Hemispherectomy for hemimegalencephaly in a 6.5-week-old infant with tuberous sclerosis complex.

The aim of this report is to present a unique case of hemimegalencephaly and concomitant tuberous sclerosis complex (TSC1 mutation) with severe neonatal-onset epilepsy, which successfully underwent an anatomical hemispherectomy at 6.5 weeks of age for refractory seizures. Genetic testing confirmed a rare pathogenic, sporadic, heterozygous c.2041 + 1G > A gene mutation in intron 16 of the TSC1 gene, diagnostic for tuberous sclerosis. Post-operatively, the infant remained seizure free for at least 1 year. Following recurrence of her seizures, she has continued on multiple anti-seizure medications and everolimus therapy. We review the pathological and molecular features of this condition and highlight the ethics of intervention and steps taken toward safe neurosurgical intervention in this very young infant.

Inflammation and obstruction of distal catheter slits in ventriculoperitoneal shunts: likely role of graphite.

OBJECTIVE: Tissue reactions that contribute to obstruction of peritoneal catheters in ventriculoperitoneal shunt systems are not well characterized. Several recent rapid obstructions in children prompted a retrospective quality assurance review. METHODS: The authors conducted a detailed investigation of 22 surgically explanted peritoneal shunt catheters and 8 autopsy cases with documented distal shunt obstruction. Patients' medical histories were reviewed, and the catheters and/or tissues were subjected to conventional histological and immunohistochemical evaluations. In addition, 3 cases were subjected to electron microscopic examination including elemental analysis. RESULTS: The majority of symptomatic obstructions were associated with distal slit catheters (17 slit, 3 open-end, and 2 unknown type). Among the autopsy cases, deaths were attributed to shunt failure in 2 cases of slit catheter obstruction, 1 case of open-end catheter obstruction, and 1 case of catheter withdrawal from the peritoneal cavity. The early tissue response consisted of a predominantly T lymphocyte accumulation with phagocytosis of graphite particles by macrophages. This is associated with proliferation of fibroblasts, mesothelial cells, and blood vessels, which can grow through the slits and occlude the catheter lumen. As the inflammation subsides after approximately 1 year, the tissue plug becomes collagenized and calcified. CONCLUSIONS: This study, supported by experimental literature in other organ systems, indicates that graphite used to coat the slit openings of distal catheters from ventriculoperitoneal shunts likely predisposes to obstruction. Neurosurgeons and manufacturers should consider the potential negative consequences of this shunt design. The authors concur with previous recommendations that slit-valve distal catheters should not be used for ventriculoperitoneal shunting unless they can be proven safe and efficacious in a controlled trial.

Dr. Dwight Parkinson: a Canadian neurosurgical pioneer.

In 1950, Dwight Parkinson was the first qualified neurosurgeon to arrive in Winnipeg, Manitoba. He played a monumental role in developing one of the earliest neurosurgical training programs in Western Canada. Parkinson was a pioneering neurosurgeon who served as the first president of the Canadian Neurosurgical Society in 1965. He was the epitome of the skull base neurosurgeon, which was not recognized as a distinct discipline at that time. He contributed to its development through detailed neuroanatomical study of the lateral sellar compartment (housing the parasellar venous plexus, a term he emphasized as more accurate than "cavernous sinus"). Parkinson also made seminal contributions to the management of cerebrovascular disease and offered new insights on cerebral concussion. Parkinson's dedication to clinical excellence and education laid a cornerstone for the development of neurosurgery and the neurosciences in Manitoba, making him a key figure in Canadian neurosurgery. Using published materials, online resources, hospital archives, and personal interviews, the authors conducted a systematic review of Parkinson's formative years, his development of the Section of Neurosurgery at the University of Manitoba, his achievements, and his legacy. This updated biography captures the exploits of this remarkable, and at times strictly disciplinarian, neurosurgeon-anatomist.

The Cerebrovascular Response to Ketamine: A Systematic Review of the Animal and Human Literature.

BACKGROUND: The aim of the study was to perform a systematic review of the literature on the cerebrovascular/cerebral blood flow (CBF) effects of ketamine in both animal and human subjects. MATERIALS AND METHODS: We searched MEDLINE, BIOSIS, EMBASE, Global Health, SCOPUS, and Cochrane Library from inception to December 2014. Two reviewers independently identified all manuscripts pertaining to the administration of ketamine in both human and animal subjects in which the impact on CBF/cerebral vasculature was recorded by means of functional magnetic resonance imaging, positron emission tomography, single-photon emission computed tomography, xenon computed tomography, transcranial Doppler velocities, arteriovenous difference in N2O method of CBF measurement, cerebral digital subtraction angiography, or any other objective means of CBF determination. RESULTS: We identified 38 animal studies with various animal models studied. Overall there was a trend to a direct vasodilatory effect of ketamine on the cerebral vasculature, with a trend in most studies to an increase or regional CBF (rCBF) or global CBF.Twenty human studies were identified. The majority displayed an increase in rCBF and global CBF on imaging in patients without neurological illness. CONCLUSIONS: Animal models indicate an increase in global CBF and rCBF with ketamine administration, with a trend to vasodilation of medium-sized intracranial vessels through a calcium-dependent mechanism. Human studies display an Oxford 2b, Grading of Recommendation Assessment Development and Education C, level of evidence to support a trend to increased global CBF and rCBF with ketamine administration in both healthy volunteers and elective surgical patients without neurological illness.

Lidocaine for Status Epilepticus in Pediatrics.

BACKGROUND: Our goal was to perform a systematic review of the literature on the use of intravenous lidocaine in pediatrics for status epilepticus (SE) and refractory status epilepticus (RSE) to determine its impact on seizure control. METHODS: All articles from MEDLINE, BIOSIS, EMBASE, Global Health, HealthStar, Scopus, Cochrane Library, the International Clinical Trials Registry Platform (inception to November 2014), and gray literature were searched. The strength of evidence was adjudicated using both the Oxford and Grading of Recommendations Assessment, Development, and Evaluation methodologies by two independent reviewers. RESULTS: Overall, 20 original studies were identified, with 19 manuscripts and one meeting abstract. Two hundred and thirty-five pediatric patients were treated for 252 episodes of SE/RSE. Patients had varying numbers of antiepileptic drugs (two to eight) on board before lidocaine therapy. During 20 of the 252 (7.9%) episodes of SE/RSE, phenytoin was on board. The dose regimen of lidocaine varied, with some using bolus dosing alone; others used a combination of bolus and infusion therapy. Overall, 60.0% of seizures responded to lidocaine, with complete cessation and greater than 50% reduction seen in 57.6% and 12.3%, respectively. Patient outcomes were sparingly reported. CONCLUSIONS: There currently exists Oxford level 2b, Grading of Recommendations Assessment Development, and Evaluation C evidence to support the consideration of lidocaine for SE and RSE in the pediatric population. Further prospective studies of lidocaine administration in this setting are warranted.

Indomethacin for control of ICP.

UNLABELLED: Our goal was to perform a systematic review of the literature on the use of indomethacin and its effects on intracranial pressure (ICP) in patients with neurological illness. All articles from MEDLINE, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library, the International Clinical Trials Registry Platform (inception to July 2014), reference lists of relevant articles, and gray literature were searched. Two reviewers independently identified all manuscripts utilizing the following inclusion and exclusion criteria. INCLUSION CRITERIA: Humans, prospective studies (five or more patients), documented ICP response to indomethacin, and English. EXCLUSION CRITERIA: non-English, retrospective studies, no documentation of ICP response to indomethacin, and animal studies. A two-tier filter of references was conducted. First, we screened manuscripts by title and abstract. Second, those references passing the first filter were pulled, and the full manuscript was checked to see if it matched the criteria for inclusion. Two reviewers independently extracted data including population characteristics and treatment characteristics. The strength of evidence was adjudicated using both the Oxford and GRADE methodology. Our search strategy produced a total of 208 citations. Twelve original articles, 10 manuscripts, and 2 meeting proceeding, were considered for the review with all utilizing indomethacin, while documenting ICP in neurological patients. All studies were prospective. Across all studies, there were a total of 177 patients studied, with 152 receiving indomethacin and 25 serving as controls in a variety of heterogeneous studies. All but one study documented a decrease in ICP with indomethacin administration, with both bolus and continuous infusions. No significant complications were described. There currently exists Oxford level 2b, GRADE C evidence to support that indomethacin reduces ICP in the severe TBI population. Similar conclusions in other populations cannot be made at this time. Comments on its impact, on patient outcome, and side effects cannot be made given the available data. At this time, indomethacin for ICP control remains experimental and further prospective study is warranted.

Treatment of recurrent ventriculoperitoneal shunt failure associated with persistent cerebrospinal fluid eosinophilia and latex allergy by use of an "extracted" shunt.

Shunt failure is commonly associated with infection or mechanical obstruction of the shunt system. The presence of eosinophilia in the cerebrospinal fluid (CSF) has been associated with CSF shunt failure and may be related to both latex and shunt allergies. The authors describe the case of a child with a latex allergy who presented with 10 episodes of shunt failure over a period of 93 months. Cerebrospinal fluid sampling demonstrated persistent eosinophilia (3-36%) and negative cultures. Pathological examination of the ventricular catheter on 3 occasions demonstrated mechanical obstruction by inflammatory debris consisting largely of eosinophils and multinucleated giant cells. On the suspicion that the child might have some uncharacterized allergy to the shunt hardware, shunt replacement was performed using an "extracted" shunt system. The child has remained free of shunt malfunction for > 2 years since the last surgery. Immune responses to unpolymerized silicone are discussed.