Publications by authors named "Gwynedd E Pickett"

22 Publications

  • Page 1 of 1

Two Curious Cases of Complete Cerebellar Agenesis.

Can J Neurol Sci 2021 Aug 20:1-3. Epub 2021 Aug 20.

Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.

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http://dx.doi.org/10.1017/cjn.2021.199DOI Listing
August 2021

Electrothermal Coil Detachment Failure in Flow Diverter-Assisted Coiling of a Small Blister Aneurysm: Technical Considerations and Possible Solutions.

Neurointervention 2021 Jul 8;16(2):171-174. Epub 2021 Apr 8.

Department of Radiology (Neuroradiology), Dalhousie University, Halifax, NS, Canada.

Flow diversion stenting combined with coiling offers both immediate protection from rebleeding for ruptured aneurysms and long-term stability for wide-necked or blister aneurysms. It is particularly useful for tiny ruptured aneurysms, alleviating the concern that small coils may prolapse between the struts of conventional stents. We employed this technique in a very small, broad-based ruptured aneurysm of the internal carotid, jailing the coiling microcatheter with a Pipeline Embolization Device. However, coil detachment repeatedly failed, until we withdrew the detachment zone into the microcatheter. We suggest that if the tip of the coiling catheter is adjacent to the stent, contact between the junction zone of the coil and the high metal density of the flow diverter may prevent proper electrothermal coil detachment. Detachment can be undertaken successfully within the microcatheter, though care must be taken thereafter to fully push the detached coil tail into the aneurysm.
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http://dx.doi.org/10.5469/neuroint.2020.00444DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8261105PMC
July 2021

Management of Ruptured Intracranial Aneurysms in the Post-International Subarachnoid Aneurysm Trial Era: A Single-Centre Prospective Series.

Can J Neurol Sci 2021 Mar 17:1-8. Epub 2021 Mar 17.

Division of Neurosurgery, Department of Surgery, Dalhousie University, Halifax, NS, Canada.

Background: Aneurysmal subarachnoid haemorrhage (aSAH) is associated with significant morbidity and mortality. The International Subarachnoid Aneurysm Trial (ISAT) reported reduced morbidity in patients treated with endovascular coiling versus surgical clipping. However, recent studies suggest that there is no significant difference in clinical outcomes. This study examines the outcomes of either technique for treating aSAH during the 15 years post-ISAT at a Canadian quaternary centre.

Methods: We reviewed prospectively collected data of patients admitted with aSAH from January 2002 to December 2017. Glasgow Outcome Scale (GOS) was compared at discharge, 6 months and 12 months' follow-up using univariate and multivariable ordinal logistic regression. Post-operative complications were assessed using binary logistic regression.

Results: Two-hundred and eighty-seven patients were treated with coiling and 95 patients with clipping. The mean age of clipped patients was significantly younger, and hypertension was significantly commoner in coiled patients. A greater proportion of coiled aneurysms were located in the posterior circulation. No difference in the odds of having a favourable GOS was seen between patients who were clipped versus coiled at any of follow-up time points on univariate or multivariable analysis. In both treatment groups, patient recovery to independence (GOS 4-5) was seen from discharge to 6 months, but not from 6 to 12 months' follow-up, without difference between clipping and coiling.

Conclusion: These real-world findings suggest clipping remains an effective and important treatment option for patients with aSAH who do not meet ISAT inclusion criteria. The results can assist in clinical decision-making processes and understanding of the natural recovery progression of aSAH.
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http://dx.doi.org/10.1017/cjn.2021.45DOI Listing
March 2021

Gender differences in the surgical management of lumbar degenerative disease: a scoping review.

J Neurosurg Spine 2020 Jan 31:1-18. Epub 2020 Jan 31.

1Division of Neurosurgery, Dalhousie University QEII Health Sciences Centre, Nova Scotia Health Authority, Halifax, Nova Scotia, Canada; and.

Objective: Despite efforts toward achieving gender equality in clinical trial enrollment, females are often underrepresented, and gender-specific data analysis is often unavailable. Identifying and reducing gender bias in medical decision-making and outcome reporting may facilitate equitable healthcare delivery. Gender disparity in the utilization of surgical therapy has been exemplified in the orthopedic literature through studies of total joint arthroplasty. A paucity of literature is available to guide the management of lumbar degenerative disease, which stratifies on the basis of demographic factors. The objective of this study was to systematically map and synthesize the adult surgical literature regarding gender differences in pre- and postoperative patient-reported clinical assessment scores for patients with lumbar degenerative disease (disc degeneration, disc herniation, spondylolisthesis, and spinal canal stenosis).

Methods: A systematic scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. MEDLINE, Embase, and the Cochrane Registry of Controlled Trials were searched from inception to September 2018. Study characteristics including patient demographics, diagnoses, procedures, and pre- and postoperative clinical assessment scores (pain, disability, and health-related quality of life [HRQoL]) were collected.

Results: Thirty articles were identified, accounting for 32,951 patients. Six studies accounted for 84% of patients; 5 of the 6 studies were published by European groups. The most common lumbar degenerative conditions were disc herniation (59.0%), disc degeneration (20.3%), and spinal canal stenosis (15.9%). The majority of studies reported worse preoperative pain (93.3%), disability (81.3%), and HRQoL (75%) among females. The remainder reported equivalent preoperative scores between males and females. The majority of studies (63.3%) did not report preoperative duration of symptoms, and this represents a limitation of the data. Eighty percent of studies found that females had worse absolute postoperative scores in at least one outcome category (pain, disability, or HRQoL). The remainder reported equivalent absolute postoperative scores between males and females. Seventy-three percent of studies reported either an equivalent or greater interval change for females.

Conclusions: Female patients undergoing surgery for lumbar degenerative disease (disc degeneration, disc herniation, spondylolisthesis, and spinal canal stenosis) have worse absolute preoperative pain, disability, and HRQoL. Following surgery, females have worse absolute pain, disability, and HRQoL, but demonstrate an equal or greater interval change compared to males. Further studies should examine gender differences in preoperative workup and clinical course.
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http://dx.doi.org/10.3171/2019.11.SPINE19896DOI Listing
January 2020

Percutaneous glycerol rhizotomy for trigeminal neuralgia in patients with multiple sclerosis: a long-term retrospective cohort study.

J Neurosurg 2019 Apr 12;132(5):1405-1413. Epub 2019 Apr 12.

1Department of Clinical Neurological Sciences, Division of Neurosurgery, London Health Sciences Centre, Western University, London, Ontario, Canada; and.

Objective: The prevalence of trigeminal neuralgia (TN) in patients with multiple sclerosis (MS-TN) is higher than in the general population (idiopathic TN [ITN]). Glycerol rhizotomy (GR) is a percutaneous lesioning surgery commonly performed for the treatment of medically refractory TN. While treatment for acute pain relief is excellent, long-term pain relief is poorer. The object of this study was to assess the efficacy of percutaneous retrogasserian GR for the treatment of MS-TN versus ITN.

Methods: A retrospective chart review was performed, identifying 219 patients who had undergone 401 GR procedures from 1983 to 2018 at a single academic institution. All patients were diagnosed with medically refractory MS-TN (182 procedures) or ITN (219 procedures). The primary outcome measures of interest were immediate pain relief and time to pain recurrence following initial and repeat GR procedures. Secondary outcomes included medication usage and presence of periprocedural hypesthesia.

Results: The initial pain-free response rate was similar between groups (p = 0.726): MS-TN initial GR 89.6%; MS-TN repeat GR 91.9%; ITN initial GR 89.6%; ITN repeat GR 87.0%. The median time to recurrence after initial GR was similar between MS-TN (2.7 ± 1.3 years) and ITN (2.1 ± 0.6 years) patients (p = 0.87). However, there was a statistically significant difference in the time to recurrence after repeat GR between MS-TN (2.3 ± 0.5 years) and ITN patients (1.2 ± 0.2 years; p < 0.05). The presence of periprocedural hypesthesia was highly predictive of pain-free survival (p < 0.01).

Conclusions: Patients with MS-TN achieve meaningful pain relief following GR, with an efficacy comparable to that following GR in patients with ITN. Initial and subsequent GR procedures are equally efficacious.
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http://dx.doi.org/10.3171/2019.1.JNS183093DOI Listing
April 2019

Electroconvulsive Therapy After Flow Diversion Stenting of Intracranial Aneurysm.

J ECT 2019 06;35(2):e17-e19

Department of Surgery (Neurosurgery) Dalhousie University Halifax, Nova Scotia, Canada Department of Psychiatry Dalhousie University Halifax, Nova Scotia, Canada.

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http://dx.doi.org/10.1097/YCT.0000000000000576DOI Listing
June 2019

Focal Cortical Dysplasia Type IIIb with Oligodendroglioma in a Seizure-Free Patient.

Can J Neurol Sci 2018 05 12;45(3):360-362. Epub 2018 Feb 12.

3Division of Neurosurgery,Nova Scotia Health AuthorityQueen Elizabeth II Health Science Centre (Halifax Infirmary)Dalhousie University,Halifax,NS,Canada.

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http://dx.doi.org/10.1017/cjn.2017.295DOI Listing
May 2018

Management of Simultaneous Symptomatic Bilateral Carotid Stenosis.

Can J Neurol Sci 2015 Jul 11;42(4):267-8. Epub 2015 Jun 11.

Division of Neurosurgery,Dalhousie University,Halifax,Nova Scotia,Canada.

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http://dx.doi.org/10.1017/cjn.2015.35DOI Listing
July 2015

Sagittal balance influences range of motion: an in vivo study with the ProDisc-C.

Spine J 2009 Feb 10;9(2):128-33. Epub 2008 Jul 10.

Division of Neurosurgery, London Health Sciences Center, Ontario, Canada.

Background Context: Cervical arthroplasty is designed to maintain cervical motion of the functional spinal unit after cervical discectomy. The impact of the ProDisc-C (Synthes Spine, Paoli, PA) on in vivo kinematics and sagittal alignment requires further assessment.

Purpose: The purpose of this study is to test the hypothesis that the ProDisc-C increases range of motion (ROM) in flexion and extension at the surgical level, and assess its impact on cervical alignment.

Study Design: Clinical study.

Patient Sample: Fifteen patients with a mean age of 49 years were included in this study. Each patient had a single-level arthroplasty. Patients with multilevel arthroplasty, previous cervical spine surgery, and length of follow-up less than 6 months were excluded from this study.

Outcome Measure: Lateral dynamic radiographs of the cervical spine were analyzed using quantitative measurement analysis (QMA) preoperatively and postoperatively. QMA software was also used to determine the ROM and sagittal translation at the surgical level.

Methods: Flexion/extension lateral radiographs of the cervical spine were prospectively collected and reviewed in 15 patients preoperatively and at early (1-3 months) and late (6-14 months) follow-up after placement of the ProDisc-C. Shell angle (SA) and C2-C7 Cobb angles were measured. Sagittal translation and ROM were calculated at each time point. Preoperative values were compared with early and late follow-up values using paired Student t tests and Pearson's correlation.

Results: The C2-C7 Cobb angle did not change significantly after surgery. Segmental ROM increased significantly from neutral to flexion (p=.02) and neutral to extension (p=.002) at late follow-up. SA correlated significantly with ROM from neutral to extension (Pearson's r=-0.55; p=.02) and translation from neutral to extension (Pearson's r=-0.58; p=.02).

Conclusions: The ProDisc-C increased overall segmental ROM. A lordotic SA may be associated with restricted segmental ROM and translation in extension. This study did not detect any change in overall cervical spinal alignment after insertion of the device.
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http://dx.doi.org/10.1016/j.spinee.2008.01.009DOI Listing
February 2009

Anterior cervical corpectomy and fusion accelerates degenerative disease at adjacent vertebral segments.

SAS J 2008 1;2(1):23-7. Epub 2008 Mar 1.

The Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.

Background: Anterior cervical corpectomy provides the most direct and thorough surgical approach for anterior decompression when spinal cord compression is found directly behind the vertebral body. However, anterior cervical fusion has been shown to be associated with the development of new degenerative changes at levels immediately adjacent to the fused segments. Th e incidence of adjacent segment disease (ASD) following anterior cervical corpectomy has not been widely reported. We set out to determine the incidence of clinical ASD following anterior cervical corpectomy.

Methods: We retrospectively reviewed all available medical charts and radiographic studies of all cases of anterior cervical corpectomy performed at the Barrow Neurological Institute over a 4-year period with a minimum 24-month follow-up. Factors assessed included the success of arthrodesis, the presence of degenerative changes on serial follow-up radiographs, and the development of new neurological symptoms.

Results: Seventy-six patients met the criteria for inclusion: 54 had undergone a 1-level corpectomy, 18 underwent a 2-level corpectomy, and 4 underwent a 3- or 4-level corpectomy. Arthrodesis was performed with either allograft or autograft and anterior cervical plating. All patients achieved successful fusion. Follow-up was available for a minimum of 2 years in all cases, with a mean length of 3.6 years. Sixteen patients (21%) eventually developed radiological and clinical evidence of degenerative changes at adjacent levels. In 10 of 11 patients who developed clinical symptoms within 2 years, the changes represented progression of pre-existing, asymptomatic degenerative disease. Five patients developed degenerative changes more than 5 years after surgery; these were all associated with an unrelated new insult to the cervical spine such as trauma.

Conclusions: Anterior cervical corpectomy with fixation can accelerate degenerative changes identified preoperatively at adjacent, asymptomatic levels of the cervical spine.

Level Of Evidence: Retrospective cohort study (level 2b).
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http://dx.doi.org/10.1016/SASJ-2007-0108-RRDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4365655PMC
March 2015

Visual pathway compromise after hydrocoil treatment of large ophthalmic aneurysms.

Neurosurgery 2007 Oct;61(4):E873-4; discussion E874

Department of Neurosurgery, Greater Manchester Neurosciences Centre, Manchester, United Kingdom.

Objective: Hydrogel-coated coils (MicroVention, Inc., Aliso Viejo, CA) for endovascular aneurysm treatment offer the theoretical advantages of increased volumetric occlusion, thrombus stabilization, and improved neointimal healing. Reports of local inflammation and hydrocephalus after coiling of unruptured aneurysms have raised questions about the safety profile or appropriate usage of these new devices.

Clinical Presentation: Two patients with large ophthalmic aneurysms underwent elective endovascular coiling with HydroCoils. Three to 4 weeks later, they developed profound, progressive bilateral visual loss. Magnetic resonance imaging scans demonstrated extensive enhancement of the coil ball, surrounding brain parenchyma, and optic chiasm, with perianeurysmal edema.

Intervention: Dexamethasone produced impressive but temporary improvement in vision in one patient; the other experienced only minor improvement. One patient also developed hydrocephalus; ventriculoperitoneal shunting reduced ventricular size but had no effect on vision. Follow-up imaging demonstrated persistent enhancement of the coil ball, as well as recurrence and extension of the abnormal signal in the parenchyma and along the optic tract.

Conclusion: Both patients have been left with no functional vision in the eye ipsilateral to the aneurysm and have experienced marked visual field loss and reduced acuity in the contralateral eye. Ongoing international studies will provide more information on the rate of inflammatory complications. The biological mechanisms underlying the phenomenon also require investigation. Meanwhile, we caution against using HydroCoils in situations in which worsened mass effect or local inflammation would have highly deleterious consequences, such as in large aneurysms adjacent to the visual pathways or the brainstem.
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http://dx.doi.org/10.1227/01.NEU.0000298918.55119.7CDOI Listing
October 2007

The kinematics of anterior cervical discectomy and fusion versus artificial cervical disc: a pilot study.

Neurosurgery 2007 Sep;61(3 Suppl):100-4; discussion 104-5

Division of Neurosurgery, University of Western Ontario, London, Canada.

Objective: Anterior cervical discectomy and fusion (ACDF) for the management of cervical spondylosis may contribute to further degenerative changes at adjacent levels secondary to abnormal spinal motion. Insertion of a Bryan Cervical Disc (AD) (Medtronic Sofamor Danek, Memphis, TN) may prevent this accelerated degeneration. This retrospective study compares the in vivo x-ray cervical spine kinematics in patients with ACDF and AD.

Methods: Ten patients with single-level AD were matched to 10 patients with single-level ACDF based on age and sex. Lateral neutral, flexion and extension cervical x-rays were obtained preoperatively and at regular intervals up to 24 months postoperatively. Kinematic parameters, including range of motion, anteroposterior translation, and disc height, were assessed for all cervical functional spinal units using quantitative motion analysis software. Changes in these parameters were compared between matched patients from both groups using paired Student's t tests.

Results: The range of motion at the operated level was greater in the AD group compared with the ACDF group at early (6.9 versus 0.89 degrees, P < 0.01) and late (8.4 versus 0.53 degrees, P < 0.01) follow-up evaluations. Translation was greater at the operated level in patients with AD at late follow-up (6.8 versus 0.8%, P < 0.03) evaluation. No significant between-group kinematic differences were seen at adjacent levels.

Conclusion: Patients with AD and those with ACDF demonstrated similar in vivo adjacent level kinematics within the first 24 months after anterior cervical decompression.
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http://dx.doi.org/10.1227/01.neu.0000289722.12459.9eDOI Listing
September 2007

Epidemiology of traumatic spinal cord injury in Canada.

Spine (Phila Pa 1976) 2006 Apr;31(7):799-805

London Health Sciences Centre, University of Western Ontario, London, Canada.

Study Design: Retrospective review.

Objective: To describe the incidence, clinical features, and treatment of traumatic spinal cord injury (SCI) treated at a Canadian tertiary care center.

Summary Of Background Data: Understanding the current epidemiology of acute traumatic SCI is essential for public resource allocation and primary prevention. Recent reports suggest that the mean age of patients with SCI may be increasing.

Methods: We retrospectively reviewed hospital records on all patients with traumatic SCI between January 1997 and June 2001 (n = 151). Variables assessed included age, gender, length of hospitalization, type and mechanism of injury, associated spinal fractures, neurologic deficit, and treatment.

Results: Annual age-adjusted incidence rates were 42.4 per million for adults aged 15-64 years, and 51.4 per million for those 65 years and older. Motor vehicle accidents accounted for 35% of SCI. Falls were responsible for 63% of SCI among patients older than 65 years and for 31% of injuries overall. Cervical SCI was most common, particularly in the elderly, and was associated with fracture in only 56% of cases. Thoracic and lumbar SCI were associated with spinal fractures in 100% and 85% of cases, respectively. In-hospital mortality was 8%. Mortality was significantly higher among the elderly. Treatment of thoracic and lumbar fractures associated with SCI was predominantly surgical, whereas cervical fractures were equally likely to be treated with external immobilization alone or with surgery.

Conclusion: A large proportion of injuries was seen among older adults, predominantly as a result of falls. Prevention programs should expand their focus to include home safety and avoidance of falls in the elderly.
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http://dx.doi.org/10.1097/01.brs.0000207258.80129.03DOI Listing
April 2006

Complications with cervical arthroplasty.

J Neurosurg Spine 2006 Feb;4(2):98-105

Division of Neurosurgery, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada.

Object: Spinal arthroplasty is becoming more widely performed in the treatment of degenerative cervical disc disease. Although this new technology may offer benefits over arthrodesis, it also requires that the surgeon acquire new operative techniques, and new potential complications are introduced. To determine the incidence and distribution of perioperative complications, the authors analyzed their early data obtained in a series of patients treated with the Bryan Cervical Disc prosthesis.

Methods: The authors prospectively recorded operative data, complications, and clinical and radiographic outcome data in all patients treated with Bryan prosthesis-based arthroplasty at two tertiary care centers since 2001. Patients underwent standard anterior cervical discectomy followed by one- to three-level arthroplasty. Ninety-six discs were implanted in 74 patients. The perioperative complication rate was 6.2% per treated level. In one patient a retropharyngeal hematoma developed, requiring evacuation. Neurological worsening occurred in three patients. Intraoperative migration of the prosthesis was observed in one two-level case, whereas delayed migration occurred in one patient with postoperative segmental kyphosis. In another patient with severe postoperative segmental kyphosis, revision was required with a customized lordotic prosthesis. Heterotopic ossification and spontaneous fusion occurred in two cases; motion was preserved in the remaining 94 prostheses. Partial dislocation of the prosthesis in extension occurred in one patient with preoperative segmental hypermobility, the first reported failure of a Bryan prosthesis. Twenty-five percent of patients reported neck and shoulder pain during the late follow-up period. There was a trend toward increased kyphosis of the C2-7 curvature postoperatively.

Conclusions: The Bryan prosthesis was effective in maintaining spinal motion. Major perioperative and device-related complications were infrequent.
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http://dx.doi.org/10.3171/spi.2006.4.2.98DOI Listing
February 2006

Kinematic analysis of the cervical spine following implantation of an artificial cervical disc.

Spine (Phila Pa 1976) 2005 Sep;30(17):1949-54

Division of Neurosurgery, London Health Sciences Centre, London, Ontario, Canada.

Study Design: Prospective cohort study.

Objective: To assess the biomechanical profile of the cervical spine following cervical arthroplasty.

Summary Of Background Data: Spinal arthroplasty offers the promise of maintaining functional spinal motion, thereby potentially avoiding adjacent segment disease. Disc replacement may become the next gold standard for the treatment of degenerative cervical spine disease, and must be studied rigorously to ensure in vivo efficacy and safety.

Methods: A total of 20 patients underwent single or 2-level implantation of the Bryan artificial cervical disc (Medtronic Sofamor Danek, Memphis TN) for treatment of cervical degenerative disc disease producing radiculopathy and/or myelopathy. Lateral neutral, flexion, and extension cervical radiographs were obtained before surgery and at intervals up to 24 months after surgery. Kinematic parameters, including sagittal rotation, horizontal translation, change in disc height, and center of rotation (COR), were assessed for each spinal level using quantitative motion analysis software.

Results: Motion was preserved in the operated spinal segments (mean range of motion 7.8 degrees) up to 24 months following surgery. The relative contribution of each spinal segment to overall spinal sagittal rotation differed depending on whether the disc was placed at C5-C6 or C6-C7. Overall cervical motion (C2-C7) was moderately but significantly increased during late follow-up. Sagittal rotation, anterior and posterior disc height, translation, and COR coordinates did not change significantly following surgery. The COR was most frequently located posterior and inferior to the center of the disc space.

Conclusions: The Bryan artificial cervical disc provided in vivo functional spinal motion at the operated level, reproducing the preoperative kinematics of the spondylotic disc.
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http://dx.doi.org/10.1097/01.brs.0000176320.82079.ceDOI Listing
September 2005

Cervical total disc replacement, part two: clinical results.

Orthop Clin North Am 2005 Jul;36(3):355-62

Spine Center, St.-Elisabeth-Klinikum, St.-Elisabeth-Str. 23, 94315 Straubing, Germany.

This article focuses on the clinical results of three prostheses (the Bryan Cervical Disc, the Bristol Disc, and the ProDisc-C) for cervical total disc replacement. Background on the development, design, and biomechanical characteristics of each prosthesis is given and surgical indications and clinical results are summarized and analyzed.
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http://dx.doi.org/10.1016/j.ocl.2005.02.009DOI Listing
July 2005

Percutaneous retrogasserian glycerol rhizotomy in the treatment of tic douloureux associated with multiple sclerosis.

Neurosurgery 2005 Mar;56(3):537-45; discussion 537-45

Division of Neurosurgery, Department of Clinical Neurological Sciences, University of Western Ontario and the London Health Sciences Centre, London, Ontario, Canada.

Objective: Patients with multiple sclerosis (MS) have a relatively high incidence of tic douloureux (TD) and often do not tolerate medical therapy well. The minimally invasive nature of percutaneous retrogasserian glycerol rhizotomy (PRGR) renders it ideal for first-line surgical treatment of TD. We sought to ascertain the benefits of PRGR in patients with MS and to determine whether hypalgesia after PRGR correlates with efficacy.

Methods: We assessed 97 glycerol procedures performed in 53 patients followed prospectively for treatment of TD associated with MS. Factors assessed included degree of pain relief, postoperative hypalgesia, procedural morbidity, medication use, time to pain recurrence, and number and type of subsequent procedures.

Results: Complete pain relief was obtained in 78% of patients after the initial glycerol injection, and partial relief was obtained in 13% of patients. Long-term follow-up (mean, 81 mo) demonstrated a recurrence rate of 59%, with a mean time to recurrence of 17 months. Actuarial recurrence rates were 50% at 12 months and 60% at 24 months. Twenty-four patients underwent a second or subsequent PRGR for recurrent pain and achieved similar rates of pain relief and time to recurrence. Facial sensory loss was associated with a higher likelihood of pain relief (P < 0.05), with longer time to pain recurrence (P < 0.05), and with decreased use of medication after surgery (P < 0.01.)

Conclusion: PRGR is an effective, low-morbidity surgical procedure in the management of TD complicating MS. The presence of facial sensory loss after PRGR is associated with prolonged efficacy.
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http://dx.doi.org/10.1227/01.neu.0000153907.43563.ffDOI Listing
March 2005

Early clinical and biomechanical results following cervical arthroplasty.

Neurosurg Focus 2004 Sep 15;17(3):E9. Epub 2004 Sep 15.

Division of Neurosurgery, Department of Clinical Neurological Sciences, London Health Sciences Centre, London, Ontario, Canada.

Object: Spinal arthroplasty may become the next gold standard for the treatment of degenerative cervical spine disease. This new modality must be studied rigorously to ensure in vivo efficacy and safety. The authors review the preliminary clinical experience and radiographic outcomes following insertion of the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN).

Methods: This prospective cohort study included 26 patients undergoing single- or two-level implantation of the Bryan artificial cervical disc for treatment of cervical degenerative disc disease resulting in radiculopathy and/or myelopathy. Radiographic and clinical assessments were made preoperatively 1.5, 3 months, and at 6, 12, and up to 24 months postoperatively. The Neck Disability Index (NDI) and Short Form-36 (SF-36) questionnaires were used to assess pain and functional outcomes. Segmental sagittal rotation from C2-3 to C6-7 was measured using quantitative motion analysis software. A total of 30 Bryan discs were placed in 26 patients. A single-level procedure was performed in 22 patients and a two-level procedure in the other four. Follow-up duration ranged from 1.5 to 27 months, with a mean duration of 12.3 months. A statistically significant improvement in the mean NDI scores was seen between pre- and late postoperative follow-up evaluations. A trend toward improvement in the SF-36 physical component was also found. Motion was preserved in the treated spinal segments (mean range of motion 7.8 degrees ) for up to 24 months postsurgery. The relative contribution of each segment to overall spinal sagittal rotation differed depending on whether the disc was placed at C5-6 or C6-7. Overall cervical motion (C2-7) was moderately increased on late follow-up evaluations.

Conclusions: The Bryan artificial cervical disc provided in vivo functional spinal motion at the treated level. Overall cervical spinal motion was not significantly altered. Sagittal rotation did not change significantly at any level after surgery.
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http://dx.doi.org/10.3171/foc.2004.17.3.9DOI Listing
September 2004

Effects of a cervical disc prosthesis on segmental and cervical spine alignment.

Neurosurg Focus 2004 Sep 15;17(3):E5. Epub 2004 Sep 15.

Division of Neurosurgery, Department of Clinical Neurological Sciences, London Health Sciences Centre, London, Ontario, Canada.

Object: Cervical arthroplasty offers the promise of maintaining motion of the functional spinal unit (FSU) after anterior cervical discectomy. The impact of cervical arthroplasty on sagittal alignment of the FSU needs to be addressed, together with its effect on overall sagittal balance of the cervical spine.

Methods: The authors prospectively reviewed radiographic and clinical outcomes in 14 patients who received the Bryan Cervical Disc prosthesis (Medtronic Sofamor Danek, Memphis, TN), for whom early (< 6 months) and late (6-24 months) follow-up data were available. Static and dynamic radiographs were measured by hand and computer to determine the angles formed by the endplates of the natural disc preoperatively, those formed by the shells of the implanted prosthesis, the angle of the FSU, and the C2-7 Cobb angle. The range of motion (ROM) was also determined radiographically, whereas clinical outcomes were assessed using the Neck Disability Index (NDI), and Short Form-36 (SF-36) questionnaires. The ROM was preserved following surgery, with a mean preoperative sagittal rotation angle of 8.96 degrees , which was not significantly different from the late postoperative value of 8.25 degrees . When compared with the preoperative disc space angle, the shell endplate angle in the neutral position became kyphotic in the early and late postoperative periods (mean change -3.8 degrees in the late follow-up period; p = 0.0035). The FSU angles also became significantly more kyphotic postoperatively, with a mean change of -6 degrees (p = 0.0006). The Cobb angles varied widely preoperatively and did not change significantly after surgery. There was no statistical correlation between the NDI and SF-36 outcomes and cervical kyphosis.

Conclusions: Cervical arthroplasty preserves motion of the FSU. Both the endplate angle of the treated disc space and the angle of the FSU became kyphotic after insertion of the Bryan prosthesis. The overall sagittal balance of the cervical spine, however, was preserved.
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http://dx.doi.org/10.3171/foc.2004.17.3.5DOI Listing
September 2004

Controversies in cervical discectomy and fusion: practice patterns among Canadian surgeons.

Can J Neurol Sci 2004 Nov;31(4):478-83

Division of Neurosurgery, London Health Sciences Centre, London, Ontario, Canada.

Objective: Optimal fusion technique and peri-operative management of patients undergoing anterior cervical discectomy (ACD) is unclear. We document current practice patterns among Canadian spinal surgeons regarding the surgical management of single level degenerative cervical spondylosis.

Methods: We conducted a web-based survey of neurosurgeons and spinal orthopedic surgeons in Canada. We asked questions pertaining to the management of single level cervical degenerative disc disease causing radiculopathy and/or myelopathy, including frequency of fusion following single-level discectomy, preferred fusion technique, indications and frequency of use of anterior plating, and use of an external cervical orthosis following surgery. Demographic factors assessed included training background, type and length of practice.

Results: Sixty respondents indicated that their practice involved at least 5% spine surgery and were included in further analysis. Neurosurgeons comprised 59% of respondents, and orthopedic surgeons 41%. Fusion was employed 93% of the time following ACD; autologous bone was the preferred fusion material, used in 76% of cases. Neurosurgeons employed anterior cervical plates in 42% of anterior cervical discectomy and fusion cases, whereas orthopedic surgeons used them 70% of the time. External cervical orthoses were recommended for 92% of patients without plates and 61% of patients with plates. Surgeons who had been in practice for less than five years were most likely to be performing spinal surgery, using anterior cervical plates, and recommending the postoperative use of cervical orthoses.

Conclusion: Practice patterns vary among Canadian surgeons, although nearly all employ fusion and many use instrumentation for single-level ACD. Training background, and type and length of practice influence practice habits.
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http://dx.doi.org/10.1017/s0317167100003668DOI Listing
November 2004

Artificial disc insertion following anterior cervical discectomy.

Can J Neurol Sci 2003 Aug;30(3):278-83

Division of Neurosurgery, London Health Sciences Centre, London, Ontario, Canada.

Objective And Importance: Fusion following anterior cervical discectomy has been implicated in the acceleration of degenerative changes in the adjacent spinal segments. Discectomy followed by implantation of an artificial cervical disc maintains the functionality of the spinal unit, while still providing excellent symptomatic relief. We describe our preliminary experience with implantation of the Bryan Cervical Disc System in two cases of single-level cervical disc herniation.

Clinical Presentation: Two male patients presented with a left C6 radiculopathy, without evidence of myelopathy. Magnetic resonance imaging revealed a disc herniation at C5-6 in both cases. Pre-operative flexion and extension radiographs demonstrated preserved motion at the involved levels.

Intervention/technique: Following a standard anterior cervical decompression, precision drilling of the vertebral endplates was carried out using a drill attached to a bed-mounted, gravitationally-referenced retraction frame. An artificial cervical disc, composed of a polyurethane nucleus with titanium endplates, was fitted between the contoured endplates without fixation to the vertebral bodies. No complications were experienced during the insertion of the prosthesis, or in the postoperative course. Both patients experienced immediate postoperative resolution of their radicular pain and were discharged from hospital the following day. At nine months following surgery, both patients continue to have complete relief of radicular symptoms. Postoperative radiographs at six months following surgery confirm accurate placement of the prosthesis and preserved mobility of the functional spinal unit.

Conclusion: Insertion of the Bryan artificial cervical disc prosthesis following anterior cervical discectomy is a relatively straightforward procedure, which appears to be safe and provides good clinical results, without requiring additional surgical time. Long-term follow-up is required to assess its safety, efficacy, and ability to prevent adjacent segment degeneration.
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http://dx.doi.org/10.1017/s0317167100002742DOI Listing
August 2003
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