bluuebunny/crossref_metadata_2025 huggingface dataset:
Brain-computer interfaces: military, neurosurgical, and ethical perspective
Authors: Kotchetkov Ivan S. , Hwang Brian Y. , Appelboom Geoffrey , Kellner Christopher P. , Connolly E. Sander
Published: February 2011

Brain-computer interfaces (BCIs) are devices that acquire and transform neural signals into actions intended by the user. These devices have been a rapidly developing area of research over the past 2 decades, and the military has made significant contributions to these efforts. Presently, BCIs can provide humans with rudimentary control over computer systems and robotic devices. Continued advances in BCI technology are especially pertinent in the military setting, given the potential for therapeutic applications to restore function after combat injury, and for the evolving use of BCI devices in military operations and performance enhancement. Neurosurgeons will play a central role in the further development and implementation of BCIs, but they will also have to navigate important ethical questions in the translation of this highly promising technology. In the following commentary the authors discuss realistic expectations for BCI use in the military and underscore the intersection of the neurosurgeon's civic and clinical duty to care for those who serve their country.
Neurosurgery in Afghanistan during “Operation Enduring Freedom”: a 24-month experience
Authors: Ragel Brian T. , Klimo Paul , Kowalski Robert J. , McCafferty Randall R. , Liu Jeannette M. , Taggard Derek A. , Garrett David , Brevard Sidney B.
Published: February 2011

Object

“Operation Enduring Freedom” is the US war effort in Afghanistan in its global war on terror. One US military neurosurgeon is deployed in support of Operation Enduring Freedom to provide care for both battlefield injuries and humanitarian work. Here, the authors analyze a 24-month neurosurgical caseload experience in Afghanistan.

Methods

Operative logs were analyzed between October 2007 and September 2009. Operative cases were divided into minor procedures (for example, placement of an intracranial pressure monitor) and major procedures (for example, craniotomy) for both battle injuries and humanitarian work. Battle injuries were defined as injuries sustained by soldiers while in the line of duty or injuries to Afghan civilians from weapons of war. Humanitarian work consisted of providing medical care to Afghans.

Results

Six neurosurgeons covering a 24-month period performed 115 minor procedures and 210 major surgical procedures cases. Operations for battlefield injuries included 106 craniotomies, 25 spine surgeries, and 18 miscellaneous surgeries. Humanitarian work included 32 craniotomies (23 for trauma, 3 for tumor, 6 for other reasons, such as cyst fenestration), 27 spine surgeries (12 for degenerative conditions, 9 for trauma, 4 for myelomeningocele closure, and 2 for the treatment of infection), and 2 miscellaneous surgeries.

Conclusions

Military neurosurgeons have provided surgical care at rates of 71% (149/210) for battlefield injuries and 29% (61/210) for humanitarian work. Of the operations for battle trauma, 50% (106/210) were cranial and 11% (25/210) spinal surgeries. Fifteen percent (32/210) and 13% (27/210) of operations were for humanitarian cranial and spine procedures, respectively. Overall, military neurosurgeons in Afghanistan are performing life-saving cranial and spine stabilization procedures for battlefield trauma and acting as general neurosurgeons for the Afghan community.
The development of military medical care for peripheral nerve injuries during World War I
Authors: Hanigan William
Published: February 2011

Although the clinical and electrical diagnoses and treatments of peripheral nerve injuries (PNIs) had been described prior to World War I, many reports were fragmented and incomplete. Individual physicians' experiences were not extensive, and in 1914 the patient with a PNI remained a subject of medical curiosity, and was hardly a focus of comprehensive care.

World War I altered these conditions; casualties with septic wounds and PNIs swamped the general hospitals. By 1915, specialized hospitals or wards were developed to care for neurological injuries. In the United Kingdom, Sir Robert Jones developed the concept of Military Orthopedic Centres, with coordinated specialized care and rehabilitation. Military appointments of neurologists and electrotherapists sharpened clinical diagnoses and examinations. Surgical techniques were introduced, then discarded or accepted as surgeons developed skills to meet the new conditions. The US Surgeon General, William Gorgas, and his consultant in neurosurgery, Charles Frazier, went a step further, with the organization of a research laboratory as well as the establishment of a Peripheral Nerve Commission and Registry.

Despite these developments and good intentions, postwar follow-up for PNIs remained incomplete at best. Records were lost, personnel transferred, and patients discharged from the system. The lack of a standardized grading system seriously impaired the ability to record clinical changes and compare outcomes. Nevertheless, specialized treatment of a large number of PNIs during World War I established a foundation for comprehensive care that influenced military medical services in the next world war.
Degenerative lumbar spinal stenosis with neurogenic intermittent claudication and treatment with the Aperius PercLID System: a preliminary report
Authors: Galarza Marcelo , Fabrizi Anthony P. , Maina Raffaella , Gazzeri Roberto , Martínez-Lage Juan F.
Published: February 2011

Object

The aim of this study was to evaluate whether clinical improvement is noticeable after a minimally invasive procedure such as that used with the Aperius PercLID System in patients with degenerative lumbar spinal stenosis (DLSS) and neurogenic intermittent claudication (NIC).

Methods

The patients were treated with the aforementioned system at 3 different centers. The initial requirement to be included in the study was a minimum follow-up of 12 months. The authors studied 40 cases of DLSS in patients with NIC (age 72.7 ± 8.08 years). Symptom severity, physical function, quality of life, and self-rated pain were assessed preoperatively and at the 12-month follow-up using the Zurich Claudication Questionnaire (ZCQ) and a visual analog scale. The procedure was conducted under spinal (35 patients) or local (5 patients) anesthesia, using biplanar fluoroscopy for visualization.

Results

Single-level treatment was performed in 28 patients and 2-level treatment was performed in 12 patients. Based on time recordings in 24 cases, the mean procedural time was 19.9 ± 5.0 minutes. The mean pain visual analog scale score improved significantly from 8.1 ± 2.19 at baseline to 3.44 ± 2.89 at the 1-year follow-up. The ZCQ score for patient satisfaction showed 90% of the patients being satisfied with the procedure. The mean rates of improvement in ZCQ score for symptom severity and physical function at 1 year were 38.7 ± 33.3% and 33.8 ± 29.7%, respectively, and both proved to be statistically significant. Most improvement was seen in mobility, pain/discomfort, and ability for self-care.

Conclusions

In this preliminary study, the Aperius system provided clinically significant improvement after 1 year of follow-up in patients older than 65 years with DLSS and NIC.
Dynamic interspinous process stabilization: review of complications associated with the X-Stop device
Authors: Bowers Christian , Amini Amin , Dailey Andrew T. , Schmidt Meic H.
Published: February 2011

Object

The X-Stop interspinous device is designed for the treatment of patients with neurogenic intermittent claudication due to lumbar spinal stenosis. It distracts the posterior elements of adjacent vertebral bodies, unloading the intervertebral disc, limiting spinal extension, and improving central canal and neuroforaminal stenosis. In this paper, the authors reviewed the complications and failure/reoperation rates in a small series of patients and compared their results with other reported complication and failure/reoperation rates.

Methods

The medical records of all patients who underwent placement of the X-Stop device for the treatment of NIC at the authors' institution were retrospectively evaluated, and demographic information, diagnosis, and preoperative pain levels were recorded. Postoperatively, patients subjectively graded the percentage (0–100%) of improvement in pain as well as the amount of residual pain and underwent imaging at 1-, 3-, and 6-month intervals. Approximately 4 years after X-Stop placement, information on long-term outcomes was obtained from patient medical records or additional follow-up.

Results

Thirteen patients (8 men and 5 women) underwent placement of the X-Stop device. Central canal stenosis with bilateral foraminal stenosis was diagnosed in all patients: 9 (69%) of 13 had severe stenosis and 4 (31%) of 13 had moderate stenosis. Five patients (38%) also had associated Grade I spondylolisthesis. Nine patients underwent placement of the X-Stop device at the L4–5 interspinous space and 4 at both the L3–4 and L4–5 levels. The average duration of follow-up was 42.9 months (range 3–48 months). Initially, pain improved an average of 72% (range 50–100%) in these patients; however, preoperative pain returned in 77% of the patients (10 of 13). The overall complication rate was 38%, including 3 spinous process fractures (23%) and 2 instances of new-onset radiculopathy (15%). The ultimate failure rate requiring additional spinal surgery was 85% (11 of 13 patients). These complication and failure rates are much higher than those previously reported.

Conclusions

Overdistraction, poor bone density, poor patient selection, and preexistent adjacent foraminal stenosis may all be factors in the development of the aforementioned complications. Thus, careful attention should be paid preoperatively to adjacent-level disease, bone density, appropriate implant size, and optimal patient selection.
Screw loosening in the Dynesys stabilization system: radiographic evidence and effect on outcomes
Authors: Ko Chin-Chu , Tsai Hsiao-Wen , Huang Wen-Cheng , Wu Jau-Ching , Chen Yu-Chun , Shih Yang-Hsin , Chen Hung-Chieh , Wu Ching-Lan , Cheng Henrich
Published: February 2011

Object

Dynamic stabilization systems are used to stabilize degenerative lumbar spondylosis. Loosening of the pedicle screws in such nonfusion implants is predictable. This retrospective study evaluated the incidence of screw loosening and its effect on clinical outcomes.

Methods

Charts, radiographic films, and medical records of 71 consecutive patients who underwent decompression using Dynesys dynamic stabilization for 1- or 2-level lumbar spondylosis were reviewed. Radiographic films were evaluated and compared to detect screw loosening. A visual analog scale (VAS) for back pain and the Oswestry Disability Index (ODI) were used for measuring clinical outcome. Statistical analysis was conducted using the chisquare test and Student t-test.

Results

The 71 patients in the study sample had a mean age of 59.2 ± 11.65 years (range 23–80 years), with slight female predominance (39 women, 32 men). The mean follow-up duration was 16.6 months (range 8–29 months). There were loose screws in 14 of 71 patients (19.7%), for a rate of 4.6% per screw (17 of 368 screws). Most screw loosening occurred in patients ≥ 55 years old (13 of 14 patients) although age and sex had no effect on screw loosening (p = 0.233 and 0.109, respectively). Both the loose screw and solid screw groups experienced significant improvement after the surgery in VAS and ODI scores. On the VAS, scores improved from 5.9 ± 2.99 to 2.1 ± 2.14 in the loose screw group (p = 0.003), and from 5.7 ± 3.45 to 2.9 ± 2.68 in the solid screw group (p < 0.001). For the ODI scale, scores improved from 43.5 ± 16.78% to 28.0 ± 18.18% (p = 0.006) in the loose screw group, and from 52.1 ± 20.92% to 24.6 ± 19.78% (p < 0.001) in the solid screw group. There were no significant differences between the 2 groups (p = 0.334 for VAS, p = 0.567 for ODI).

Conclusions

The preliminary study of this pedicle-based dynamic stabilization device for 1- and 2-level lumbar spondylosis shows radiographic evidence of screw loosening in 19.7% of patients and 4.6% of screws. Nonetheless, the loosening of screws has no adverse effect on clinical improvement.
The use of a hybrid dynamic stabilization and fusion system in the lumbar spine: preliminary experience
Authors: Maserati Matthew B. , Tormenti Matthew J. , Panczykowski David M. , Bonfield Christopher M. , Gerszten Peter C.
Published: February 2011

Object

The authors report the use and preliminary results of a novel hybrid dynamic stabilization and fusion construct for the surgical treatment of degenerative lumbar spine pathology.

Methods

The authors performed a retrospective chart review of all patients who underwent posterior lumbar instrumentation with the Dynesys-to-Optima (DTO) hybrid dynamic stabilization and fusion system. Preoperative symptoms, visual analog scale (VAS) pain scores, perioperative complications, and the need for subsequent revision surgery were recorded. Each patient was then contacted via telephone to determine current symptoms and VAS score. Follow-up was available for 22 of 24 patients, and the follow-up period ranged from 1 to 22 months. Clinical outcome was gauged by comparing VAS scores prior to surgery and at the time of telephone interview.

Results

A total of 24 consecutive patients underwent lumbar arthrodesis surgery in which the hybrid system was used for adjacent-level dynamic stabilization. The mean preoperative VAS score was 8.8, whereas the mean postoperative VAS score was 5.3. There were five perioperative complications that included 2 durotomies and 2 wound infections. In addition, 1 patient had a symptomatic medially placed pedicle screw that required revision. These complications were not thought to be specific to the DTO system itself. In 3 patients treatment failed, with treatment failure being defined as persistent preoperative symptoms requiring reoperation.

Conclusions

The DTO system represents a novel hybrid dynamic stabilization and fusion construct. The technique holds promise as an alternative to multilevel lumbar arthrodesis while potentially decreasing the risk of adjacent-segment disease following lumbar arthrodesis. The technology is still in its infancy and therefore follow-up, when available, remains short. The authors report their preliminary experience using a hybrid system in 24 patients, along with short-interval clinical and radiographic follow-up.
Biomechanics of a posture-controlling cervical artificial disc: mechanical, in vitro, and finite-element analysis
Authors: Crawford Neil R. , Arnett Jeffery D. , Butters Joshua A. , Ferrara Lisa A. , Kulkarni Nikhil , Goel Vijay K. , Duggal Neil
Published: February 2011

Different methods have been described by numerous investigators for experimentally assessing the kinematics of cervical artificial discs. However, in addition to understanding how artificial discs affect range of motion, it is also clinically relevant to understand how artificial discs affect segmental posture. The purpose of this paper is to describe novel considerations and methods for experimentally assessing cervical spine postural control in the laboratory. These methods, which include mechanical testing, cadaveric testing, and computer modeling studies, are applied in comparing postural biomechanics of a novel postural control arthroplasty (PCA) device versus standard ball-and-socket (BS) and ball-in-trough (BT) arthroplasty devices. The overall body of evidence from this group of tests supports the conclusion that the PCA device does control posture to a particular lordotic position, whereas BS and BT devices move freely through their ranges of motion.
Glial scar and neuroregeneration: histological, functional, and magnetic resonance imaging analysis in chronic spinal cord injury
Authors: Hu Rong , Zhou Jianjun , Luo Chunxia , Lin Jiangkai , Wang Xianrong , Li Xiaoguang , Bian Xiuwu , Li Yunqing , Wan Qi , Yu Yanbing , Feng Hua
Published: February 2011

Object

A glial scar is thought to be responsible for halting neuroregeneration following spinal cord injury (SCI). However, little quantitative evidence has been provided to show the relationship of a glial scar and axonal regrowth after injury.

Methods

In this study performed in rats and dogs, a traumatic SCI model was made using a weight-drop injury device, and tissue sections were stained with H & E for immunohistochemical analysis. The function and behavior of model animals were tested using electrophysiological recording and the Basso-Beattie-Bresnahan Locomotor Rating Scale, respectively. The cavity in the spinal cord after SCI in dogs was observed using MR imaging.

Results

The morphological results showed that the formation of an astroglial scar was defined at 4 weeks after SCI. While regenerative axons reached the vicinity of the lesion site, the glial scar blocked the extension of regrown axons. In agreement with these findings, the electrophysiological, behavioral, and in vivo MR imaging tests showed that functional recovery reached a plateau at 4 weeks after SCI. The thickness of the glial scars in the injured rat spinal cords was also measured. The mean thickness of the glial scar rostral and caudal to the lesion cavity was 107.00 ± 20.12 μm; laterally it was 69.92 ± 15.12 μm.

Conclusions

These results provide comprehensive evidence indicating that the formation of a glial scar inhibits axonal regeneration at 4 weeks after SCI. This study reveals a critical time window of postinjury recovery and a detailed spatial orientation of glial scar, which would provide an important basis for the development of therapeutic strategy for glial scar ablation.
Symptomatic relevance of intravertebral cleft in patients with osteoporotic vertebral fracture
Authors: Kawaguchi Satoshi , Horigome Keiko , Yajima Hideki , Oda Takashi , Kii Yuichiro , Ida Kazunori , Yoshimoto Mitsunori , Iba Kousuke , Takebayashi Tsuneo , Yamashita Toshihiko
Published: February 2011

Object

The present study was designed to determine clinical and radiographic characteristics of unhealed osteoporotic vertebral fractures (OVFs) and the role of fracture mobility and an intravertebral cleft in the regulation of pain symptoms in patients with an OVF.

Methods

Patients who had persistent low-back pain for 3 months or longer and a collapsed thoracic or lumbar vertebra that had an intervertebral cleft and abnormal mobility were referred to as having unhealed OVFs. Twenty-four patients with an unhealed OVF and 30 patients with an acute OVF were compared with regard to several clinical and radiographic features including the presence of an intravertebral fluid sign. Subsequently, the extent of dynamic mobility of the fractured vertebra was analyzed for correlation with the patients' age, duration of symptoms, back pain visual analog scale (VAS) score, and performance status. Finally, in cases of unhealed OVFs, the subgroup of patients with positive fluid signs was compared with the subgroup of patients with negative fluid signs.

Results

Patients with an unhealed OVF were more likely to have a crush-type fracture, shorter vertebral height of the fractured vertebra, and a fracture with a positive fluid sign than those with an acute OVF. The extent of dynamic mobility of the vertebra correlated significantly with the VAS score in patients with an unhealed OVF. In addition, a significant correlation with the extent of dynamic vertebral mobility with performance status was seen in patients with an unhealed OVF and those with an acute OVF. Of the 24 patients with an unhealed OVF, 14 had a positive fluid sign in the affected vertebra. Patients with a positive fluid sign exhibited a statistically significantly greater extent of dynamic vertebral mobility, a higher VAS score, a higher performance status grade, and a greater likelihood of having a crush-type fracture than those with a negative fluid sign. All but 1 patient with an unhealed OVF and a positive fluid sign had an Eastern Cooperative Oncology Group Performance Status Grade 3 or 4 (bedridden most or all of the time). In sharp contrast, all 10 patients with an unhealed OVF and a negative fluid sign were Grade 1 or 2.

Conclusions

Unhealed OVFs form a group of fractures that are distinct from acute OVFs regarding radiographic morphometry and contents of the intravertebral cleft. Dynamic vertebral mobility serves as a primal pain determinant in patients with an unhealed OVF and potentially in those with an acute OVF. Fluid accumulation in the intravertebral cleft of unhealed OVFs likely reflects long-term bedridden positioning of the patients in daily activity.
Sacral fractures following stand-alone L5–S1 anterior lumbar interbody fusion for isthmic spondylolisthesis
Authors: Lastfogel Jeffrey F. , Altstadt Thomas J. , Rodgers Richard B. , Horn Eric M.
Published: February 2011

Recent studies have demonstrated excellent results in treating isthmic spondylolisthesis via an anterior lumbar interbody fusion (ALIF). The authors describe 3 patients with isthmic spondylolisthesis at L5–S1 who experienced sacral fractures after insertion of a unique, stand-alone anterior interbody fixation device.

Three consecutive patients at a single institution were treated for Grade I spondylolisthesis at L5–S1 via a standalone ALIF with insertion of a novel biomechanical interbody device. This device is made of polyetheretherketone and has an integrated system for internal fixation into the vertebral bodies. In each patient a bone morphogenetic protein–soaked sponge was placed for the fusion. The indications for treatment in each patient were back and radicular pain that had been unsuccessfully treated with conservative measures.

All 3 patients had reduction of their spondylolisthesis and resolution of their unilateral radiculopathies immediately postoperatively. Within 1 month of surgery, all 3 patients had failure of the device and recurrence of their symptoms. In each case the failure was due to fracture of the anterior portion of the S-1 body. Each patient underwent reduction and pedicle screw fixation at L5–S1. In all cases, there was successful reduction in their recurrent spondylolisthesis and resolution of their radiculopathies.

Treatment of Grade I isthmic spondylolisthesis at L5–S1 with stand-alone ALIF and fixation can lead to sacral fracture from high stress loads at that level in the spine, and consideration should be made either for supplemental pedicle screw fixation or a completely posterior approach.
Surgical site infection in spinal surgery: detection and management based on serial C-reactive protein measurements
Authors: Kang Byung-Uk , Lee Sang-Ho , Ahn Yong , Choi Won-Chul , Choi Young-Geun
Published: February 2011

Object

C-reactive protein (CRP) is a well-known sensitive laboratory parameter that shows an increase within 6 hours after the onset of bacterial infection. In relation to surgery, a normal CRP response is a rapid increase followed by a gradual reduction, eventually returning to the normal range. The goal of this study was to determine the diagnostic significance of CRP as a detector for early onset surgical site infection in spinal surgery and to discuss effective medical treatment through clinical interpretation and application of the measured CRP values.

Methods

A prospective study was performed in 348 consecutive cases involving patients who underwent spinal surgery under general anesthesia between February and September 2008. Blood samples were obtained preoperatively and on postoperative Days 1, 3, and 5 in patients undergoing single-level decompression surgery. An additional blood specimen was obtained at postoperative Day 7 in patients requiring more extensive surgeries. Recorded laboratory results were compared with the patients' clinical course to determine the diagnostic significance of CRP. All of the patients received intravenous prophylactic antibiotic therapy. Once an abnormal response of CRP, indicated by a tendency toward continuous elevation, was noted on Day 5 or Day 7, the prophylactic antibiotics were replaced with another regimen and administration was resumed along with careful observation for signs of surgical site infection.

Results

Monitoring of CRP revealed a characteristic increase and decrease pattern in 332 of 348 patients (95.4%) showing a normal clinical course with regard to early infectious complications. The mean measured CRP (reference range < 4 mg/L) averaged 14.9 ± 20.3 mg/L on Day 1, 15.4 ± 25.1 mg/L on Day 3, and 7.9 ± 13.3 mg/L on Day 5. In contrast, there were 16 cases (4.6%) of abnormal CRP responses resulting in the resumption of intravenous antibiotic treatment, which included a second rise (in 12 cases) and a steady rise (in 4) in the CRP value. Five (1.4%) of 16 patients experienced infectious complications related to spinal surgery. Three patients (0.9%) received long-term antibiotic therapy for 4–6 weeks; however, all patients recovered with medical treatment alone and did not experience gross wound disruption or subsequent discitis. As a predictor for early wound infection, the sensitivity, specificity, positive predictive value, and negative predictive value for abnormal CRP responses were calculated as 100%, 96.8%, 31.3%, and 100%, respectively.

Conclusions

The above results demonstrate that CRP screening is a simple and reliable test for the detection of early infectious complications after spinal surgery. Close observation and appropriate medical management should be performed in a timely fashion when abnormal CRP responses are observed at 5 or 7 days after surgery.
Autologous growth factors versus autogenous graft for anterior cervical interbody fusion: an in vivo caprine model
Authors: Cunningham Bryan W. , Sefter John C. , Hu Nianbin , McAfee Paul C.
Published: February 2011

Object

Using an in vivo caprine model, authors in this study compared the efficacy of autologous growth factors (AGFs) with autogenous graft for anterior cervical interbody arthrodesis.

Methods

Fourteen skeletally mature Nubian goats were used in this study and followed up for a period of 16 weeks postoperatively. Anterior cervical interbody arthrodesis was performed at the C3–4 and C5–6 vertebral levels. Four interbody treatment groups (7 animals in each group) were equally randomized among the 28 arthrodesis sites: Group 1, autograft alone; Group 2, autograft + cervical cage; Group 3, AGFs + cervical cage; and Group 4, autograft + anterior cervical plate. Groups 1 and 4 served as operative controls. Autologous growth factors were obtained preoperatively from venous blood and were ultra-concentrated. Following the 16-week survival period, interbody fusion success was evaluated based on radiographic, biomechanical, and histological analyses.

Results

All goats survived surgery without incidence of vascular or infectious complications. Radiographic analysis by 3 independent observers indicated fusion rates ranging from 9 (43%) of 21 in the autograft-alone and autograft + cage groups to 12 (57%) of 21 in the autograft + anterior plate group. The sample size was not large enough to detect any statistical significance in these observed differences. Biomechanical testing revealed statistical differences (p < 0.05) between all treatments and the nonoperative controls under axial rotation and flexion and extension loading. Although the AGF + cage and autograft-alone treatments appeared to be statistically different from the intact spine during lateral bending, larger variances and smaller relative differences precluded a determination of statistical significance. Histomorphometric analysis of bone formation within the predefined fusion zone indicated quantities of bone within the interbody cage ranging from 21.3 ± 14.7% for the AGF + cage group to 34.5 ± 9.9% for the autograft-alone group.

Conclusions

The results indicated no differences in biomechanical findings among the treatment groups and comparable levels of trabecular bone formation within the fusion site between specimens treated with autogenous bone and those filled with the ultra-concentrated AGF extract. In addition, interbody cage treatments appeared to maintain disc space height better than autograft-alone treatments.
Midline trough corpectomies for the evacuation of an extensive ventral cervical and upper thoracic spinal epidural abscess
Authors: Deshmukh Vinay R.
Published: February 2011

The author reports on a 59-year-old woman with a history of a chronic, nonhealing skin ulcer who presented with sepsis, neck pain, and rapidly progressive quadriparesis. Precontrast and postcontrast MR imaging studies revealed a multifocal ventral cervical and upper thoracic spinal epidural abscess. Compression of the spinal cord from the abscess was greatest behind the disc space of C2–3 and C7–T1. Because of the patient's tenuous medical status, the author elected to apply a technique that would allow expeditious decompression without necessitating concomitant fusion and instrumentation. Multilevel, contiguous trough corpectomies were performed for evacuation of the compressive lesions. A high-speed matchstick bur was used to create a 5- to 7-mm midline trough in the vertebrae and intervening disc spaces from C-2 to T-3. Rapid and successful decompression of the entire ventral cervical and upper thoracic epidural space was achieved using this technique. Understanding that the surgical treatment of discitis or osteomyelitis can often result in a kyphotic deformity or frank instability, the patient was immobilized in a cervical collar following surgery and underwent vigilant monitoring with serial plain radiographs, CT scans, and MR images. These neuroimaging studies confirmed complete resolution of the abscess and the slow development of a mild, stable kyphotic deformity. At the 1-year follow-up, the patient was ambulating and had returned to work. A trough corpectomy is a viable surgical approach that allows for rapid decompression of ventral cervical and upper thoracic epidural abscesses while obviating the need for same-setting fusion and fixation.
Healos graft carrier with bone marrow aspirate instead of allograft as adjunct to local autograft for posterolateral fusion in degenerative lumbar scoliosis: a minimum 2-year follow-up study
Authors: Ploumis Avraam , Albert Todd J. , Brown Zoe , Mehbod Amir A. , Transfeldt Ensor E.
Published: February 2011

Object

The objective of this study was to examine the efficacy and safety of Healos graft carrier with bone marrow aspirate and local autograft compared with the results of allograft in patients with lumbar degenerative scoliosis undergoing posterolateral fusion.

Methods

Twenty-eight patients with degenerative scoliosis underwent posterolateral instrumented fusion and decompression. Patients were grouped according to the graft used. Group A consisted of 12 cases in which the authors used a Healos graft carrier, bone marrow aspirate, and local autograft, and Group B consisted of 16 cases in which the authors used cancellous allograft and local autograft. Patients were followed for a minimum of 2 years postoperatively in terms of pain (visual analog scale), function (Oswestry Disability Index), curve magnitude (Cobb angle), and fusion status (plain and dynamic radiographs). The 2 groups did not differ statistically significantly (p > 0.05) in age, sex, smoking habits, magnitude of preoperative visual analog scale score, Oswestry Disability Index score, Cobb angle, or number of levels requiring decompression and fusion.

Results

The groups had similar (p > 0.05) results in terms of pain, function, curve progression, and fusion rates at the 2-year follow-up examination. Radiographic fusion was achieved in all but 2 cases, 1 in each group, in which the patients were asymptomatic. Patients in the allograft group (Group B) showed evidence of fusion earlier than in the Healos group (p < 0.05). No toxicity from Healos graft was recorded.

Conclusions

The combination of Healos hydroxyapatite sponge and bone marrow aspirate plus local allograft had significantly slower fusion rates but equal clinical outcomes compared with cancellous allograft plus local autograft when used for posterolateral fusion in patients with degenerative lumbar scoliosis.
Upper thoracic spine arthroplasty via the anterior approach
Authors: Keachie Krista , Shahlaie Kiarash , Muizelaar J. Paul
Published: February 2011

Significant progress has been made in lumbar and cervical disc replacement therapy. Several cervical disc prostheses have recently gained FDA approval. Although arthroplasty has not been previously described in the thoracic spine, selected patients with long-segment fusion to the level of C-7 have altered cervicothoracic and upper thoracic biomechanics and may benefit from motion-preservation therapy for T1–2 disc herniation. Currently, FDA-approved prostheses are indicated only for patients with single-level degenerative disc disease between C-3 and C-7 and no history of cervical arthrodesis.

The authors describe a 52-year-old woman who had previously undergone C3–7 fusion and returned 4 years later with symptoms of C-8 myeloradiculopathy and radiological evidence of T1–2 degenerative disc disease. She underwent T1–2 arthroplasty in which a Prestige artificial cervical disc was placed via an anterior cervicothoracic approach. Motion at C7–T1 and T1–2 was preserved, and the patient made an excellent clinical recovery.
Defining the safe working zones using the minimally invasive lateral retroperitoneal transpsoas approach: an anatomical study
Authors: Uribe Juan S. , Arredondo Nicolas , Dakwar Elias , Vale Fernando L.
Published: February 2011

Object

The lateral retroperitoneal transpsoas approach is being increasingly employed to treat various spinal disorders. The minimally invasive blunt retroperitoneal and transpsoas dissection poses a risk of injury to major nervous structures. The addition of electrophysiological monitoring potentially decreases the risk of injury to the lumbar plexus. With respect to the use of the direct transpsoas approach, however, there is sparse knowledge regarding the relationship between the retroperitoneum/psoas muscle and the lumbar plexus at each lumbar segment. The authors undertook this anatomical cadaveric dissection study to define the anatomical safe zones relative to the disc spaces for prevention of nerve injuries during the lateral retroperitoneal transpsoas approach.

Methods

Twenty lumbar segments were dissected and studied. The relationship between the retroperitoneum, psoas muscle, and the lumbar plexus was analyzed. The area between the anterior and posterior edges of the vertebral body (VB) was divided into 4 equal zones. Radiopaque markers were placed in each disc space at the midpoint of Zone III (middle posterior quarter). At each segment, the psoas muscle, lumbar plexus, and nerve roots were dissected. The distribution of the lumbar plexus with reference to the markers at each lumbar segment was analyzed.

Results

All parts of the lumbar plexus, including nerve roots, were found within the substance of the psoas muscle dorsal to the posterior fourth of the VB (Zone IV). No Zone III marker was posterior to any part of the lumbar plexus with the exception of the genitofemoral nerve. The genitofemoral nerve travels obliquely in the substance of the psoas muscle from its origin to its innervations. It emerges superficially and anterior from the medial border of the psoas at the L3–4 level and courses along the anterior medial fourth of the L-4 and L-5 VBs (Zone I). The nerves of the plexus that originate at the upper lumbar segments emerge from the lateral border of the psoas major and cross obliquely into the retroperitoneum in front of the quadratus lumborum and the iliacus muscles to the iliac crest.

Conclusions

With respect to prevention of direct nerve injury, the safe anatomical zones at the disc spaces from L1–2 to L3–4 are at the middle posterior quarter of the VB (midpoint of Zone III) and the safe anatomical zone at the L4–5 disc space is at the midpoint of the VB (Zone II–Zone III demarcation). There is risk of direct injury to the genitofemoral nerve in Zone II at the L2–3 space and in Zone I at the lower lumbar levels L3–4 and L4–5. There is also a potential risk of injury to the ilioinguinal, iliohypogastric, and lateral femoral cutaneous nerves in the retroperitoneal space where they travel obliquely, inferiorly, and anteriorly to the reach the iliac crest and the abdominal wall.
Real-time control of a prosthetic hand using human electrocorticography signals
Authors: Yanagisawa Takufumi , Hirata Masayuki , Saitoh Youichi , Goto Tetsu , Kishima Haruhiko , Fukuma Ryohei , Yokoi Hiroshi , Kamitani Yukiyasu , Yoshimine Toshiki
Published: February 2011

Object

A brain-machine interface (BMI) offers patients with severe motor disabilities greater independence by controlling external devices such as prosthetic arms. Among the available signal sources for the BMI, electrocorticography (ECoG) provides a clinically feasible signal with long-term stability and low clinical risk. Although ECoG signals have been used to infer arm movements, no study has examined its use to control a prosthetic arm in real time. The authors present an integrated BMI system for the control of a prosthetic hand using ECoG signals in a patient who had suffered a stroke. This system used the power modulations of the ECoG signal that are characteristic during movements of the patient's hand and enabled control of the prosthetic hand with movements that mimicked the patient's hand movements.

Methods

A poststroke patient with subdural electrodes placed over his sensorimotor cortex performed 3 types of simple hand movements following a sound cue (calibration period). Time-frequency analysis was performed with the ECoG signals to select 3 frequency bands (1–8, 25–40, and 80–150 Hz) that revealed characteristic power modulation during the movements. Using these selected features, 2 classifiers (decoders) were trained to predict the movement state—that is, whether the patient was moving his hand or not—and the movement type based on a linear support vector machine. The decoding accuracy was compared among the 3 frequency bands to identify the most informative features. With the trained decoders, novel ECoG signals were decoded online while the patient performed the same task without cues (free-run period). According to the results of the real-time decoding, the prosthetic hand mimicked the patient's hand movements.

Results

Offline cross-validation analysis of the ECoG data measured during the calibration period revealed that the state and movement type of the patient's hand were predicted with an accuracy of 79.6% (chance 50%) and 68.3% (chance 33.3%), respectively. Using the trained decoders, the onset of the hand movement was detected within 0.37 ± 0.29 seconds of the actual movement. At the detected onset timing, the type of movement was inferred with an accuracy of 69.2%. In the free-run period, the patient's hand movements were faithfully mimicked by the prosthetic hand in real time.

Conclusions

The present integrated BMI system successfully decoded the hand movements of a poststroke patient and controlled a prosthetic hand in real time. This success paves the way for the restoration of the patient's motor function using a prosthetic arm controlled by a BMI using ECoG signals.
Quality of life in patients with intracranial gliomas: the impact of modern image-guided surgery
Authors: Jakola Asgeir S. , Unsgård Geirmund , Solheim Ole
Published: February 2011

Object

Outcome following brain tumor operations is often assessed by health professionals using various gross function scales. However, surprisingly little is known about how modern glioma surgery affects quality of life (QOL) as reported by the patients themselves. In the present study the authors aimed to assess changes in QOL after glioma surgery, to explore the relationship between QOL and traditional outcome parameters, and to examine possible predictors of change in QOL.

Methods

Eighty-eight patients with glioma were recruited from among those 16 years or older who had been admitted to the authors' department for brain tumor surgery in the period between January 2007 and December 2009. A 3D ultrasonography–based navigation system was utilized in nearly all operations and functional MR imaging data on eloquent lesions were incorporated into the neuronavigation system. Preoperative scores for QOL (EuroQol 5D [EQ-5D]) and functional status (Karnofsky Performance Scale [KPS]) were obtained. The EQ-5D and KPS scores were subsequently recorded 6 weeks postoperatively, as were responses to a structured interview about new deficits and possible complications.

Results

There was no change in the median EQ-5D indexes following surgery, 0.76 versus 0.75 (p = 0.419). The EQ-5D index value was significantly correlated with the KPS score (p < 0.001; rho = 0.769). The EQ-5D index values and KPS scores improved in 35.2% and 24.1% of cases, were equal in 20.5% and 47.2% of cases, and deteriorated in 44.3% and 28.7%, respectively. Thus, both improvement and deterioration were underestimated by the KPS score as compared with the patient-reported QOL assessment. New motor deficits (p = 0.003), new language deficits (p = 0.035), new unsteadiness and/or ataxia (p = 0.001), occipital lesions (p = 0.019), and no use of ultrasonography for resection control (p = 0.021) were independent predictors of worsening QOL in a multivariate model.

Conclusions

The surgical procedures per se may not significantly alter QOL in the average patient with glioma; however, new deficits have a major undesirable effect on QOL. It seems that the active use of intraoperative ultrasonography may be associated with a preservation of QOL. The EQ-5D seems like a good outcome measure with a strong correlation to traditional variables while offering a more detailed description of outcome.
Olivecrona on the development of neurosurgery in the middle of the twentieth century: reflections with the wisdom of today
Authors: Machinis Theofilos G. , Fountas Kostas N.
Published: February 2011

✓ Herbert Olivecrona was one of the pioneers of modern neurosurgery. In one of his articles, published more than half a century ago, Olivecrona shared his thoughts on the development of neurosurgery in the first half of the twentieth century and his vision regarding the future of neurosurgery and neurosurgical training. In the present paper, the authors communicate their reflections and thoughts on Herbert Olivecrona's visionary article.
The BION devices: injectable interfaces with peripheral nerves and muscles
Authors: Loeb Gerald E. , Richmond Frances J. R. , Baker Lucinda L.
Published: February 2011

Object

The purpose of this study was to describe a novel technology for implantable neuromuscular stimulation to treat complications of paralysis and disuse atrophy, including shoulder subluxation, hand contractures, drop foot, and osteoarthritis. The authors review the results so far of several pilot clinical studies of these muscle stimulation devices.

Methods

Miniature wireless stimulators received power and individually addressed command signals from an external radiofrequency transmission coil. One or more implants were injected through a 12-gauge hypodermic insertion tool into muscles or adjacent to motor nerves, where they provided the means to activate the muscles in any desired pattern of intensity and frequency. Randomized controlled studies in small numbers of patients are underway to identify efficacy, acceptability, best methods of practice, and any design changes that may be required to improve the technology.

Fifty patients have been enrolled in five studies; 35 patients have undergone implantation of a total of 79 BION1 devices. Comparisons with surface stimulation in patients who have suffered a stroke with shoulder subluxation and hand contractures show similar improvements in objective measures of efficacy but higher comfort levels for stimulation by implants.

Conclusions

Injected microstimulators represent a promising new class of technology for the rehabilitation of patients with upper motor neuropathies. As the technology evolves, practitioners may be able to use it to facilitate functional reanimation of paralyzed limbs.
On the design of robotic hands for brain–machine interface
Authors: Matsuoka Yoky , Afshar Pedram , Oh Michael
Published: February 2011

✓ Brain–machine interface (BMI) is the latest solution to a lack of control for paralyzed or prosthetic limbs. In this paper the authors focus on the design of anatomical robotic hands that use BMI as a critical intervention in restorative neurosurgery and they justify the requirement for lower-level neuromusculoskeletal details (relating to biomechanics, muscles, peripheral nerves, and some aspects of the spinal cord) in both mechanical and control systems. A person uses his or her hands for intimate contact and dexterous interactions with objects that require the user to control not only the finger endpoint locations but also the forces and the stiffness of the fingers. To recreate all of these human properties in a robotic hand, the most direct and perhaps the optimal approach is to duplicate the anatomical musculoskeletal structure. When a prosthetic hand is anatomically correct, the input to the device can come from the same neural signals that used to arrive at the muscles in the original hand. The more similar the mechanical structure of a prosthetic hand is to a human hand, the less learning time is required for the user to recreate dexterous behavior. In addition, removing some of the nonlinearity from the relationship between the cortical signals and the finger movements into the peripheral controls and hardware vastly simplifies the needed BMI algorithms. (Nonlinearity refers to a system of equations in which effects are not proportional to their causes. Such a system could be difficult or impossible to model.) Finally, if a prosthetic hand can be built so that it is anatomically correct, subcomponents could be integrated back into remaining portions of the user's hand at any transitional locations. In the near future, anatomically correct prosthetic hands could be used in restorative neurosurgery to satisfy the user's needs for both aesthetics and ease of control while also providing the highest possible degree of dexterity.
Acute microelectrode array implantation into human neocortex: preliminary technique and histological considerations
Authors: House Paul A. , MacDonald Joel D. , Tresco Patrick A. , Normann Richard A.
Published: February 2011

Object

Researchers at The Center for Neural Interfaces at the University of Utah have designed and produced a silicon-based high-density microelectrode array that has been used successfully in mammalian models. The authors investigate the ability to transfer array insertion techniques to humans and examine the acute response of human cortical tissue to array implantation.

Methods

Six patients who were scheduled to undergo temporal lobectomy surgery were enrolled in an Institutional Review Board–approved protocol. Before the patients underwent lateral temporal cortical resection, one or two high-density microelectrode arrays were implanted in each individual by using a pneumatic insertion device. Cortical tissue was then excised and preserved in formalin. The specimens were sectioned and stained for histological examination.

Pneumatic insertion of a microelectrode array into human cortex in the operating room was feasible. There were no clinical complications associated with implantation and no evidence of significant insertion-related hemorrhage. Tissue responses ranged from mild cortical deformity to small focal hemorrhages several millimeters below the electrode tines. Based on initial results, the insertion device was modified. A footplate that mechanically isolates a small area of cortex and a calibrated micromanipulator were added to improve the reproducibility of insertion.

Conclusions

A high-density microelectrode array designed to function as a direct cortical interface device can be implanted into human cortical tissue without acute clinical complications. Further modifications to the insertion device and array design are ongoing and future work will assess the functional significance of the tissue reactions observed.