to its eye-tracking capabilities. Finally, the data was used to compute several pupil variables. We applied our methods to 36 control subjects. Pupil variables such as maximum and minimum pupil size, constriction amplitude, average constriction amplitude, maximum constriction velocity, latency and dilation velocity were computed for each control data. We compared our methods of calculation of pupil variables with the non-XR methods existing in the literature. Distributions of the pupil variables such as latency, constriction amplitude, and velocity of 36 control data displayed near-identical results from the non-XR literature for normal subjects. We propose a new method to evaluate pupil reactivity with XR technology to further understand ICP's role in SANS and provide further insight into SANS countermeasure development for future spaceflight.

Sensitivity of Papilledema as a Sign of Increased Intracranial Pressure

Our study evaluates the sensitivity of papilledema as a sign of high intracranial pressure in children. Patients younger than 18 years old, diagnosed with increased ICP, and who had received dilated fundus examination between 2019 and 2021 were retrospectively reviewed. Factors including the patient's age, sex, aetiology, duration of signs or symptoms, intracranial pressure (ICP), and presence of papilledema were evaluated. We included 39 patients in this study, whose mean age was 6.7 years. The 31 patients without papilledema had a mean age of 5.7 years, and 8 patients (20%) with papilledema had a mean age of 10.4 (p < 0.037). The mean duration of signs or symptoms was nine weeks in patients without papilledema and seven weeks in those with papilledema (p = 0.410). The leading causes of increased ICP with papilledema were supratentorial tumor (12.5%), infratentorial tumor (33.3%), and hydrocephalus (20%) (p = 0.479). Papilledema was statistically significantly more common in older patients. We found no statistical significance between sex, diagnosis, and symptoms. The relatively low incidence of papilledema (20%) in our study shows that papilledema's absence does not ensure the absence of increased ICP, especially in younger patients.

Diagnosis of Optic Disc Oedema: Fundus Features, Ocular Imaging Findings, and Artificial Intelligence

Optic disc swelling is a manifestation of a broad range of processes affecting the optic nerve head and/or the anterior segment of the optic nerve. Accurately diagnosing optic disc oedema, grading its severity, and recognising its cause, is crucial in order to treat patients in a timely manner and limit vision loss. Some ocular fundus features, in light of a patient's history and visual symptoms, may suggest a specific mechanism or aetiology of the visible disc oedema, but current criteria can at most enable an educated guess as to the most likely cause. In many cases only the clinical evolution and ancillary testing can inform the exact diagnosis. The development of ocular fundus imaging, including colour fundus photography, fluorescein angiography, optical coherence tomography, and multimodal imaging, has provided assistance in quantifying swelling, distinguishing true optic disc oedema from pseudo-optic disc oedema, and differentiating among the numerous causes of acute optic disc oedema. However, the diagnosis of disc oedema is often delayed or not made in busy emergency departments and outpatient neurology clinics. Indeed, most non-eye care providers are not able to accurately perform ocular fundus examination, increasing the risk of diagnostic errors in acute neurological settings. The implementation of non-mydriatic fundus photography and artificial intelligence technology in the diagnostic process addresses these important gaps in clinical practice.

Variability of Retinal Vessel Tortuosity Measurements Using a Semiautomated Method Applied to Fundus Images in Subjects With Papilledema

Purpose

To develop methods to quantitatively measure retinal vessel tortuosity from fundus images acquired in subjects with papilledema and assess sources of variability in these measurements.

Methods

Digital fundus images from 30 eyes of subjects with untreated idiopathic intracranial hypertension and papilledema were analyzed. Retinal vein and artery tortuosities for three to four vessels of each type were measured in a region of interest 1.8 to 2.7 mm from the center of the optic nerve head. Measurements were averaged to generate a venous tortuosity index (VTI) and arterial tortuosity index (ATI) for each eye. One image of each eye was analyzed two times by the same rater. Two images of each eye, differing by focal depth, were analyzed by the same rater. Correlations between VTI and ATI for the same image and different images were calculated.

Results

Intrarater Pearson correlations (r) were 0.8 (95% confidence interval [CI], 0.59–0.9) and 0.90 (95% CI, 0.73–0.96) for VTI and ATI, respectively, with one outlier removed. Interimage r values were 0.72 (95% CI, 0.48–0.87) and 0.96 (95% CI, 0.89–0.99) for VTI and ATI, respectively, with one outlier removed. The intraclass correlation coefficients for agreement and consistency were similar, suggesting that the discrepancy between measurements was due to residual random error.

Conclusions

The finding of similar intrarater and interimage variability suggests that intrarater variability may be a more dominant source than physiology and image acquisition.

Translational Relevance

Standardizing rater procedures and averaging multiple measuring sessions are strategies to reduce variability and improve reliability of detecting retinal vessel tortuosity changes in images of eyes with papilledema.

Retinal Vein Changes as a Biomarker to Guide Diagnosis and Management of Elevated Intracranial Pressure

Retinal vein changes, which can be observed on clinical exam or ophthalmic imaging, are promising non-invasive biomarkers for elevated intracranial pressure (ICP) as a complement to other markers of high ICP including optic nerve head swelling. Animal and human studies have demonstrated increase in retinal vein pressure associated with elevated ICP mediated by increase in cerebral venous pressure, compression of venous outflow by elevated cerebral spinal fluid pressure in the optic nerve sheath, and compression of venous outflow by optic nerve head swelling. Retinal vein pressure can be estimated using ophthalmodynamometry. Correlates of retinal vein pressure include spontaneous retinal venous pulsations, retinal vein diameter, and retinal vein tortuosity. All of these have potential for clinical use to diagnose and monitor elevated ICP. Challenges include diagnostic prediction based on single clinical measurements and accurate assessment of retinal vein parameters in cases where optic nerve head swelling limits visualization of the retinal veins.

The role of optic nerve sheath diameter ultrasound in brain infection

Brain infections cause significant morbidity and mortality worldwide, especially in resource-limited settings with high HIV co-infection rates. Raised intracranial pressure [ICP] may complicate brain infection and worsen neurological injury, yet invasive ICP monitoring is often unavailable. Optic nerve sheath diameter [ONSD] ultrasound may allow detection of raised ICP at the bedside; however, pathology in brain infection is different to traumatic brain injury, in which most studies have been performed. The use of ONSD ultrasound has been described in tuberculous meningitis, cryptococcal meningitis and cerebral malaria; however correlation with invasive ICP measurement has not been performed. Normal optic nerve sheath values are not yet established for most populations, and thresholds for clinical intervention cannot be assumed to match those used in non-infective brain pathology. ONSD ultrasound may be suitable for use in resource-limited settings by clinicians with limited ultrasound training. Standardisation of scanning technique, consensus on normal ONSD values, and action on abnormal results, are areas for future research. This scoping review examines the role of ONSD ultrasound in brain infection. We discuss pathophysiology, and describe the rationale, practicalities, and challenges of utilising ONSD ultrasound for brain infection monitoring and management. We discuss the existing evidence base for this technique, and identify knowledge gaps and future research priorities.

Current Perspectives on Idiopathic Intracranial Hypertension without Papilloedema

The pseudotumor cerebri syndrome embraces disorders characterised by raised intracranial pressure, where the commonest symptom is headache (90%). Idiopathic intracranial hypertension without papilloedema (IIHWOP) is increasingly recognised as a source of refractory headache symptoms and resultant neurological disability. Although the majority of patients with IIHWOP are phenotypically similar to those with idiopathic intracranial hypertension (IIH), it remains uncertain as to whether IIHWOP is nosologically distinct from IIH. The incidence, prevalence, and the degree of association with the world-wide obesity epidemic is unknown. Establishing a diagnosis of IIHWOP can be challenging, as often lumbar puncture is not routinely part of the work-up for refractory headaches. There are published diagnostic criteria for IIHWOP; however, some report uncertainty regarding a pathologically acceptable cut off for a raised lumbar puncture opening pressure, which is a key criterion. The literature provides little information to help guide clinicians in managing patients with IIHWOP. Further research is therefore needed to better understand the mechanisms that drive the development of chronic daily headaches and a relationship to intracranial pressure; and indeed, whether such patients would benefit from therapies to lower intracranial pressure. The aim of this narrative review was to perform a detailed search of the scientific literature and provide a summary of historic and current opinion regarding IIHWOP.

OS reboot

Cerebrospinal fluid (CSF) diversion or shunting procedures are the most commonly performed surgery for the treatment of hydrocephalus and are often employed in the management of elevated intracranial pressure due to a variety of diseases. Despite their popularity however, approximately 50% of shunts fail within the first two years, and several revisions are required within the first decade after placement. Ophthalmologists may encounter patients with a CSF shunt to evaluate for concerns of vision loss or diplopia and to determine if papilledema is present. We discuss the neuro-ophthalmic manifestations and evaluation of possible CSF shunt malfunction.

The Effects of Acute Intracranial Pressure Changes on the Episcleral Venous Pressure, Retinal Vein Diameter and Intraocular Pressure in a Pig Model

PURPOSE

Orbital veins such as the retinal veins and episcleral veins drain into the cavernous sinus, an intracranial venous structure. We studied the effects of acute intracranial pressure (ICP) elevation on episcleral venous pressure, intraocular pressure and retinal vein diameter in an established non-survival pig model.

METHODS

In six adult female domestic pigs, we increased ICP in 5 mm Hg increments using saline infusion through a lumbar drain. We measured ICP (using parenchymal pressure monitor), intraocular pressure (using pneumatonometer), episcleral venous pressure (using venomanometer), retinal vein diameter (using OCT images) and arterial blood pressure at each stable ICP increment. The average baseline ICP was 5.4 mm Hg (range 1.5-9 mm Hg) and the maximum stable ICP ranged from 18 to 40 mm Hg. Linear mixed models with random intercepts were used to evaluate the effect of acute ICP increase on outcome variables.

RESULTS

With acute ICP elevation, we found loss of retinal venous pulsation and increased episcleral venous pressure, intraocular pressure and retinal vein pressure in all animals. Specifically, acute ICP increase was significantly associated with episcleral venous pressure (β = 0.31; 95% CI 0.14-0.48, p < .001), intraocular pressure (β = 0.37, 95%CI 0.24-0.50; p < .001) and retinal vein diameter (β = 11.29, 95%CI 1.57-21.00; p = .03) after controlling for the effects of arterial blood pressure.

CONCLUSION

We believe that the ophthalmic effects of acute ICP elevation are mediated by increased intracranial venous pressure producing upstream pressure changes within the orbital and retinal veins. These results offer exciting possibilities for the development of non-invasive ophthalmic biomarkers to estimate acute ICP elevations following significant neuro-trauma.

Spontaneous Venous Pulsations Detected With Infrared Videography

BACKGROUND

Assessment of spontaneous venous pulsation (SVP) is commonly undertaken to help determine whether intracranial pressure (ICP) is elevated. Previous studies using direct ophthalmoscopy or slit-lamp assessments have found that SVP is not observed in 67%-81% of subjects with normal ICP, and that interobserver agreement when grading SVP is poor.

METHODS

Patients (n = 105) undergoing clinically indicated retinal OCT scans, who were all believed to have normal ICP, had 10-second infrared video recordings performed with the Heidelberg Spectralis OCT system (Heidelberg Engineering GmbH, Heidelberg, Germany). The presence and amplitude of SVP in each video was independently graded by 2 neuro-ophthalmologists.

RESULTS

The 2 observers found SVP present in 97% and 98% of right eyes and in one or both eyes in 99% and 100% of subjects. Interobserver agreement was high (Cohen's kappa 0.82 for right eyes). Optic discs with a smaller cup had a significantly lower SVP amplitude (Spearman's rho = 0.22, P = 0.02).

CONCLUSIONS

Infrared video is widely available in eye clinics by the use of OCT imaging systems and is substantially more sensitive in detecting SVP than traditional assessments using ophthalmoscopy. SVP is absent in as few as 1% of people with presumed normal ICP.

Retinal vessel diameter changes after 6 months of treatment in the Idiopathic Intracranial Hypertension Treatment Trial

BACKGROUND/AIMS

Prior studies support an association between increased retinal venule diameter and elevated intracranial pressure (ICP). The purpose of this study was to test the hypothesis that retinal venule diameters decrease in association with long-term therapy for high ICP in subjects with idiopathic intracranial hypertension (IIH).

METHODS

This is a retrospective analysis of multicentre randomised controlled trial data. Standardised procedures were used to measure area of optic nerve head elevation (ONHA) and diameters of 4 arterioles and 4 venules 2.7 mm from the optic disc centre on fundus photos collected at baseline and after 6 months of randomised treatment with placebo+diet or acetazolamide+diet in subjects participating in the IIH Treatment Trial (IIHTT) (n=115). Change in arteriole (Da) and venule (Dv) diameters from baseline to 6 months was studied as a function of IIH, haemodynamic and demographic variables.

RESULTS

Dv decreased following 6 months of therapy (8.1 µm, 5.9%, p<0.0005) but Da did not change. Dv change was associated with ONHA change (p<0.0005, r=0.47) and this association persisted in multiple variable models.

CONCLUSIONS

Retinal venule diameter decreased, and arteriole diameter did not change in association with treatment for elevated ICP with a weight loss intervention and placebo or acetazolamide in IIHTT participants. Further study is needed to determine how retinal vessel measurements can be combined with other clinical observations to inform disease management.

Retinal Findings in Young Children With Increased Intracranial Pressure From Nontraumatic Causes

OBJECTIVES

Increased intracranial pressure (ICP) has been suggested in legal settings as an alternative cause of retinal hemorrhages (RHs) in young children who may have sustained abusive head trauma. We assessed the prevalence and characteristics of RHs in children with increased ICP.

METHODS

We conducted a prospective, multicenter study of children <4 years old with newly diagnosed increased ICP as determined by using direct measurement and/or clinical criteria. Infants who were premature, neonates, and suspected survivors of abusive head trauma were excluded on the basis of nonocular findings. Fundus examinations were performed; extent, number, and type of RH in each of 4 distinct retinal zones were recorded.

RESULTS

Fifty-six children (27 boys) were studied (mean age 15.4 months; range 1-43 months). All of the children had elevated ICP that required intervention. One child had papilledema. No child (0%; 95% confidence interval: 0%-6.4%) or eye (0%; 95% confidence interval: 0%-3.3%) was found to have an RH. Causes of increased ICP included hydrocephalus, intraventricular hemorrhage, congenital malformations, malfunctioning shunts, and the presence of intracranial space-occupying lesions.

CONCLUSIONS

Although acute increased ICP can present in children with a pattern of peripapillary superficial RHs in the presence of papilledema, our study supports the conclusion that RHs rarely occur in the absence of optic disc swelling and do not present beyond the peripapillary area in the entities we have studied.

Multimodality Monitoring in Neurocritical Care: Decision-Making Utilizing Direct And Indirect Surrogate Markers

Substantial progress has been made to create innovative technology that can monitor the different physiological characteristics that precede the onset of secondary brain injury, with the ultimate goal of intervening prior to the onset of irreversible neurological damage. One of the goals of neurocritical care is to recognize and preemptively manage secondary neurological injury by analyzing physiologic markers of ischemia and brain injury prior to the development of irreversible damage. This is helpful in a multitude of neurological conditions, whereby secondary neurological injury could present including but not limited to traumatic intracranial hemorrhage and, specifically, subarachnoid hemorrhage, which has the potential of progressing to delayed cerebral ischemia and monitoring postneurosurgical interventions. In this study, we examine the utilization of direct and indirect surrogate physiologic markers of ongoing neurologic injury, including intracranial pressure, cerebral blood flow, and brain metabolism.

Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip

OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p < 0.001). Measures for CN VI were most prominently affected. The area under the curve (AUC) for eye-tracking metrics to discriminate between ICP < 12 and ≥ 12 mm Hg was 0.798. To discriminate an ICP < 15 from ≥ 15 mm Hg the AUC was 0.833, and to discriminate ICP < 20 from ≥ 20 mm Hg the AUC was 0.889. CONCLUSIONS Increasingly elevated ICP was associated with increasingly abnormal eye tracking detected while patients were watching a short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.

Papilledema in children with hydrocephalus: incidence and associated factors

OBJECTIVE The aim of this study was to report the incidence of and the factors associated with papilledema in children with hydrocephalus. METHODS Patients younger than 15 years of age who had been diagnosed with hydrocephalus and treated by extra-ventricular drainage or ventriculoperitoneal shunt surgery between 2005 and 2015 were retrospectively reviewed. Factors including patient age and sex, etiology of hydrocephalus, duration of signs or symptoms, intracranial pressure (ICP), and presence of papilledema were evaluated. RESULTS Forty-six patients, whose mean age was 6.3 ± 4.7 years, were included in the study. The 19 patients without papilledema had a mean age of 2.7 ± 2.7 years, and the 27 patients with papilledema had a mean age of 8.8 ± 4.2 years (p < 0.001). The mean ICP was 19.9 ± 10.0 cm H₂O among those without papilledema and 33.3 ± 9.1 cm H₂O among those with papilledema (p < 0.001). The mean duration of signs or symptoms was 3.0 ± 4.6 months in the patients without papilledema and 3.4 ± 3.9 months in those with papilledema (p = 0.704). The patients with papilledema were older and presented with higher ICP than those without. The causes of hydrocephalus were tumor (59%), congenital anomaly (19%), hemorrhage (13%), and infection (9%). CONCLUSIONS Papilledema was more common in patients who were older, who had higher ICP, and whose hydrocephalus had been induced by brain tumor. However, since papilledema was absent in 41% of the children with hydrocephalus, papilledema's absence does not ensure the absence of hydrocephalus, especially in younger patients.

A Practical Concussion Physical Examination Toolbox

CONTEXT

With heightened awareness of concussion, there is a need to assess and manage the concussed patient in a consistent manner. Unfortunately, concussion physical examination has not been standardized or supported by evidence. Important questions remain about the physical examination.

EVIDENCE ACQUISITION

Review of ClinicalKey, Cochrane, MEDLINE, and PubMed prior to July 2015 was performed using search terms, including concussion, mTBI, physical examination, mental status, cranial nerves, reflexes, cervical, vestibular, and oculomotor. The references of the pertinent articles were reviewed for other relevant sources.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 3.

RESULTS

The pertinent physical examination elements for concussion include evaluation of cranial nerves, manual muscle testing, and deep tendon reflexes; inspecting the head and neck for trauma or tenderness and cervical range of motion; Spurling maneuver; a static or dynamic balance assessment; screening ocular examination; and a mental status examination that includes orientation, immediate and delayed recall, concentration, mood, affect, insight, and judgment. Other examination elements to consider, based on signs, symptoms, or clinical suspicion, include testing of upper motor neurons, cervical strength and proprioception, coordination, pupillary reactivity, and visual acuity; examination of the jaw, temporomandibular joint, and thoracic spine; fundoscopic evaluation; orthostatic vital signs; assessment of dynamic visual acuity; and screening for depression, anxiety, substance abuse disorders, and preinjury psychiatric difficulties.

CONCLUSION

Various elements of the physical examination, such as screening ocular examination, cervical musculoskeletal examination, static and/or dynamic balance assessment, and mental status examination, appear to have utility for evaluating concussion; however, data on validity are lacking.

Noninvasive methods of detecting increased intracranial pressure

The detection of elevated intracranial pressure (ICP) is of paramount importance in the diagnosis and management of a number of neurologic pathologies. The current gold standard is the use of intraventricular or intraparenchymal catheters; however, this is invasive, expensive, and requires anesthesia. On the other hand, diagnosing intracranial hypertension based on clinical symptoms such as headaches, vomiting, and visual changes lacks sensitivity. As such, there exists a need for a noninvasive yet accurate and reliable method for detecting elevated ICP. In this review, we aim to cover both structural modalities such as computed tomography (CT), magnetic resonance imaging (MRI), ocular ultrasound, fundoscopy, and optical coherence tomography (OCT) as well as functional modalities such as transcranial Doppler ultrasound (TCD), visual evoked potentials (VEPs), and near-infrared spectroscopy (NIRS).

Optical coherence tomography of the optic nerve head detects acute changes in intracranial pressure

We aimed to determine if there are measurable objective changes in the optic nerve head (ONH) immediately after cerebrospinal fluid (CSF) drainage in a prospective case-series of five patients undergoing a clinically indicated lumbar puncture (LP) for diagnosis of idiopathic intracranial hypertension. A Cirrus high-definition optical coherence tomography machine (Carl Zeiss Meditec, Dublin, CA, USA) was used to acquire images in the lateral decubitus position. Optic disc cube and high-definition line raster scans centered on the ONH were obtained immediately before and after draining CSF, while the patient maintained the lateral decubitus position. Measured parameters included retinal nerve fiber layer (RNFL) thickness, peripapillary retinal pigment epithelium/Bruch's membrane (RPE/BM) angulation, transverse neural canal diameter (NCD) and the highest vertical point of the internal limiting membrane from the transverse diameter (papillary height). The mean (±standard deviation) opening and closing CSF pressures were 34.3±11.8 and 11.6±3.3cmH2O, respectively. Mean RNFL thickness (pre LP: 196±105μm; post LP: 164±77μm, p=0.1) and transverse NCD (pre LP: 1985±559μm; post LP: 1590±228μm, p=2.0) decreased in all subjects, but with non-significant trends. The RPE/BM angle (mean change: 5.8±2.0degrees, p=0.003) decreased in all subjects. A decrease in papillary height was seen in three of five subjects (mean: pre LP: 976±275μm; post LP: 938±300μm, p=0.9). Our results show a measurable, objective change in the ONH after acute lowering of the lumbar CSF pressure, suggesting a direct link between the lumbar subarachnoid space and ONH regions, and its potential as a non-invasive method for monitoring intracranial pressures.

Elevated Intracranial Pressure Diagnosis with Emergency Department Bedside Ocular Ultrasound

Bedside sonographic measurement of optic nerve sheath diameter can aid in the diagnosis of elevated intracranial pressure in the emergency department. This case report describes a 21-year-old female presenting with 4 months of mild headache and 2 weeks of recurrent, transient binocular vision loss. Though limited by patient discomfort, fundoscopic examination suggested the presence of blurred optic disc margins. Bedside ocular ultrasound (BOUS) revealed wide optic nerve sheath diameters and bulging optic discs bilaterally. Lumbar puncture demonstrated a cerebrospinal fluid (CSF) opening pressure of 54 cm H2O supporting the suspected diagnosis of idiopathic intracranial hypertension. Accurate fundoscopy can be vital to the appropriate diagnosis and treatment of patients with suspected elevated intracranial pressure, but it is often technically difficult or poorly tolerated by the photophobic patient. BOUS is a quick and easily learned tool to supplement the emergency physician's fundoscopic examination and help identify patients with elevated intracranial pressure.

Increased Intracranial Pressure in Spontaneous CSF Leak Patients Is Not Associated with Papilledema

Objective

Spontaneous cerebrospinal fluid (CSF) leaks typically present in patients with undiagnosed idiopathic intracranial hypertension (IIH) secondary to pressure erosion of the skull base. Despite elevated intracranial pressure (ICP) on lumbar puncture or ventriculostomy, patients with spontaneous CSF leaks rarely complain of visual disturbances. The objective of this study is to correlate the presence of preoperative papilledema with opening ICP in patients undergoing endoscopic repair of spontaneous CSF leaks.

Study Design

Prospective study.

Setting

Tertiary hospital.

Methods

Prospective evaluation of patients with spontaneous CSF leaks was performed over a 1-year period (December 2012 to December 2013). Fundoscopic examination for papilledema was completed preoperatively and CSF pressure measured by lumbar puncture or ventriculostomy intraoperatively. Data regarding demographics, nature of presentation, and body mass index (BMI) were also recorded and compared to a control cohort of IIH patients with papilledema.

Results

Sixteen patients (average age 52) were evaluated. Obesity was present in 94% of individuals (average BMI = 43, range, 27-65). Papilledema was absent preoperatively in all subjects. Opening pressures via lumbar puncture/ventriculostomy were 27.4 ± 7.7 cmH20. Following 6 hours of clamping, measurements significantly increased to 36 ± 9.6 cmH20 ( P < .001). IIH controls (average age 33, average BMI = 36, range, 21-52) exhibited average ICP (36.2 ± 11.7) identical to postclamp measurements in the spontaneous CSF leak cohort.

Conclusions

Subjects with spontaneous CSF leaks had postclamping average ICP identical to controls with IIH and papilledema. Such evidence suggests that a CSF leak in this patient population provides sufficient pressure diversion to avoid the development of papilledema.

Yield and clinical efficacy of funduscopic examinations performed in the pediatric emergency room

Consultations by ophthalmologists to rule out papilledema are frequently requested by emergency room (ER) physicians. The clinical setting and optimal timing for examination are not well established, and the impact on patient management is unclear. We evaluated the yield of emergency funduscopic examinations, aiming at establishing the optimal timing and efficacy of the consultation. The medical records of all children aged 0-18 years referred for funduscopic examinations from the ER between June 2010 and May 2011 were reviewed. Of 19,772 ER visits, 1,920 (9.7 %) were seen by an ophthalmologist and 479 (2.4 %) to rule out papilledema. Headache (44.5 %) and head trauma (18.4 %) were the most common indications. Sixty percent of the 479 patients had been symptomatic for <24 h, all having normal eye exams. Only 6/479, with diverse etiologies, depicted papilledema. Among these six children, visual complaints associating with headache were statistically significant to suggest the presence of papilledema (p = 0.014). Seventy-one of the 479 children underwent neuroimaging studies despite normal funduscopic examinations. A single tumor case (medulloblastoma), symptomatic for weeks, had normal funduscopy.

CONCLUSION

The vast majority of ER consultations to rule out papilledema show normal findings, particularly among children with signs and symptoms lasting for <24 h. The yield of funduscopy may be higher if visual disturbances are reported. If neuroimaging studies are considered, emergency room ophthalmological consultation is probably not warranted, except for young infants with neurological signs and symptoms in whom retinal hemorrhages suggestive of physical abuse must be ruled out.

Non-invasive methods of estimating intracranial pressure

Non-invasive measurement of intracranial pressure can be invaluable in the management of critically ill patients. We performed a comprehensive review of the literature to evaluate the different methods of measuring intracranial pressure. Several methods have been employed to estimate intracranial pressure, including computed tomography, magnetic resonance imaging, transcranial Doppler sonography, near-infrared spectroscopy, and visual-evoked potentials. In addition, multiple techniques of measuring the optic nerve and the optic nerve sheath diameter have been studied. Ultrasound measurements of the optic nerve sheath diameter and Doppler flow are especially promising and may be useful in selected settings.

[Headaches from an ophthalmological perspective]

Headaches are a common and widespread complaint. Differential diagnostics are crucial for successful therapy and often require an interdisciplinary approach. General practitioners tend to refer patients with extraordinary types of headaches to physicians specialized in neurology, ophthalmology and otolaryngology. This article offers an overview about the range of headache disorders particularly associated with the ophthalmologic anatomy and function.

Papilledema: the vexing issues

Papilledema has long been recognized as a valuable sign of increased intracranial pressure (ICP). But because papilledema is based on interruption of the energy-dependent process of axoplasmic flow, it appears late after a rise in ICP. Papilledema is usually present in chronically high ICP but sometimes asymmetrically in the 2 eyes and rarely in 1 eye only. Distinguishing it from other optic neuropathies that produce elevated optic discs is challenging, especially in the chronic phase, when visual function may be impaired. Papilledema is often an unrecognized cause of optic disc edema in inflammatory and compressive meningeal disorders that interfere with cerebrospinal fluid (CSF) passage through the arachnoid granulations. Its detection is particularly critical in patients with noncompliant ventricles or extraventricular blockage of cerebrospinal flow because imaging may fail to disclose conventional signs of high ICP. Therefore, patients with indwelling CSF shunts, tuberous sclerosis, chronic granulomatous meningitis, or meningiomatosis should be periodically examined for papilledema so that timely ICP-lowering measures can be instituted to preserve vision.

Are ultrasonography measurements of optic nerve sheath diameter an alternative to funduscopy in children with syndromic craniosynostosis?

OBJECT

Children with syndromic or complex craniosynostosis are evaluated for increased intracranial pressure (ICP) using funduscopy to detect papilledema. However, papilledema is a late sign of increased ICP. Because papilledema might be preceded by an increase in optic nerve sheath (ONS) diameter, the authors conducted a prospective study to establish the validity and applicability of measuring the ONS using ultrasonography.

METHODS

From January 2007 to December 2009, 175 bilateral ultrasonography ONS measurements were performed in 128 patients with syndromic or complex craniosynostosis during the daytime. The measurements were correlated with ONS diameter assessed on CT and simultaneous funduscopy, when available. Furthermore, results were compared by using thresholds for ONS diameters on ultrasonography that are available in the literature.

RESULTS

The mean ONS diameter on ultrasonography was 3.1 ± 0.5 mm. The CT measurement was significantly correlated with the ultrasonography measurement (r = 0.41, p < 0.001). The mean ONS diameter in 38 eyes with papilledema was 3.3 ± 0.5 mm, compared with 3.1 ± 0.5 mm in the eyes of patients without papilledema (p = 0.039). Relative to the age-related thresholds, the ONS diameter was too large in 11 eyes (3%), particularly in patients with Crouzon syndrome. Compared with funduscopy, ultrasonography sensitivity was 11%, specificity was 97%, and positive and negative predictive values were 40% and 86%, respectively.

CONCLUSIONS

Ultrasonography is a valid and easy way of quantifying the ONS. Although the ONS diameter is larger in children with papilledema, it cannot be used as a daytime screening tool instead of funduscopy. The ONS diameter is possibly a more real-time indicator of ICP.

Portable ultrasound for remote environments, part II: current indications

BACKGROUND

With recent advances in ultrasound technology, it is now possible to deploy lightweight portable imaging devices in the field. Techniques and studies initially developed for hospital use have been extrapolated out of the hospital setting in a wide variety of environments in an effort to increase diagnostic accuracy in austere or prehospital environments.

OBJECTIVES

This review summarizes current ultrasound applications used in out-of-hospital arenas and highlights existing evidence for such use. The diversity of applications and environments is organized by indication to better inform equipment selection as well as future directions for research and development.

DISCUSSION

Trauma evaluation, casualty triage, and assessment for pneumothorax, acute mountain sickness, and other applications have been studied by field medical teams. A wide range of outcomes have been reported, from alterations in patient care to determinations of accuracy compared to clinical judgment or other diagnostic modalities.

CONCLUSIONS

The use of lightweight portable ultrasound shows great promise in augmenting clinical assessment for field medical operations. Although some studies of diagnostic accuracy exist in this setting, further research focused on clinically relevant outcomes data is needed.

[Indications and technique of optic nerve sheath fenestration]

An optic nerve sheath fenestration is indicated when papilloedema leads to progressive visual loss despite previous, conservative measures and when no cause of increased intracranial pressure can be indentified and eliminated. This rather rare constellation usually occurs in idiopathic intracranial hypertension. The procedure is performed via a medial transconjunctival orbitotomy. If headaches and neurologic symptoms other than visual deterioration prevail, the placement of a ventricular shunt is preferred. This review covers the symptoms of idiopathic intracranial hypertension and optic nerve sheath fenestration with its technical aspects and results.

Sensitivity of papilledema as a sign of shunt failure in children

PURPOSE

Papilledema is considered one of the cardinal ophthalmologic signs of shunt failure. However, the prevalence of papilledema in children with shunt malfunction has not been systematically investigated. The purpose of this study is to determine the sensitivity of papilledema as a sign of shunt failure in children.

METHODS

A prospective evaluation was undertaken of all children (n = 29; <19 years of age) with surgically confirmed shunt malfunction who were treated at Arkansas Children's Hospital between July 2007 and April 2008. Each child had a dilated fundus examination and/or RetCam photograph while under anesthesia immediately before shunt repair. The optic disk was evaluated for the presence of papilledema and pallor. Intracranial pressure was measured during surgical shunt repair at the discretion of the neurosurgeon.

RESULTS

Twenty-nine patients had surgically confirmed shunt failure. Patient's age ranged from 36 days to 18 years, 8 months. Four patients (14%) had papilledema, and 1 patient had severe optic disk pallor. The remaining 24 patients had flat optic disks. Five patients had flat optic disks despite an intracranial pressure >/=300 mm H(2)O.

CONCLUSIONS

Papilledema is not a sensitive sign of shunt failure. Even children with severe elevations in intracranial pressure from shunt malfunction may have flat optic disks. Therefore, physicians that evaluate children with shunts should be aware that a normal optic disk does not preclude shunt malfunction.

A comparison of idiopathic intracranial hypertension with and without papilledema

OBJECTIVE

To compare clinical features, visual characteristics, and treatment of idiopathic intracranial hypertension patients with and without papilledema.

BACKGROUND

Idiopathic intracranial hypertension does not often occur without papilledema. This study estimates the prevalence and compares the clinical characteristics of idiopathic intracranial hypertension patients with and without papilledema.

METHODS

We performed a cross-sectional analysis of all idiopathic intracranial hypertension patients diagnosed at the University of Utah Neuro-Ophthalmology Unit between 1990 and 2003. Patient records were reviewed for presence of papilledema and other signs, symptoms, and treatment characteristics. Each patient without papilledema was matched to the patient with papilledema who was closest to his/her age and sex. McNemar's and Wilcoxon-signed rank sum tests were used to compare characteristics between matched pairs.

RESULTS

Among all patients (n = 353), the prevalence of those without papilledema was 5.7% (n = 20). Patients without papilledema reported photopsias (20%), and were found to have spontaneous venous pulsations (75%) and non-physiologic visual field constriction (20%) more often than did those with papilledema. Mean opening pressure, although above normal, was lower in patients without papilledema (mean = 309 mm cerebrospinal fluid) compared with those with papilledema (mean = 373 mm cerebrospinal fluid, P = .031). Idiopathic intracranial hypertension patients without papilledema had more frequent diagnostic lumbar punctures than did patients with papilledema. Visual acuities and treatment were similar between groups.

CONCLUSIONS

The clinical presentation of idiopathic intracranial hypertension without papilledema is only somewhat different from that of idiopathic intracranial hypertension with papilledema. The lower opening pressure in patients without papilledema may explain variations in symptoms and signs between the 2 groups. When there are visual field changes in idiopathic intracranial hypertension without papilledema, non-physiologic visual loss should be considered.

Mechanisms of visual loss in papilledema

The term "papilledema" indicates swelling of the optic discs secondary to increased intracranial pressure. Papilledema can be caused by an intracranial mass lesion or by other factors. Visual symptoms frequently accompany papilledema, which can lead to permanent visual loss if left untreated. Starting with an illustrative case, the authors review the pathophysiology of the visual signs and symptoms of papilledema. They also briefly review potential treatment options, focusing on the role of the neurosurgeon in the treatment of patients with papilledema.

The correlation between neurological evaluations and neurological outcome in acute encephalitis: a hospital-based study

Acute encephalitis is a common CNS infectious disease in children. However, there are limited studies concerning about the correlation between the clinical evaluations and neurological outcome. To investigate the value of neurological evaluations, and the correlation between these evaluations and neurological outcomes of acute encephalitis, in the present study we retrospectively evaluated the neurological outcome of 0- to 16-year-old children with encephalitis or meningoencephalitis between 1999 and 2000. Of 101 children enrolled, 4 died and 25 had other neurological sequelae, including epilepsy, headache, developmental delay, and emotional or behavioral changes during the 5 years of follow-up. The causative organisms in patients with neurological sequelae were herpes virus (HSV) 2/2 (100%), influenza 2/3 (67%), mycoplasma 5/12 (42%), and enterovirus 71 2/7 (29%). The important predictors for adverse outcomes were focal neurological signs, multiple seizures or status epilepticus on admission, leukopenia, focal slow waves or continuous generalized delta waves in electroencephalography (EEG), and focal cortical parenchymal hyperintensity in the magnetic resonance imaging (MRI) (p<0.05). Patients with initial presentations of focal neurological signs, papilledema, myoclonic jerks, and status epilepticus tended to have higher incidence of abnormal findings in brain MRI, although not achieving statistic significances. In addition, children with focal spikes or continuous generalized delta waves in EEG also had higher incidence of MRI abnormalities. We conclude that brain MRI studies may be indicated in patients with focal neurological signs, intractable seizure, and focal spikes, focal delta waves, or continuous generalized delta waves in EEG. For those with MRI examinations, focal cortical hyperintensity suggests poorer neurological outcomes.

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension is a secondary headache disorder characterized by headaches and visual symptoms. It most frequently occurs in obese women of childbearing age. However, many secondary causes exist, and it may affect children, men, and slim individuals. Prompt recognition, evaluation, and treatment are needed to prevent permanent visual loss.

Clinical findings precede objective diagnostic testing in the identification of increased ICP in syndromic craniosynostosis

Crouzon syndrome is an autosomal dominant disorder resulting in facial dysmorphism and craniosynostosis involving multiple cranial sutures. A common but often unrecognized early complication associated with craniosynostosis is a finding of increased intracranial pressure (ICP). This increase in ICP can lead to optic atrophy, neuronal damage, and mental deficits. The case of a 21-month-old girl with Crouzon syndrome is described. Although the child was clinically asymptomatic, a routine ophthalmic exam revealed papilledema and subsequently increased intracranial pressure and craniosynostosis were found. Cranial expansion and bicanthal advancement were performed to relieve the increased pressure. In cases such as these, long-term follow-up is essential because of the progressive nature of the disorder as well as the possibility of a recurrence of elevated intracranial pressure and a need for secondary decompressive surgery.

Severe papilledema identified 3 weeks after head injury

A 62-year-old woman presented with rapidly developed visual disturbance without associated headache or nausea 3 weeks after head injury. Ophthalmologic examination revealed bilateral severe papilledema with retinal hemorrhage, and intracranial pressure (ICP) was 17.5 cmH2O estimated by lumbar puncture. Computed tomography and magnetic resonance (MR) imaging showed no evidence of increased ICP, except dilation of the subarachnoid space around the optic nerves with distortion of the nerves. Her visual acuity remarkably improved after steroid and glycerol treatment, and optic fundus examination revealed bilateral clear optic papillae without atrophic changes. Follow-up MR imaging demonstrated that the bilateral optic nerves had regained the normal appearance. These results indicate that the bilateral papilledema was caused by increased subarachnoid pressure around the bilateral optic nerves. We conclude that papilledema can occur with a mildly increased ICP and trapped subarachnoid cerebrospinal fluid around the optic nerves, and papilledema may progress after the ICP is normalized. Papilledema is a warning sign for increased ICP, associated with future visual loss from retinal hemorrhage. Therefore, repeated funduscopic investigation is necessary for the early diagnosis and treatment of papilledema.

[Intracranial complications of otitis]

Since the advent of antibiotics, endocranial complications due to infectious ear disease are actually unfrequent. They occur predominantly in young adults with a long term chronic otitis media and cholesteatoma. The mortality for endocraneal complications still remains significant. We report six cases of endocraneal complications due to infectious ear disease, that have been seen in our service over the last eight years; remarking that half of the studied patients had an acute ear disease. A review of the literature helps to understand the actual standard of diagnosis and treatment.