bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinal arteriovenous malformations: new classification and surgical treatment
Authors: Zozulya Yuri P. , Slin'ko Eugene I. , Al-Qashqish Iyad I.
Published: February 2011

Object

Spinal vascular malformations represent rare and insufficiently studied pathological entities characterized by considerable variation. Insufficient study of this disease is connected with the complexity of its diagnosis, which restricts the development of surgical treatments that are differentiated according to the type of malformation. Great difficulties are caused by the lack of a clear structural–hemodynamic classification of spinal arteriovenous malformations (AVMs). At present the classification created between 1991 and 1998 by the combined efforts of different authors is the most widely used one. According to this classification, four categories are distinguishable: Type I, dural arteriovenous fistulas (AVFs); Type II, intramedullary glomus AVMs; Type III, juvenile or combined AVMs; and Type IV, intradural perimedullary AVFs. Vascular tumors are also classified, as follows: hemangiomas, hemangioblastomas, angiosarcomas, hemangiopericytomas, angiofibromas, angiolipomas, and hemangioendotheliomas, as well as cavernous malformations.

Methods

In this study the authors analyze the diagnostic data and results of treatment in 91 patients with AVMs and AVFs who were treated at the Institute of Neurosurgery between 1995 and 2005. The patients' ages ranged from 9 to 83 years; the mean age was 42.9 years. For spinal vascular malformations we devised a classification that took into account the aforementioned features of AVMs: the anatomical characteristics of a malformation and its angiostructural and hemodynamic features. In all patients the neuroimaging modalities used in the investigation of their lesions included magnetic resonance (MR) imaging and selective spinal angiography. Three-dimensional computerized tomography angiography studies were obtained in 14 patients, and MR angiography was used in 17.

Conclusions

For successful surgical treatment of spinal AVMs it is necessary to obtain data about their localization, vascular structure, and hemodynamics that are as complete as possible. This information will promote the use of optimum surgical procedures and the latest methods of microsurgical and endovascular interventions, with treatments differentiated according to the type of malformation. One should try to use the least invasive endovascular approach in these cases,where possible, to occlude the AVM or reduce the intensity of blood flow by means of embolization. To perform an AVM resection or occlusion, one should use a direct approach to the malformation, blocking only the vessels supplying blood to the malformation and preserving the vessels feeding the spinal cord.
Survival after stereotactic biopsy and irradiation of cerebral nonanaplastic, nonpilocytic astrocytoma
Authors: Lunsford L. Dade , Somaza Salvador , Kondziolka Douglas , Flickinger John C.
Published: February 2011

✓ The authors investigated the outcome of stereotactic biopsy and radiotherapy in 35 consecutive adult patients with nonanaplastic, nonpilocytic astrocytomas who were diagnosed between 1982 and 1992. The median patient age at presentation was 32 years. All received fractionated external-beam radiation therapy (median dose 56 Gy) as the initial management strategy. Additional treatment in two patients included intracavitary irradiation with colloidal phosphorus-32.

Six patients (17%) had documented tumor progression during the follow-up interval and died. Three others died of causes unrelated to their tumor. Median survival after stereotactic biopsy and irradiation was 118 months (9.8 years). Median survival from the time of onset of neurological symptoms was 148 months (12.3 years). Only three patients required delayed cytoreductive surgery.

The outcome of brain astrocytomas, although improved because of earlier diagnosis and therapy, does not substantiate this tumor as having benign behavior; early recognition with neuroimaging, immediate histological diagnosis via stereotactic biopsy, and initial fractionated radiation therapy may provide the potential for longer survival for patients with low-grade astrocytomas. The majority of such surviving patients have a satisfactory quality of life, which is manifested by prolonged normal functional and employment status. The survival data reported in this prospective Phase I–II clinical trial suggest that stereotactic biopsy and radiation therapy are appropriate initial management strategies for astrocytomas.
Spinal cord mapping with evoked responses for accurate localization of the dorsal root entry zone
Authors: Fazl Mahmood , Houlden David A. , Kiss Zelma
Published: February 2011

✓ Direct spinal cord stimulation and recording techniques were used intraoperatively to localize the dorsal root entry zone (DREZ) in four patients with brachial plexus avulsion and severe intractable pain. The spinal cord was stimulated by a cordotomy needle placed on the pia-arachnoid at the DREZ or the dorsal or dorsolateral aspect of the spinal cord. Recordings were obtained from a subdural silver ball electrode placed rostral or caudal to the stimulation site. Spinal cord conduction velocity was significantly faster following dorsolateral stimulation than dorsal stimulation (mean = 66 and 45 m/sec respectively). The spinal cord evoked potential was significantly larger in amplitude following dorsolateral stimulation than dorsal stimulation at a specific stimulus intensity. Stimulation at the DREZ failed to evoke a response. These neurophysiological phenomena helped to accurately localize the DREZ before DREZ lesioning was undertaken. There were no untoward neurological deficits related to the DREZ lesions and all patients had satisfactory pain relief following the procedure. Intraoperative spinal cord mapping facilitates accurate DREZ localization when the DREZ cannot be visually identified.
Preirradiation chemotherapy including “eight drugs in 1 day” regimen and high-dose methotrexate in childhood medulloblastoma: results of the M7 French Cooperative Study
Authors: Gentet J. C. , Bouffet E. , Doz F. , Tron P. , Roche H. , Thyss A. , Plantaz D. , Stephan J. L. , Mottolese C. , Ponvert D. , Carrie C. , Raybaud C. , Brunat-Mentigny M. , Choux M. , Philip T. , Zucker J. M. , Bernard J. L.
Published: February 2011

✓ The aim of this study was to evaluate the feasibility and efficacy of a protocol that includes “sandwich” chemotherapy, that is, chemotherapy alternated with radiotherapy, and reduced doses of supratentorial irradiation in children with medulloblastoma. Between March 1985 and September 1988, 70 successive children with newly diagnosed medulloblastoma from eight centers were treated in this prospective nonrandomized study. Patients were assigned to two risk groups. Group A included patients with macroscopically complete or subtotal excision, no brainstem involvement, no atypical cells in the cerebrospinal fluid, normal myelography, and who were more than 2 years of age. Group B patients encompassed those who did not fit the criteria for Group A. Two children were excluded from analysis after histological review confirmed ependymoma. Thus, a population of 68 children was selected, with 31 in Group A and 37 in Group B.

Treatment consisted of two courses of the “eight drugs in 1 day” (“8/1”) regimen followed by two courses of high-dose methotrexate (12 g/m2). Radiotherapy was begun during the 7th week after surgery in Group A and during the 5th week in Group B. In patients older than 2 years, the median radiation dose to the posterior fossa, the spinal axis, and the brain was 54 Gy, 36 Gy, and 27 Gy, respectively. Group B patients received postirradiation chemotherapy with four 8/1 courses monthly. The median time from surgery to radiation therapy was 50 days (range 21 to 141 days). One fatality due to chicken pox on Day 102 and one World Health Organization Grade IV infection occurred. The estimated 5- and 7-year disease-free survival (DFS) rates were 62% and 59%, respectively. These were 74% and 62% in Group A and 57% and 57% in Group B. Patient age, extent of resection, and radiation dose to the whole brain had no prognostic value. Patients with metastasis had a nonsignificant trend for a worse prognosis than patients with nonmetastatic disease (7-year DFS 45% vs. 68%, p = 0.11). In Group B, the 7-year DFS rates for children who received more or less than 30 Gy to the brain were 69% and 52% respectively (p = 0.15). There were recurrences in the posterior fossa (37%), spine (20%), and brain (20%). After a review of radiotherapeutic treatments, only one supratentorial failure could be blamed on reduction of the supratentorial radiation dose. This “sandwich” chemotherapy appeared to be feasible and did not show adverse survival data when compared to other series.
Cortical stimulation mapping of phantom limb rolandic cortex
Authors: Ojemann Jeffrey O. , Silbergeld Daniel L.
Published: February 2011

✓ Findings of intraoperative rolandic cortex mapping during awake craniotomy for a tumor in a patient with a contralateral upper-extremity amputation are presented. This patient sustained a traumatic amputation at the mid-humerus 24 years previously. Initially he had experienced rare painless phantom limb sensations but none in the past 10 years. Functional mapping during an awake craniotomy was performed to maximize safe tumor resection. Typical temporal and frontal speech areas were identified; motor representation of face and jaw extended more superiorly than sensory representation. Shoulder movements were evoked more laterally than usual at the superior aspect of the craniotomy. A small region of precentral gyrus, between the jaw and shoulder representations, elicited no detectable effect when stimulated. Somatosensory mapping showed a similar topographical distribution of face and mouth cortex; however, posterior and inferior to the shoulder motor cortex, right arm and hand (phantom) sensations were evoked. Evidence suggests that significant motor reorganization occurs following an amputation, with expansion of neighboring homuncular representations without loss of somatosensory representation, despite a long period of time without any sensation referable to the amputated limb. Contrary to models of sensory cortex plasticity, the plasticity of the adult cortex may be system specific, with reorganization present in motor, but not in sensory, cortical systems.
Multiple suture synostosis, macrocephaly, and intracranial hypertension in a child with α-d-mannosidase deficiency
Authors: Grabb Paul A. , Albright A. Leland , Zitelli Basil J.
Published: February 2011

✓ The authors present an unusual case in which increased intracranial pressure developed because of multiple-suture craniosynostosis and megaloencephaly in a child with a previously undiagnosed lysosomal storage disease, α-d-mannosidase deficiency. This 3-year-old boy presented with a history of frequent naps, headaches, florid papilledema, enlarged head (> 95th percentile), elevated opening pressure by lumbar puncture, a “beaten copper” appearance on skull radiographs, and no hydrocephalus. Multiple synostectomies were performed. Postoperatively, the child's headaches and papilledema resolved and his level of physical activity increased dramatically. The authors discuss the paradoxical presentation of prematurely fused sutures and macrocrania in light of this lysosomal storage disease and its subsequent management.
Nonsurgical approach to paraparesis due to extramedullary hematopoiesis
Authors: Parsa Khosrov , Oreizy Ahmad
Published: February 2011

✓ Two cases of spinal cord compression due to extradural extramedullary hematopoiesis are reported and the non-surgical means used for their diagnosis and treatment are presented. One patient was treated with blood transfusions and radiation therapy, the other with blood transfusions alone. Both patients have made almost complete clinical recoveries from spinal cord compression. A mechanism is proposed to explain how blood transfusions can serve as an important diagnostic, as well as a therapeutic, tool in the management of this entity.
Isotonic mannitol and the prevention of local heat generation and tissue adherence to bipolar diathermy forceps tips during electrical coagulation
Authors: Sakatani Kaoru , Ohtaki Masafumi , Morimoto Shigefumi , Hashi Kazuo
Published: February 2011

✓ The authors observed temperature levels of saline and mannitol on the tips of bipolar diathermy forceps during application of power to the forceps and compared the effects of irrigation with saline and isotonic mannitol on electrical coagulation of vessels during neurosurgical operations. There was a marked rise in the temperature of saline corresponding to increased output power of the coagulator; there was no rise in the temperature of the mannitol. Irrigation with isotonic mannitol during surgery resulted in a considerable reduction of adherence of burned tissue and blood clots to forceps tips during coagulation of both arteries and veins compared with that which occurred during irrigation with saline. These results demonstrate that irrigation with an isotonic mannitol surpasses that with conventional ionic fluids, such as a saline, for prevention of both tissue adherence to bipolar diathermy forceps and removal of heat generated during electrical coagulation.
The Brigham Diary of Loyal Davis: a portrait of Harvey Cushing and a neurosurgical acolyte
Authors: Davis Richard A.
Published: February 2011

✓ At 27 years of age, Loyal Davis wrote the Brigham Diary while training as an Associate in Surgery with Dr. Harvey Cushing. The diary is a daily record of the Cushing neurosurgical service between 1923 and 1924. The literary tone of the document is one of youthful enthusiasm and candor. Its contemporary portrayal of Harvard University's third Moseley Professor displays a demanding surgeon and scholar whose primary concern was the care of his patients and who taught the meticulous techniques of neurosurgery by example. In contrast to the experiences offered by current neurosurgical residency programs, Loyal Davis examined 107 patients, observed 81 operations, assisted Dr. Cushing during 23 operations, assisted Dr. Gilbert Horrax in 13 operations, and never performed an operation independently during his year at the Peter Bent Brigham Hospital. Despite these technical constraints, the young assistant learned the Cushing method of surgery and skilled patient care and was encouraged to continue laboratory investigations. Davis also emulated Cushing's exacting method of preparation of medical manuscripts, which were characterized by scientific innovation and an engaging literary style.

The diary shows that Cushing often held inflexible surgical and scientific opinions and was contentious in their defense. These opinions were modified only when he was presented with unequivocal facts. The young surgeon sought Cushing's approval which carried a genuine but restrained benevolence.

Harvey Cushing's impression on Davis was lasting and profound. The diary conveys the philosophy that uncompromised discipline is a necessary virtue and hard work is full satisfaction in itself. In the following years, Loyal Davis systematically patterned his surgical and scholarly endeavors after those of Harvey Cushing, an exemplar whose unstinting resolve was the pursuit of excellence.
Cadaveric study for placement of occipital condyle screws: technique and effects on surrounding anatomic structures
Authors: La Marca Frank , Zubay Geoffrey , Morrison Thomas , Karahalios Dean
Published: February 2011

Object

The occipital condyle has never been studied as a viable structure that could permit bone purchase by fixation devices for occipitocervical fusion. The authors propose occipital condyle screw placement as a possible alternative to conventional occipitocervical fixation techniques.

Methods

Six adult cadaver heads (12 total occipital condyles) were studied, and the StealthStation image-guidance system was used for preoperative planning of occipital condyle screw placement. Morphometric studies of the occipital condyle were performed. A 3.5-mm Vertex screw was then placed in the occipital condyle with image-guided assistance in 3 specimens. Operations in the remaining 3 specimens proceeded using anatomical markers and calculated degrees of angulation for screw placement with a free-hand technique. Postoperatively the cadaver heads were rescanned and reanalyzed to determine the success of screw placement and its effect on hypoglossal canal volume.

Results

All screws were successfully placed with no sign of lateral or medial cortical breach. Two screws had bicortical purchase. There was no change in hypoglossal canal volume in any specimen.

Conclusions

Occipital condyle screw placement is a safe and viable option for occipitocervical fixation and could be a preferred procedure in selected cases. However, further biomechanical studies are required to compare its reliability to other more established techniques.
Endoscopic transnasal decompression for management of basilar invagination in osteogenesis imperfecta
Authors: Hansen Mitchell A. , da Cruz Melville J. , Owler Brian K.
Published: February 2011

Osteogenesis imperfecta (OI) is a disorder of bone development caused by a genetic dysfunction of collagen synthesis. Basilar invagination (BI) is an uncommon but serious complication of OI. Brainstem decompression in OI is undertaken in certain circumstances. Transoral-transpalatopharyngeal ventral decompression with posterior occipitocervical fusion has become the treatment of choice when required. This technical note outlines a novel endoscopic transnasal approach for ventral decompression. The literature is reviewed and a strategy for the management of BI in patients with OI is outlined.
Biomechanical evaluation of different asymmetrical posterior stabilization methods for minimally invasive transforaminal lumbar interbody fusion
Authors: Schleicher Philipp , Beth Paavo , Ottenbacher Andreas , Pflugmacher Robert , Scholz Matti , Schnake Klaus John , Haas Norbert P. , Kandziora Frank
Published: February 2011

Object

Beside several other advantages, the transforaminal approach for lumbar interbody fusion offers the possibility of reducing surgical trauma by limiting the approach to only 1 side. This requires posterior stabilization methods, which are applied without the need to damage contralateral muscles and soft tissues. The goal in this study was to compare different posterior stabilization methods for minimally invasive transforaminal lumbar interbody fusion (TLIF) biomechanically.

Methods

Stiffness testing was performed in 8 fresh-frozen human cadaveric lumbar spine motion segments, including the following sequentially tested configurations: 1) native motion segment; 2) TLIF and bilateral pedicle screw (PS) construct; 3) TLIF and ipsilateral PS construct; 4) TLIF and ipsilateral PSs plus contralateral translaminar facet screws according to the Magerl technique; and 5) TLIF and ipsilateral PSs plus contralateral lumbar facet interference screw (LFIS).

Results

In extension, the unilateral range of motion (uROM) and elastic zone (EZ) were significantly lower than native motion segments for bilateral PS and LFIS. There were no significant differences among the different stabilization methods. In flexion, uROM and EZ were significantly lower than the native segment in the spines treated with bilateral PSs and translaminar facet screws. The LFIS differed from the native segment in EZ only. Again, there were no significant differences between the different posterior stabilization methods. In lateral bending, the EZ of spines treated with uni- and bilateral PS differed significantly. There were no additional significant differences. In rotation, the stiffness values of bilateral PS were significantly higher than native, unilateral PS, and LFIS. The comparison between ipsi- and bilateral PS showed a tendency, but not a significant difference for uROM and EZ. There was no statistically significant evidence that the TLIF method led to an asymmetrical motion behavior in our study.

Conclusions

Bilateral PS augmentation offers significantly more stability than unilateral PSs in the majority of the test modes. There was no significant difference between the other tested methods. All tested stabilization methods could achieve at least the stability of the native segment.
Computed tomography–guided lumbar drain placement
Authors: Gold Menachem M. , Miller Todd S. , Farinhas Joaquim M. , Altschul David J. , Bello Jacqueline A. , Brook Allan L.
Published: February 2011

The authors describe a technique for lumbar drain placement using CT guidance. Midline or paramidline interlaminar approaches to the thecal sac can be used. The major advantage to CT guidance is direct visualization of the needle tip in relation to the thecal sac. This technical approach is a safe and rapid alternative to fluoroscopic guidance for the placement of lumbar drains in patients in whom standard lumbar drain placement techniques have failed.
Predictive factors for subsequent vertebral fracture after percutaneous vertebroplasty
Authors: Ahn Yong , Lee June Ho , Lee Ho-Yeon , Lee Sang-Ho , Keem Sang-Hyun
Published: February 2011

Object

The purpose of this study was to evaluate the predictive factors for subsequent vertebral fracture occurring after percutaneous vertebroplasty (PVP) at the neighboring levels (adjacent vs nonadjacent levels).

Methods

The medical records of 508 consecutive patients treated with PVP between January 2000 and December 2002 were retrospectively reviewed. A total of 45 patients with 49 painful vertebral fractures occurring after PVP was identified based on clinical and radiological findings. New vertebral fractures, developing at any of the 3 consecutive vertebral bodies (VBs) above or below the previously treated level, were the focus of the study. The patients were divided into 3 groups: an adjacent-level fracture group, nonadjacent-level fracture group, and a control group composed of 50 randomly selected patients in whom there was no evidence of a new fracture. Clinical, imaging, and procedure-related factors for each group were statistically analyzed.

Results

In 31 patients 35 VBs were classified as adjacent-level fractures, and in 14 patients 14 VBs were classified as nonadjacent-level fractures. After further vertebroplasty, the overall pain intensity and satisfaction rate in patients with post-PVP fractures were similar to those in the control group. In cases involving adjacent fractures, lower body mass index and intradiscal cement leakage were the significant predictive factors of fracture. In contrast, lower mobility of the index segment was related to nonadjacent-level fracture.

Conclusions

According to the authors' results, the mechanisms of subsequent fracture at adjacent and nonadjacent vertebrae are different. A direct pillar effect (that is, the difference in strength caused by cement augmentation) may provoke an adjacent-level fracture, whereas a dynamic hammer effect (the difference in segmental mobility) may lead to a nonadjacent fracture.
Single-level instrumented mini-open transforaminal lumbar interbody fusion in elderly patients
Authors: Lee Dong Yeob , Jung Tag-Geun , Lee Sang-Ho
Published: February 2011

Object

The purpose of this study was to analyze the surgical outcomes in cases involving elderly patients who underwent single-level instrumented mini-open transforaminal lumbar interbody fusion (TLIF).

Methods

The authors performed a retrospective review of 27 consecutive cases involving elderly patients (≥ 65 years of age) who underwent single-level instrumented mini-open TLIF and were followed up for at least 3 years. Degenerative spondylolisthesis was diagnosed in 16 patients, stenosis with instability in 8, and lytic spondylolisthesis in 3. All cases were Grade I or II based on the American Society of Anesthesiologists' classification system. Clinical outcomes were assessed using a visual analog scale, the Oswestry Disability Index, and patients' subjective satisfaction. Sagittal balance, bone union, and adjacent segment degeneration (ASD) were assessed using plain radiography and 3D CT.

Results

The mean age of patients at the time of surgery was 69.3 years (range 65–80 years). Minor complications occurred in 2 patients (7.4%) in the perioperative period. At a mean follow-up duration of 38.6 months (range 36–42 months), clinical success was achieved in 88.9% of cases. The mean segmental lordosis and sacral tilt significantly increased after surgery (from 11.9 and 33.5° to 13.9 and 37.2°, p = 0.024 and p = 0.001, respectively). Solid fusion was achieved in 77.8% of the patients. Adjacent segment deterioration was found in 44.4% of the patients. No patients underwent revision surgery due to nonunion or ASD. The development of ASD was significantly related to postoperative sacral tilt (p = 0.006).

Conclusions

Single-level instrumented mini-open TLIF yielded good clinical and radiological outcomes with a low complication rate in elderly patients.
Traumatic spondyloptosis of the thoracolumbar spine
Authors: Yadla Sanjay , LeBude Bryan , Tender Gabriel C. , Sharan Ashwini D. , Harrop James S. , Hilibrand Alan S. , Vaccaro Alexander R. , Ratliff John K.
Published: February 2011

Object

Traumatic Grade V thoracolumbar spondylolisthesis, or traumatic spondyloptosis (severe translation injuries), are uncommon spinal injuries. To the best of the authors' knowledge, this article represents the first reported case series of these unique spinal lesions.

Methods

The authors undertook a retrospective review of a tertiary care regional spinal cord injury patient population treated over a 10-year period (1997–2007). They analyzed data regarding age, sex, mechanism of injury, neurological status, and treatment.

Results

Five patients were identified (3 men and 2 women) with ages ranging from 17 to 44 years. All patients had sustained high-energy closed spinal injuries: 3 motor vehicle accidents, 1 injured in a building collapse, and 1 hurt by a fallen steel beam. Four patients, all with sagittal-plane spondyloptosis, had a complete neurological deficit (American Spinal Injury Association [ASIA] Grade A), and 1, with coronal-plane spondyloptosis, presented with an incomplete neurological deficit (ASIA Grade C). Four patients had sustained concurrent multisystem trauma. All patients underwent surgery: an isolated posterior fusion in 2 and combined posterior-anterior fusion in 3. Only the patient with an incomplete neurological deficit (coronal-plane spondyloptosis) recovered neurological function postoperatively.

Conclusions

Traumatic thoracolumbar junction spondyloptosis is rare. Surgical reconstruction and stabilization allow for early mobilization and rehabilitation. In the present series, a patient with coronal-plane spondyloptosis presented with preserved neurological function. This may be due to the result of differences in resultant neurological compression due to displacement mechanics compared with sagittally displaced injuries.
Surgical treatment of cervical spondylotic myelopathy with anterior compression: a review of 67 cases
Authors: Gok Beril , Sciubba Daniel M. , McLoughlin Gregory S. , McGirt Matthew , Ayhan Selim , Wolinsky Jean-Paul , Bydon Ali , Gokaslan Ziya L. , Witham Timothy F.
Published: February 2011

Object

In patients with cervical spondylotic myelopathy (CSM), ventral disease and loss of cervical lordosis are considered to be relative indications for anterior surgery. However, anterior decompression and fusion operations may be associated with an increased risk of swallowing difficulty and an increased risk of nonunion when extensive decompression is performed. The authors reviewed cases involving patients with CSM treated via an anterior approach, paying special attention to neurological outcome, fusion rates, and complications.

Methods

Retrospectively, 67 cases involving consecutive patients with CSM requiring an anterior decompression were reviewed: 46 patients underwent anterior surgery only (1-to3-level anterior cervical discectomy and fusion [ACDF] or 1-level corpectomy), and 21 patients who required > 3-level ACDF or ≥ 2-level corpectomy underwent anterior surgery supplemented by a posterior instrumented fusion procedure.

Results

Postoperative improvement in Nurick grade was seen in 43 (93%) of 46 patients undergoing anterior decompression and fusion alone (p < 0.001) and in 17 (81%) of 21 patients undergoing anterior decompression and fusion with supplemental posterior fusion (p = 0.0015). The overall complication rate for this series was 25.4%. Interestingly, the overall complication rate was similar for both the lone anterior surgery and combined anterior-posterior groups, but the incidence of adjacent-segment disease was greater in the lone anterior surgery group.

Conclusions

Significant improvement in Nurick grade can be achieved in patients who undergo anterior surgery for cervical myelopathy for primarily ventral disease or loss of cervical lordosis. In selected high-risk patients who undergo multilevel ventral decompression, supplemental posterior fixation and arthrodesis allows for low rates of construct failure with acceptable added morbidity.
Posterolateral protrusion of the vertebral artery over the posterior arch of the atlas: quantitative anatomical study using three-dimensional computed tomography angiography
Authors: Yamaguchi Satoshi , Eguchi Kuniki , Kiura Yoshihiro , Takeda Masaaki , Kurisu Kaoru
Published: February 2011

Object

The vertebral artery (VA) often takes a protrusive course posterolaterally over the posterior arch of the atlas. In this study, the authors attempted to quantify this posterolateral protrusion of the VA.

Methods

Three-dimensional CT angiography images obtained for various cranial or cervical diseases in 140 patients were reviewed and evaluated. Seven patients were excluded for various reasons. To quantify the protrusive course of the VA, the diameter of the VA and 4 parameters were measured in images of the C1–VA complex obtained in the remaining 133 patients. The authors also checked for anomalies and anatomical variations.

Results

When there was no dominant side, mean distances from the most protrusive part of the VA to the posterior arch of the atlas were 6.73 ± 2.35 mm (right) and 6.8 ± 2.15 mm (left). When the left side of the VA was dominant, the distance on the left side (8.46 ± 2.00 mm) was significantly larger than that of the right side (6.64 ± 2.0 mm). When compared by age group (≤ 30 years, 31–60 years, and ≥ 61 years), there were no significant differences in the extent of the protrusion. When there was no dominant side, the mean distances from the most protrusive part of the VA to the midline were 30.73 ± 2.51 mm (right side) and 30.79 ± 2.47 mm (left side). When the left side of the VA was dominant, the distance on the left side (32.68 ± 2.03 mm) was significantly larger than that on the right side (29.87 ± 2.53 mm). The distance from the midline to the intersection of the VA and inner cortex of the posterior arch of the atlas was ~ 12 mm, irrespective of the side of VA dominance. The distance from the midline to the intersection of the VA and outer cortex of the posterior arch was ~ 20 mm on both sides. Anatomical variations and anomalies were found as follows: bony bridge formation over the groove for the VA on the posterior arch of C-1 (9.3%), an extracranial origin of the posterior inferior cerebellar artery (8.2%), and a VA passing beneath the posterior arch of the atlas (1.8%).

Conclusions

There may be significant variation in the location and branches of the VA that may place the vessel at risk during surgical intervention. If concern is noted about the vulnerability of the VA or its branches during surgery, preoperative evaluation by CT angiography should be considered.
Dynamic electrophysiological examination of cervical flexion myelopathy
Authors: Kato Yoshihiko , Imajo Yasuaki , Kanchiku Tsukasa , Kojima Takanori , Kataoka Hideo , Taguchi Toshihiko
Published: February 2011

Cervical flexion myelopathy is thought to arise following compression of the spinal cord by vertebrae or intervertebral discs and dura mater, or from overstretching of the spinal cord induced by cervical spinal flexion. However, the influence of spinal flexion on the spinal cord and the detailed origins of this disease are unknown. In this article the authors report a case of cervical flexion myelopathy in which dynamic electrophysiological examination was performed using an epidural electrode. This investigation showed the real-time influence of flexion of the cervical spine on spinal cord function. This technique was considered to be useful for diagnosis and in decision making for treatment. Anterior fusion was the optimal surgical method for treating this disease.
Subclavian artery stenosis causing transient bilateral brachial diplegia: an unusual cause of anterior spinal artery syndrome
Authors: Rughani Anand I. , Visioni Agostino , Hamill Robert W. , Tranmer Bruce I.
Published: February 2011

The author report a case of a 74-year-old man who had presented with transient bilateral brachial diplegia. Investigations led to the diagnosis and treatment of subclavian artery stenosis. There are no known published cases of subclavian artery stenosis associated with transient bilateral arm weakness, and the authors believe that a steal phenomenon leading to vertebrobasilar artery insufficiency and subsequent anterior spinal artery insufficiency may have caused these symptoms, which resolved after correction of the patient's stenosis.
Intradural microanatomy of the nerve roots S1–S5 at their origin from the conus medullaris
Authors: Hauck Erik F. , Wittkowski Werner , Bothe Hans W.
Published: February 2011

Object

The conus medullaris and the nerve roots from S-1 to S-5 regulate bladder function as well as movement and sensation of the lower extremities. This most caudal region of the spinal cord has not been studied in great detail anatomically despite its important regulatory role. The goal of this analysis is to characterize the normal intradural microanatomy of the sacral nerve roots at their origin from the conus medullaris.

Methods

The thecal sacs from 20 cadavers were fixated in formaldehyde and dissected under the operative microscope.

Results

More than 50 rootlets originated from the conus medullaris over a distance of < 3 cm. The rootlets were loosely organized into bundles by the arachnoid membrane with decreasing diameters. These diameters were 1.7 mm (ventral)/2.4 mm (dorsal) at S-1, and 0.17 mm (ventral)/0.4 mm (dorsal) at S-5. The roots were separated by neither the dentate ligament nor interradicular gaps. The number of rootlets decreased in the rostrocaudal direction with 2 ventral and 5 dorsal rootlets at S-1, but only 1 ventral (inconsistently found) and 2 dorsal rootlets at S-5. Typically, 1 nerve anastomosis was present between adjacent dorsal roots from S-1 to S-4. Nerve anastomoses between ventral roots or rootlets of the same root were less frequent. The dorsal segment of origin (linea radicularis) decreased in length from 7.2 mm at S-1 to 4.8 mm at S-5.

Conclusions

The current study provides anatomical details and specific morphometric data of the intradural contents at the level of the conus medullaris. This information is valuable for intraoperative orientation, endoscopic navigation, and possible intradural nerve stimulation.
Treatment of neuroinflammation by soluble tumor necrosis factor receptor Type II fused to a thermally responsive carrier
Authors: Shamji Mohammed F. , Jing Liufang , Chen Jun , Hwang Priscilla , Ghodsizadeh Odelia , Friedman Allan H. , Richardson William J. , Setton Lori A.
Published: February 2011

Object

Biochemical irritation of the dorsal root ganglion (DRG) after intervertebral disc herniation contributes to radiculopathy through tumor necrosis factor–α (TNFα)–mediated inflammation. Soluble TNF receptor Type II (sTNFRII) sequesters this cytokine, providing clinical benefit. Previous work involving conjugation of sTNFRII with thermally responsive elastin-like polypeptide (ELP) yielded a chimeric protein (ELP–sTNFRII) with in vitro anti-TNFα bioactivity. Furthermore, temperature-triggered ELP aggregation into a “depot” prolongs protein residence time following perineural injection. In this study the authors evaluated the inflammatory phenotype of DRG explants after TNFα stimulation, and assessed the abilities of sTNFRII or ELP–sTNFRII to attenuate these neuro-inflammatory changes.

Methods

Rat lumbar DRGs (35 animals) were treated in 6 groups, as follows: control; TNFα (25 ng/ml); TNFα with low-(0.2 μg/ml) or high-dose (1 μg/ml) sTNFRII; and TNFα with low-(52.5 μg/ml) or high-dose (262.5 μg/ml) ELP–sTNFRII. After 24 hours, supernatant was evaluated for inflammatory cytokines (interleukin [IL]–1, IL-6, and IL-10); prostaglandin E2; and metabolites (glutamate, lactate, and pyruvate). Single-factor analysis of variance with post hoc Dunn analysis (α = 0.05) was used to assess treatment differences.

Results

Incubation of explants with TNFα caused metabolic stress reflected by an increased lactate/pyruvate ratio (1.8 ± 0.5–fold) and extracellular glutamate (79 ± 8% increase). Inflammatory activation was observed with heightened IL-6 release (5.2 ± 1.4–fold) and prostaglandin E2production (14 ± 3–fold). An autoregulatory response occurred with an 11.8 ± 0.6–fold increase in sTNFRI shedding. Treatment with high doses of sTNFRII or ELP–sTNFRII reversed all changes. Values are expressed as the mean ± standard deviation.

Conclusions

These results demonstrate that TNFα stimulation of DRG explants yields a phenotype of neurotoxic metabolite release and inflammatory mediator expression. Coincubation with either sTNFRII or ELP–sTNFRII antagonizes TNFα activity to abrogate these changes, suggesting potential for therapeutic intervention to treat peripheral nerve inflammatory disease.
Mitomycin protection of peridural fibrosis in lumbar disc surgery
Authors: Çelik Suat E. , Altan Tugrul. , Çelik Sevinç , Göksu Kamber , İnce İrfan , Kapran Ziya
Published: February 2011

Object

In this prospective, randomized clinical study the authors sought to evaluate the effects of locally applied mitomycin C on peridural fibrosis during lumbar microdiscectomy.

Methods

Patients undergoing lumbar disc surgery were randomly divided into 2 groups. Thirty patients had 1 mg/ml mitomycin C applied at the site of discectomy for 5 minutes, and 30 age- and sex-matched patients underwent lumbar microdiscectomy without mitomycin C application as the control group. The groups were compared for degree of postoperative neurological function, radicular/back pain, and degree of peridural fibrosis on MR imaging 6 months after the operation.

Results

The median follow-up was 18 months. No serious drug adverse effects and no clinically significant laboratory adverse effects were reported in patients in the mitomycin C group. Patients in both groups showed similar clinical recoveries postoperatively. On postoperative evaluation of the MR images, pain scores, and neurological function, patients given mitomycin C have shown no reduction of peridural fibrosis either clinically or radiographically.

Conclusions

Mitomycin C is easy to use and safe in patients undergoing lumbar microdiscectomy. However, no benefit was observed either clinically or radiographically in this study.
Spinal root arteriovenous malformations and same-segment cord cavernous malformation in familial cerebral cavernous malformation
Authors: De Souza Jorge Marcondes , Domingues Flavio S. , Chimelli Leila , Gault Judith
Published: February 2011

Spinal vascular malformations are uncommon lesions, and controversy persists regarding optimal investigation, classification, and treatment strategies. The authors report on a patient with a spinal root arteriovenous malformation (AVM) associated with a parenchymal cavernous malformation (CM) in the same spinal cord segment and describe a complete familial and molecular investigation. This 35-year-old woman presented with symptoms of progressive clinical spastic paraparesis. Magnetic resonance imaging results were suggestive of a spinal cord cavernoma associated with cerebral CMs. Her family history included 2 sisters treated for epilepsy. At surgery an intraspinal root AVM was found at the same level of the cord CM, and both lesions were completely removed. Cerebral gradient echo MR imaging disclosed multiple cavernomas in her relatives, which prompted the molecular diagnosis. On sequence analysis, a novel mutation on the cerebral CM1 (CCM1) gene (c796insA) was found. The authors report on a unique case of familial cerebral CM in which a spinal root AVM was situated next to a cord CM, and discuss the concomitant occurrence of altered nervous system angiogenesis and vasculogenesis.
Anterior approach to cervical intramedullary pilocytic astrocytoma
Authors: Ogden Alfred T. , Feldstein Neil A. , McCormick Paul C.
Published: February 2011

Although there has been considerable experience with anterior approaches to ventral intradural, extramedullary, and pial-based spinal lesions, there is no information in the literature regarding the safety and feasibility of the resection of an intramedullary tumor via an anterior approach. The authors report on the gross-total resection of an intramedullary cervical pilocytic astrocytoma via a C-7 corpectomy and anterior myelotomy. The surgery proceeded without complication, and postoperatively the patient maintained the preoperative deficit of mild unilateral hand weakness but had no sensory deficits. Follow-up MR imaging at 6 months showed gross-total macroscopic resection. Selected intramedullary tumors can be safely removed via an anterior approach. This approach avoids the typical sensory dysfunction associated with posterior midline myelotomy.
Immediate postoperative regression of retroodontoid pannus after lateral mass reconstruction in a patient with rheumatoid disease of the craniovertebral junction
Authors: Goel Atul , Dange Nitin
Published: February 2011

The authors report the case of a 35-year-old man who had polyarthritic affliction with rheumatoid disease. He presented with complaints of quadriparesis that had progressed over the course of 2 years. Investigations revealed telltale evidence of rheumatoid disease of the craniovertebral junction with retroodontoid pannus, basilar invagination, and “fixed” atlantoaxial dislocation. The patient underwent lateral mass reconstruction with distraction of the facets and impaction of a spiked metal spacer and bone graft within the joint. Investigations done in the immediate postoperative phase showed complete disappearance of retroodontoid pannus in addition to reduction of basilar invagination and atlantoaxial dislocation. He had remarkable and sustained relief from symptoms. The authors also review the pathogenesis and treatment of retroodontoid pannus.
The cervical end of an occipitocervical fusion: a biomechanical evaluation of 3 constructs
Authors: Finn Michael A. , Fassett Daniel R. , Mccall Todd D. , Clark Randy , Dailey Andrew T. , Brodke Darrel S.
Published: February 2011

Object

Stabilization with rigid screw/rod fixation is the treatment of choice for craniocervical disorders requiring operative stabilization. The authors compare the relative immediate stiffness for occipital plate fixation in concordance with transarticular screw fixation (TASF), C-1 lateral mass and C-2 pars screw (C1L-C2P), and C-1 lateral mass and C-2 laminar screw (C1L-C2L) constructs, with and without a cross-link.

Methods

Ten intact human cadaveric spines (Oc–C4) were prepared and mounted in a 7-axis spine simulator. Each specimen was precycled and then tested in the intact state for flexion/extension, lateral bending, and axial rotation. Motion was tracked using the OptoTRAK 3D tracking system. The specimens were then destabilized and instrumented with an occipital plate and TASF. The spine was tested with and without the addition of a cross-link. The C1L-C2P and C1L-C2L constructs were similarly tested.

Results

All constructs demonstrated a significant increase in stiffness after instrumentation. The C1L-C2P construct was equivalent to the TASF in all moments. The C1L-C2L was significantly weaker than the C1L-C2P construct in all moments and significantly weaker than the TASF in lateral bending. The addition of a cross-link made no difference in the stiffness of any construct.

Conclusions

All constructs provide significant immediate stability in the destabilized occipitocervical junction. Although the C1L-C2P construct performed best overall, the TASF was similar, and either one can be recommended. Decreased stiffness of the C1L-C2L construct might affect the success of clinical fusion. This construct should be reserved for cases in which anatomy precludes the use of the other two.
‘Half Art’: Baudelaire's Le Peintre de la vie moderne
Authors: Bowlby Rachel
Published: February 2011

This article considers Baudelaire's essay Le Peintre de la vie moderne as a possible response to the question of why art matters. Baudelaire's exhilarating innovation is to downgrade the significance of eternal value in art, in favour of what he designates its other half, the fleeting presentness that is modernity. Baudelaire explores this idea through a mock-anonymous celebration of the artist Constantin Guys, referred to as M. G., whose prolific sketches, done at speed, for rapid journal publication, chart the day-by-day miniscule changes in the appearances of the city. Guys's pictures — the art of modernity — give to the fleeting moment a second life, and ‘translate’ into a different medium — from sight to (mental) impression to its ‘rebirth’ as a sketch — what would otherwise be lost in its passing.
Beckett's Humour, from an Ethics of Finitude to an Ethics of the Real
Authors: Dow Suzanne
Published: February 2011

This article explores the ethics of Samuel Beckett's humour. It takes issue with the dominant reading of Beckettian humour as the redemption of a negativity occasioned by humanity's finitude. The paradigmatic case in point is here taken to be Simon Critchley's account, wherein ethics is cast as a process of coming to terms with disappointment ensuing from the inaccessibility of the Kantian Thing-in-Itself. This article takes up a Lacanian psychoanalytic perspective to recast Beckett's humour as, far from offering solace for finitude, highlighting instead the excess or remainder that insists, and resists philosophy's attempts to sublate it into a version of the Good. As such, the ethical demand evoked by Beckettian humour is not the attenuation of the disappointing lack implied by finitude, but rather a coping with the egregious excess of inhuman infinitude.
Hazardous Compounds in Tobacco Smoke
Authors: Talhout Reinskje , Schulz Thomas , Florek Ewa , Van Benthem Jan , Wester Piet , Opperhuizen Antoon
Published: February 2011

Tobacco smoke is a toxic and carcinogenic mixture of more than 5,000 chemicals. The present article provides a list of 98 hazardous smoke components, based on an extensive literature search for known smoke components and their human health inhalation risks. An electronic database of smoke components containing more than 2,200 entries was generated. Emission levels in mainstream smoke have been found for 542 of the components and a human inhalation risk value for 98 components. As components with potential carcinogenic, cardiovascular and respiratory effects have been included, the three major smoke-related causes of death are all covered by the list. Given that the currently used Hoffmann list of hazardous smoke components is based on data from the 1990s and only includes carcinogens, it is recommended that the current list of 98 hazardous components is used for regulatory purposes instead. To enable risk assessment of components not covered by this list, thresholds of toxicological concern (TTC) have been established from the inhalation risk values found: 0.0018 µg day−1 for all risks, and 1.2 µg day−1 for all risks excluding carcinogenicity, the latter being similar to previously reported inhalation TTCs.