Focal Spinal Nondisjunctional Disorders: Including a Discussion on the Embryogenesis of Cranial Focal Nondisjunctional Lesions.

The publication of a comprehensive report on limited dorsal myeloschisis by the senior author (DP) in 2010 has brought full attention to the concept of limited myeloschisis that he first formulated in 1992 and ignited interests in the whole spectrum of focal spinal nondisjunctional disorders. Now that focal nondisjunctional disorders have become well known, new clinical reports on these conditions or relevant subjects are frequently seen. Here we present an updated review on the full spectrum of focal spinal nondisjunctional disorders and extend the scope to include a discussion on the embryogenesis of cranial focal nondisjunctional malformations.

Frameless versus frame-based stereotactic radiosurgery for intracranial arteriovenous malformations: A propensity-matched analysis.

Objective: The frameless linear accelerator (LINAC) based stereotactic radiosurgery (SRS) has been evolving with a reduction in patient discomfort. However, there was limited evidence comparing frame-based and frameless SRS for intracranial arteriovenous malformations (AVM). We aimed to compare the treatment outcomes between frame-based and frameless LINAC SRS.

Multidimensional Outcomes of Selective Dorsal Rhizotomy for Children With Spastic Cerebral Palsy: Single-Level Laminectomy vs Multiple-Level Laminotomy Techniques.

Background: Selective dorsal rhizotomy (SDR) reduces lower limb spasticity, improves gait patterns, and restores normal physical and social activity in children with spastic cerebral palsy. Single-level laminectomy (SLL) and multiple-level laminotomy (MLL) are 2 surgical approaches for SDR with limited clinical data comparing their postoperative outcomes.

Objective: To compare the differences in multidimensional outcomes after SDR between SLL and MLL for children with spastic cerebral palsy.

Focal Spinal Nondisjunction in Primary Neurulation : Limited Dorsal Myeloschisis and Congenital Spinal Dermal Sinus Tract.

Spinal dysraphic lesions due to focal nondisjunction in primary neurulation are commonly encountered in paediatric neurosurgery, but the "fog-of-war" on these conditions was only gradually dispersed in the past 10 years by the works of the groups led by the senior author and Prof. Kyu-Chang Wang. It is now clear that limited dorsal myeloschisis and congenital spinal dermal sinus tract are conditions at the two ends of a spectrum; and mixed lesions of them with various configurations exist.

Radiotherapy-induced glioblastoma: distinct differences in overall survival, tumor location, pMGMT methylation and primary tumor epidemiology in Hong Kong chinese patients.

Introduction: Radiotherapy-induced glioblastomas (RIGB) are a well-known late and rare complication of brain irradiation. Yet the clinical, radiological and molecular characteristics of these tumors are not well characterized.

Methods: This was a retrospective multicentre study that analysed adult patients with newly diagnosed glioblastoma over a 10-year period.

Newly-Diagnosed, Histologically-Confirmed Central Nervous System Tumours in a Regional Hospital in Hong Kong : An Epidemiological Study of a 21-Year Period.

Objective: To investigate the epidemiology of newly-diagnosed, histologically-confirmed (NDHC) central nervous system (CNS) tumours and its changes over a 21-year period in a regional hospital in Hong Kong.

Methods: This is a single-institute retrospective descriptive study of patients undergoing surgery for CNS tumours in a regional hospital of Hong Kong in the period from January 1996 to December 2016. The histological definition of CNS tumours was according to the World Health Organization classification, while the site definition for case ascertainment of CNS tumours was as set out by the Central Brain Tumour Registry of the United States.

Determining a cut-off residual tumor volume threshold for patients with newly diagnosed glioblastoma treated with temozolomide chemoradiotherapy: A multicenter cohort study.

Standard-of-care treatment of glioblastomas involves maximal safe resection and adjuvant temozolomide chemo-radiotherapy. Although extent of resection (EOR) is a well-known surgical predictor for overall survival most lesions cannot be completely resected. We hypothesize that in the event of incomplete resection, residual tumor volume (RTV) may be a more significant predictor than EOR.

Epidural multi-slitted microporous non-absorbable patch in decompressive craniectomy to facilitate cranioplasty: a preliminary study.

Developing a surgical plane between the temporalis muscle and the dura is the most technically challenging step when performing cranioplasty for post-decompressive craniectomy defects. The authors report a simple technique to demarcate this surgical plane by laying a multi-slitted, microporous polyesterurethane (MPU) patch during decompressive craniectomy. Specifically, they tried to avoid creating potential spaces around the patch, which is the inherent drawback of published anti-adhesive techniques.

A Comparative Analysis of the Usefulness of Survival Prediction Models for Patients with Glioblastoma in the Temozolomide Era: The Importance of Methylguanine Methyltransferase Promoter Methylation, Extent of Resection, and Subventricular Zone Location.

Objective: Several survival prediction models for patients with glioblastoma have been proposed, but none is widely used. This study aims to identify the predictors of overall survival (OS) and to conduct an independent comparative analysis of 5 prediction models.

Methods: Multi-institutional data from 159 patients with newly diagnosed glioblastoma who received adjuvant temozolomide concomitant chemoradiotherapy (CCRT) were collected.

Isolated unilateral rupture of the alar ligament.

Only 6 cases of isolated unilateral rupture of the alar ligament have been previously reported. The authors report a new case and review the literature, morbid anatomy, and pathogenesis of this rare injury. The patient in their case, a 9-year-old girl, fell head first from a height of 5 feet off the ground.

Innervation of the brain, intracerebral Schwann cells and intracerebral and intraventricular schwannomas.

The cerebral vasculature and the choroid plexus are innervated by peripheral nerves. The anatomy of the vascular supply to the brain and its related perivascular nerves is reviewed. Intracerebral and intraventricular schwannomas most likely come from neoplastic transformation of Schwann cells investing the perivascular nerves and nerves within the choroid plexus.

Traumatic rupture of the neurocentral synchondrosis of the axis in a child.

The authors report the first case of unilateral traumatic rupture of the C-2 neurocentral synchondrosis. A 26-month-old child was in a vehicular collision that caused his head to be rotated sharply to the left with the neck flexed. He had severe neck pain but was neurologically normal.

Surgical treatment of complex spinal cord lipomas.

Purpose: This paper shows the long-term benefits of total/near-total resection of complex spinal cord lipomas and meticulous reconstruction of the neural placode, and specifically, its advantage over partial resection, and over non-surgical treatment for the subset of children with asymptomatic virgin lipomas.

Methods: The technique of total resection and placode reconstruction, together with technical nuances, are described in detail. We added 77 patients with complex lipomas to our original lipoma series published in 2009 and 2010, to a total of 315 patients who had had total or near-total resection and followed for a span of 20 years.

Limited dorsal myeloschisis: a not-so-rare form of primary neurulation defect.

Purpose: Limited dorsal myeloschisis (LDM) is a distinctive form of spinal dysraphism characterized by two constant features: a focal "closed" midline skin defect and a fibroneural stalk that links the skin lesion to the underlying cord. The embryogenesis is hypothesized to be incomplete disjunction between cutaneous and neural ectoderms, thus preventing complete midline skin closure and allowing persistence of a physical link (fibroneural stalk) between the disjunction site and the dorsal neural tube.

Objective: We utilize the experience gained from the management of 63 patients with LDM to illustrate these features.

Parallel angulated frontal bone slat cuts for treatment of metopic synostosis and other frontal skull deformities: the "cathedral dome procedure".

Purpose: This study aims to describe a new procedure for the treatment of metopic synostosis and other frontal skull deformities.

Method: The procedure comprises a supraorbital bandeau widened with an interpositional graft and rounded laterally to eliminate the acute angle, and parallel angulated slat cuts in the frontal bones. Greenstick fracturing of the medial bases of these slats along a parasagittal hinge line causes fanning of the slats and expansion of the frontal flap both anteriorly and laterally making the forehead contour wider and more rounded.

Programming jammed Codman Hakim programmable valves: study of an explanted valve and successful programming in a patient.

Malfunction of a Codman Hakim programmable valve due to jamming of its programmable component may necessitate shunt revision. The authors report a method for programming jammed Codman Hakim programmable valves by using a Strata II magnet and additional neodymium magnets. The programming method was derived after studying a jammed valve in the laboratory that was explanted from an 10-year-old boy with a history of fourth ventricle ependymoma.

Reducing radiation exposure from computed tomography of the brain in children--report of a practical approach.

Purpose: To reduce radiation exposure to paediatric neurosurgical patients from computed tomography (CT), a CT scanning protocol - lower radiation dose and selective scan segment (LDSS) protocol was used for CT brain at the authors' hospital. To evaluate the amount of reduction in radiation exposure by using this LDSS protocol compared to their usual protocol, the authors prospectively documented their findings.

Methods: From May 2010 to June 2011, paediatric neurosurgical patients requiring CT brain, and when it was not a clinical emergency and there was baseline CT or MRI brain available, were evaluated for the LDSS protocol.

Ruptured brain arteriovenous malformations in children: correlation of clinical outcome with admission parameters.

Aims: To gain a better understanding of how clinical outcome in children with ruptured brain arteriovenous malformations (bAVMs) correlates with clinical and imaging parameters on admission.

Methods: The authors retrospectively reviewed patients with bAVMs, aged 18 or below, managed at their hospital between January 1992 and December 2008. Clinical outcome was assessed using the modified Rankin Scale (mRS).

Results of excision of cerebral radionecrosis: experience in patients treated with radiation therapy for nasopharyngeal carcinoma.

Object: In theory, the purpose of the treatment of cerebral radionecrosis (CRN), a nonneoplastic condition, is to minimize loss of brain function by preventing the progression and reversing some of the processes of CRN. In a practical sense, factors for achieving this purpose may include the following: removal of a CRN lesion that is causing mass effect, control of brain edema, prevention of recurrence of CRN lesions, minimization of adverse effects from treatments, and achievement of reasonably long and good-quality survivals. Based on these practical issues, the authors performed a retrospective study to evaluate the results of excision for the treatment of CRN.

Pathophysiological mechanism of ipsilateral cerebral and brainstem hemiatrophy in basal ganglia germ cell tumors: case report.

Introduction: The basal ganglia is an uncommon location for germ cell tumors. It has been reported that basal ganglia germinomas and mixed germ cell tumors are associated with ipsilateral cerebral and brainstem hemiatrophy on presentation. Several pathophysiological mechanisms including autoimmune process and direct tumor infiltration of the thalamus or the internal capsule have been postulated to explain this association.

Redistribution of hematoma to spinal subdural space as a mechanism for the rapid spontaneous resolution of posttraumatic intracranial acute subdural hematoma: case report.

Background: Rapid spontaneous resolution of posttraumatic intracranial ASDH has been reported in the literature since 1986. We report a case to demonstrate that redistribution of hematoma to the spinal subdural space is a mechanism for the rapid spontaneous resolution of posttraumatic intracranial ASDH.

Case Description: A 73-year-old woman with a slipped-and-fell injury had a worst GCS score of 8/15.