Treatment evaluation by volumetric segmentation in pediatric optic pathway glioma: evaluation of the effect of bevacizumab on intra-tumor components.

PURPOSE: Progressive pediatric optic pathway gliomas (OPGs) are treated by diverse systemic antitumor modalities. Refined insights on the course of intra-tumoral components are limited. METHODS: We performed an exploratory study on the longitudinal volumetric course of different (intra-)tumor components by manual segmentation of MRI at the start and after 3, 6 and 12 months of bevacizumab (BVZ) treatment. RESULTS: Thirty-one patients were treated with BVZ (median 12 months, range: 2-39 months). During treatment the total tumor volume decreased with median 19.9% (range: - 62.3 to + 29.7%; n = 30) within the first 3 months, decreased 19.0% (range: - 68.8 to + 96.1%; n = 28) between start and 6 months and 27.2% (range: -73.4 to + 36.0%; n = 21) between start and 12 months. Intra-tumoral cysts were present in 12 OPGs, all showed a decrease of volume during treatment. The relative contrast enhanced volume of NF1 associated OPG (n = 11) showed an significant reduction compared to OPG with a KIAA1549-BRAF fusion (p < 0.01). Three OPGs progressed during treatment, but were not preceded by an increase of relative contrast enhancement. CONCLUSION: Treatment with BVZ of progressive pediatric OPGs leads to a decrease of both total tumor volume and cystic volume for the majority of OPGs with emphasis on the first three months. NF1 and KIAA1549-BRAF fusion related OPGs showed a different (early) treatment effect regarding the tumor enhancing component on MRI, which did not correlate with tumor volume changes. Future research is necessary to further evaluate these findings and its relevance to clinical outcome parameters.

Effects of Stimulus Luminance, Stimulus Color and Intra-Stimulus Color Contrast on Visual Field Mapping in Neurologically Impaired Adults Using Flicker Pupil Perimetry.

Purpose: We improve pupillary responses and diagnostic performance of flicker pupil perimetry through alterations in global and local color contrast and luminance contrast in adult patients suffering from visual field defects due to cerebral visual impairment (CVI). Methods: Two experiments were conducted on patients with CVI (Experiment 1: 19 subjects, age M and SD 57.9 ± 14.0; Experiment 2: 16 subjects, age M and SD 57.3 ± 14.7) suffering from absolute homonymous visual field (VF) defects. We altered global color contrast (stimuli consisted of white, yellow, cyan and yellow-equiluminant-to-cyan colored wedges) in Experiment 1, and we manipulated luminance and local color contrast with bright and dark yellow and multicolor wedges in a 2-by-2 design in Experiment 2. Stimuli consecutively flickered across 44 stimulus locations within the inner 60 degrees of the VF and were offset to a contrasting (opponency colored) dark background. Pupil perimetry results were compared to standard automated perimetry (SAP) to assess diagnostic accuracy. Results: A bright stimulus with global color contrast using yellow (p= 0.009) or white (p= 0.006) evoked strongest pupillary responses as opposed to stimuli containing local color contrast and lower brightness. Diagnostic accuracy, however, was similar across global color contrast conditions in Experiment 1 (p= 0.27) and decreased when local color contrast and less luminance contrast was introduced in Experiment 2 (p= 0.02). The bright yellow condition resulted in highest performance (AUC M = 0.85 ± 0.10, Mdn = 0.85). Conclusion: Pupillary responses and pupil perimetry's diagnostic accuracy both benefit from high luminance contrast and global but not local color contrast.

Treatment and outcome of the Dutch Childhood Craniopharyngioma Cohort study: First results after centralization of care.

BACKGROUND: Childhood craniopharyngioma (cCP) has excellent survival, but quality of life may be severely hampered by hypothalamic dysfunction. We aimed to evaluate treatment and hypothalamic outcomes of a Dutch cCP cohort, and evaluate the effect of centralization of care. METHODS: A retrospective cohort study was performed, including cCP patients diagnosed between 2004 and 2021. Treatment characteristics and hypothalamic outcomes were evaluated and compared before and since centralization of care in May 2018. RESULTS: We included 87 cCP patients. Cyst drainage/fenestration was performed in 29.9%, limited resection in 27.6%, near-total resection in 16.1%, and gross total resection (GTR) in 25.4%. Radiotherapy was given in 46.0%. After a median follow-up of 6.5 years, hypothalamic obesity (HO) was present in 24.7% and panhypopituitarism with diabetes insipidus in 71.3%. Higher body mass index (BMI) SDS at diagnosis and Muller grade II at last magnetic resonance imaging of follow-up were associated with overweight/obesity. No association was found between extensiveness of resection and overweight/obesity at last follow-up. When comparing before and after centralization of care, rates of GTR remained similar, but BMI outcomes changed; mean ΔBMI SDS 1 year after diagnosis from 1.12 (SD 1.15) to 0.81 (SD 1.24), and HO after 1 year decreased from 33.3% to 12.0% (P = .067), and after 2 years from 28.6% to 6.7% (P = NS). CONCLUSIONS: In our nationwide cohort, GTR was performed in a relatively low percentage of patients and extensiveness of resection was no longer associated with HO at follow-up. A trend toward improvement of BMI is observed since centralization of care, which needs further exploration.

Diagnostic accuracy of retinal optical coherence tomography in children with a newly diagnosed brain tumour.

PURPOSE: To estimate the diagnostic accuracy of circumpapillary retinal nerve fibre layer (RNFL) thickness and macular ganglion cell layer-inner plexiform layer (GCL-IPL) thickness measurements to discriminate an abnormal visual function (i.e. abnormal age-based visual acuity and/or visual field defect) in children with a newly diagnosed brain tumour. METHODS: This cross-sectional analysis of a prospective longitudinal nationwide cohort study was conducted at four hospitals in the Netherlands, including the national referral centre for paediatric oncology. Patients aged 0-18 years with a newly diagnosed brain tumour and reliable visual acuity and/or visual field examination and optical coherence tomography were included. Diagnostic accuracy was evaluated with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: Of 115 patients included in the study (67 [58.3%] male; median age 10.6 years [range, 0.2-17.8 years]), reliable RNFL thickness and GCL-IPL thickness measurements were available in 92 patients (80.0%) and 84 patients (73.0%), respectively. The sensitivity for detecting an abnormal visual function was 74.5% for average RNFL thickness and 41.7% for average GCL-IPL thickness at a specificity of 44.5% and 82.9%, respectively. The PPV and NPV were 33.0% and 82.6% for the average RNFL thickness and 57.1% and 82.2% for the average GCL-IPL thickness. CONCLUSION: An abnormal visual function was discriminated correctly by using the average RNFL thickness in seven out of ten patients and by using the average GCL-IPL thickness in four out of ten patients. The relatively high NPVs signified that patients with normal average RNFL thickness and average GCL-IPL thickness measurements had a relative high certainty of a normal visual function.

The Trade-Off Between Luminance and Color Contrast Assessed With Pupil Responses.

Purpose: A scene consisting of a white stimulus on a black background incorporates strong luminance contrast. When both stimulus and background receive different colors, luminance contrast decreases but color contrast increases. Here, we sought to characterize the pattern of stimulus salience across varying trade-offs of color and luminance contrasts by using the pupil light response. Methods: Three experiments were conducted with 17, 16, and 17 healthy adults. For all experiments, a flickering stimulus (2 Hz; alternating color to black) was presented superimposed on a background with a complementary color to the stimulus (i.e., opponency colors in human color perception: blue and yellow for Experiment 1, red and green for Experiment 2, and equiluminant red and green for Experiment 3). Background luminance varied between 0% and 45% to trade off luminance and color contrast with the stimulus. By comparing the locus of the optimal trade-off between color and luminance across different color axes, we explored the generality of the trade-off. Results: The strongest pupil responses were found when a substantial amount of color contrast was present (at the expense of luminance contrast). Pupil response amplitudes increased by 15% to 30% after the addition of color contrast. An optimal pupillary responsiveness was reached at a background luminance setting of 20% to 35% color contrast across several color axes. Conclusions: These findings suggest that a substantial component of pupil light responses incorporates color processing. More sensitive pupil responses and more salient stimulus designs can be achieved by adding subtle levels of color contrast between stimulus and background. Translational Relevance: More robust pupil responses will enhance tests of the visual field with pupil perimetry.

Impact of Bevacizumab on Visual Function, Tumor Size, and Toxicity in Pediatric Progressive Optic Pathway Glioma: A Retrospective Nationwide Multicentre Study.

BACKGROUNDS: Bevacizumab (BVZ) is used as a subsequent line of treatment for pediatric optic pathway glioma (OPG) in the case of progression. Data on the treatment effect concerning tumor progression and visual function are scarce and nationwide studies are lacking. METHODS: We performed a retrospective, nationwide, multicentre cohort study including all pediatric patients with OPG treated with BVZ in the Netherlands (2009-2021). Progression-free survival, change in visual acuity and visual field, MRI-based radiologic response, and toxicity were evaluated. RESULTS: In total, 33 pediatric patients with OPG were treated with BVZ (median 12 months). Visual acuity improved in 20.5%, remained stable in 74.4%, and decreased in 5.1% of 39 of all analysed eyes. The monocular visual field improved in 73.1%, remained stable in 15.4%, and decreased in 7.7% of 25 analysed eyes. Radiologic response at the end of therapy showed a partial response in 7 patients (21.9%), minor response in 7 (21.9%), stable disease in 15 (46.9%), and progressive disease in 3 (9.3%). Progression-free survival at 18 and 36 months after the start of BVZ reduced from 70.9% to 38.0%. Toxicity (≥grade 3 CTCAE) during treatment was observed in five patients (15.2%). CONCLUSION: Treatment of BVZ in pediatric patients with OPG revealed stabilisation in the majority of patients, but was followed by progression at a later time point in more than 60% of patients. This profile seems relatively acceptable given the benefits of visual field improvement in more than 70% of analysed eyes and visual acuity improvement in more than 20% of eyes at the cessation of BVZ.

Ophthalmological Findings in Youths With a Newly Diagnosed Brain Tumor.

Importance: Visual impairment is an irreversible adverse effect in individuals who experienced a childhood brain tumor. Ophthalmological evaluation at diagnosis enables early detection of vision loss, decision-making about treatment, and when applicable, the timely use of visual interventions. However, awareness of visual impairment in clinical practice is suboptimal, and adherence to ophthalmological evaluation needs to be improved. Objective: To assess the prevalence and types of abnormal ophthalmological findings in youths with a newly diagnosed brain tumor. Design, Setting, and Participants: In this nationwide, prospective cohort study, youths aged 0 to 18 years with a newly diagnosed brain tumor between May 15, 2019, and August 11, 2021, were consecutively enrolled in 4 hospitals in the Netherlands, including the dedicated tertiary referral center for pediatric oncology care. Exposures: A standardized and comprehensive ophthalmological examination, including orthoptic evaluation, visual acuity testing, visual field examination, and ophthalmoscopy, was performed within 4 weeks from brain tumor diagnosis. Main Outcomes and Measures: The main outcomes were prevalence and types of visual symptoms and abnormal ophthalmological findings at brain tumor diagnosis. Results: Of 170 youths included in the study (96 [56.5%] male; median age, 8.3 years [range, 0.2-17.8 years]), 82 (48.2%) had infratentorial tumors; 53 (31.2%), supratentorial midline tumors; and 35 (20.6%), cerebral hemisphere tumors. A total of 161 patients (94.7%) underwent orthoptic evaluation (67 [41.6%] preoperatively; 94 [58.4%] postoperatively); 152 (89.4%), visual acuity testing (63 [41.4%] preoperatively; 89 [58.6%] postoperatively); 121 (71.2%), visual field examination (49 [40.4%] preoperatively; 72 [59.6%] postoperatively); and 164 (96.5%), ophthalmoscopy (82 [50.0%] preoperatively; 82 [50.0%] postoperatively). Overall, 101 youths (59.4%) presented with visual symptoms at diagnosis. Abnormal findings were found in 134 patients (78.8%) during ophthalmological examination. The most common abnormal findings were papilledema in 86 of 164 patients (52.4%) who underwent ophthalmoscopy, gaze deficits in 54 of 161 (33.5%) who underwent orthoptic evaluation, visual field defects in 32 of 114 (28.1%) with reliable visual field examination, nystagmus in 40 (24.8%) and strabismus in 32 (19.9%) of 161 who underwent orthoptic evaluation, and decreased visual acuity in 13 of 152 (8.6%) with reliable visual acuity testing. Forty-five of 69 youths (65.2%) without visual symptoms at diagnosis had ophthalmological abnormalities on examination. Conclusions and Relevance: The results of this study suggest that there is a high prevalence of abnormal ophthalmological findings in youths at brain tumor diagnosis regardless of the presence of visual symptoms. These findings support the need of standardized ophthalmological examination and the awareness of ophthalmologists and referring oncologists, neurologists, and neurosurgeons for ophthalmological abnormalities in this patient group.

Comparison of unifocal, flicker, and multifocal pupil perimetry methods in healthy adults.

To this day, the most popular method of choice for testing visual field defects (VFDs) is subjective standard automated perimetry. However, a need has arisen for an objective, and less time-consuming method. Pupil perimetry (PP), which uses pupil responses to onsets of bright stimuli as indications of visual sensitivity, fulfills these requirements. It is currently unclear which PP method most accurately detects VFDs. Hence, the purpose of this study is to compare three PP methods for measuring pupil responsiveness. Unifocal (UPP), flicker (FPP), and multifocal PP (MPP) were compared by monocularly testing the inner 60 degrees of vision at 44 wedge-shaped locations. The visual field (VF) sensitivity of 18 healthy adult participants (mean age and SD 23.7 ± 3.0 years) was assessed, each under three different artificially simulated scotomas for approximately 4.5 minutes each (i.e. stimulus was not or only partially present) conditions: quadrantanopia, a 20-, and 10-degree diameter scotoma. Stimuli that were fully present on the screen evoked strongest, partially present stimuli evoked weaker, and absent stimuli evoked the weakest pupil responses in all methods. However, the pupil responses in FPP showed stronger discriminative power for present versus absent trials (median d-prime = 6.26 ± 2.49, area under the curve [AUC] = 1.0 ± 0) and MPP performed better for fully present versus partially present trials (median d-prime = 1.19 ± 0.62, AUC = 0.80 ± 0.11). We conducted the first in-depth comparison of three PP methods. Gaze-contingent FPP had best discriminative power for large (absolute) scotomas, whereas MPP performed slightly better with small (relative) scotomas.

Maintaining fixation by children in a virtual reality version of pupil perimetry.

The assessment of the visual field in young children continues to be a challenge. Children often do not sit still, fail to fixate stimuli for longer durations, and have limited verbal capacity to report visibility. Therefore, we introduced a head-mounted VR display with gazecontingent flicker pupil perimetry (VRgcFPP). We presented large flickering patches at different eccentricities and angles in the periphery to evoke pupillary oscillations, and three fixation stimulus conditions to determine best practices for optimal fixation and pupil response quality. A total of twenty children (3-11y) passively fixated a dot, counted the repeated appearance of an animated character (counting task), and watched an animated movie in separate trials of 80s each (20 patch locations, 4s per location). The results showed that gaze precision and accuracy did not differ significantly across the fixation conditions but pupil amplitudes were strongest for the dot and count task. The VR set-up appears to be an ideal apparatus for children to allow free range of movement, an engaging visual task, and reliable eye measurements. We recommend the use of the fixation counting task for pupil perimetry because children enjoyed it the most and it achieved strongest pupil responses.

Ophthalmological Evaluation in Children Presenting With a Primary Brain Tumor.

BACKGROUND: Children with a brain tumor are prone to develop visual impairment, which to date is often underestimated and unrecognized. Our aim was to assess the prevalence of ophthalmological evaluation and abnormal ophthalmological findings, and investigate whether demographic and tumor-related characteristics are associated with abnormal ophthalmological findings in children presenting with a primary brain tumor. METHODS: Medical records of all 90 children diagnosed with a primary brain tumor between June 2018 and May 2019 and treated at the Princess Máxima Center for Pediatric Oncology, a tertiary referral center in the Netherlands, were retrospectively reviewed. Univariate regression analysis was used to investigate associations between demographic, tumor-related and clinical characteristics, and abnormal ophthalmological findings. RESULTS: Sixty children (34 male [56.7%]; median [range] age, 9.3 [0-16.9] years) underwent ophthalmological evaluation within 6 weeks before or after diagnosis, 11 children (5 male [45.5%]; median [range] age, 5.7 [0.1-17.2] years) were seen more than 6 weeks before or after diagnosis, and 19 children (7 male [36.8%]; median [range] age, 7.2 [1.9-16.6] years) did not receive ophthalmological evaluation within at least 6 months from diagnosis. A total of 19 children (21.1%) presented with visual symptoms as first sign leading to the diagnosis of a brain tumor. Children who presented with visual symptoms (odds ratio [OR], 22.52; 95% confidence interval [CI], 4.90-103.60) and/or hydrocephalus (OR, 3.60; 95% CI, 1.38-9.36) at diagnosis were more often seen for ophthalmological evaluation. The most common abnormal ophthalmological findings were eye movement disorders (66.0%), papilledema (44.1%), and visual field defects (58.1%). Eye movement disorders occurred more frequently in patients with an infratentorial tumor (OR, 4.71; 95% CI, 1.03-21.65). The risk of papilledema was associated with older age (OR, 1.19; 95% CI, 1.05-1.34), hydrocephalus (OR, 9.63; 95% CI, 2.68-34.61), and infratentorial (OR, 9.11; 95% CI, 1.77-46.78) and supratentorial (OR, 13.13; 95% CI, 1.92-89.52) tumors. CONCLUSIONS: In this study, most children with a primary brain tumor underwent ophthalmological evaluation around diagnosis, 21% of the children were not evaluated. The high prevalence of abnormal ophthalmological findings stresses the importance of early standardized ophthalmological evaluation to detect visual impairment and provide timely treatment to potentially prevent permanent visual loss.

Blind spot and visual field anisotropy detection with flicker pupil perimetry across brightness and task variations.

The pupil can be used as an objective measure for testing sensitivities across the visual field (pupil perimetry; PP). The recently developed gaze-contingent flicker PP (gcFPP) is a promising novel form of PP, with improved sensitivity due to retinotopically stable and repeated flickering stimulations, in a short time span. As a diagnostic tool gcFPP has not yet been benchmarked in healthy individuals. The main aims of the current study were to investigate whether gcFPP has the sensitivity to detect the blind spot, and upper versus lower visual field differences that were found before in previous studies. An additional aim was to test for the effects of attentional requirements and background luminance. A total of thirty individuals were tested with gcFPP across two separate experiments. The results showed that pupil oscillation amplitudes were smaller for stimuli presented inside as compared to outside the blind spot. Amplitudes also decreased as a function of eccentricity (i.e., distance to fixation) and were larger for upper as compared to lower visual fields. We measured the strongest and most sensitive pupil responses to stimuli presented on dark- and mid-gray backgrounds, and when observers covertly focused their attention to the flickering stimulus. GcFPP thus evokes pupil responses that are sensitive enough to detect local, and global differences in pupil sensitivity. The findings further encourage (1) the use of a gray background to prevent straylight without affecting gcFPPs sensitivity and (2) the use of an attention task to enhance pupil sensitivity.

Lessons Learned from 23 Years of Experience in Testing Visual Fields of Neurologically Impaired Children.

We sought to investigate the reliability of standard conventional perimetry (SCP) in neurologically impaired (NI) children using the examiner-based assessment of reliability scoring system and to determine the difference in time to diagnosis of a visual field defect between SCP and a behavioural visual field (BVF) test. Patient records of 115 NI children were retrospectively analysed. The full field peritest (FFP) had best reliability with 44% 'good' scores versus 22% for Goldmann perimetry (p < .001). The mean age of NI children able to perform SCP was 8.3 years versus 4.6 years for the BVF test (p < .001). Use of the BVF test may significantly reduce time to diagnosis.

Visual functions in children with craniopharyngioma at diagnosis: A systematic review.

Childhood craniopharyngioma is a rare and slow growing brain tumour, often located in the sellar and suprasellar region. It commonly manifests with visual impairment, increased intracranial pressure and hypothalamic and/or pituitary deficiencies. Visual impairment in childhood adversely affects a child's daily functioning and quality of life. We systematically reviewed the literature to provide an extensive overview of the visual function in children with craniopharyngioma at diagnosis in order to estimate the diversity, magnitude and relevance of the problem of visual impairment. Of the 543 potentially relevant articles, 84 studies met our inclusion criteria. Visual impairment at diagnosis was reported in 1041 of 2071 children (50.3%), decreased visual acuity was reported in 546 of 1321 children (41.3%) and visual field defects were reported in 426 of 1111 children (38.3%). Other ophthalmological findings described were fundoscopic (32.5%) and orthoptic abnormalities (12.5%). Variations in ophthalmological testing methods and ophthalmological definitions precluded a meta-analysis. The results of this review confirm the importance of ophthalmological examination in children with craniopharyngioma at diagnosis in order to detect visual impairment and provide adequate support. Future studies should focus on long-term visual follow-up of childhood craniopharyngioma in response to different treatment strategies to provide insight in risks and ways to prevent further loss of vision.

Gaze-Contingent Flicker Pupil Perimetry Detects Scotomas in Patients With Cerebral Visual Impairments or Glaucoma.

Background: The pupillary light reflex is weaker for stimuli presented inside as compared to outside absolute scotomas. Pupillograph perimetry could thus be an objective measure of impaired visual processing. However, the diagnostic accuracy in detecting scotomas has remained unclear. We quantitatively investigated the accuracy of a novel form of pupil perimetry. Methods: The new perimetry method, termed gaze-contingent flicker pupil perimetry, consists of the repetitive on, and off flickering of a bright disk (2 hz; 320 cd/m2; 4° diameter) on a gray background (160 cd/m2) for 4 seconds per stimulus location. The disk evokes continuous pupil oscillations at the same rate as its flicker frequency, and the oscillatory power of the pupil reflects visual sensitivity. We monocularly presented the disk at a total of 80 locations in the central visual field (max. 15°). The location of the flickering disk moved along with gaze to reduce confounds of eye movements (gaze-contingent paradigm). The test lasted ~5 min per eye and was performed on 7 patients with cerebral visual impairment (CVI), 8 patients with primary open angle glaucoma (age >45), and 14 healthy, age/gender-matched controls. Results: For all patients, pupil oscillation power (FFT based response amplitude to flicker) was significantly weaker when the flickering disk was presented in the impaired as compared to the intact visual field (CVI: 12%, AUC = 0.73; glaucoma: 9%, AUC = 0.63). Differences in power values between impaired and intact visual fields of patients were larger than differences in power values at corresponding locations in the visual fields of the healthy control group (CVI: AUC = 0.95; glaucoma: AUC = 0.87). Pupil sensitivity maps highlighted large field scotomas and indicated the type of visual field defect (VFD) as initially diagnosed with standard automated perimetry (SAP) fairly accurately in CVI patients but less accurately in glaucoma patients. Conclusions: We provide the first quantitative and objective evidence of flicker pupil perimetry's potential in detecting CVI-and glaucoma-induced VFDs. Gaze-contingent flicker pupil perimetry is a useful form of objective perimetry and results suggest it can be used to assess large VFDs with young CVI patients whom are unable to perform SAP.

Visual outcome in Sturge-Weber syndrome: a systematic review and Dutch multicentre cohort.

Visual functions in Sturge-Weber syndrome (SWS) may be impaired by glaucoma, diffuse choroidal haemangioma (DCH) or leptomeningeal angioma. The aim of this study was to gain better insight in the visual deficits of SWS patients. A systematic literature search using PubMed and Embase medical databases was performed to identify articles describing visual acuity (VA) and/or visual field (VF) findings in SWS patients. In addition, a Dutch multicentre cohort with 33 SWS patients was collected and the combined results of VA and VF findings are presented. Visual acuity results of 25 studies and VF results of 12 studies were suitable for data extraction. Description of the combination of both VA and VF findings was scarce. Homonymous hemianopia (HH) was present in 42% of SWS patients. Seventy per cent of eyes had a (near) normal vision, while VA of eyes with glaucoma or DCH was severely impaired in 28% and 67%, respectively. In the Dutch cohort, only 18% (6/33) of patients had (near) normal findings of both visual parameters. In addition, half of the patients with glaucoma suffered from a combination of a HH and VA impairment. In conclusion, although SWS patients are exposed to severe functional visual impairment due to the possible cumulative consequences of glaucoma, DCH and cerebral injury, description of the combination of both VA and VF results is scarce in the literature. Particularly, the combination of visual impairment due to glaucoma or DCH, and HH might be invalidating.

Bilateral population receptive fields in congenital hemihydranencephaly.

PURPOSE: Congenital hemihydranencephaly (HH) is a very rare disorder characterised by prenatal near-complete unilateral loss of the cerebral cortex. We investigated a patient affected by congenital right HH whose visual field extended significantly into the both visual hemifields, suggesting a reorganisation of the remaining left visual hemisphere. We examined the early visual cortex reorganisation using functional MRI (7T) and population receptive field (pRF) modelling. METHODS: Data were acquired by means of a 7T MRI while the patient affected by HH viewed conventional population receptive field mapping stimuli. Two possible pRF reorganisation schemes were evaluated: where every cortical location processed information from either (i) a single region of the visual field or (ii) from two bilateral regions of the visual field. RESULTS: In the patient affected by HH, bilateral pRFs in single cortical locations of the remaining hemisphere were found. In addition, using this specific pRF reorganisation scheme, the biologically known relationship between pRF size and eccentricity was found. CONCLUSIONS: Bilateral pRFs were found in the remaining left hemisphere of the patient affected by HH, indicating reorganisation of intra-cortical wiring of the early visual cortex and confirming brain plasticity and reorganisation after an early cerebral damage in humans.

Prediction of visual field defects in newborn infants with perinatal arterial ischemic stroke using early MRI and DTI-based tractography of the optic radiation.

PURPOSE: Visual field (VF) defects are common sequelae of perinatal arterial ischemic stroke (PAIS). The aim of this study was to investigate the predictive value of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) for VF defects following PAIS. METHODS: Nineteen infants with unilateral PAIS, who underwent conventional MRI (T1/T2) and DTI at three months of age and a VF examination later in life (median age 3.2 yrs) were included. Conventional T1-weighted MRI was used to assess asymmetry of the optic radiation (OR). DTI-based tractography of the bilateral OR was performed, and the average fractional anisotropy (FA), axial (λ1), radial (λ23) and mean diffusivity (MD) were extracted. Asymmetry of the OR on MRI and DTI was used as a predictor of VF defects using receiver operating characteristic (ROC) analysis. RESULTS: Of the 19 infants, nine had a normal VF, eight had a VF defect (six hemianopia and two quadrantanopia), and two had an inconclusive VF test. The presence or absence of a VF defect could be correctly predicted using conventional MRI assessment in the majority of the infants, with an area under the curve (AUC) of 0.90 (95% CI 0.66-0.99). Prediction based on DTI parameter asymmetry indices showed an AUC of 0.96 (95% CI 0.74-1.00), 0.78 (95% CI 0.52-0.94), 0.93 (95% CI 0.70-1.00) and 0.90 (95% CI 0.66-0.99) for FA, λ1, λ23 and MD, respectively. CONCLUSIONS: VF defects following PAIS can be reliably predicted by assessment of asymmetry of the OR at three months on conventional MRI and DTI-based tractography with comparable predictive values. Conventional T1-weighted MRI can be used in clinical practice.

[Idiopathic intracranial hypertension and obesity]. / Idiopathische intracraniële hypertensie bij obesitas.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a neurological syndrome characterized by elevated intracranial pressure in the absence of intracerebral abnormalities or hydrocephalus. CASE DESCRIPTION: A 17-year-old girl gained more than 25 kg in weight during treatment with risperidone and subsequently developed headache, diplopia and loss of vision due to IIH. After insertion of a ventriculoperitoneal drain and discontinuation of risperidone she lost weight and her symptoms improved. Her visual functions recovered almost fully during follow-up. CONCLUSION: Patients with IIH are mainly overweight young women who present with raised intracranial pressure evidenced by headache, nausea, vomiting and vision disturbances. Prescribed medication-induced weight gain may lead to IIH. Treatment of IIH should be focused on the prevention of severe and irreversible loss of vision.

Perimetry in young and neurologically impaired children: the Behavioral Visual Field (BEFIE) Screening Test revisited.

IMPORTANCE: Visual field examination in young or neurologically impaired children is a challenge. As a result, the Behavioral Visual Field (BEFIE) Screening Test was developed in 1995. OBJECTIVES: To evaluate the applicability of the BEFIE test in a large population of young or neurologically impaired children, its reliability and consistency of findings across time, and its potential diagnostic value compared with standard conventional perimetry. DESIGN, SETTING, AND PARTICIPANTS: The BEFIE tests were performed at an academic tertiary center and measured the peripheral visual field extension in degrees by observing an individual's response to a stimulus on a graded arc that moved from the periphery to the center of the visual field along different meridians. Patient files from all children who underwent this test were retrospectively analyzed. In total, 1788 BEFIE tests were performed in 835 children (median age, 3.4 years). MAIN OUTCOMES AND MEASURES: Reliability and results of all tests were longitudinally evaluated. The diagnostic value of the BEFIE test was assessed by comparing monocular BEFIE test results with those of standard conventional perimetry in children who underwent both. RESULTS: Of 1788 tests, 74% (95% CI, 72%-76%) were considered reliable from the age of 4 months and older, with increasing success with higher ages; 56% reliable in children younger than 1 year; 71% reliable in children between 1 and 2 years; and more than 75% reliable in children 2 years and older (Spearman r = 0.506; P = .11). Peripheral visual field defects were found in 28% (95% CI, 25%-31%) of all first reliable tests. In 75% of children who underwent serial testing, results were consistent and there were good explanations in the case of discrepancies. Comparison of monocular BEFIE tests with standard conventional perimetry results in 147 eyes yielded a positive predictive value of 98% (95% CI, 94%-100%), negative predictive value of 66% (95% CI, 56%-75%), specificity of 98% (95% CI, 95%-100%), sensitivity of 60% (95% CI, 50%-71%), and superior sensitivity of 80% (95% CI, 70%-91%) when only absolute peripheral visual field defects at standard conventional perimetry were accounted for. CONCLUSIONS AND RELEVANCE: These data suggest that the BEFIE test is a valuable tool to detect peripheral visual field defects when standard conventional perimetry cannot be performed in young or neurologically impaired children.