Longitudinal study of the neurodevelopmental characteristics of treated and untreated nonsyndromic craniosynostosis in infancy.

PURPOSE: Nonsyndromic craniosynostosis (NSC) are a group of congenital disorders sharing premature fusion of one or more of the cranial sutures that restricts and distorts growth of the skull and underlying brain. This study examined the neurodevelopmental sequelae of NSC both prior to and following reconstructive cranial surgery. METHODS: Sixty-four consecutive referrals with mixed forms of untreated NSC aged 4 to 16 months (M = 8.9, SD = 2.9) comprised the pre-operative cohort. Forty-four of these patients aged 6 to 32 months (M = 21.2, SD = 4.5) underwent post-operative developmental evaluation. Neurodevelopmental function was assessed with the mental (Mental Development Index) and motor (Psychomotor Development Index) scales of the Bayley Scales of Infant Development-2nd edition. RESULTS: Children with untreated NSC displayed significantly lower mental (M = 97.5) and motor (M = 87.7) scores than normative expectations, with the distribution of scores also differing significantly from the normative distribution. Post-operatively, children continued to display significantly lower mental (M = 89.5) and motor (M = 88.0) abilities, with mental abilities falling significantly lower than pre-operative levels. An increased prevalence of severe motor delay was found, and no child displayed accelerated development. Subgroup comparisons revealed no differences in mental or motor skills between the primary diagnostic subtypes (sagittal and metopic synostosis) both prior to and following corrective surgery. CONCLUSIONS: NSC is associated with an increased incidence of developmental delay in both treated and untreated conditions. Timing of surgery appears unrelated to developmental outcome.

Karawun: a software package for assisting evaluation of advances in multimodal imaging for neurosurgical planning and intraoperative neuronavigation.

PURPOSE: The neuroimaging research community-which includes a broad range of scientific, medical, statistical, and engineering disciplines-has developed many tools to advance our knowledge of brain structure, function, development, aging, and disease. Past research efforts have clearly shaped clinical practice. However, translation of new methodologies into clinical practice is challenging. Anything that can reduce these barriers has the potential to improve the rate at which research outcomes can contribute to clinical practice. In this article, we introduce Karawun, a file format conversion tool, that has become a key part of our work in translating advances in diffusion imaging acquisition and analysis into neurosurgical practice at our institution. METHODS: Karawun links analysis workflows created using open-source neuroimaging software, to Brainlab (Brainlab AG, Munich, Germany), a commercially available surgical planning and navigation suite. Karawun achieves this using DICOM standards supporting representation of 3D structures, including tractography streamlines, and thus offers far more than traditional screenshot or color overlay approaches. RESULTS: We show that neurosurgical planning data, created from multimodal imaging data using analysis methods implemented in open-source research software, can be imported into Brainlab. The datasets can be manipulated as if they were created by Brainlab, including 3D visualizations of white matter tracts and other objects. CONCLUSION: Clinicians can explore and interact with the results of research neuroimaging pipelines using familiar tools within their standard clinical workflow, understand the impact of the new methods on their practice and provide feedback to methods developers. This capability has been important to the translation of advanced analysis techniques into practice at our institution.

Delayed sagittal sinus tear: a complication of spring cranioplasty for sagittal craniosynostosis.

Spring cranioplasty is now a well-established surgical technique in the treatment of sagittal craniosynostosis. It is widely regarded as a less invasive modality compared with operations such as cranial vault remodeling. Indeed, very few complications have been described in the literature in association with spring cranioplasty. We present a case of delayed sagittal sinus tear with hemorrhage following spring cranioplasty in a 4-month-old patient with sagittal craniosynostosis. Likely causes of the injury are discussed highlighting sagittal sinus injury as a potential risk of spring cranioplasty.

Analysis of morbidity and mortality in surgical management of craniosynostosis.

Multidisciplinary care involving plastic surgery and neurosurgery is generally accepted as optimal to manage craniosynostosis to avoid complications and to identify patients at risk. We conducted a retrospective 30-year review of craniosynostosis surgery at a single major craniofacial institute to establish the rate and predictors of complications. Medical records of 796 consecutive patients who underwent primary surgery for craniosynostosis from 1981 to 2010 at our institute were analyzed for complications. Complications were defined as intraoperative and postoperative adverse events requiring changed management. Reoperation was defined as a repeat transcranial procedure. Multivariate logistic regression was used to identify predictors for complications or revision. Across the years, the procedures evolved from technically simple to complex, which increased complications but better outcomes. Complications occurred in 111 patients (14%), and 33 (5.4%) needed major revision. Multivariate analysis identified multisuture and syndromic craniosynostosis, more recent surgeries, younger age (<9 months), spring-assisted cranioplasty, longer surgery, and greater transfusion as predictors of complications. Patients with syndromic and multisutural craniosynostosis and those operated on younger than 9 months had increased risk of major revision surgery for regression to phenotype. Our experience over 30 years indicates that pediatric transcranial craniosynostosis surgery can be safely carried out in our tertiary referral center. There were no deaths from primary surgery, and complication and reoperation rates mirror those of other published studies. Syndromic and complex craniosynostosis predicted both complications and need for major revision. Spring cranioplasty was associated with higher complications. Overall results support a recommended age for craniosynostosis surgery between 9 and 12 months.

Changing epidemiology of nonsyndromic craniosynostosis and revisiting the risk factors.

Recent studies in Europe and the United States report increased incidence of metopic synostosis. Whether a similar trend had occurred in Australia remains unknown. This research aimed to determine changes in incidence and subtypes of craniosynostosis in Victoria and to identify perinatal risk factors. A retrospective audit of patients (n = 522) presenting to the Royal Children's Hospital in Melbourne with nonsyndromic craniosynostosis from 1982 to 2008 was undertaken. Perinatal data were sourced from the Victorian Perinatal Data Collection. The changes in incidence of craniosynostosis subtypes were calculated based on Poisson regression, and risk factors for craniosynostosis and subtypes were analyzed by univariate logistic regression analysis. The prevalence of nonsyndromic craniosynostosis was 3.1 in 10,000 live births in Victoria. On average, the incidence of nonsyndromic craniosynostosis increased by 2.5% per year among Victorian live births. Over 25 years, metopic synostosis incidence significantly increased by 7.1% per year in the population of Victoria, outpacing other subtypes. The risk factors for metopic synostosis include being male, multiple births (ie, twins), preterm gestation, low birth weight, high maternal age, and emergency cesarean birth. This study revealed a true increase in incidence of metopic synostosis in Victoria, which could be a result of increased frequency of multiple births, preterm gestation, low birth weight, and high maternal age in the Victorian population from 1982 to 2008. The incidence of other nonsyndromic craniosynostoses, which include sagittal, unicoronal, and multisutural craniosynostoses, however, has remained unchanged.

Assessment of intraoperative diffusion EPI distortion and its impact on estimation of supratentorial white matter tract positions in pediatric epilepsy surgery.

The effectiveness of correcting diffusion Echo Planar Imaging (EPI) distortion and its impact on tractography reconstruction have not been adequately investigated in the intraoperative MRI setting, particularly for High Angular Resolution Diffusion Imaging (HARDI) acquisition. In this study, we evaluated the effectiveness of EPI distortion correction using 27 legacy intraoperative HARDI datasets over two consecutive surgical time points, acquired without reverse phase-encoded data, from 17 children who underwent epilepsy surgery at our institution. The data was processed with EPI distortion correction using the Synb0-Disco technique (Schilling et al., 2019) and without distortion correction. The corrected and uncorrected b0 diffusion-weighted images (DWI) were first compared visually. The mutual information indices between the original T1-weighted images and the fractional anisotropy images derived from corrected and uncorrected DWI were used to quantify the effect of distortion correction. Sixty-four white matter tracts were segmented from each dataset, using a deep-learning based automated tractography algorithm for the purpose of a standardized and unbiased evaluation. Displacement was calculated between tracts generated before and after distortion correction. The tracts were grouped based on their principal morphological orientations to investigate whether the effects of EPI distortion vary with tract orientation. Group differences in tract distortion were investigated both globally, and regionally with respect to proximity to the resecting lesion in the operative hemisphere. Qualitatively, we observed notable improvement in the corrected diffusion images, over the typically affected brain regions near skull-base air sinuses, and correction of additional distortion unique to intraoperative open cranium images, particularly over the resection site. This improvement was supported quantitatively, as mutual information indices between the FA and T1-weighted images were significantly greater after the correction, compared to before the correction. Maximum tract displacement between the corrected and uncorrected data, was in the range of 7.5 to 10.0 mm, a magnitude that would challenge the safety resection margin typically tolerated for tractography-informed surgical guidance. This was particularly relevant for tracts oriented partially or fully in-line with the acquired diffusion phase-encoded direction. Portions of these tracts passing close to the resection site demonstrated significantly greater magnitude of displacement, compared to portions of tracts remote from the resection site in the operative hemisphere. Our findings have direct clinical implication on the accuracy of intraoperative tractography-informed image guidance and emphasize the need to develop a distortion correction technique with feasible intraoperative processing time.

Global Epidemiology of Craniosynostosis: A Systematic Review and Meta-Analysis.

OBJECTIVE: Craniosynostosis leads to craniofacial deformity and may result in raised intracranial pressure, neurocognitive deficits, and psychosocial issues if left untreated. The global epidemiology of craniosynostosis is unknown. We conducted a meta-analysis to estimate global birth prevalence. METHODS: PubMed, Embase, and Scopus were searched. Articles were screened by title and abstract and then full text. Meta-analysis of birth prevalence was conducted. Birth prevalence figures were combined with metrics detailing the number of births in 2019 to estimate the number of children worldwide born with craniosynostosis annually. RESULTS: Of 1378 resultant articles, 24 studies were included, including 20 providing data for craniosynostosis overall and 9 for nonsyndromic craniosynostosis. World Health Organization regions of included studies were 9 (37.5%) European Region, 8 (33.3%) Region of the Americas, 4 (16.7%) Western Pacific region, 2 (8.3%) African Region, and 1 (4.2%) Eastern Mediterranean Region. Lower middle-income countries represented only 4% of study manuscripts. The overall birth prevalence of craniosynostosis was 5.9 per 10,000 live births (20 studies; 95% confidence interval [CI]: 3.9, 8.4; I2 = 100%). The birth prevalence of nonsyndromic craniosynostosis was 5.2 per 10,000 live births (9 studies; 95% CI: 3.4, 7.3; I2 = 98%). The number of children born globally with craniosynostosis in 2019 was estimated to be 84,665 (95% CI: 55,965, 120,540), including 72,857 (95% CI: 47,637, 120,280) with nonsyndromic craniosynostosis. CONCLUSIONS: Craniosynostosis is a common condition that affects the neurocognitive and craniofacial skeletal development of children worldwide. Initiatives to scale up capacity for craniosynostosis epidemiologic research and clinical care are warranted, particularly in low- and middle-income countries.

Pediatric pineoblastoma: A pooled outcome study of North American and Australian therapeutic data.

Background: Pineoblastoma is a rare brain tumor usually diagnosed in children. Given its rarity, no pineoblastoma-specific trials have been conducted. Studies have included pineoblastoma accruing for other embryonal tumors over the past 30 years. These included only occasional children with pineoblastoma, making clinical features difficult to interpret and determinants of outcome difficult to ascertain. Patients and Methods: Centrally or independently reviewed series with treatment and survival data from North American and Australian cases were pooled. To investigate associations between variables, Fisher's exact tests, Wilcoxon-Mann-Whitney tests, and Spearman correlations were used. Kaplan-Meier plots, log-rank tests, and Cox proportional hazards models were used in survival analyses. Results: We describe a pooled cohort of 178 pineoblastoma cases from Children's Oncology Group (n = 82) and institutional series (n = 96) over 30 years. Children <3 years of age have significantly worse survival compared to older children, with 5-year progression-free survival (PFS) and overall survival (OS) estimates of 13.5 ± 5.1% and 16.2 ± 5.3%, respectively, compared with 60.8 ± 5.6% and 67.3 ± 5.0% for ≥3 years old (both P < .0001). Multivariable analysis showed male sex was associated with worse PFS in children <3 years of age (hazard ratio [HR] 3.93, 95% CI 1.80-8.55; P = .0006), suggestive of sex-specific risks needing future validation. For children ≥3 years of age, disseminated disease at diagnosis was significantly associated with an inferior 5-year PFS of 39.2 ± 9.7% (HR 2.88, 95% CI 1.52-5.45; P = .0012) and 5-year OS of 49.8 ± 9.1% (HR 2.87, 95% CI 1.49-5.53; P = .0016). Conclusion: Given the rarity of this tumor, prospective, collaborative international studies will be vital to improving the long-term survival of these patients.

One-Stage, Limited-Resection Epilepsy Surgery for Bottom-of-Sulcus Dysplasia.

OBJECTIVE: To determine whether 1-stage, limited corticectomy controls seizures in patients with MRI-positive, bottom-of-sulcus dysplasia (BOSD). METHODS: We reviewed clinical, neuroimaging, electrocorticography (ECoG), operative, and histopathology findings in consecutively operated patients with drug-resistant focal epilepsy and MRI-positive BOSD, all of whom underwent corticectomy guided by MRI and ECoG. RESULTS: Thirty-eight patients with a median age at surgery of 10.2 (interquartile range [IQR] 6.0-14.1) years were included. BOSDs involved eloquent cortex in 15 patients. Eighty-seven percent of patients had rhythmic spiking on preresection ECoG. Rhythmic spiking was present in 22 of 24 patients studied with combined depth and surface electrodes, being limited to the dysplastic sulcus in 7 and involving the dysplastic sulcus and gyral crown in 15. Sixty-eight percent of resections were limited to the dysplastic sulcus, leaving the gyral crown. Histopathology was focal cortical dysplasia (FCD) type IIb in 29 patients and FCDIIa in 9. Dysmorphic neurons were present in the bottom of the sulcus but not the top or the gyral crown in 17 of 22 patients. Six (16%) patients required reoperation for postoperative seizures and residual dysplasia; reoperation was not correlated with ECoG, neuroimaging, or histologic abnormalities in the gyral crown. At a median 6.3 (IQR 4.8-9.9) years of follow-up, 33 (87%) patients are seizure-free, 31 off antiseizure medication. CONCLUSION: BOSD can be safely and effectively resected with MRI and ECoG guidance, corticectomy potentially being limited to the dysplastic sulcus, without need for intracranial EEG monitoring and functional mapping. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that 1-stage, limited corticectomy for BOSD is safe and effective for control of seizures.

Communication Empowerment Framework: An integrative framework to support effective communication and interaction between carers and people living with dementia.

OBJECTIVES: To demonstrate the power of integrating three theoretical perspectives (Mentalization Theory, Perceptual Control Theory and the Communicative Impact model), which jointly illuminate the communication challenges and opportunities faced by family carers of people with dementia. To point the way to how this framework informs the design and delivery of carer communication and interaction training. METHOD: Conceptual synthesis based on a narrative review of relevant literature, supported by examples of family carers. RESULTS: We use the conceptual models to show how the capacity to mentalize ("holding mind in mind") offers a greater sense of control over internal and external conflicts, with the result that they can be deescalated in pursuit of mutual goals. CONCLUSIONS: The integrative conceptual framework presented here highlights specific psychological and relational mechanisms that can be targeted through carer training to enhance communication with a person living with dementia.

Pediatric Neuroschistosomiasis: A Case Report and Review of the Literature.

Neuroschistosomiasis is a rare but severe manifestation of Schistosoma infection. Diagnosis is challenging and surgical biopsy is often required to confirm diagnosis and exclude malignancy. We present a pediatric case of presumed pseudotumoral cerebral schistosomiasis secondary to Schistosoma mansoni with an excellent therapeutic response to empirical praziquantel and corticosteroid treatment.

Outcome of vein of Galen malformation presenting in the neonatal period.

OBJECTIVE: Vein of Galenaneurysmal malformation (VGAM) is a rare but important congenital malformation presenting to neonatal intensive care units (NICUs), and with a change from surgical to endovascular management, survival for this condition has improved. However, there is little reported about the medical management decisions of infants with this condition and the associated long-term neurodevelopmental outcomes. We aim to report a single centre experience of both acute treatment and long-term outcomes of VGAM for those infants admitted to our NICU soon after birth. DESIGN: Retrospective cohort study over a 15-year period from 2001 to 2015 inclusive. SETTING: A quaternary NICU at The Royal Children's Hospital, Melbourne, Australia. PARTICIPANTS: 24 newborn infants referred for management of VGAM. There were no eligibility criteria set for this study; all presenting infants were included. INTERVENTIONS: None. MAIN OUTCOMES MEASURES: Clinical neuroimaging data were gathered. Surviving children were formally assessed with a battery of tests administered by a neuropsychologist and occupational therapist/physiotherapist at various ages across early to middle childhood. RESULTS: Fifteen neonates with VGAM did not survive beyond their NICU admission. 10 of these were not offered endovascular intervention. Of the nine surviving infants, only one had a normal neurodevelopmental outcome. CONCLUSIONS: The mortality of VGAM presenting in the neonatal period was high, and rates of normal neurodevelopmental outcome for survivors were low. These findings contribute to our understanding of which neonates should be treated and highlights the importance of providing clinical neurodevelopmental follow-up to survivors beyond their infant years.

Second-hit DEPDC5 mutation is limited to dysmorphic neurons in cortical dysplasia type IIA.

Focal cortical dysplasia (FCD) causes drug-resistant epilepsy and is associated with pathogenic variants in mTOR pathway genes. How germline variants cause these focal lesions is unclear, however a germline + somatic "2-hit" model is hypothesized. In a boy with drug-resistant epilepsy, FCD, and a germline DEPDC5 pathogenic variant, we show that a second-hit DEPDC5 variant is limited to dysmorphic neurons, and the somatic mutation load correlates with both dysmorphic neuron density and the epileptogenic zone. These findings provide new insights into the molecular and cellular correlates of FCD determining drug-resistant epilepsy and refine conceptualization of the epileptogenic zone.

Australian Clinical Consensus Guideline: The diagnosis and acute management of childhood stroke.

Stroke is among the top 10 causes of death in children and survivors carry resulting disabilities for decades, at substantial cost to themselves and their families. Children are not currently able to access reperfusion therapies, due to limited evidence supporting safety and efficacy and long diagnostic delays. The Australian Clinical Consensus Guideline for the Diagnosis and Acute Management of Childhood Stroke was developed to minimize unwarranted variations in care and document best evidence on the risk factors, etiologies, and conditions mimicking stroke that differ from adults. Clinical questions were formulated to inform systematic database searches from 2007 to 2017, limited to English and pediatric studies. SIGN methodology and the National Health and Medical Research Council system were used to screen and classify the evidence. The Grades of Recommendation, Assessment, Development, and Evaluation system (GRADE) was used to grade evidence as strong or weak. The Guideline provides more than 60 evidence-based recommendations to assist prehospital and acute care clinicians in the rapid identification of childhood stroke, choice of initial investigation, to confirm diagnosis, determine etiology, selection of the most appropriate interventions to salvage brain at risk, and prevent recurrence. Recommendations include advice regarding the management of intracranial pressure and congenital heart disease. Implementation of the Guideline will require reorganization of prehospital and emergency care systems, including the development of regional stroke networks, pediatric Code Stroke, rapid magnetic resonance imaging and accreditation of primary pediatric stroke centers with the capacity to offer reperfusion therapies. The Guideline will allow auditing to benchmark timelines of care, access to acute interventions, and outcomes. It will also facilitate the development of an Australian childhood stroke registry, with data linkage to international registries, to allow for accurate data collection on stroke incidence, treatment, and outcomes.

Chiari-like tonsillar herniation associated with intracranial hypotension in Marfan syndrome. Case report.

The authors describe the case of a 12-year-old girl with Marfan syndrome, sacral dural ectasia, and tonsillar herniation, who presented with headache. Initially, it was hypothesized that the headaches were secondary to the tonsillar herniation, and the patient consequently underwent surgical decompression of the foramen magnum. Postoperatively, the patient's condition did not improve, and additional magnetic resonance (MR) imaging demonstrated evidence of a cerebrospinal fluid (CSF) leak at the level of the dural ectasia. It was surmised that the girl's symptoms were due to spontaneous intracranial hypotension (SIH) and that the tonsillar herniation was caused by the leakage. The patient responded well to application of a blood patch at the level of the demonstrated leak, and her headache resolved. This appears to be the first reported case of a patient with Marfan syndrome presenting with a symptomatic spontaneous CSF leak complicated by tonsillar herniation. In this rare association of SIH and connective tissue disorders, recognition of the clinical signs and typical MR imaging features of SIH may lead to more appropriate and less invasive treatment, potentially avoiding surgery.

Thalamic tumors in children: a reappraisal.

OBJECT: Two to five percent of pediatric brain tumors are located in the thalamus. The optimal management for these tumors remains unclear. The aim of this study was to determine whether clinical and neuroimaging features could guide treatment, and to what extent these features, together with histological diagnosis and treatment modalities, influenced survival. METHODS: The records of 69 children who presented with a thalamic tumor between 1989 and 2003 were retrospectively reviewed. Three groups of tumors were analyzed separately: 1) unilateral thalamic tumors (54 lesions); 2) thalamopeduncular tumors (six); and 3) bilateral thalamic tumors (nine). In the patients in whom a unilateral thalamic tumor was diagnosed, 33 had an astrocytic tumor. Of the 54 patients, 32 had a low-grade and 22 had a high-grade tumor. The survival rate was significantly better for patients with the following characteristics: symptom duration longer than 2 months (p < 0.001), lesions with low-grade histological features (p = 0.003), and tumor excision greater than 90% at surgery (p = 0.04). The perioperative morbidity and mortality rates were 37 and 4%, respectively. Fifty-four percent of the patients in this group had a long-term and independent survival. The thalamopeduncular tumors were mostly pilocytic astrocytomas, which had a good prognosis following surgery. The bilateral thalamic tumors in this series were mainly low-grade astrocytic lesions, and more than half of the children attained long-term survival (mean follow-up duration 4.5 years). CONCLUSIONS: The majority of tumors arising in the thalamus are astrocytic, of which less than half are high-grade lesions. Histological evaluations should be performed in all patients in whom resection is being considered for discrete lesions. Long-term survival is possible in patients with these tumors.

Pediatric craniopharyngiomas: classification and treatment according to the degree of hypothalamic involvement.

OBJECT: The current treatment of craniopharyngiomas is evolving into one of a multimodal approach in which the aim is disease control and improved preservation of quality of life (QOL). To date, an appropriate classification system with which to individualize treatment is absent. The objectives of this study were to identify preoperative prognostic factors in patients with craniopharyngiomas and to develop a risk-based treatment algorithm. METHODS: The authors reviewed data obtained in a retrospective cohort of 66 children (mean age 7.4 years, mean follow-up period 7 years) who underwent resection between 1984 and 2001. Postoperative recurrence rates, vision status, and endocrine function were consistent with those reported in the literature. The postoperative morbidity was related to hypothalamic dysfunction. The preoperative magnetic resonance imaging grade, clinically assessed hypothalamic function, and the sugeon's operative experience (p = 0.007, p = 0.047, p = 0.035, respectively) significantly predicted poor outcome. Preoperative hypothalamic grading was used in a prospective cohort of 22 children (mean age 8 years, mean follow-up period 1.2 years) treated between 2002 and 2004 to stratify patients according to whether they underwent gross-total resection (GTR) (20%), complete resection avoiding the hypothalamus (40%), or subtotal resection (STR) (40%). In cases in which residual disease was present, the patient underwent radiotherapy. There have been no new cases of postoperative hyperphagia, morbid obesity, or behavioral dysfunction in this prospective cohort. CONCLUSIONS: For many children with craniopharyngiomas, the cost of resection is hypothalamic dysfunction and a poor QOL. By using a preoperative classification system to grade hypothalamic involvement and stratify treatment, the authors were able to minimize devastating morbidity. This was achieved by identifying subgroups in which complete resection or STR, performed by an experienced craniopharyngioma surgeon and with postoperative radiotherapy when necessary, yielded better overall results than the traditional GTR.

Formulaic Sequences as a Regulatory Mechanism for Cognitive Perturbations During the Achievement of Social Goals.

This paper explores two questions central to understanding the nature of formulaic sequences: (1) What are they for? and (2) What determines how many there are? The "Communicative Impact" model draws into a single account how language is shaped by cognitive processing on the one hand and socio-interactional function on the other: Formulaic sequences play a range of coordinated roles in neutralizing unanticipated perturbations in the cognitive management of language, so the speaker's socio-interactional goals can still be achieved. One role involves compensatory actions to sustain fluency. However, these actions are themselves context-sensitive, so the balance of types of formulaic sequence will vary according to situation. The model applies equally to temporary cognitive pressure and chronic problems such as dementia and limited linguistic competency in a foreign language.

Tectal plate lesions in children.

OBJECT: The authors characterized the clinical course of tectal plate lesions in a group of pediatric patients to identify the prognostic factors at presentation that predict progression, in an attempt to differentiate tectal hamartomas from tumors. METHODS: A retrospective review was conducted of the management of tectal plate lesions in children since the advent of magnetic resonance (MR) imaging at the authors' hospital (1984-2003). The lesion volume seen on MR images, the clinical and radiological features at presentation, and the clinical course of the population were analyzed for correlations. Forty children with tectal lesions presented in the typical delayed fashion (mean 8.5 months) with symptoms referable to hydrocephalus (93%). Fourteen children whose tumors demonstrated radiological progression (enlargement, contrast enhancement, or cystic change) were treated surgically. Histologically, 80% of the surgically treated lesions were low grade (with the other 20% consisting of one dysplasia, one high-grade tumor, and one unidentified tumor). Five patients required a second operation and one required a third. One patient died of a high-grade astrocytoma after undergoing surgery and radiotherapy; the other 39 patients remain clinically stable. The only factor predictive of tumor enlargement was lesion volume at presentation (p = 0.002). Distribution analysis revealed three subgroups based on lesion volume (< 4, 4-10, and > 10 cm3), which correlated with the clinical course of the disease. CONCLUSIONS: Children with tectal lesions should undergo contrast-enhanced MR imaging and volume assessment at the time of presentation. After hydrocephalus has been managed with endoscopic third ventriculostomy, these children require prolonged, close clinical and radiological surveillance. Lesions with a volume less than 4 cm3 were likely to be hamartomas and followed a predominantly benign course, with few atypical cases progressing. All large lesions, defined as having a volume greater than 10 cm3 at presentation, eventually required treatment, and all were histologically determined to be tumors. An argument is made for earlier treatment of larger lesions with the aim of improving outcome.