Gwynedd E. Pickett

Epidemiology of traumatic spinal cord injury in 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.

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

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°) 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.

Visual pathway compromise after hydrocoil treatment of large ophthalmic aneurysms.

OBJECTIVEHydrogel-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 PRESENTATIONTwo 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. INTERVENTIONDexamethasone 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. CONCLUSIONBoth 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.

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

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 Pearsons 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 (Pearsons r=-0.55; p=.02) and translation from neutral to extension (Pearsons 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.

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

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 Students 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.

SILK flow diverter for treatment of intracranial aneurysms: initial experience and cost analysis

Background The flow diverting stent is a new and expansive tool in the endovascular therapy of complex intracranial aneurysms. We present our experience using SILK flow diverter (SFD) in patients with complex intracranial aneurysms, and a cost analysis. Methods Between September 2010 and May 2012, 19 consecutive patients with 29 complex intracranial aneurysms were treated with SFD without the adjunctive use of coils. We retrospectively evaluated the technical aspects, thromboembolic events, adjunctive therapies, and short term results in patients with complex intracranial aneurysms treated with SFD. A cost analysis of patients who were treated with SFD was performed and compared with similar sized aneurysms coiled with stent assisted coiling. Results The primary technical success rate was 100%. An adjunctive device was required in two of our patients. The technique related complication rate and the 30 day mortality and morbidity rates were 5% (1/20) and 10% (2/20), respectively. We had a total of 263 patient months of clinical and 166 patient months of imaging follow-up. Follow-up imaging revealed two asymptomatic occlusions of the parent artery. Complete occlusion of the aneurysm with fully patent parent artery was observed in 59% of patients where follow-up images were available. The cost analysis showed that the mean cost of treatment with SFD was significantly cheaper compared with the presumed cost of stent assisted coiling (p<0.001). Conclusions The SFD provides a very feasible, efficient, relatively safe, and cost effective method to treat complex intracranial aneurysms without the use of adjunct coiling.

Artificial Disc Insertion following anterior cervical discectomy

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.

Incidental finding of fenestration of the supraclinoid internal carotid artery with appearances on magnetic resonance angiography

A case of incidentally diagnosed fenestration of the supraclinoid internal carotid artery (ICA) with an associated aneurysm is presented. We present appearances on magnetic resonance angiography, which have not been previously described. Careful interrogation of the data in volume-rendered and multiplanar reformats was required to make the diagnosis. The relationship between fenestrations and aneurysms in the anterior circulation is discussed both in general terms and with specific regard to the supraclinoid ICA. We also review the embryology of the distal ICA, which may help explain the adult anatomy of this rare lesion as a failure of caudal separation of the rostral and caudal divisions of the primitive distal ICA.

Rupture of aneurysms in the immediate post-coiling period

Purpose We present a series of cases featuring re-rupture of posterior communicating artery aneurysms in the immediate post-coiling period, where clots obscured the neck of the aneurysm during the procedure. We report on the incidence of re-rupture and discuss possible mechanisms behind this phenomenon. Methods This study included 462 aneurysms over a 10-year period which were treated with endovascular coiling. 137 of these were ruptured aneurysms. Radiographic and clinical information pertaining to the patients was collected. The immediate post-coiling period was defined as ≤3 days following the procedure. Results The incidence of re-rupture in the immediate post-coiling period was 1.4% (2/137). Of these two, one received recombinant tissue plasminogen activator and both received acetylsalicylic acid. One patient presented with adjacent hematoma on re-rupture. In both cases, clot obscured the aneurysm neck during the procedure. Conclusions Re-rupture of intracranial aneurysms in the immediate post-coiling period is an exceedingly rare complication, and the events leading to it have not been discussed at length. Repeat treatment, follow-up imaging and close observation are merited in the setting of re-rupture of a posterior communicating artery aneurysm.

Glioblastoma in a former Chernobyl resident 24 years later

A previously healthy right-handed 39-year-old man presented to the emergency department with a 5-month history of self-described personality changes, including anger issues. He had a 6-day history of expressive dysphasia, word substitution and slurring of speech. His medical history was notable only