Faculty Bibliography

PURPOSE/OBJECTIVE:The Posterior Fossa Society (PFS) was founded 4 years ago to systematically gather and exchange information on the post-operative (CMS) and cerebellar cognitive affective syndrome (CCAS). With its consensus meetings, the PFS orchestrates research studies in the field of cerebellar injury and progresses the knowledge of post-operative pediatric cerebellar mutism syndrome (CMS). In this article, we captured the 3-day program of presentations, group discussions, interactive workshops, and dialogue, highlighting the key topic areas of CMS and its research advances. METHODS:This synopsis is based on the third consensus meeting which was held in Reykjavik, Iceland, in August 2018. RESULTS:Three working groups have been defined to drive the future research priorities on post-surgical CMS: (i) refining definition and symptoms scoring of CMS; (ii) understanding the pathogenesis and enhancing risk-stratification strategies; and (iii) developing rehabilitation approaches and protocols. CONCLUSIONS:The third consensus meeting highlighted a unanimous desire for data-driven information to advance the knowledge and guide future research efforts. The PFS constitutes an established and expanding network of multi-disciplinary expertise that can facilitate the development of collaborative studies and produce official guidelines on the topic.

BACKGROUND:New-onset hydrocephalus following foramen magnum decompression (FMD) for Chiari I malformation (CM-I) is rare; its natural history and pathophysiology are poorly understood. OBJECTIVE:To describe a series of patients who developed hydrocephalus following FMD for CM-I, provide possible explanations of this phenomenon, and outline treatment options. METHODS:Out of patients undergoing FMD for CM-I from 6 different tertiary centers, we evaluated patients presenting with new-onset hydrocephalus following FMD. The retrospectively collected data included demographics, clinical, and radiological findings of the CM-I and hydrocephalus patients. Time from FMD and hydrocephalus onset, treatment, and surgical techniques were assessed. RESULTS:Of 549 patients who underwent FMD for CM-I, 28 (5.1%) subsequently developed hydrocephalus (18 females, 10 males), with a mean age of 11.7 ± 11.9 yr (range 6 mo to 52 yr). Hydrocephalus occurred on average 2.2 ± 2.6 mo after FMD (range 1 wk to 8 mo). Four patients did not have a violation of the arachnoid during the FMD surgery. Main presenting symptoms of hydrocephalus were headaches (17, 41%), vomiting (10, 24.4%), and cerebrospinal fluid (CSF) leak or pseudomeningocele (7, 17%).Overall, 23 patients (82.1%) underwent CSF shunting, 1 patient (3.5%) had an endoscopic third ventriculostomy, 3 patients (10.7%) temporary CSF diversion only, and 1 patient (3.5%) was treated with acetazolamide. CONCLUSION/CONCLUSIONS:Hydrocephalus following FMD for CM-I is uncommon, but important. Based on our series and literature review, its incidence is about 5% to 7% and most likely will require further surgery. Shunting appears to be the favored treatment option.

PURPOSE/OBJECTIVE:All treatments for childhood craniopharyngioma are associated with complications that potentially affect quality of life. This study was designed to investigate the impact of gross total resection on long-term quality of life and sexual functioning in adulthood. METHODS:Adults treated with primary gross total resection for childhood craniopharyngioma and ≥ 10 years of follow-up were included in this retrospective cohort study. The Short Form 36 Health Survey Questionnaire Version 2 (SF-36v2), Medical Outcomes Study (MOS) sexual functioning survey, and a sociodemographic/health questionnaire were administered. RESULTS:). Preoperative hypothalamic involvement correlated with a significantly higher BMI, although the proportion of participants with class 3 obesity (BMI ≥ 40) did not differ significantly from that of the general population (9% and 7%, respectively). CONCLUSIONS:Young adults with gross total resection of childhood craniopharyngioma report similar quality of life and sexual functioning compared to the general population, but appear to be less sexually active. Hypothalamic involvement on preoperative imaging was associated with a higher BMI in long-term follow-up.

BACKGROUND:Ventriculoatrial shunts can be afflicted with distal malfunctions due to thrombus formation at the distal tip. Distal tip thrombus formation may occur more commonly in oncologic patients who are predisposed to hypercoagulability. CASE DESCRIPTION/METHODS:A patient who had a ventriculo-atrial shunt placed for leptomeningeal carcinomatosis presented with headaches and confusion and was found to have a partial distal shunt obstruction. Intra-reservoir administration of alteplase resulted in resolution of her symptoms. Nuclear medicine shunt patency test demonstrated restoration of distal flow. CONCLUSIONS:Intra-reservoir administration of alteplase can be a useful non-operative treatment strategy for ventriculo-atrial shunt malfunction. This strategy may be particularly useful in cases with higher peri-operative risk, such as patients with advanced metastatic cancer.

CONTEXT/BACKGROUND:X-linked acrogigantism (X-LAG), a condition of infant-onset acrogigantism marked by elevated GH, IGF-1, and prolactin (PRL), is extremely rare. Thirty-three cases, including three kindreds, have been reported. These patients have pituitary adenomas that are thought to be mixed lactotrophs and somatotrophs. CASE DESCRIPTION/METHODS:The patient's mother, diagnosed with acrogigantism at 21 months, underwent pituitary tumor excision at 24 months. For over 30 years, stable PRL, GH, and IGF-1 concentrations and serial imaging studies indicated no tumor recurrence. During pre-conception planning, X-LAG was diagnosed: single-nucleotide polymorphism (SNP) microarray showed chromosome Xq26.3 microduplication. After conception, SNP microarray on a chorionic villus sample showed the same microduplication in the fetus, confirming familial X-LAG. The infant grew rapidly with rising PRL, GH, and IGF-1 concentrations and an enlarging suprasellar pituitary mass, despite treatment with bromocriptine. At 15 months, he underwent tumor resection. The pituitary adenoma resembled the mother's pituitary adenoma, with tumor cells arranged in trabeculae and glandular structures. In both cases, many tumor cells expressed PRL, GH, and PIT1. Furthermore, the tumor expressed other lineage-specific transcription factors, as well as SOX2 and OCT4, demonstrating the multipotentiality of X-LAG tumors. Both showed an elevated Ki-67 proliferation index-5.6% (mother) and 8.5% (infant)-the highest reported in X-LAG. CONCLUSIONS:This is the first prenatally diagnosed case of X-LAG. Clinical follow-up and biochemical evaluation have provided insight into the natural history of this disease. Expression of stem cell markers and several cell lineage-specific transcription factors suggests that these tumors are multipotential.

OBJECTIVEThe authors describe the demographics and clinical characteristics of the first 517 patients enrolled in the Adult Hydrocephalus Clinical Research Network (AHCRN) during its first 2 years.METHODSAdults ≥ 18 years were nonconsecutively enrolled in a registry at 6 centers. Four categories of adult hydrocephalus were defined: transition (treated before age 18 years), unrecognized congenital (congenital pattern, not treated before age 18 years), acquired (secondary to known risk factors, treated or untreated), and suspected idiopathic normal pressure hydrocephalus (iNPH) (≥ age 65 years, not previously treated). Data include etiology, symptoms, examination findings, neuropsychology screening, comorbidities, treatment, complications, and outcomes. Standard evaluations were administered to all patients by trained examiners, including the Montreal Cognitive Assessment, the Symbol Digit Modalities Test, the Beck Depression Inventory-II, the Overactive Bladder Questionnaire Short Form symptom bother, the 10-Meter Walk Test, the Boon iNPH gait scale, the Lawton Activities of Daily Living/Instrumental Activities of Daily Living (ADL/IADL) questionnaire, the iNPH grading scale, and the modified Rankin Scale.RESULTSOverall, 517 individuals were enrolled. Age ranged from 18.1 to 90.7 years, with patients in the transition group (32.7 ± 10.0 years) being the youngest and those in the suspected iNPH group (76.5 ± 5.2 years) being the oldest. The proportion of patients in each group was as follows: 16.6% transition, 26.5% unrecognized congenital, 18.2% acquired, and 38.7% suspected iNPH. Excluding the 86 patients in the transition group, who all had received treatment, 79.4% of adults in the remaining 3 groups had not been treated at the time of enrollment. Patients in the suspected iNPH group had the poorest performance in cognitive evaluations, and those in the unrecognized congenital group had the best performance. The same pattern was seen in the Lawton ADL/IADL scores. Gait velocity was lowest in patients in the suspected iNPH group. Categories that had the most comorbidities (suspected iNPH) or etiologies of hydrocephalus that directly cause neurological injury (transition, acquired) had greater degrees of impairment compared to unrecognized congenital, which had the fewest comorbidities or etiologies associated with neurological injury.CONCLUSIONSThe clinical spectrum of hydrocephalus in adults comprises more than iNPH or acquired hydrocephalus. Only 39% of patients had suspected iNPH, whereas 43% had childhood onset (i.e., those in the transition and unrecognized congenital groups). The severity of symptoms and impairment was worsened when the etiology of the hydrocephalus or complications of treatment caused additional neurological injury or when multiple comorbidities were present. However, more than half of patients in the transition, unrecognized congenital, and acquired hydrocephalus groups had minimal or no impairment. Excluding the transition group, nearly 80% of patients in the AHCRN registry were untreated at the time of enrollment. A future goal for the AHCRN is to determine whether patients with unrecognized congenital and acquired hydrocephalus need treatment and which patients in the suspected iNPH cohort actually have possible hydrocephalus and should undergo further diagnostic testing. Future prospective research is needed in the diagnosis, treatment, outcomes, quality of life, and macroeconomics of all categories of adult hydrocephalus.

OBJECTIVEThe choice of treatment modality for optic pathway gliomas (OPGs) is controversial. Chemotherapy is widely regarded as first-line therapy; however, subtotal resections have been reported for decompression or salvage therapy as first- and second-line treatment. The goal of this study was to further investigate the role and efficacy of resection for OPGs.METHODSA retrospective chart review was performed on 83 children who underwent surgical treatment for OPGs between 1986 and 2014. Pathology was reviewed by a neuropathologist. Clinical outcomes, including progression-free survival (PFS), overall survival (OS), and complications, were analyzed.RESULTSThe 5- and 10-year PFS rates were 55% and 46%, respectively. The 5- and 10-year OS rates were 87% and 78%, respectively. The median extent of resection was 80% (range 30%-98%). Age less than 2 years at surgery and pilomyxoid features of the tumor were found to be associated with significantly lower 5-year OS. No difference was seen in PFS or OS of children treated with surgery as a first-line treatment compared with children with surgery as a second- or third-line treatment. Severe complications included new disabling visual deficit in 5%, focal neurological deficit in 8%, and infection in 2%. New hormone deficiency occurred in 22% of the children.CONCLUSIONSApproximately half of all children experience a long-term benefit from resection both as primary treatment and as a second-line therapy after failure of primary treatment. Primary surgery does not appear to have a significant benefit for children younger than 2 years or tumors with pilomyxoid features. Given the risks associated with surgery, an interdisciplinary approach is needed to tailor the treatment plan to the individual characteristics of each child.

OBJECTIVE: New onset hydrocephalus following foramen magnum decompression (FMD) for Chiari I malformation (CMI) is rare, and its natural history and pathophysiology is poorly understood. We describe a series of patients who presented with hydrocephalus following FMD for CMI, provide possible explanations of this condition, and outline treatment options. MATERIAL-METHODS: Of patients undergoing FMD for CMI from 6 different tertiary centres in North America, Europe and Middle East, we evaluated patients presenting with new onset hydrocephalus following the FMD. Retrospectively collected data included demographics, clinical and radiological findings of both the CMI and hydrocephalus, time from FMD and hydrocephalus onset, and treatment as well as surgical techniques. RESULTS: None of the patients had obvious symptoms related to idiopathic intracranial hypertension nor hydrocephalus prior to FMD. Of 367 patients who underwent FMD for CMI, 28 (7.6%) subsequently developed symptoms related to hydrocephalus (18 females-64.2%, and 10 males - 35.8%), (7 Le Bonheur Children's Hospital, 6 Tel Aviv Medical Center and Dana Children's Hospital, 6 Cincinnati Children's Hospital Medical Center, 5 Children's National Medical Center, 3 NYU Langone Medical Center, 1 Charite Universitatsmedizin) with a mean age of 11.7 +/- 11.9 years old (range 6 months to 52 years old). Hydrocephalus occurred on average 2.2 +/- 2.6 months after FMD (ranging from 1 week to 8 months). Presenting symptoms of hydrocephalus were headaches (41%), vomiting (24.4%), CSF leak/pseudomeningocele (17%), decreased level of consciousness (7.3%), cranial nerves signs (7.3%) and papilledema (2.4%). 23 patients (82.1%) underwent CSF shunting, 1 patient had an endoscopic third ventriculostomy (3.5%), 3 patients (10.7%) temporary CSF diversion only, and 1 patient (3.5%) acetazolamide. CONCLUSION: Hydrocephalus following FMD for CMI is uncommon. Based on our series and literature review, its incidence is ~7% and most likely will require further surgery. Considering different treatment options, shunting appears to be the favoured option

OBJECTIVE:Duraplasty is one technique successfully used to treat Chiari malformation type I (CM-I). This study describes the timely manner of clinical outcomes and the postoperative course after craniectomy and duraplasty for the treatment of symptomatic CM-I in pediatric children. METHODS:A retrospective chart review was done on 105 consecutive children who underwent surgical decompression of symptomatic CM-I with dural opening by a single surgeon between 1999 and 2015. RESULTS:In 16 of 28 children (57%) with typical Valsalva-related/tussive and mixed headaches, the symptoms resolved before discharge; by 6 months all children were headache free. Two of 28 children (7%) had recurrent headaches 9 months after surgery. In 78 children with syrinx, syrinx resolved or decreased in 68 children (87%), recurred in 8 children (10%), and was stable in 2 children (3%). In 51 children (65%), syrinx resolved or decreased by 3 months and in 62 children (79%) by 6 months. Complications included aseptic meningitis requiring reoperation in 3% and infection in one child (1%). Twelve reoperations occurred, none within the first 30 days. No child had a major morbidity or mortality. CONCLUSIONS:In carefully selected children with CM-I, a high success rate can be achieved with suboccipital decompression and duraplasty. Valsalva-related/tussive headaches resolved in the majority of children at discharge from the hospital; syrinx resolved or decreased in two thirds of the children by 3 months. By 6 months, headaches were resolved in all cases, and syrinx was resolved or decreased in 79% of cases.