Primary neoplasms of the pituitary gland are uncommon in children. Physiological enlargement of the gland, however, is universal and can sometimes be confused with a tumor. Due to widespread availability of MR imaging, the number of children referred to pediatric neurosurgeons with an enlarged pituitary associated with nonspecific symptoms, most commonly headache, is increasing. In this review, the authors illustrate two common causes of pituitary enlargement in children, namely physiological hypertrophy of puberty, more commonly seen in females, and secondary hyperplasia caused by hypothyroidism. The importance of early and accurate diagnosis, without recourse to extensive endocrine investigations or inappropriate surgery, is underscored.
Kristian Aquilina and Frederick A. Boop
Matthew A. Kirkman, Richard Hayward, Kim Phipps, and Kristian Aquilina
It is relatively unusual for pediatric CNS tumors to be disseminated at presentation, and the literature on the clinical features, management, and outcomes of this specific group is scarce. Surgical management in this population is often challenging, particularly in the presence of hydrocephalus. The authors present their recent experience of treating pediatric CNS tumors that were disseminated at presentation, and they compare these lesions with focal tumors.
The authors performed a retrospective review of prospectively collected data on children presenting to a tertiary center between 2003 and 2016 inclusive.
Of 361 children with CNS tumors, the authors identified 53 patients with disease dissemination at presentation (male/female ratio 34:19, median age 3.8 years, age range 7 days to 15.6 years) and 308 without dissemination at presentation (male/female ratio 161:147, median age 5.8 years, age range 1 day to 16.9 years). Five tumor groups were studied: medulloblastoma (disseminated n = 29, focal n = 74), other primitive neuroectodermal tumor (n = 8, n = 17), atypical teratoid rhabdoid tumor (n = 8, n = 22), pilocytic astrocytoma (n = 6, n = 138), and ependymoma (n = 2, n = 57). The median follow-up duration in survivors was not significantly different between those with disease dissemination at presentation (64.0 months, range 5.2–152.0 months) and those without it (74.5 months, range 4.7–170.1 months) (p > 0.05). When combining data from all 5 tumor groups, dissemination status at presentation was significantly associated with a higher risk of requiring CSF diversion, a higher surgical complication rate, and a reduced likelihood of achieving gross-total resection of the targeted lesion (all variables p < 0.05). Differences between the 5 tumor groups were evident. No factors that predicted the need for permanent CSF diversion following temporary external ventricular drainage were identified on multivariate analysis, and there was no clear superiority of either ventriculoperitoneal shunt surgery or endoscopic third ventriculostomy as a permanent CSF diversion procedure.
Tumor type and dissemination status at initial presentation significantly affect outcomes across a range of measures. The management of hydrocephalus in patients with CNS tumors is challenging, and further prospective studies are required to identify the optimal CSF diversion strategy in this population.
Jakob V. E. Gerstl, Kristian Aquilina, and Jeffrey E. Florman
Colloid cysts of the posterior third ventricle are exceedingly rare. This location is a high-risk zone for colloid cysts because of potential obstruction of the cerebral aqueduct.
The authors report a case of a 57-year-old man who presented with a 6-month history of progressive headache, short-term memory loss, visual blurring, and an episode of double vision. Magnetic resonance imaging (MRI) revealed a colloid cyst, 22 mm in diameter, attached to the roof of the posterior third ventricle. The posterior third ventricle was obstructed, but both foramina of Monro were patent. The entirety of the cyst was resected via a right frontal parasagittal, interhemispheric, transventricular approach through the foramen of Monro. It was not contained within the velum interpositum. The patient did not experience any postoperative deficits.
This case supports the theoretical evidence that colloid cysts in the posterior zone of the third ventricle pose a risk for obstructive hydrocephalus. This report of a large cyst in a rare location describes a unique lesion and provides the first published MRI description.
Kristian Aquilina, Ela Chakkarapani, and Marianne Thoresen
The optimal management of neonatal intraventricular hemorrhage (IVH) and posthemorrhagic ventricular dilation is challenging. The importance of early treatment has been demonstrated in a recent randomized study, involving early ventricular irrigation and drainage, which showed significant cognitive improvement at 2 years. The objective of this study was to define the changes in CSF absorption capacity over time in a neonatal piglet model of IVH.
Ten piglets (postnatal age 9–22 hours) underwent intraventricular injection of homologous blood. A ventricular access device was inserted 7–10 days later. Ventricular dilation was measured by ultrasonography. Serial constant flow infusion studies were performed through the access device from Week 2 to Week 8.
Seven piglets survived long term, 43–60 days, and developed ventricular dilation; this reached a maximum by Week 6. There was no significant difference in baseline intracranial pressure throughout this period. The resistance to CSF outflow, Rout, increased from 63.5 mm Hg/ml/min in Week 2 to 118 mm Hg/ml/min in Week 4. Although Rout decreased after Week 5, the ventriculomegaly persisted.
In this neonatal piglet model, reduction in CSF absorptive capacity occurs early after IVH and accompanies progressive and irreversible ventriculomegaly. This suggests that early treatment of premature neonates with IVH is desirable.
Dora Steel, Matthew A. Kirkman, Dominic N. P. Thompson, and Kristian Aquilina
Open anterolateral cordotomy is an effective treatment option for adults with intractable pain, but it has seldom been attempted in children. In the 2 previously reported cases in children, the procedure was used within 10 days of death from neoplastic disease. In this paper the authors describe 2 cases in which open cordotomy was used successfully in children outside the immediate terminal phase of disease. Both patients experienced effective analgesia with minimal adverse effects. The authors propose that consideration of cordotomy as an option for the management of intractable pain in children does not need to be delayed until death is imminent.
M. Omar Iqbal, Ashirwad Merve, Nathalie Galea, and Kristian Aquilina
Tumors of the CNS represent the largest group of solid tumors found in the pediatric patient population. Langerhans cell histiocytosis (LCH) is an inflammatory lesion that may present in bone and/or soft tissue, including the CNS. Management depends on the extent of multisystem involvement, which determines resection with or without systemic chemotherapy. The authors report on the case of a child who underwent an open craniotomy for biopsy of a pituitary stalk lesion followed by neuropathological assessment, procedures used to diagnose LCH. The patient then underwent 12 months of systemic chemotherapy with subsequent resolution of the pituitary stalk lesion. Two years following pathological diagnosis, the patient presented with frontal orbital pain at the site of the prior craniotomy. Advanced imaging revealed MRI enhancement and radiotracer uptake of a soft-tissue growth at the frontal burr-hole site and MRI enhancement at a posterior burr-hole site without soft-tissue growth. The patient then underwent open biopsy and curettage that revealed LCH recurrence at the site of prior craniotomy. This case demonstrates that LCH may represent an abnormal reactive clonal proliferation of dendritic cells, rather than a de novo malignant neoplasm that can occur at sites of prior craniotomy despite systemic chemotherapy. The authors advocate close follow-up with contrast-enhanced imaging. Special attention should be given to sites of prior surgical manipulation to avoid missing distant sites of recurrence.
Amy L. Bowes, Josh King-Robson, William J. Dawes, Greg James, and Kristian Aquilina
The aim of this study was to review the safety of pediatric intraventricular endoscopy across separate age groups and to determine whether intraventricular endoscopy is associated with an increased risk of complications or reduced efficacy in infants younger than 1 year.
In this retrospective cohort study, 286 pediatric patients younger than 17 years underwent intraventricular endoscopy at Great Ormond Street Hospital between December 2005 and December 2014. The primary diagnosis, procedure, and complications were recorded.
Neuroendoscopic surgery was performed in 286 pediatric patients (51 neonates 0–6 months [Group 1]; 37 infants 6–12 months [Group 2]; 75 patients 1–5 years [Group 3]; 54 patients 5–10 years [Group 4]; and 69 patients ≥ 10 years [Group 5]; male/female ratio 173:113). The most common procedures included endoscopic third ventriculostomy (ETV) in 159 patients and endoscopic fenestration of intracranial cysts in 64 patients. A total of 348 consecutive neuroendoscopic procedures were undertaken. Nine different complications were identified, of which postoperative seizures (1.7%), CSF leak (3.1%), CSF infection (2.4%), and intracranial hemorrhage (1.7%) were the most common. Specifically, no significant difference in complication rate (11.9%) or infection rate (2.4%) was observed among age groups (p = 0.40 and p = 0.91, respectively). In addition, there were no perioperative deaths; 30-day mortality was 1.1%. After neuroendoscopy for CSF diversion (n = 227), a significantly higher rate of shunt insertion was observed in the youngest group (Group 1, 63.0%) when compared with older groups (Group 2, 46.4%; Group 3, 26.3%; Group 4, 38.6%; and Group 5, 30.8%; p = 0.03). Similarly, for patients who underwent ETV as their initial neuroendoscopic procedure or in combination with additional surgical interventions (n = 171), a significantly higher rate of shunt insertion was also observed within young infants (Group 1, 67.9%; Group 2, 47.6%; Group 3, 19.6%; Group 4, 27.3%; and Group 5, 23.3%; p = 0.003).
Intraventricular endoscopy is a safe neurosurgical intervention in pediatric patients of all ages, although it might be associated with increased shunt rates after endoscopic surgery, specifically ETV, in younger infants.
Kristian Aquilina, Dave F. Clarke, James W. Wheless, and Frederick A. Boop
Temporal lobe encephaloceles can be associated with temporal lobe epilepsy. The authors report on the case of an adolescent with multiple microencephaloceles, in the anterolateral middle fossa floor, identified at surgery (temporal lobectomy) for intractable partial-onset seizures of temporal origin. Magnetic resonance imaging revealed only hippocampal atrophy. Subdural electrodes demonstrated ictal activity arising primarily from the anterior and lateral temporal lobe, close to the microencephaloceles, spreading to the anterior and posterior mesial structures. Pathological examination revealed diffuse temporal gliosis involving the hippocampus, together with microdysgenesis of the amygdala. The literature on epilepsy secondary to encephaloceles is reviewed and the contribution of the microencephaloceles to the seizure disorder in this patient is discussed.
Amit Parmar, Kristian Aquilina, and Michael R. Carter
Chronic obstructive hydrocephalus is known to cause ventricular diverticula and, rarely, spontaneous ventriculostomy. The authors present the case of a patient in whom a spontaneous third ventriculostomy was identified with long-standing hydrocephalus secondary to aqueductal stenosis. To their knowledge, this is the first report in which a spontaneous stoma in the floor of the third ventricle was evaluated using endoscopy and cerebrospinal fluid dynamics studies. Both studies confirmed that the spontaneous stoma is similar in structure and function to surgical third ventriculostomy.
Kristian Aquilina, Ian K. Pople, Jenny Sacree, Michael R. Carter, and Richard J. Edwards
The evaluation of third ventriculostomy function in hydrocephalic patients is challenging. The utility of the constant flow infusion test in predicting response to shunt insertion in normal-pressure hydrocephalus, as well as in identifying shunt malfunction, has been previously demonstrated. The object of this study was to evaluate its usefulness in determining whether a revision CSF diversion procedure was indicated in patients presenting with recurring symptoms and persisting ventriculomegaly after endoscopic third ventriculostomy (ETV).
The authors conducted a prospective study of all patients who, after undergoing ETV at their institution, presented postoperatively with recurring symptoms and persisting ventriculomegaly.
Forty-six patients (mean age 40.7 years, including 11 patients younger than 18 years) underwent 56 constant flow ventricular infusion tests (VITs) at a mean of 24.7 months post-ETV. Thirty-three patients with resistance to CSF outflow (Rout) less than 13 mm Hg/ml/min underwent follow-up (median 17 months) and experienced resolution of symptoms. In 10 episodes Rout was greater than 13 mm Hg/ml/min; the patients in these cases underwent revisional CSF diversion. Two patients demonstrated high and frequent B (slow) waves despite a low Rout; these patients also underwent successful revisions. Patients who improved after surgery had increased B wave activity in the plateau phase of the VIT (p = 0.01). Thirty-four patients underwent MR imaging at the same time; 4 had high Rout despite evidence of flow across the stoma. These 4 patients underwent surgery and experienced resolution of symptoms. Of 9 patients without flow, Rout was less than 13 mm Hg/ml/min in 4; these patients were successfully treated conservatively.
The VIT is a useful and safe adjunct to clinical and MR imaging evaluation when ETV failure is suspected.