Christopher R P Lind

Sir Charles Gairdner Hospital, Perth City, Western Australia, Australia

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Publications (44)88.6 Total impact

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    ABSTRACT: We describe a rare case of vascularised orbital roof and calvarial erosions with an associated venous malformation. In the absence of infection, malignancy, trauma and eosinophillic granuloma, the closest previously described entity is vanishing bone disease. Computed tomography (CT), MRI, catheter angiography and pathology were all important in the diagnostic workup to enable surgical planning for biopsy and reconstruction. Ongoing CT and MRI follow-up imaging will determine future treatment planning.
    Journal of Medical Imaging and Radiation Oncology 06/2014; · 0.98 Impact Factor
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    ABSTRACT: Anterior lumbar surgery for degenerative disc disease (DDD) is a relatively novel technique that can prevent damage to posterior osseous, muscular and ligamentous spinal elements. This study reports the outcomes and complications in 286 patients who underwent fusion – with artificial disc implants or combined fusion and artificial disc implants – by a single-operator neurosurgeon, with up to 24 months of follow-up. The visual analogue scale (VAS), Oswestry Disability Index (ODI), Short Form 36 (SF36) and prospective log of adverse events were used to assess the clinical outcome. Radiographic assessments of implant position and bony fusion were analysed. Intraoperative and postoperative complications were also recorded. Irrespective of pre-surgical symptoms (back pain alone or back and leg pain combined), workers’ compensation status and type of surgical implant, clinically significant improvements in VAS, ODI and SF36 were primarily observed at 3 and/or 6 month follow-up, and improvements were maintained at 24 months after surgery. A 94% fusion rate was obtained; the overall complication was 9.8% which included 3.5% with vascular complications. The anterior lumbar approach can be used for treating DDD for both back pain and back and leg pain with low complication rates. With appropriate training, single-operator neurosurgeons can safely perform these surgeries.
    Journal of Clinical Neuroscience 04/2014; · 1.25 Impact Factor
  • Stephen Honeybul, Kwok M Ho, Christopher R P Lind, Grant R Gillett
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    ABSTRACT: Object The goal in this study was to assess the validity of the corticosteroid randomization after significant head injury (CRASH) collaborators prediction model in predicting mortality and unfavorable outcome at 18 months in patients with severe traumatic brain injury (TBI) requiring decompressive craniectomy. In addition, the authors aimed to assess whether this model was well calibrated in predicting outcome across a wide spectrum of severity of TBI requiring decompressive craniectomy. Methods This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia between 2004 and 2012 and for whom 18-month follow-up data were available. Clinical and radiological data on initial presentation were entered into the Web-based model and the predicted outcome was compared with the observed outcome. In validating the CRASH model, the authors used area under the receiver operating characteristic curve to assess the ability of the CRASH model to differentiate between favorable and unfavorable outcomes. Results The ability of the CRASH 6-month unfavorable prediction model to differentiate between unfavorable and favorable outcomes at 18 months after decompressive craniectomy was good (area under the receiver operating characteristic curve 0.85, 95% CI 0.80-0.90). However, the model's calibration was not perfect. The slope and the intercept of the calibration curve were 1.66 (SE 0.21) and -1.11 (SE 0.14), respectively, suggesting that the predicted risks of unfavorable outcomes were not sufficiently extreme or different across different risk strata and were systematically too high (or overly pessimistic), respectively. Conclusions The CRASH collaborators prediction model can be used as a surrogate index of injury severity to stratify patients according to injury severity. However, clinical decisions should not be based solely on the predicted risks derived from the model, because the number of patients in each predicted risk stratum was still relatively small and hence the results were relatively imprecise. Notwithstanding these limitations, the model may add to a clinician's ability to have better-informed conversations with colleagues and patients' relatives about prognosis.
    Journal of Neurosurgery 03/2014; · 3.15 Impact Factor
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    Miu Fei Lam, Stacy W L Foo, Meghan G Thomas, Christopher R P Lind
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    ABSTRACT: Background: Acute convection-enhanced delivery (CED) is a neurosurgical delivery technique that allows for precise and uniform distribution of an infusate to a brain structure. It remains experimental due to difficulties in ensuring successful delivery. Real-time monitoring is able to provide immediate feedback on cannula placement, infusate distribution, and if the infusion is proceeding as planned or is failing due to reflux or catheter obstruction. New method: Pressure gradient is the driving force behind CED, with the infusion pressure being directly proportional to the flow-rate. The aim of this study was to assess the feasibility of using infusion-line pressure profiling to distinguish in real-time between succeeding and failing CED infusions. To do so we delivered cresyl violet dye at 0.5, 1.0 and 2.0 μl/min via CED in vitro using 0.6% agarose gel and in vivo to the rat striatum. Results: Infusions that failed in agarose gel models could only be differentiated late during the procedures. In the rat in vivo model, the infusion-line profiles of obstructed infusions were not distinctive from those of successful infusions. Comparison with existing method: Intraoperative magnetic resonance imaging (MRI) is used for real-time visualisation of cannula placement and infusate distribution. Particularly for animal pre-clinical work, it would be advantageous to supplement MRI with a cheap, accessible technique to monitor infusions and provide a real-time measure of infusion success or failure. Conclusions: Infusion-line pressure monitoring was of limited value in identifying successful CED with small volume infusions, whilst its utility for large volume infusion remains unknown.
    Journal of Neuroscience Methods 01/2014; 221:127-131. · 2.11 Impact Factor
  • Charles Watson, Christopher R P Lind, Meghan G Thomas
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    ABSTRACT: The caudal zona incerta is the target of a recent modification of established procedures for deep brain stimulation (DBS) for Parkinson's disease and tremor. The caudal zona incerta contains a number of neuronal populations that are distinct in terms of their cytoarchitecture, connections, and pattern of immunomarkers and is located at a position where a number of major tracts converge before turning toward their final destination in the forebrain. However, it is not clear which of the anatomical features of the region are related to its value as a target for DBS. This paper has tried to identify features that distinguish the caudal zona incerta of rodents (mouse and rat) and primates (marmoset, rhesus monkey, and human) from the remainder of the zona incerta. We studied cytoarchitecture, anatomical relationships, the pattern of immunomarkers, and gene expression in both of these areas. We found that the caudal zona incerta has a number of histological and gene expression characteristics that distinguish it from the other subdivisions of the zona incerta. Of particular note are the sparse population of GABA neurons and the small but distinctive population of calbindin neurons. We hope that a clearer appreciation of the anatomy of the region will in the end assist the interpretation of cases in which DBS is used in human patients.
    Journal of Anatomy 10/2013; · 2.36 Impact Factor
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    ABSTRACT: In this paper, we present a method to combine a Gaussian Process regression and a particle filter to track the 3D human pose in video sequences. We first build the probabilistic discriminative model that maps the silhouette descriptor to multiple 3D human poses using a Gaussian Process regression. The multimodal output distribution from the Gaussian Process regression is combined with the particle filter to track the 3D human pose in each frame of the video sequence. The predictions from the discriminative model are used to generate the hypothesis space for the particle filter and to initialize the tracking. We evaluate our approach on the HumanEva-I dataset and on the video sequences of Parkinson’s patients. The evaluation results show that our approach does not require initialization and successfully tracks the 3D human pose over long video sequences.
    IEEE 8th Conference on Industrial Electronics and Applications (ICIEA), Melbourne, Australia; 06/2013
  • Investigative ophthalmology & visual science 11/2012; 53(11):6880. · 3.43 Impact Factor
  • S Honeybul, K M Ho, C R P Lind, G R Gillett
    Acta Neurochirurgica 10/2012; · 1.55 Impact Factor
  • S Honeybul, K M Ho, C R P Lind
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    ABSTRACT: Over the past two decades there has been a resurgence of interest in the use of decompressive craniectomy for severe traumatic brain injury. A number of studies have demonstrated that the procedure can consistently lower the intracranial pressure (ICP) and a significant number of patients achieve a good long term functional recovery. There has however been debate regarding clinical indications and patient selection and until recently there has been limited clinical data which can be used to guide clinical decision making. The DECRA study compared patients who had had an early decompressive craniectomy for diffuse traumatic brain injury with patients who had received standard medical therapy. The trial demonstrated that 70% of patients in the Craniectomy group has an unfavourable outcome versus 51% of patients in the standard care group (OR = 2.21 [95%CI: 1.14-4.26] p=0.02). The authors concluded that based on these results not only was decompressive craniectomy associated with more unfavourable outcomes but also by adopting standard medical therapy rather than surgical decompression the healthcare system will save millions of dollars. Unfortunately, these conclusions are not really supported by closer examination of the basic data. There were problems with randomisation such that the patients in the surgical arm appeared to have sustained a more severe primary brain injury, the intracranial pressure threshold of greater than 20mmHg for more than fifteen minutes did not really reflect clinical practice and there was a high crossover rate from the standard care arm to the surgical arm. Because of these problems the trial has received a great deal of criticism indeed some authorities have claimed that the results should have no influence on clinical practice. This is perhaps slightly unfair and in this paper we offer an alternative interpretation.
    World Neurosurgery 09/2012; · 1.77 Impact Factor
  • Stephen Honeybul, Grant Gillett, Kwok Ho, Christopher Lind
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    ABSTRACT: In all fields of clinical medicine, there is an increasing awareness that outcome must be assessed in terms of quality of life and cost effectiveness, rather than merely length of survival. This is especially the case when considering decompressive craniectomy for severe traumatic brain injury. The procedure itself is technically straightforward and involves temporarily removing a large section of the skull vault in order to provide extra space into which the injured brain can expand. A number of studies have demonstrated many patients going on to make a good long-term functional recovery, however, this is not always the case and a significant number survive but are left with severe neurocognitive impairment. Unfortunately, many of these patients are young adults who were previously fit and well and are, therefore, likely to spend many years in a condition that they may feel to be unacceptable, and this raises a number of ethical issues regarding consent and resource allocation. In an attempt to address these issues, we have used the analytical framework proposed by Jonsen, that requires systematic consideration of medical indications, patient preferences, quality of life and contextual features.
    Journal of medical ethics 07/2012; · 1.42 Impact Factor
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    ABSTRACT: As efforts to noninvasively measure intracranial pressure (ICP) increase, we thought it important to investigate the timing of retinal venous pulsation in relation to the intraocular and intracranial pressure pulses. Neurosurgical patients undergoing continuous direct ICP monitoring had video recordings of ICP, IOP, and retinal venous pulsation waveforms taken with constant timing relative to the cardiac cycle using pulse oximetry. Video frames of the maxima and minima of these parameters, including retinal vein diameter, were identified. The times from pulse oximetry "beep" to these parameters were measured and converted into a percentage of the respective cardiac cycle. A total of 338 measurements from nine subjects with a mean age of 39 years, mean ICP of 4.4 mm Hg and IOP 15.1 mm Hg were taken. Vein diameter minima occurred an insignificant 0.6% of cardiac cycle before ICP minima (P = 0.6620) and a significant 3.2% after IOP minima (P = 0.0097) and significantly later than IOP (51%) and ICP maxima (74%, all P < 0.0001). Maximum vein diameter occurred an insignificant 2.0% before IOP maxima (P = 0.2267) and was significantly different from IOP and ICP minima (P < 0.00001). Mean venous pulsation pressure between the two eyes was significantly associated with ICP (r = 0.89, P = 0.0075). During pulsation, central retinal vein collapse occurs in time with IOP and ICP diastole. Venous collapse is not induced by intraocular systole. These results suggest that ICP pulse pressure dominates the timing of venous pulsation.
    Investigative ophthalmology & visual science 06/2012; 53(8):4676-81. · 3.43 Impact Factor
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    ABSTRACT: How do decisions change if we can assess risk of "unacceptable badness"?
    The Medical journal of Australia 05/2012; 196(8):531-3. · 2.85 Impact Factor
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    ABSTRACT: Decompressive craniectomy has been traditionally used as a lifesaving rescue procedure for patients with refractory intracranial hypertension after severe traumatic brain injury (TBI), but its cost-effectiveness remains uncertain. Using data on length of stay in hospital, rehabilitation facility, procedural costs, and Glasgow Outcome Scale (GOS) up to 18 months after surgery, the average total hospital costs per life-year and quality-adjusted life-year (QALY) were calculated for patients who had decompressive craniectomy for TBI between 2004 and 2010 in Western Australia. The Corticosteroid Randomisation After Significant Head Injury prediction model was used to quantify the severity of TBI. Of the 168 patients who had 18-month follow-up data available after the procedure, 70 (42%) achieved a good outcome (GOS-5), 27 (16%) had moderate disability (GOS-4), 34 (20%) had severe disability (GOS-3), 5 (3%) were in vegetative state (GOS-2), and 32 (19%) died (GOS-1). The hospital costs increased with the severity of TBI and peaked when the predicted risk of an unfavorable outcome was about 80%. The average cost per life-year gained (US$671,000 per life-year) and QALY (US$682,000 per QALY) increased substantially and became much more than the usual acceptable cost-effective limit (US$100,000 per QALY) when the predicted risk of an unfavorable outcome was >80%. Changing different underlying assumptions of the analysis did not change the results significantly. Severity of TBI had an important effect on cost-effectiveness of decompressive craniectomy. As a lifesaving procedure, decompressive craniectomy was not cost-effective for patients with extremely severe TBI.
    The Journal of trauma 12/2011; 71(6):1637-44; discussion 1644. · 2.35 Impact Factor
  • Hari Ramakonar, Elizabeth A Franz, Christopher R P Lind
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    ABSTRACT: The rubber hand illusion (RHI) is a perceptual experience which often occurs when an administered tactile stimulation of a person's real hand hidden from view, occurs synchronously with a corresponding visual stimulation of an observed rubber hand placed in full vision of the person in a position corresponding to where their real hand might normally be. The perceptual illusion is that the person feels a sense of "ownership" of the rubber hand which they are looking at. Most studies have focused on the underlying neural properties of the illusion and the experimental manipulations that lead to it. The illusion could also be used for exploring the sense of limb and prosthetic ownership for people after amputation. Cortical electrodes such as those used in sensorimotor stimulation surgery for pain may provide an opportunity to further understand the cortical representation of the illusion and possibly provide an opportunity to modulate the individual's sense of body ownership. Thus, the RHI might also be a critical tool for development of neurorehabilitative interventions that will be of great interest to the neurosurgical and rehabilitation communities.
    Journal of Clinical Neuroscience 12/2011; 18(12):1596-601. · 1.25 Impact Factor
  • Stephen Honeybul, Kwok M Ho, Christopher R P Lind, Grant R Gillett
    Journal of neurotrauma 10/2011; 28(10):2199-200. · 4.25 Impact Factor
  • S Honeybul, G R Gillett, K M Ho, C R P Lind
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    ABSTRACT: The rule of rescue describes the powerful human proclivity to rescue identified endangered lives, regardless of cost or risk. Deciding whether or not to perform a decompressive craniectomy as a life-saving or 'rescue' procedure for a young person with a severe traumatic brain injury provides a good example of the ethical tensions that occur in these situations. Unfortunately, there comes a point when the primary brain injury is so severe that if the patient survives they are likely to remain severely disabled and fully dependent. The health resource implications of this outcome are significant. By using a web-based outcome prediction model this study compares the long-term outcome and designation of two groups of patients. One group had a very severe injury as adjudged by the model and the other group a less severe injury. At 18 month follow-up there were significant differences in outcome and healthcare requirements. This raises important ethical issues when considering life-saving but non-restorative surgical intervention. The discussion about realistic outcome cannot be dichotomised into simply life or death so that the outcome for the patient must enter the equation. As in other 'rescue situations', the utility of the procedure cannot be rationalised on a mere cost-benefit analysis. A compromise has to be reached to determine at what point either the likely outcome would be unacceptable to the person on whom the procedure is being performed or the social utility gained from the rule of rescue intervention fails to justify the utilitarian value and justice of equitable resource allocation.
    Journal of medical ethics 09/2011; 37(12):707-10. · 1.42 Impact Factor
  • Miu Fei Lam, Meghan G Thomas, Christopher R P Lind
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    ABSTRACT: Convection-enhanced delivery (CED) is a promising neurosurgical technique for the delivery of potential therapeutic agents to the Parkinson's disease (PD)-affected striatum. CED utilises stereotactic insertion of a catheter to the striatum and continuous infusion to distribute agents in the brain parenchyma. Insufficient attention to the details of CED may have contributed to early failures of translating candidate therapeutic agents from the laboratory to PD patients. A literature review was performed to examine the factors that govern CED in the laboratory as well as translation in PD and we found that although there have been significant developments in implant design, infusion parameters and infusate composition, there have not been enough comparative trials of different technologies. Further optimisation of CED is required before it can be applied in the clinical setting and this will require a step-by-step breakdown of the different elements of delivery for independent testing. We conclude that CED is a promising technique for delivering therapeutic agents to the striatum for the treatment of PD but further refinements are necessary for successful clinical translation. The risk is that early clinical translation of exciting new therapies may lead to therapeutic failure which is not due to the agent in question but simply the neurosurgical delivery.
    Journal of Clinical Neuroscience 09/2011; 18(9):1163-7. · 1.25 Impact Factor
  • Nova B Thani, Arul Bala, Christopher R P Lind
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    ABSTRACT: Accurate placement of a probe to the deep regions of the brain is an important part of neurosurgery. In the modern era, magnetic resonance image (MRI)-based target planning with frame-based stereotaxis is the most common technique. To quantify the inaccuracy in MRI-guided frame-based stereotaxis and to assess the relative contributions of frame movements and MRI distortion. The MRI-directed implantable guide-tube technique was used to place carbothane stylettes before implantation of the deep brain stimulation electrodes. The coordinates of target, dural entry point, and other brain landmarks were compared between preoperative and intraoperative MRIs to determine the inaccuracy. The mean 3-dimensional inaccuracy of the stylette at the target was 1.8 mm (95% confidence interval [CI], 1.5-2.1. In deep brain stimulation surgery, the accuracy in the x and y (axial) planes is important; the mean axial inaccuracy was 1.4 mm (95% CI, 1.1-1.8). The maximal mean deviation of the head frame compared with brain over 24.1 ± 1.8 hours was 0.9 mm (95% CI, 0.5-1.1). The mean 3-dimensional inaccuracy of the dural entry point of the stylette was 1.8 mm (95% CI, 1.5-2.1), which is identical to that of the target. Stylette positions did deviate from the plan, albeit by 1.4 mm in the axial plane and 1.8 mm in 3-dimensional space. There was no difference between the accuracies at the dura and the target approximately 70 mm deep in the brain, suggesting potential feasibility for accurate planning along the whole trajectory.
    Neurosurgery 08/2011; 70(1 Suppl Operative):114-23; discussion 123-4. · 2.53 Impact Factor
  • Miu Fei Lam, Bryant Allan Rigby Stokes, Christopher Raymond Peter Lind
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    ABSTRACT: We describe the phenomenon of paradoxical intracranial hypertension with upright posture with normal recumbent intracranial pressure (ICP). This effect was measured by direct ICP monitoring in a patient who had a lumboperitoneal shunt for idiopathic intracranial hypertension. Bilateral subtemporal surgical decompression to increase intracranial compliance with confirmatory perioperative pressure monitoring was central to the successful management of this patient.
    Journal of Clinical Neuroscience 07/2011; 18(7):988-9. · 1.25 Impact Factor

Publication Stats

286 Citations
88.60 Total Impact Points

Institutions

  • 2005–2014
    • Sir Charles Gairdner Hospital
      Perth City, Western Australia, Australia
  • 2010–2013
    • University of Western Australia
      • • School of Surgery
      • • School of Sport Science, Exercise and Health
      Perth City, Western Australia, Australia
    • University of Otago
      Taieri, Otago Region, New Zealand
  • 2003–2009
    • Auckland City Hospital
      Окленд, Auckland, New Zealand
  • 2006
    • University of Auckland
      • Faculty of Medical and Health Sciences
      Auckland, Auckland, New Zealand