Neuroimaging in Nonsyndromic Craniosynostosis: Key Concepts to Unlock Innovation.

Craniosynostoses (CRS) are caused by the premature fusion of one or more cranial sutures, with isolated nonsyndromic CRS accounting for most of the clinical manifestations. Such premature suture fusion impacts both skull and brain morphology and involves regions far beyond the immediate area of fusion. The combined use of different neuroimaging tools allows for an accurate depiction of the most prominent clinical-radiological features in nonsyndromic CRS but can also contribute to a deeper investigation of more subtle alterations in the underlying nervous tissue organization that may impact normal brain development. This review paper aims to provide a comprehensive framework for a better understanding of the present and future potential applications of neuroimaging techniques for evaluating nonsyndromic CRS, highlighting strategies for optimizing their use in clinical practice and offering an overview of the most relevant technological advancements in terms of diagnostic performance, radiation exposure, and cost-effectiveness.

Primary leptomeningeal medulloblastoma: a case-based review.

BACKGROUND: Medulloblastoma (MB) is the most common malignant pediatric brain tumor, accounting for 40% of childhood tumors in posterior fossa. Metastatic disease, occurring in 20-30% of all medulloblastoma cases at diagnosis, is largely exclusive to the leptomeninges. On the contrary, primary leptomeningeal medulloblastoma or so-called chameleon medulloblastoma, defined by the absence of a detectable intraparenchymal lesion with a widespread diffusion along leptomeninges, is a rare entity of difficult diagnosis with only a few cases reported in literature. METHODS AND RESULTS: A comprehensive literature search of three databases (PubMed, Ovid Medline, and Ovid Embase) have been conducted to identify pertinent papers focusing on the diagnostic process, management, and treatment of primary leptomeningeal medulloblastoma and its peculiar features. To our knowledge, only eight cases are described in literature, including five pediatric patients and three adults, two of which with the initial involvement of the spinal cord. In addition, we report another two pediatric cases, showing widespread primary diffusion along leptomeninges of brain and spinal cord. Finally, we analyze in-depth the peculiar morphological MRI features of this tumor. CONCLUSION: The classification and treatment of medulloblastomas are likely to change in the coming years due to new insights into the molecular biology of medulloblastoma. Primary leptomeningeal medulloblastoma could represent another potential challenge for biologists to start exploring the underlying mechanisms of this different clinical and pathological entity, with different implications for diagnosis and its management.

Neuroendoscopic treatment of symptomatic cyst of the septum pellucidum in children: A case series.

BACKGROUND: Symptomatic cysts of the septum pellucidum (CSP) are extremely rare in children and surgical indications are not well defined. A very careful clinical and neuroradiologic evaluation is necessary to consider a patient for surgical indication. METHODS: We present a surgical series of 7 pediatric patients. Clinical and radiological features of the patients, including clinical presentation, previous treatment, pre, and post-operative MRI, immediate postoperative, neuropsychiatric assessment, and outcomes were reviewed. RESULTS: There were 5 males and 2 females (mean age 8 yrs). Five patients presented a history of severe intermittent headaches, two of them were admitted with acute symptoms of raised intracranial pressure. One patient presented Epilepsy and ADHD and one patient had severe psychosis. Overall, psychiatric disorders were diagnosed in six patients, three patients had Intellectual Disability (ID). In all cases, the cyst presented a ballooning feature, with a mean volume of 18,36 cm3 (range 10,62-28,5) and significant lateral bulging of both layers. All were operated on endoscopically without complications. After surgery, a very significant decrease in cyst volume was observed (mean volume 5,68 cm3; range 3,18-10,1) with complete disappearance of the ballooning aspect. Headaches resolved in all patients. In two patients operated in emergency papilloedema and vision improved in the first week after surgery. No recurrence of the cysts was noted during follow-up in all patients. CONCLUSIONS: CSP may be associated with behavioral or psychiatric problems also in children. Neuroendoscopic surgery is a safe and effective therapeutic modality to treat CSP presenting with symptoms and signs of intracranial hypertension with good clinical results.

Neuroimaging in tuberous sclerosis complex.

INTRODUCTION: Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder affecting multiple systems, due to inactivating mutations of TSC1 or TSC2 mTOR pathway genes. Neurological manifestations are observed in about 95% cases, representing the most frequent cause of morbidity and one of the most common causes of mortality. BACKGROUND: Neuroimaging is crucial for early diagnosis, monitoring, and management of these patients. While computed tomography is generally used as first-line investigation at emergency department, magnetic resonance imaging is the reference method to define central nervous system involvement and investigate subtle pathophysiological alterations in TSC patients. PURPOSE: Here, we review the state-of-the-art knowledge in TSC brain imaging, describing conventional findings and depicting the role of advanced techniques in providing new insights on the disease, also offering an overview on future perspectives of neuroimaging applications for a better understanding of disease pathophysiology.

Brain Herniation into the Subdural Space: Rare Iatrogenic Complication of Treatment of a Giant Calcified Subdural Hematoma.

BACKGROUND: Chronic subdural hematoma associated with dural calcifications in previously pediatric shunted patients is a rare condition. The inner dural membrane opening can lead to progressive brain herniation into the subdural space due to brain reexpansion. CASE DESCRIPTION: A 15-year-old boy, previously shunted at birth for congenital hydrocephalus, presented with a giant chronic right hemispheric subdural hematoma. After 2 surgical procedures in which the subdural calcified neomembrane was opened and a subdural shunt was implanted, he developed a cortical brain herniation into the subdural space, resulting in brain ischemia and upper limb weakness and vomiting. The final surgical treatment consisted of an extensive wide peeling of visceral calcified membrane mutually to programmable valve placement along the subduroperitoneal shunt, in order to create a positive gradient between the subdural space and the ventricles. The patient experienced a prompt clinical improvement. CONCLUSIONS: This case illustrates a rare complication of the treatment of a chronic subdural hematoma caused by insufficient opening of the calcified inner mambrane of the hematoma and encouraged by gradient pressure between the ventricular and subdural compartments. To avoid this complication, it is preferable to not open a thick, calcified, unelastic inner membrane. However, in case of lack of clinical and radiologic improvement, it may become necessary to open it: a wide opening should be attempted, in order to prevent brain strangulation.

Interhypothalamic Adhesion as Cause of Aborted Third Ventriculostomy: Neuroradiologic and Neuroendoscopic Considerations in Pediatric Case.

BACKGROUND: Interhypothalamic adhesions (IHAs) are horizontally oriented parenchymal bands of tissue connecting the medial hypothalamic regions across the third ventricle. They can be assessed with high-resolution magnetic resonance (MR) techniques. CASE DESCRIPTION: We report MR and neuroendoscopic features of IHA in a 3-year-old boy without symptoms referable to the hypothalamus. He presented with obstructive hydrocephalus secondary to posterior fossa tumor. An endoscopic third ventriculostomy (ETV) was attempted but not performed because of the presence of a thick IHA, which prevented an approach to the floor of the third ventricle. During the procedure the patient also experienced supraventricular tachycardia. The procedure was aborted, and an external ventricular drainage was left in the ventricles until resolution of hydrocephalus after posterior fossa surgery. To the best of our knowledge, no study has previously described in detail endoscopic images of IHA. CONCLUSIONS: MR imaging allows one to preoperatively identify most anatomic anomalies of the ventricular system and the floor of the third ventricle. However, an IHA that may prevent an approach to the floor of the third ventricle due to his thickness may be missed. This can be recognized only on direct vision, underlining the importance of endoscopy in neurosurgery.

Surgical treatment of thalamic tumors in children.

OBJECTIVE In the past, the outcome of surgical treatment for thalamic tumor was poor. These lesions were often considered inoperable. However, contemporary microsurgical techniques, together with improvements in neuroimaging that enable accurate presurgical planning, allow resection to be accomplished in a safer way. METHODS The medical records, imaging studies, and operative and pathology reports obtained for pediatric patients who were treated for thalamic tumors at the authors' department were reviewed. Neuronavigation and intraoperative monitoring of motor and somatosensory evoked potentials were used. Preoperative tractography, which helped to identify internal capsule fibers, was very important in selecting the surgical strategy. Postoperatively, an MRI study performed within 24 hours was used to assess the extent of tumor resection as partial (≤ 90%), subtotal (> 90%), or gross total (no residual tumor). RESULTS Since 2002, 27 children with thalamic tumors have been treated at the authors' department. There were 9 patients with unilateral thalamic tumors, 16 with thalamopeduncular tumors, and 2 with a bilateral tumor. These last 2 patients underwent endoscopic biopsy and implantation of a ventriculoperitoneal shunt. Thirty-nine tumor debulking procedures were performed in the remaining 25 patients. Different surgical approaches were chosen according to tumor location and displacement of the posterior limb of the internal capsule (as studied on axial T2-weighted MRI) and corticospinal tract (as studied on diffusion tensor imaging with tractography, after it became available). In 12 cases, multiple procedures were performed; in 7 cases, these were done as part of a planned multistage resection. In the remaining 5 cases, the second procedure was necessary because of late recurrence or regrowth of residual tumor. At the end of the surgical phase, of 25 patients, 15 (60%) achieved a gross-total resection, 4 (16%) achieved a subtotal resection, and 6 (24%) achieved a partial resection. Eighteen patients harbored low-grade tumors in our series. In this group, the mean follow-up was 45 months (range 4-132 months). At the end of follow-up, 1 patient was dead, 12 patients were alive with no evidence of disease, 4 patients were alive with stable disease, and 1 was lost to follow-up. All patients were independent in their daily lives. The outcome of high-grade tumors in 9 patients was very poor: 2 patients died immediately after surgery, 6 died of progressive disease, and 1 was alive with residual disease at the time of this report. CONCLUSIONS This institutional review seems to offer further evidence in favor of attempts at radical resection in pediatric patients harboring unilateral thalamic or thalamopeduncular tumors. In low-grade gliomas, radical resection in a single or staged procedure can be curative without complementary treatment. Recurrences or residual regrowth can be safely managed surgically. In high-grade tumors, the role of and opportunity for radical or partial resection remains a matter of debate.

Acute triventricular hydrocephalus caused by choroid plexus cysts: a diagnostic and neurosurgical challenge.

OBJECTIVE Intraventricular choroid plexus cysts are unusual causes of acute hydrocephalus in children. Radiological diagnosis of intraventricular choroid plexus cysts is difficult because they have very thin walls and fluid contents similar to CSF and can go undetected on routine CT studies. METHODS This study reports the authors' experience with 5 patients affected by intraventricular cysts originating from the choroid plexus. All patients experienced acute presentation with rapid neurological deterioration, sometimes associated with hypothalamic dysfunction, and required urgent surgery. In 2 cases the symptoms were intermittent, with spontaneous remission and sudden clinical deteriorations, reflecting an intermittent obstruction of the CSF pathway. RESULTS Radiological diagnosis was difficult in these cases because a nonenhanced CT scan revealed only triventricular hydrocephalus, with slight lateral ventricle asymmetry in all cases. MRI with driven-equilibrium sequences and CT ventriculography (in 1 case) allowed the authors to accurately diagnose the intraventricular cysts that typically occupied the posterior part of the third ventricle, occluding the aqueduct and at least 1 foramen of Monro. The patients were managed by urgent implantation of an external ventricular drain in 1 case (followed by endoscopic surgery, after completing a diagnostic workup) and by urgent endoscopic surgery in 4 cases. Endoscopic surgery allowed the shrinkage and near-complete removal of the cysts in all cases. Use of neuronavigation and a laser were indispensable. All procedures were uneventful, resulting in restoration of normal neurological conditions. Long-term follow-up (> 2 years) was available for 2 patients, and no complications or recurrences occurred. CONCLUSIONS This case series emphasizes the necessity of an accurate and precise identification of the possible causes of triventricular hydrocephalus. Endoscopic surgery can be considered the ideal treatment of choroid plexus cysts in children.

Symptomatic epidural compression in infants with neuroblastoma: a single-center experience with 5 cases.

Infants affected by neuroblastoma with symptomatic epidural compression require early diagnosis and appropriate treatment to avoid severe late complications. However, no established guidelines are available regarding the optimal treatment of these patients. We describe 5 such infants. The interval between the onset of symptoms and tumor diagnosis was 3 to 8 days in 4/5 cases. None developed paraplegia before or after treatment. Treatment for epidural compression included first-line laminoplasty followed by chemotherapy in 3 patients, and chemotherapy first in the remaining 2. To date, all are alive and none have developed severe complications after a follow-up of 9 to 39 months (median, 20).

Hydrocephalus in Dandy-Walker malformation.

INTRODUCTION: Even if the first description of Dandy-Walker dates back 1887, difficulty in the establishment of correct diagnosis, especially concerning differential diagnosis with other types of posterior fossa CSF collection, still persists. Further confusion is added by the inclusion, in some classification, of different malformations with different prognosis and therapeutic strategy under the same label of "Dandy-Walker". METHODS: An extensive literature review concerning embryologic, etiologic, pathogenetic, clinical and neuroradiological aspects has been performed. Therapeutic options, prognosis and intellectual outcome are also reviewed. CONCLUSION: The correct interpretation of the modern neuroradiologic techniques, including CSF flow MR imaging, may help in identifying a "real" Dandy-Walker malformation. Among therapeutical strategies, single shunting (ventriculo-peritoneal or cyst-peritoneal shunts) appears effective in the control of both ventricle and cyst size. Endoscopic third ventriculostomy may be considered an acceptable alternative, especially in older children, with the aim to reduce the shunt-related problems. Prognosis and intellectual outcome mostly depend on the presence of associated malformations, the degree of vermian malformation and the adequate control of hydrocephalus.

Optic pathway ganglioglioma with intraventricular cyst.

Gangliogliomas originating in the optic pathway are rare, with less than 20 cases reported in the literature. Diffuse, bilateral involvement of the entire optico-chiasmatic pathway is exceptional. We report a case of suprasellar ganglioglioma that involved bilaterally the entire pregeniculate optic pathway. The patient presented with visual deficit, nystagmus, papilledema and acute biventricular hydrocephalus secondary to intraventricular cyst that required urgent surgery. Endoscopic fenestration of the tumoral cyst allowed control of hydrocephalus and decompression of the visual pathway. Through microsurgical procedure by pterional approach, partial removal of the tumor and histological diagnosis were accomplished 1 week later. The patient was managed with chemotherapy and radiation therapy. He presents stable residual disease at 4-year follow-up. Embryological origins, histological features, neuroradiological appearance, management and prognosis of optic pathway gangliogliomas are reviewed.

Central nervous system complications during treatment of acute lymphoblastic leukemia in a single pediatric institution.

Central nervous system (CNS) complications during treatment of childhood acute lymphoblastic leukemia (ALL) remain a challenging clinical problem. Outcome improvement with more intensive chemotherapy has significantly increased the incidence and severity of adverse events. This study analyzed the incidence of neurological complications during ALL treatment in a single pediatric institution, focusing on clinical, radiological, and electrophysiological findings. Exclusion criteria included CNS leukemic infiltration at diagnosis, therapy-related peripheral neuropathy, late-onset encephalopathy, or long-term neurocognitive defects. During a 9-year period, we retrospectively collected 27 neurological events (11%) in as many patients, from 253 children enrolled in the ALL front-line protocol. CNS complications included posterior reversible leukoencephalopathy syndrome (n = 10), stroke (n = 5), temporal lobe epilepsy (n = 2), high-dose methotrexate toxicity (n = 2), syndrome of inappropriate antidiuretic hormone secretion (n = 1), and other unclassified events (n = 7). In conclusion, CNS complications are frequent events during ALL therapy, and require rapid detection and prompt treatment to limit permanent damage.