Neuro-Ophthalmic Complications of Raised Intracranial Pressure, Hydrocephalus, and Shunt Malfunction

Comparison of the effect of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing middle ear surgery

PURPOSE

During middle ear surgery, the patient's head is turned away from the surgical site, which may increase the intracranial pressure. Anesthetics also affect the intracranial pressure. The optic nerve sheath diameter (ONSD) measured using ultrasonography is a reliable marker for estimating the intracranial pressure. This aim of this study was to investigate the effect of sevoflurane and propofol on the ONSD in patients undergoing middle ear surgery.

METHODS

Fifty-eight adult patients were randomized into sevoflurane group (n = 29) or propofol group (n = 29). The ONSD was measured using ultrasound after anesthesia induction before head rotation (T0), and at the end of surgery (T1). The occurrence and severity of postoperative nausea and vomiting (PONV) were assessed 1 h after the surgery.

RESULTS

The ONSD was significantly increased from T0 to T1 in the sevoflurane group [4.3 (0.5) mm vs. 4.9 (0.6) mm, respectively; P < 0.001] and the propofol group [4.2 (0.3) mm vs. 4.8 (0.5) mm, respectively; P < 0.001]. No significant difference was observed in the ONSD at T0 (P = 0.267) and T1 (P = 0.384) between the two groups. The change in the ONSD from T0 to T1 was not significantly different between the sevoflurane and propofol groups [0.6 (0.4) mm vs. 0.6 (0.3) mm, respectively; P = 0.972]. The occurrence and severity of PONV was not significantly different between the sevoflurane and propofol groups (18% vs. 0%, respectively; P = 0.053).

CONCLUSION

The ONSD was significantly increased during middle ear surgery. No significant difference was observed in the amount of ONSD increase between the sevoflurane and propofol groups.

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.

Resolution of Papilledema Following Ventriculoperitoneal Shunt or Endoscopic Third Ventriculostomy for Obstructive Hydrocephalus: A Pilot Study

Background and Objectives: Ventriculoperitoneal Shunt (VPS) and Endoscopic Third Ventriculostomy (ETV) are both gold standard procedures to reduce intracranial pressure (ICP) in patients with obstructive hydrocephalus, which often results in papilledema. This comparative study was carried out at the Department of Neurosurgery of Dhaka Medical College and Hospital to compare the efficacy of VPS and ETV in the resolution of papilledema in 18 patients with obstructive hydrocephalus. Materials and Methods: The success of CSF diversion was evaluated by a decrease in retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT) and modified Frisen grading of papilledema at the same time. The statistical analyses were carried out by using paired sample t test and the Spearman’s correlation coefficient test. The level of significance (p value) was set at <0.05. Results: After 7 days, both VPS and ETV were able to reduce RNFL thickness of both eyes with a p value = 0.016 (right eye) and 0.003 (left eye) in group A (VPS) and with a p value <0.001 (both eyes) in group B (ETV). Change of Frisen grading after CSF diversion was not satisfying for both the procedures with p value > 0.05. Further, the inter-group comparison between VPS and ETV showed no difference in decreasing RNFL thickness and modified Frisen grading (p value = 0.56). Conclusion: VPS and ETV procedures both appear very efficient in treating obstructive hydrocephalus, which in turn reduces papilledema in these patients. This paper is preliminary and requires further work.

Pattern of oculomotor and visual function in children with hydrocephalus

PURPOSE

To investigate the ocular motility disturbances, optic nerve changes, and refractive errors in children with or without surgically treated hydrocephalus.

METHODS

This retrospective study included 63 subjects diagnosed with hydrocephalus between 2007 and 2019 at the Baskent University Hospital. Full orthoptic and ophthalmic examination and brain magnetic resonance imaging were performed in all subjects.

RESULTS

The mean age of patients was 68.4±27.6 months, and the mean follow-up time was 21.3±5.2 months. Twenty-one (51.2%) patients had esotropia (ET), and 14 (34.1%) had exotropia (XT). Of the patients with ET, 9 (14.2%) had a sixth nerve palsy. Four patients (6.3%) had a fourth nerve palsy, and 1 had a superior rectus palsy. Eleven patients had manifest, and 2 latent, nystagmus. Thirteen (20.6%) patients had optic disc abnormalities. The mean BCVA was 0.4±0.2 (0.05-1.0) in the right eye and 0.5±0.2 (0.1-1.0) in the left eye. Of the 19 (30.1%) patients who had a significant refractive error, 9 (47.3%) had hyperopia. Thirty-six (57.1%) patients had ventriculoperitoneal shunt surgery, and 11 (30.5%) of them had shunt revision due to occlusion. Ocular motility disorders were found to be significantly more common in patients who underwent single shunt surgery and shunt revision than those who had no surgical procedure (P=0.041and P=0.032, respectively).

CONCLUSION

The evaluation of ocular motility disorders and visual dysfunction in hydrocephalic children can be a source of valuable information when diagnosing and following the disease.

It's not always the shunt: Microthombi formation in venous collaterals causing symptoms of shunt failure in the setting of shunted hydrocephalus

We present a patient with a history of shunted hydrocephalus due to neonatal iatrogenic thoracic venous occlusion with subsequent interval development of spontaneous thoracic venous collateral occlusion as a young adult presenting with symptoms of ventriculoperitoneal shunt failure. Though the patient's presenting symptoms were suggestive of shunt failure in the setting of known shunt dependent hydrocephalus, specific ophthalmologic findings, including venous engorgement, retinal and subconjunctival hemorrhages as well as periorbital edema in conjunction with papilledema, led to the correct diagnosis of cranio-orbital congestion secondary to microthrombi formation in the venous collateral anomalies of her chest wall. This pathology was successfully managed with warfarin.

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.

Presenting symptoms and time to diagnosis for Pediatric Central Nervous System Tumors in Qatar: a report from Pediatric Neuro-Oncology Service in Qatar

INTRODUCTION

There are no previous published reports on primary pediatric tumors of the central nervous system (CNS) in Qatar. We undertook this retrospective cohort study to review the diagnosis of CNS tumors in children in Qatar to analyze the presentation characteristics including symptoms, referral pathways, and time to diagnosis.

METHODS

All children registered with Pediatric Neuro-Oncology service (PNOS) were included in the study. Data from the time of diagnosis (October 2007 to February 2020) were reviewed retrospectively. Presenting symptoms were recorded and pre-diagnosis symptom interval (PSI) was calculated from the onset of the first symptom to the date of diagnostic imaging.

RESULTS

Of the 61 children registered with PNOS during the study period, 51 were included in the final analysis. Ten children were excluded because they were either diagnosed outside Qatar (n = 7) or were asymptomatic at the time of diagnosis (n = 3). The median age was 45 (range 1-171) months. Common tumor types included low-grade glioma (LGG) (47.1%) and medulloblastoma/primitive neuro-ectodermal tumors (PNET) (23.5%). Nine children had an underlying neurocutaneous syndrome. Thirty-eight patients (74.5%) had at least one previous contact with healthcare (HC) professional, but 27 (52%) were still diagnosed through the emergency department (ED). Presenting symptoms included headache, vomiting (36.2%), oculo-visual symptoms (20.6%), motor weakness (18.9%), seizures, ataxia (17.2% each), irritability, cranial nerve palsies (12% each), and endocrine symptoms (10.3%). Median PSI was 28 days (range 1-845 days) for all CNS tumors. Longest PSI was seen with germ cell tumors (median 146 days), supratentorial location (39 days), and age above 3 years (30 days). Tumor characteristics of biological behavior (high-grade tumor) and location (infratentorial) were significantly associated with shorter PSI, as were presenting symptoms of ataxia, head tilt, and altered consciousness.

CONCLUSIONS

Although overall diagnostic times were acceptable, some tumor types were diagnosed after a significant delay. The awareness campaign, such as the "HeadSmart" campaign in the United Kingdom (UK), can improve diagnostic times in Qatar. Further research is required to better understand the reasons for the delay.

Bilateral Proptosis in a Child-A Rare Manifestation of Ventriculoperitoneal Shunt Obstruction

Ventriculoperitoneal shunt (VPS) obstruction may have a myriad of presentations. We reported a case of an 11-year-old girl presenting with acute, bilateral proptosis secondary to VPS obstruction. While neuroimaging was interpreted as unremarkable, fundoscopy revealed bilateral papilledema and lumbar puncture showed elevated intracranial pressure. Neurosurgical exploration demonstrated VPS valve obstruction and a new VPS was inserted. Postoperatively, she developed a recurrent extradural hematoma, which was initially evacuated and later managed conservatively. To our knowledge, this is the first report of bilateral proptosis secondary to VPS obstruction. This case highlights the value of key clinical findings and limitations of neuroimaging.

Strabismus in hydrocephalus patients

PURPOSE

To evaluate the characteristics and outcomes of strabismus in patients with hydrocephalus.

METHODS

A retrospective chart review of patients with strabismus and hydrocephalus is performed in the Department of Pediatric Ophthalmology between 2012 and 2018.

RESULTS

Seventeen patients between the ages of 6 months and 13 years met the criteria of strabismus and hydrocephalus. Although all had developmental delay, five patients out of 17 were premature (lower than 36 weeks of gestation). All patients had ventriculoperitoneal shunt placement for congenital hydrocephalus. Three patients had exotropia, whereas 14 had esotropia. Glasses were prescribed to 13 patients: hyperopic correction in 12 and myopic correction in one patient. Surgical correction with bimedial recession was performed in five patients. Four of them achieved successful ocular alignment.

CONCLUSIONS

Children with hydrocephalus most likely have esotropia. Although good ocular alignment is achieved with surgical correction in some patients, some patients may benefit from glasses.

Intraoperative intracranial pressure monitoring in the pediatric craniosynostosis population

OBJECTIVEEvaluation of increased intracranial pressure (ICP) in the pediatric craniosynostosis population based solely on ophthalmological, clinical, and radiographic data is subjective, insensitive, and inconsistent. The aim of this study was to examine the intraoperative ICP before and after craniectomy in this patient population.METHODSThe authors measured the ICP before and after craniectomy using a subdural ICP monitor in 45 children. They regulated end-tidal carbon dioxide and the monitoring site under general anesthesia to record consistent ICP readings.RESULTSThe average age of the patient population was 29 months (range 3.8-180.5 months). Thirty-seven patients (82.2%) were undergoing initial craniosynostosis procedures. All craniosynostosis procedures were categorized as one of the following: frontoorbital advancement (n = 24), frontoorbital advancement with distraction osteogenesis (n = 1), posterior vault distraction osteogenesis (n = 10), and posterior vault reconstruction (n = 10). Nineteen of 45 patients (42.2%) had syndromic or multisuture craniosynostosis. The mean postcraniectomy ICP (8.8 mm Hg, range 2-18 mm Hg) was significantly lower than the precraniectomy ICP (16.5 mm Hg, range 6-35 mm Hg) (p < 0.001). Twenty-four patients (53%) had elevated ICP prior to craniectomy, defined as ≥ 15 mm Hg. Only 4 (8.9%) children had papilledema on preoperative funduscopic examination (sensitivity 17%, specificity 100%, negative predictive value 51%, and positive predictive value 100%). There were no significant differences in elevated precraniectomy ICP based on type of craniosynostosis (syndromic/multisuture or nonsyndromic) or age at the time of surgery. Patients undergoing initial surgery in the first 12 months of life were significantly less likely to have elevated precraniectomy ICP compared with patients older than 12 months (26.3% vs 73.1%, p = 0.005).CONCLUSIONSIn this study, the authors report the largest cohort of syndromic and nonsyndromic craniosynostosis patients (n = 45) who underwent precraniectomy and postcraniectomy ICP evaluation. A craniectomy or completed craniotomy cuts for distractors effectively reduced ICP in 43/45 patients. The authors' findings support the notion that papilledema on funduscopy is a highly specific, however poorly sensitive, indicator of increased ICP, and thus is not a reliable screening method. These findings indicate that even nonsyndromic patients with craniosynostosis are at risk for increased ICP. Furthermore, patients who present prior to 12 months of age appear less likely to have elevated ICP on presentation. Further studies with other noninvasive imaging of the retina may be useful as an adjunct tool for determining elevated ICP.

Delays in diagnosis for children with newly diagnosed central nervous system tumors

Background

United States studies documenting time interval from symptom onset to definitive diagnosis for childhood central nervous system (CNS) tumors are more than a quarter-century old. The purpose of this study is to establish an accurate and contemporary Ohio baseline of the diagnostic interval for children with newly diagnosed CNS tumors.

Methods

Medical records were retrospectively reviewed for 301 children with newly diagnosed CNS tumors from January 2004 to August 2015 at Nationwide Children's Hospital. We obtained comprehensive data on 171 patients (56.8%). Records were reviewed for age, gender, tumor type, presenting symptoms, number of health care visits prior to diagnosis, time interval (in months) from onset of symptoms to definitive diagnosis, and any associated genetic syndromes.

Results

Of the 171 patients with newly diagnosed CNS tumors, 25 children (14.6%) had a known cancer predisposition syndrome (all with neurofibromatosis type 1). Among the remaining 146 children, the median and mean time intervals from symptom onset to definitive diagnosis were 42 days and 138 days (range < 1 to 2190 days), respectively.

Conclusions

We have documented and quantified the contemporary delays in diagnosis of childhood brain tumors in central Ohio to serve as a benchmark for our future planned interventions to reduce the time interval from symptom onset to diagnosis through adaptation of the United Kingdom HeadSmart program throughout the state of Ohio and ultimately throughout the United States.

From Symptom to Diagnosis-The Prediagnostic Symptomatic Interval of Pediatric Central Nervous System Tumors in Austria

BACKGROUND

Children with central nervous system (CNS) tumours may present with a multitude of symptoms, ranging from elevated intracranial pressure to focal neurological deficit. In everyday practice, some signs may be misleading, thereby causing prolonged prediagnostic symptomatic intervals. Prediagnostic symptomatic intervals are longer for pediatric brain tumors than for other childhood malignancies. This study evaluated prediagnostic symptomatic intervals and parental and diagnostic intervals for pediatric patients with CNS tumours in Austria. It also considered socioeconomic factors.

METHODS

Patients ≤ 19 years of age treated at the Medical University of Vienna and diagnosed during the years 2008 to 2013 were included. Patients diagnosed incidentally or by screening were excluded.

RESULTS

Two hundred twelve consecutive patients were included in the study. They reflected the expected spectrum of CNS tumors. Patients presented with a median of five symptoms at diagnosis, most frequently with signs of elevated intracranial pressure. The median prediagnostic symptomatic interval was 60 days (0 days to seven years), the median parental interval was 30 days (0 days to 6.7 years), and the median diagnostic interval was three days (0 days to 6.5 years). In spinal tumors alone (n = 7), the median prediagnostic symptomatic interval was 70 days (ten days to seven years), and three of seven patients had a prediagnostic symptomatic interval longer than 320 days. Young age, higher tumor grade, and ataxia were associated with a shorter prediagnostic symptomatic interval. Localization in the supratentorial midline, histology of craniopharyngioma, and endocrine symptoms prolonged the prediagnostic symptomatic interval. There was a clear trend for longer prediagnostic symptomatic interval in non-native speakers.

CONCLUSIONS

Results are comparable to other industrialized countries. However, long delays in diagnosis of central nervous system tumors still occur, urging increased awareness.

Shunt age-related complications in adult patients with suspected shunt dysfunction. A recommended diagnostic workup

BACKGROUND

Patients admitted for suspicion of shunt dysfunction (SD) often show unspecific symptoms and require time-consuming, expensive and even invasive diagnostics involving significant radiation exposure. The purpose of this retrospective study was to analyse the current diagnostic procedures and to propose a process optimisation.

METHOD

As all patients admitted for suspicion of SD receive imaging studies, we searched for adult patients receiving neuroimaging in the period from January 2010 to July 2013, analysing referring diagnosis, clinical signs, products, diagnostic process and final diagnosis. Recursive partitioning was used to define time intervals for differentiating types of SD.

RESULTS

A total of 148 patients, aged 18-89 (mean, 54) years, were studied. Forty-two percent were referred by a hospital or rehabilitation centre, 30% by general practitioners and 24% were self-referrals. The admission diagnosis was in the majority "shunt dysfunction" only. Further differentiations were rarely made. An SD was confirmed in 46% of the patients. In 17%, the symptoms were based on another cause and in 37% they could not be clearly attributed to any specific disorder. Abdominal dislocations (2%) and shunt infections (5%) were found within the first 6 months. Over- (3%) and under-drainage (14%) were the most frequent complications during the first 4 years. Disconnections (13%) occurred generally 4 years or more after implantation. Only shunt obstruction (9%) showed no temporal pattern.

CONCLUSIONS

Symptoms of SD remain mostly unspecific. This study showed that the type of SD depends on the time interval from implantation. We propose a workup strategy for patients with SD based on the temporal profile.

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.

Electroretinography and Visual Evoked Potentials in Childhood Brain Tumor Survivors

This population-based cross-sectional study evaluates the clinical value of electroretinography and visual evoked potentials in childhood brain tumor survivors. A flash electroretinography and a checkerboard reversal pattern visual evoked potential (or alternatively a flash visual evoked potential) were done for 51 survivors (age 3.8-28.7 years) after a mean follow-up time of 7.6 (1.5-15.1) years. Abnormal electroretinography was obtained in 1 case, bilaterally delayed abnormal visual evoked potentials in 22/51 (43%) cases. Nine of 25 patients with infratentorial tumor location, and altogether 12 out of 31 (39%) patients who did not have tumors involving the visual pathways, had abnormal visual evoked potentials. Abnormal electroretinographies are rarely observed, but abnormal visual evoked potentials are common even without evident anatomic lesions in the visual pathway. Bilateral changes suggest a general and possibly multifactorial toxic/adverse effect on the visual pathway. Electroretinography and visual evoked potential may have clinical and scientific value while evaluating long-term effects of childhood brain tumors and tumor treatment.

[Semiology of ventriculoperitoneal shunting dysfunction in children - a review]

INTRODUCTION

Ventriculoperitoneal shunting (VPS) is a treatment of the hydrocephalus that may dysfunction. The clinical presentation of shunt dysfunction is variable. We therefore decided to focus on the clinical presentation of VPS malfunction in children, as this condition requires immediate emergency treatment and because of the sometimes confusing signs of intracranial hypertension in a shunted child.

MATERIALS AND METHODS

We searched PubMed with the following groups of keywords: (dysfunction OR blockage) AND shunting AND hydrocephalus; shunt complications AND hydrocephalus; hydrocephalus AND shunt AND malfunction. Articles dealing with ventriculo-atrial shunt were excluded. A total of 79 articles were retained for analysis (English and French). Case reports were excluded.

RESULTS

The clinical presentation varies by age: vomiting and alterated level of consciousness are the most frequent signs in older children, whereas infants present more often with raised intracranial pressure symptoms such as nausea, vomiting, irritability and bulging fontanel. Drowsiness is a good predictor of VPS dysfunction. An asymptomatic presentation is rare but possible. Abdominal presentation is also possible, ranging from abdominal discomfort to peritonitis. Fever, occurring a short time after the last intervention, and irritability are good predictors of shunt infection. Pumping the chamber of the VPS has a weak positive predictive value (12%). Shunt dysfunction can lead to death, with an estimated mortality rate at 1% per year during the first years.

CONCLUSION

It is essential to be aware of the variability of the clinical presentation of VPS dysfunction, because of the potential severity of this condition. Also it is important to pay attention to the comments of the parents, especially if the child experienced a previous shunt malfunction.

Delayed diagnosis of childhood low-grade glioma: causes, consequences, and potential solutions

PURPOSE

Diagnosis of childhood brain tumors is delayed more than diagnosis of other pediatric cancers. However, the contribution of the most common pediatric brain tumors, lowgrade gliomas (LGG), to this delay has never been investigated.

METHODS

We retrospectively reviewed cases of childhood LGG diagnosed from January 1995 through December 2005 at our institution. The pre-diagnosis symptom interval (PSI) was conservatively calculated, and its association with race, sex, age, tumor site, tumor grade, and outcome measures (survival, disease progression, shunt use, seizures, extent of resection) was analyzed. Cases of neurofibromatosis type 1 were reported separately.

RESULTS

The 258 children had a median follow-up of 11.1 years, and 226 (88 %) remained alive. Greater pre-diagnosis symptom interval (PSI) was significantly associated with grade I (vs. grade II) tumors (p = 0.03) and age >10 years at diagnosis (p = 0.03). Half of the 16 spinal tumors had a PSI > 6 months. PSI was significantly associated with progression (p = 0.02) in grade I tumors (n = 195) and in grade I tumors outside the posterior fossa (n = 134, p = 0.03). Among children with grade I tumors, median PSI was longer in those who had seizures (10.3 months) than in those who did not (2.5 months) (p = 0.09).

CONCLUSIONS

Delayed diagnosis of childhood LGG allows tumor progression. To reduce time to diagnosis, medical curricula should emphasize inclusion of LGG in the differential diagnosis of CNS neoplasm.

The baric probe: a novel long-term implantable intracranial pressure monitor with ultrasound-based interrogation

OBJECT

Prompt diagnosis of shunt malfunction is critical in preventing neurological morbidity and death in individuals with hydrocephalus; however, diagnostic methods for this condition remain limited. For several decades, investigators have sought a long-term, implantable intracranial pressure (ICP) monitor to assist in the diagnosis of shunt malfunction, but efforts have been impeded by device complexity, marked measurement drift, and limited instrumentation lifespan. In the current report, the authors introduce an entirely novel, simple, compressible gas design that addresses each of these problems.

METHODS

The device described herein, termed the "baric probe," consists of a subdural fluid bladder and multichannel indicator that monitors the position of an air-fluid interface (AFI). A handheld ultrasound probe is used to interrogate the baric probe in vivo, permitting noninvasive ICP determination. To assess the function of device prototypes, ex vivo experiments were conducted using a water column, and short- and long-term in vivo experiments were performed using a porcine model with concurrent measurements of ICP via a fiberoptic monitor.

RESULTS

Following a toe region of approximately 2 cm H(2)O, the baric probe's AFI demonstrated a predictable linear relationship to ICP in both ex vivo and in vivo models. After a 2-week implantation of the device, this linear relationship remained robust and reproducible. Further, changes in ICP were observed with the baric probe, on average, 3 seconds in advance of the fiberoptic ICP monitor reading.

CONCLUSIONS

The authors demonstrate "proof-of-concept" and feasibility for the baric probe, a long-term implantable ICP monitor designed to facilitate the prompt and accurate diagnosis of shunt malfunction. The baric probe showed a consistent linear relationship between ICP and the device's AFI in ex vivo and short- and long-term in vivo models. With a low per-unit cost, a reduced need for radiography or CT, and an indicator that can be read with a handheld ultrasound probe that interfaces with any smart phone, the baric probe promises to simplify the care of patients with shunt-treated hydrocephalus throughout both the developed and the developing world.

Neonatal neurocritical care: overlooked neurologic syndromes

Although encephalopathy, seizures, and changes in tone comprise the most common signs of neurologic disruption in neonates (and in older children and adults), careful neurologic examination can yield additional clues to assist with the management of underlying neurologic conditions.

Hypothalamic-pituitary lesions in pediatric patients: endocrine symptoms often precede neuro-ophthalmic presenting symptoms

OBJECTIVE

To evaluate whether analyses of clinical and endocrine presenting symptoms could help to shorten the time to diagnosis of hypothalamic-pituitary lesions in children.

STUDY DESIGN

A retrospective, single-center, cohort study of 176 patients (93 boys), aged 6 years (range, 0.2-18 years), with hypothalamic-pituitary lesions was performed.

RESULTS

The lesions were craniopharyngioma (n = 56), optic pathway glioma (n = 54), suprasellar arachnoid cyst (n = 25), hamartoma (n = 22), germ cell tumor (n = 12), and hypothalamic-pituitary astrocytoma (n = 7). The most common presenting symptoms were neurologic (50%) and/or visual complaints (38%), followed by solitary endocrine symptoms (28%). Precocious puberty led to diagnosis in 19% of prepubertal patients (n = 131), occurring earlier in patients with hamartoma than in patients with optic-pathway glioma (P < .02). Isolated diabetes insipidus led to diagnosis for all germ-cell tumors. For 122 patients with neuro-ophthalmic presenting symptoms, the mean symptom interval was 0.5 year (95% CI, 0.4-0.6 year), although 66% of patients had abnormal body mass index or growth velocity, which preceded the presenting symptom interval onset by 1.9 years (95% CI, 1.5-2.4 years) (P < .0001) and 1.4 years (95% CI, 1-1.8 years) (P < .0001), respectively. Among them, 41 patients were obese before diagnosis (median 2.2 years [IQR, 1-3 years] prior to diagnosis) and 35 of them had normal growth velocity at the onset of obesity. The sensitivity of current guidelines for management of childhood obesity failed to identify 61%-85% of obese children with an underlying hypothalamic-pituitary lesion in our series.

CONCLUSIONS

Endocrine disorders occurred in two-thirds of patients prior to the onset of the neuro-ophthalmic presenting symptom but were missed. Identifying them may help to diagnose hypothalamic-pituitary lesions earlier.

Relapsing dorsal midbrain syndrome following interventions for hydrocephalus in aqueductal stenosis

Dorsal midbrain syndrome (DMS) is a recognized clinical manifestation of increased intracranial pressure (ICP) associated with ventricular enlargement, especially in shunt malfunction, but the mechanism by which DMS occurs in this setting is unsettled. We report a patient with triventriculomegaly attributed to aqueductal narrowing by a tectal mass who went through 2 cycles of developing and resolving DMS promptly after undergoing interventions that altered the size of the posterior third ventricle and proximal aqueduct but probably did not markedly alter ICP. This case provides additional evidence that DMS in this setting is caused by deformation of the dorsal midbrain region produced by rapid expansion of the posterior third ventricle or proximal aqueduct.

Progression from first symptom to diagnosis in childhood brain tumours

This study was undertaken to investigate the evolution of clinical features between onset of symptoms and diagnosis in children with brain tumours and to identify ways of shortening the time to diagnosis. One hundred and thirty-nine children with a brain tumour were recruited from four UK paediatric neuro-oncology centres. Children had a median of one symptom or sign at symptom onset and six by diagnosis. The symptoms and/or signs experienced at symptom onset and at diagnosis were as follows: headache in 55 and 81 children, nausea and vomiting in 39 and 88 children, motor system abnormalities in 31 and 93 children, cranial nerve palsies in 24 and 75 children, visual system abnormalities in 23 and 96 children, endocrine or growth abnormalities in 10 and 35 children and behavioural change in 4 and 55 children. The median time between symptom onset and diagnosis (symptom interval) was 3.3 months. A longer symptom interval was associated with head tilt, cranial nerve palsies, endocrine and growth abnormalities and reduced visual acuity. More than half of children with brain tumours developed problems with vision and more than a third developed motor problems, cranial nerve palsies, behavioural change, or nausea and vomiting between symptom onset and diagnosis.

Visual field constriction in children with shunt-treated hydrocephalus

OBJECT

Many ophthalmological abnormalities are described in conjunction with hydrocephalus. The results of visual field diagnosis remain a matter of further discussion. The aim of this study was to investigate visual field deficits in children with shunt-treated hydrocephalus.

METHODS

All children over 6 years of age treated for hydrocephalus at the authors' institute between December 2007 and December 2008 were included in the study. The children underwent an ophthalmological investigation for strabismus and binocular function, ophthalmoscopy, visual acuity, and refraction. The special focus was the visual field diagnosis, which the authors established in all children with cognitive conditions. The investigation was made by using the Goldmann visual field examination (kinetic perimetry). Children with and without visual field defects were compared concerning age at the time of ophthalmological examination, genesis of hydrocephalus, and fronto-occipital horn ratio measured on current CT or MR images.

RESULTS

Complete investigations were undertaken in 56 children (24 girls and 32 boys, mean age 15.1 years). The following orthoptic pathological entities were diagnosed: 29 children have a strabismus in 29 cases, 17 of these have an exotropia, 12 an esotropia, 4 children a hypotropia, 2 a hypertropia and 3 children a heterophoria. A nystagmus was found in 10 children. The ocular fundus investigation showed 13 children with an optic nerve atrophy. A visual field diagnosis was possible in 44 of the 56 patients and was incomplete in 12 patients with cognitive deficits or inadequate compliance. In 24 of 42 children there was a concentric visual field constriction between 10° and 50° out of the center. Children with visual field deficits were older than those with a normal visual field (p = 0.051). Nine of 10 children with postmenigitic hydrocephalus had a visual field defect (p = 0.025). In children with visual field defects the fronto-occipital horn ratio was significantly higher (p = 0.013).

CONCLUSIONS

The results suggest that children with shunt-treated hydrocephalus have a higher risk of having ophthalmological abnormalities. Visual field deficits are often a problem in these patients. A diagnostic visual field examination can complete the ophthalmological monitoring in patients with hydrocephalus, especially in patients with large ventricles. Children with postmeningitic hydrocephalus should be ophthalmologically monitored more frequently and intensively.

Visual improvement after optic nerve sheath decompression in a case of congenital hydrocephalus and persistent visual loss despite intracranial pressure correction via shunting

Among the sequelae of persistent raised intracranial pressure (ICP) are ophthalmologic signs and symptoms, including cranial nerve palsies, visual field deficits, papilledema, and vision loss. Elevated pressure within the optic nerve sheath may not be relieved by shunt procedures, which can decrease generalized ICP. The authors present a case of acute visual loss in the setting of chronic hydrocephalus and multiple shunt revisions. Despite shunt correction resolving systemic symptoms of raised ICP, this child had persistent visual loss. Bilateral optic nerve sheath decompression was performed, and the visual acuity improved over the next 3 days. This case highlights the importance of routine ophthalmologic examination in patients with hydrocephalus and shunts and demonstrates the utility of optic nerve sheath decompression as a surgical intervention when shunting alone does not resolve visual loss.

Sylvian aqueduct syndrome with slit ventricles in shunted hydrocephalus due to adult aqueduct stenosis

The authors report on 3 patients who developed sylvian aqueduct syndrome (SAS) in the context of shunt dysfunction and slit ventricles. All 3 patients had received shunts for adult onset hydrocephalus due to aqueduct stenosis and were stable for years before presenting with loss of upward gaze, convergence-retraction nystagmus, and slit ventricles, all due to shunt overdrainage. All 3 improved after either shunt revision or a third ventriculostomy procedure. Although it is well known that SAS can be caused by shunt blockage producing a transtentorial pressure gradient, these cases emphasize that an identical clinical pattern can occur with a reverse transtentorial pressure gradient and slit ventricles due to shunt overdrainage. The authors propose a simple management plan for patients with shunted hydrocephalus who develop SAS.

Optic nerve sheath fenestration for vision preservation in idiopathic intracranial hypertension

Idiopathic intracranial hypertension, also known as pseudotumor cerebri, is a condition of increased intracranial pressure without the presence of mass lesions and with normal cerebrospinal fluid composition. Patients may experience papilledema and vision loss. Optic nerve sheath fenestration (ONSF) is one method of stabilizing visual function and decreasing optic nerve edema. The authors report on 10 patients who underwent bilateral ONSF and in whom visual function was stable or improved postoperatively. The results obtained in these cases suggest that ONSF plays a role in visual preservation in idiopathic intracranial hypertension patients in the acute setting.

Case Studies in Neuro-Ophthalmology for the Neurologist

In summary, neurologists should be aware of emergent neuro-ophthalmic conditions: (1) temporal arteritis (GCA), (2) IIH, (3) intracranial shunt malfunction, (4) pituitary apoplexy, and (5) pupil-involved TNP. Earlier recognition and treatment of these disorders makes a difference in final out-come. Appropriate evaluation and management may be vision or life saving.

Risk of strabismus and ambylopia in children with hydrocephalus

OBJECTIVES

The present study was undertaken to determine the risk of strabismus and ambylopia in children who underwent operation for hydrocephalus and to compare our results with those in previous studies.

METHODS

Full orthoptic and ophthalmological examinations, including cycloplegic refraction, were performed in all subjects.

RESULTS

Ten of 25 patients (40%) were found to have manifest squint. Four of these had esotropia and six had exotropia. No paretic squint or alphabetic pattern strabismus was determined. Refraction measurements revealed amblyogenic refractive errors (significant refractive errors that cause amblyopia) in five of the 25 (20%) patients in this study. Strabismus and the risk of amblyopia were found to be significantly higher in patients who experienced shunt revision than those who had not (P<0.05).

CONCLUSION

Amblyopia, strabismus, and other acquired defects in the visual system related to hydrocephalus should be closely monitored and treated when indicated. Regular ophthalmic supervision will provide and help to maintain the best possible standard of vision in children with hydrocephalus.

Neuro-Ophthalmic Emergencies for the Neurologist

A variety of acute neurologic disorders present with visual signs and symptoms. In this review the authors focus on those disorders in which the clinical outcome is dependent on timely and accurate diagnosis. The first section deals with acute visual loss, specifically optic neuritis, ischemic optic neuropathy (ION), retinal artery occlusion, and homonymous hemianopia. The authors include a discussion of those clinical features that are helpful in distinguishing between inflammatory and ischemic optic nerve disease and between arteritic and nonarteritic ION. The second section concerns disc edema with an emphasis on the prevention of visual loss in patients with increased intracranial pressure. The third section deals with abnormal ocular motility, and includes orbital inflammatory disease, carotid-cavernous fistulas, painful ophthalmoplegia, conjugate gaze palsies, and neuromuscular junction disorders. The final section concerns pupillary abnormalities, with a particular emphasis on the dilated pupil and on carotid artery dissection. Throughout there are specific guidelines for the management of these disorders, and areas are highlighted in which there is ongoing controversy.

Changes in visual acuity associated with shunt failure

OBJECT

The object of this article was to report on a retrospective analysis of the clinical findings in a series of patients with changes in visual acuity associated with shunt failure.

METHODS AND RESULTS

Over a 10-year period, 350 patients underwent revisions for shunt failure. The clinical course of patients who demonstrated changes in visual acuity (VA) before or during hospitalization were reviewed; follow-up was achieved using outpatient records and telephone calls with physicians, family, or caregivers. Six patients (4 male) ranging in age from 2.5 years to 40 years demonstrated changes in vision associated with shunt failure. The youngest patient lapsed into coma before transfer and showed bilateral occipital lobe infarctions on the CT scan. Three patients had no complaints referable to the visual system prior to revision. Two patients with symptoms lasting more than 21 days showed unequivocal signs of increased intracranial pressure. Serial CT scans remained unchanged in 2 patients. A 3rd patient showed questionable progression in ventricular volume, while another patient's ventricles dilated after a period of 48-72 h. Four patients demonstrated a pattern of aqueductal stenosis, long-term shunting without revision, small ventricles, and poor outpatient follow-up. Four patients showed partial or complete recovery following revision.

CONCLUSIONS

Changes in vision are uncommon and can be an isolated finding associated with shunt failure. Patients with aqueductal stenosis, long-term shunting without revision, and small, potentially non-compliant ventricles may be at risk of this complication. Misdiagnosis or inadequate follow-up places these patients at additional risk, but rapid revision can result in partial or complete recovery.

Classification and quantification of neuronal fiber pathways using diffusion tensor MRI

Quantitative characterization of neuronal fiber pathways in vivo is of significant neurological and clinical interest. Using the capability of MR diffusion tensor imaging to determine the local orientations of neuronal fibers, novel algorithms were developed to bundle neuronal fiber pathways reconstructed in vivo with diffusion tensor images and to quantify various physical and geometric properties of fiber bundles. The reliability of the algorithms was examined with reproducibility tests. Illustrative results show that consistent physical and geometric measurements of novel properties of neuronal tissue can be obtained, which offer considerable potential for the quantitative study of fiber pathways in vivo.

Idiopathic intracranial hypertension headache

Idiopathic intracranial hypertension (IIH) is a disorder of increased intracranial pressure that may have papilledema with normal imaging study results. Headache is the most frequent symptom. Although the headache characteristics are indistinguishable from the symptoms of migraine headache, accompanying symptoms of increased intracranial pressure, such as pulsatile tinnitus, transient visual obscurations, and radicular neck pain, may aid in the diagnosis. Magnetic resonance imaging, including venography, is essential for the diagnosis of the primary idiopathic intracranial hypertension. Medical treatment for the headache includes weight loss for obese patients, diuretic therapy, and migraine preventive medications. If medical therapy does not abolish the headache, surgical options should be considered. Because patients with IIH have a poor quality of life, patient education and supportive materials are important.

Ophthalmic complications of slit-ventricle syndrome in children

OBJECTIVE

To present the ophthalmic features and visual prognosis of patients with slit-ventricle syndrome (SVS).

DESIGN

Observational case series.

PARTICIPANTS

Six patients diagnosed and treated with SVS at the Montreal Children's Hospital between 1985 and 1999.

METHODS

Patients were included in this study if they had an appropriate ophthalmologic follow-up and if they fulfilled the criteria for the diagnosis of SVS based on intracranial pressure monitoring and neuroimaging studies.

MAIN OUTCOME MEASURES

Features studied included patients' baseline ophthalmologic evaluation, visual outcome, and neurosurgical characteristics.

RESULTS

The follow-up ranged from 1 to 14 years. The average number of shunting procedures was 3.7. Ocular examination performed on the initial visit revealed a normal visual acuity in four patients, esotropia in three of six patients, and nystagmus in two of six patients. Cycloplegic refraction was normal in all the subjects. Initial funduscopic evaluation revealed optic atrophy in a 4-month-old infant, whereas two children developed optic atrophy later in the course of the disease. One child developed severe visual field defects. The two children with optic atrophy had moderate to severe loss of visual acuity associated with SVS.

CONCLUSIONS

A prompt recognition of patients with SVS is crucial, because these individuals are at an increased risk for significant visual loss.