Peri-Insular Hemispherotomy: A Systematic Review and Institutional Experience.

INTRODUCTION: Peri-insular hemispherotomy (PIH) is a hemispheric separation technique under the broader hemispherotomy group, a surgical treatment for patients with intractable epilepsy. Hemispherotomy techniques such as the PIH, vertical parasagittal hemispherotomy (VPH), and modified-lateral hemispherotomy are commonly assessed together, despite significant differences in anatomical approach and patient selection. We aim to describe patient selection, outcomes, and complications of PIH in its own right. METHODS: A systematic review of the literature, in accordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) guidelines, was conducted, with searches of the PubMed and Embase databases. A local series including patients receiving PIH and followed up at the Queensland Children's Hospital between 2014 and 2020 was included. RESULTS: Systematic review of the literature identified 393 patients from 13 eligible studies. Engel class 1 outcomes occurred in 82.4% of patients, while 8.6% developed post-operative hydrocephalus. Hydrocephalus was most common in the youngest patient cohorts. Developmental pathology was present in 114 (40.8%) patients, who had fewer Engel 1 outcomes compared to those with acquired pathology (69.1% vs. 83.7%, p = 0.0167). The local series included 13 patients, 11/13 (84.6%) had Engel class 1 seizure outcomes. Post-operative hydrocephalus occurred in 2 patients (15.4%), and 10/13 (76.9%) patients had worsened neurological deficit. CONCLUSION: PIH delivers Engel 1 outcomes for over 4 in 5 patients selected for this procedure, greater than described in combined hemispherectomy analyses. It is an effective technique in patients with developmental and acquired pathologies, despite general preference of VPH in this patient group. Finally, very young patients may have significant seizure and cognitive benefits from PIH; however, hydrocephalus is most common in this group warranting careful risk-benefit assessment. This review delivers a dedicated PIH outcomes analysis to inform clinical and patient decision-making.

Growth of Intramedullary Spinal Cord Dermoid Cyst from a Congenital Thoracic Dermal Sinus Tract after Negative Screening Ultrasound Imaging.

INTRODUCTION: Intramedullary thoracic dermoid cysts are rare lesions that are associated with dermal sinus tracts (DSTs). Current recommendations advocate for imaging-based screening of suspected DSTs shortly after birth to exclude associated inclusion lesions. CASE PRESENTATION: A 6-year-old male child presented with a 2-week history of progressive ataxia, lower limb weakness, and hyperreflexia. He was suspected to have a thoracic DST at birth, though initial screening ultrasound was negative for an inclusion lesion or intradural tract. On representation, MRI demonstrated a 3.9-cm intramedullary thoracic dermoid cyst causing significant spinal cord compression. Intraoperatively, a DST extending intradurally was found. The associated dermoid cyst was removed via intracapsular resection. CONCLUSIONS: Whilst dermoid cysts are presumed to progressively develop from DSTs, to our knowledge, this is the first case in English literature documenting a thoracic spinal cord intramedullary dermoid cyst following a negative screening ultrasound for a suspected DST. We use this case to highlight the false-negative rates associated with postnatal screening and advocate for early neurosurgical referral of suspected DSTs, regardless of imaging findings.

Minimally invasive lumbar decompression: long-term outcome, morbidity, and the learning curve from the first 50 cases.

STUDY DESIGN: Prospective observational study. OBJECTIVE: To describe our experience with the first 50 cases of minimally invasive lumbar canal decompression in terms of patient outcome up to 2 years, the learning curve incurred, and complications when compared with our most recent 50 cases. SUMMARY OF BACKGROUND DATA: Lumbar canal stenosis is a common condition in the elderly population, the symptoms of which respond well to surgical decompression. A minimally invasive approach offers potential short and long-term benefits to patients but the technique is associated with a learning curve and equivalence to open surgery regarding efficacy and complications needs to be demonstrated. METHODS: Fifty patients (mean age 70 y) who presented with clinical and radiological features of lumbar canal stenosis and who had failed a period of conservative management underwent lumbar canal decompression through a paramedian oblique, muscle splitting approach using a 16 to 18 mm operating tube and microscope. Outcome was assessed using the Oswestry Disability Index and Short Form-36 at 3 months, 1 year, and 2 years. RESULTS: Significant clinical improvements were seen at 3 months that were sustained at 1 and 2 years. Clinical outcome improved whereas operative time and complications fell as experience increased, helping to define the learning curve with this technique. CONCLUSIONS: Minimally invasive lumbar decompression seems to offer patients a clinical benefit comparable to that observed in published open series, with potential advantages in terms of postoperative pain and recovery. However, there is a learning curve and whether this technique offers long-term benefits with regard to a reduction in back pain or postoperative spondylolisthesis is not yet known.

Pinless frameless electromagnetic image-guided neuroendoscopy in children.

OBJECTIVES: Frameless imaged-guided neuronavigation is a useful adjunct to neuroendoscopy in paediatric patients, especially those with abnormal or complex ventricular or cyst anatomy. The development of electromagnetic neuronavigation has allowed the use of image-guided navigation in the very young patient in whom rigid fixation in cranial pins is contraindicated. The technique and the authors' experience of its use in a series of paediatric patients are described. MATERIALS AND METHODS: Nineteen paediatric patients were treated with endoscopic surgery at two paediatric neurosurgery centres over a period of 18 months. A total of 29 endoscopic procedures were performed. The cases were reviewed and surgical outcomes assessed. In all of the cases, the goal of surgery was realised successfully at the time of surgery, as confirmed by post-operative imaging. No technical failures were encountered. None of the patients suffered worsened neurological function as a result of their procedures. CONCLUSION: Pinless, frameless electromagnetic neuronavigation was found to be a safe technique that can supplement endoscopic surgery in the very young patient. It allows the use of direct navigation of the endoscope in patients that are unable safely to undergo rigid cranial fixation in pins due to young age or thin skull vaults. This has proven to be a useful adjunct to neuroendoscopy in the subset of infants who have complicated or distorted ventricular anatomy and can improve the safety and accuracy of this type of surgery. It is also an alternative to optical neuronavigation in conjunction with neuroendoscopy in patients of any age.

Experiences and views of patients, carers and healthcare professionals on using modems in domiciliary non-invasive ventilation (NIV): a qualitative study.

BACKGROUND: Advances in technology means that domiciliary non-invasive ventilation (NIV) devices can be remotely monitored via modems in patients' homes. Possible benefits and challenges of modem technology have yet to be established. This study explored the perspectives and experiences of patients, their carers and healthcare professionals (HCPs) on the addition of modem technology in managing home NIV. METHODS: A qualitative study using a combination of focus groups for HCPs and interviews for carers/patients was undertaken. 12 HCPs and 22 patients/carers participated. These focus groups and interviews were audio-recorded, transcribed verbatim and analysed thematically. RESULTS: Five main themes were identified. 'Surveillance: a paradox of findings': HCPs were concerned about unduly scrutinising patients' lives, potentially impacting on HCP patient relationships. Conversely, patients welcomed modem monitoring and did not express concerns regarding invasion of privacy. 'Sanctions': HCPs reported the modem increased access to care and allowed appropriate assessment of ongoing treatment. 'Complacency and ethics': HCPs expressed concerns patients may become complacent in seeking help due to expectations of modem monitoring, as well as being concerned regarding the ethics of modems. There was a suggestion patients and carers' expectations of monitoring were different to that of clinical practice, resulting in complacency in some cases. 'Increased time for patient focused care': HCPs in the focus groups described a number of ways in which using modems was more efficient. 'Confidence: can be improved with technology': patients and carers were positive about the impact of the modems on their health and well-being, particularly their confidence. CONCLUSION: HCPs expressed concerns about surveillance were not corroborated by patients, suggesting acceptability of remote monitoring. Data suggests a need for increased clarity to patients/carers regarding clinical practice relating to responsiveness to modem data. The issue of complacency requires further consideration. Modem technology was acceptable and considered a useful addition by HCPs, patients and carers. TRIAL REGISTRATION NUMBER: NCT03905382.

Using domiciliary non-invasive ventilator data downloads to inform clinical decision-making to optimise ventilation delivery and patient compliance.

INTRODUCTION: Ventilation parameter data from patients receiving home mechanical ventilation can be collected via secure data cards and modem technology. This can then be reviewed by clinicians and ventilator prescriptions adjusted. Typically available measures include tidal volume (VT), leak, respiratory rate, minute ventilation, patient triggered breaths, achieved pressures and patient compliance. This study aimed to assess the potential impact of ventilator data downloads on management of patients requiring home non-invasive ventilation (NIV). METHODS: A longitudinal within-group design with repeated measurements was used. Baseline ventilator data were downloaded, reviewed and adjustments made to optimise ventilation. Leak, VT and compliance data were collected for comparison at the first review and 3-7 weeks later. Ventilator data were monitored and amended remotely via a modem by a consultant physiotherapist between the first review and second appointment. RESULTS: Analysis of data from 52 patients showed increased patient compliance (% days used >4 hours) from 90% to 96% (p=0.007), increased usage from 6.53 to 6.94 hours (p=0.211) and a change in VT(9.4 vs 8.7 mL/kg/ideal body weight, p=0.022). There was no change in leak following review of NIV prescriptions (mean (SD): 43 (23.4) L/min vs 45 (19.9)L/min, p=0.272). CONCLUSION: Ventilator data downloads, via early remote assessment, can help optimise patient ventilation through identification of modifiable factors, in particular interface leak and ventilator prescriptions. However, a prospective study is required to assess whether using ventilator data downloads provides value in terms of patient outcomes and cost-effectiveness. The presented data will help to inform the design of such a study.

Epidemiological aspects of spontaneous subarachnoid haemorrhage in Queensland, Australia.

AIMS: To examine the epidemiology of spontaneous subarachnoid haemorrhage (SAH) within the population of Queensland, Australia in 2002. METHODS: A retrospective population and hospital-based survey of all cases of spontaneous SAH occurring within the population of Queensland (3.7 million) during the calendar year 2002 was performed. Cases were identified from hospital separation coding data and the register of births, deaths and marriages. Standard demographic data was recorded for each case identified. RESULTS: The annual incidence of SAH in our population was 9.4 cases per 100,000. There was a steady increase in the incidence of SAH with increasing age, with the incidence rising to 38.8 per 100,000 in those aged greater than 80. The overall mortality rate was 33.1%, with 6% of all cases dying before reaching hospital care. The annual incidence in the indigenous population of Queensland was 8.9 /100,000.

Penicillins. A current review of their clinical pharmacology and therapeutic use.

The penicillins are a large group of bicyclic ring compounds which contain a 4-membered beta-lactam ring (penams) fused to a 5-membered thiazolidine ring. Benzylpenicillin (penicillin G) was the first natural penicillin with potent activity against all Gram-positive pathogens, Gram-negative cocci and some spirochaetes and actinomycetes. For the last 50 years benzylpenicillin has been the mainstay of therapy for serious pneumococcal, streptococcal, meningococcal and gonococcal infections. However, the past decade has seen the emergence of resistance in certain parts of the world, initially among the gonococci, and more recently among the pneumococci and meningococci. Discovery of the 6-aminopenicillinamic acid nucleus has led to considerable manipulation of the basic ring structure, resulting initially in the synthesis of ampicillin, and subsequently the other aminopenicillins, analogues, esters and prodrugs. These drugs have the advantages of improved oral bioavailability and superior activity against Haemophilus influenzae, certain Gram-negative bacilli, salmonellae, enterococci and Listeria monocytogenes, making these agents popular in the treatment of upper and lower respiratory tract infections and urinary tract infections. The increasing spread of bacterial resistance, particularly among Enterobacteriaceae and H. influenzae, has curtailed the usefulness of these drugs in these clinical settings. To counteract this problem, a number of agents combining a penicillin and a beta-lactamase inhibitor (e.g. clavulanic acid, tazobactam and sulbactam) have been developed. These inhibitors have no intrinsic antibacterial activity, but combining them with a penicillin (e.g. amoxicillin/clavulanic acid) confers greater stability to beta-lactamases and hence a broader spectrum of activity. The emergence of penicillinase-producing staphylococci that rendered benzylpenicillin ineffective also stimulated the search for penicillinase-resistant penicillins--methicillin and nafcillin, followed by the acid-stable isoxazolyl penicillins. These agents are now the principle antistaphylococcal treatment. Methicillin-resistant coagulase-negative staphylococci are currently a major cause of hospital sepsis, and are resistant to these latter agents. Enteric Gram-negative bacilli have been the predominant cause of serious hospital infections during the last 30 years. Further manipulation of the penicillin structure has resulted in compounds with broader activity against Gram-negative bacilli, particularly Pseudomonas aeruginosa, while retaining activity against Gram-positive pathogens. The carboxypenicillins were the first step in this direction, but have been largely superseded by the ureidopenicillins. These agents have better activity against P. aeruginosa, and are still effective against Gram-negative and Gram-positive bacteria, including enterococci and anaerobic organisms.(ABSTRACT TRUNCATED AT 400 WORDS)

History of Varicella Zoster Virus.

The earliest reports of vesicular rashes of the type we now recognize to be caused by herpes simplex and zoster date to the ancient civilizations. It was not until 1888, however, that a relationship between herpes zoster and chickenpox was suggested. Establishing this link represented one of the major hurdles in the history of varicella zoster virus. There was no animal host and this meant that much of the evidence needed to be obtained by clinical and epidemiological observation. Since the link was proven, in the 1950s, the advent of the live attenuated vaccine virus, in 1974, and aciclovir in the 1980s, has had a huge impact on prevention and treatment, respectively. The complete DNA sequence of VZV was established in 1986. A more complete understanding of the VZV genome and its gene products may enable recombinant vaccines and specific therapies to be advanced. We also need to determine the long-term effects of the use of the varicella vaccine. The ultimate aim: to prevent VZV infection completely.

Clinical applications for change-point analysis of herpes zoster pain.

Pain is the most frequent and disabling complication of herpes zoster. The analysis of pain severity data is complicated by the nonlinear rate of resolution. Further, three distinct phases characterize pain resolution--acute, subacute, and chronic. Using two clinical trial datasets as the bases for analyses, the rates of baseline pain resolution were computed across each of three phases and compared for age, severity of pain at onset, and number of lesions at baseline. The results defined transition points of 24.4 +/- 3.34 for the subacute phase and 110.3 +/- 11.9 days for the chronic phase. The model demonstrated a treatment effect of valiciclovir (VACV) during the subacute phase as compared to acyclovir (ACV) (P = 0.006) and supports effects of age, baseline pain and number lesions on pain cessation rates in the acute phase. This model verifies three phases of zoster pain and delineates the impact of treatment and other factors on the phase-specific rates of pain cessation.

Complications from minimally invasive lumbar interbody fusion: experience from 100 patients.

Minimally invasive lumbar fusion is well described and is reported to offer significant advantages to patients in terms of blood loss, a reduction in post-operative pain and a quicker recovery. However, this technique may expose patients to a greater risk of complications when compared to open lumbar instrumented fusion that may negate these advantages. Between January 2007 and March 2001, we conducted a prospective observational study of 100 consecutive patients (48 males and 52 females, mean age of 54 years) to investigate complications occurring from minimally invasive lumbar interbody fusion surgery using an image-guided technique. All patients underwent post-operative CT scans to assess implant placement. Scanning was repeated at 6 months to assess bony fusion. We observed the following complications: 2.5% (11/435) pedicle screw misplacement, 1.7% (2/120) interbody cage misplacement; 0.8% (1/120) interbody cage migration; 0.8% (1/120) patients requiring a post-operative blood transfusion; 2% (2/100) venous thrombo-embolism and 3% (3/100) patients with complications thought to be related to the use of bone morphogenic protein. There were no occurrences of infection and no cerebrospinal fluid leaks. We concluded that the rate of complications from minimally invasive lumbar interbody fusion is low, and compares favourably with the rates of complication from open procedures. Moreover, computerised navigation systems can be used in place of real-time fluoroscopy to guide implant placement, without an increase in the rate of complications.

Promoting fusion in minimally invasive lumbar interbody stabilization with low-dose bone morphogenic protein-2--but what is the cost?

BACKGROUND: Using bone morphogenic protein (BMP) to augment fusion in spine surgery is widespread and lends itself in particular to minimally invasive lumbar fusion, where the surface area for fusion is significantly less than the equivalent open procedure. PURPOSE: Here we described the use of very low-dose BMP in promoting fusion in minimally invasive lumbar interbody fixation but also highlight some of the potential complications of BMP-2 use and techniques available to reduce or avoid them. STUDY DESIGN: Prospective observational study of consecutive patients undergoing minimally invasive lumbar interbody fusion with percutaneous pedicle screws. PATIENT SAMPLE: Thirty patients aged between 22 and 78 years (mean 53 years). OUTCOME MEASURES: Thin-slice lumbar computed tomography scanning with multiplanar reconstruction at 6 and 12 months postoperative. METHODS: Thirty-six spinal levels were instrumented in total, of which four underwent posterior lumbar interbody fusion and 32 underwent transforaminal lumbar interbody fusion. Bone graft harvested locally was placed in the disc space with low-dose BMP-2 (1.4 mg per level). RESULTS: Thirty-three of 36 spinal levels showed complete fusion at a mean postoperative scan time of 7.1 months. Two levels demonstrated partial fusion at 6 months, which was complete at 12 months. There was one case of nonunion at 12 months, which also demonstrated vertebral body osteolysis. Despite very low-dose BMP-2, two cases of asymptomatic heterotopic ossification were observed, and there were two cases of perineural cyst formation, one of whom required revision of the interbody cage. CONCLUSIONS: The use of BMP with autograft in the disc space during minimally invasive lumbar interbody fusion is associated with a high rate of early fusion. Even with very low-dose BMP used in this study, complications related to BMP usage were not avoided completely.

Safety and efficacy of intradural extramedullary spinal tumor removal using a minimally invasive approach.

BACKGROUND: Although minimally invasive surgery for intradural tumors offers the potential benefits of less postoperative pain, a quicker recovery, and the avoidance of long-term instability from multilevel laminectomy, there are concerns over whether one can safely and effectively remove intradural extramedullary tumors in a fashion comparable to open techniques and whether the advantages of minimally invasive surgery are clinically significant. OBJECTIVE: To review our early experience with minimally invasive techniques for intradural extramedullary tumors of the spine. METHODS: Thirteen intradural tumors (1 cervical, 6 thoracic, 6 lumbar) in 11 patients were operated on using a muscle-splitting, tube-assisted paramedian oblique approach with hemilaminectomy to access the spinal canal while preserving the spinous process and ligaments. Fluoroscopy and navigation were used to determine the surgical level in all thoracic and lumbar cases. RESULTS: Satisfactory tumor resection using standard microsurgical techniques was achieved in all but 1 case using a minimally invasive approach. Surgical time and intraoperative blood loss were favorable compared with our open technique cases. There was no postoperative morbidity with the minimally invasive approach, although in 2 patients with tumors in the mid- and upper thoracic spine, the surgical incision was inaccurately placed by 1 level. In 1 case, the approach was converted to open when the tumor could not be found, and postoperatively there was a cerebrospinal fluid leak with infection that required readmission. CONCLUSION: Intradural extramedullary tumors can be safely and effectively removed using minimally invasive techniques. The pros and cons of minimally invasive vs open surgery are discussed.