bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pathophysiology of tethered cord syndrome: correlation with symptomatology
Authors: Yamada Shokei , Won Daniel J. , Yamada Shoko M. 
Published: January 2008

Tethered cord syndrome (TCS) is a stretch-induced functional disorder of the spinal cord. The mechanical cause of TCS is an inelastic structure anchoring the caudal end of the spinal cord that prevents cephalad movement of the lumbosacral cord. Stretching of the spinal cord occurs in patients either when the spinal column grows faster than the spinal cord or when the spinal cord undergoes forcible flexion and extension.
Research in patients and experimental animals suggests that there is a link between the clinical dysfunctions that characterize TCS and putative pathophysiological changes that accompany this syndrome. Among these changes are depression of electrophysiological activity and shifts in the reduction/oxidation ratio of cytochrome oxidase. The latter suggests that there is impairment of oxidative metabolism. These putative pathophysiological changes in TCS occur mainly within the lumbosacral cord under excessive tension.
The authors discuss the pathophysiology of TCS and examine related symptoms.
Tethered spinal cord following repair of myelomeningocele
Authors: Hudgins Roger J. , Gilreath C. Lynn 
Published: January 2008

Object
The goal of this paper is to elucidate the clinical presentation of tethered cord syndrome (TCS) following repair of a myelomeningocele.

Methods
Approximately 10 to 30% of children will develop TCS following repair of a myelomeningocele. Because essentially all children with repaired myelomeningocele will have a tethered spinal cord, as demonstrated on MR imaging, the diagnosis of TCS is made based on clinical criteria. The six common clinical presentations of TCS are increased weakness (55%), worsening gait (54%), scoliosis (51%), pain (32%), orthopedic deformity (11%), and urological dysfunction (6%). The primary goal of surgery is to detach the spinal cord where it is adherent to the thecal sac, relieving the stretch on the terminal portion of the cord.

Conclusions
Early diagnosis and surgical release of the tethered cord results in stabilization or improvement in most cases. Because TCS may present with orthopedic and/or urological signs or symptoms, children with myelomeningocele should by followed, ideally in a multidisciplinary clinic, by neurosurgeons, orthopedic surgeons, and urologists who are aware of this condition.
Lumbar interbody fusion after treatment with recombinant human bone morphogenetic protein–2 added to 70:30 poly(L-lactide-co-D,L-lactide) bioresorbable implants
Authors: Lanman Todd H. , Hopkins Thomas J. 
Published: January 2008

Object
To evaluate the effectiveness of recombinant human bone morphogenetic protein–2 (rhBMP-2) combined with a bioresorbable implant, the authors conducted a prospective study of 43 patients with degenerative lumbar disc disease who underwent transforaminal lumbar interbody fusion.

Methods
The authors used Infuse bone graft, which consisted of rhBMP-2 applied to an absorbable collagen sponge and contained within a HYDROSORB Telamon bioresorbable implant to perform the fusion. Multilevel fusions were performed in 30% of the 43 patients, for a total of 57 levels. At 6 months postoperatively, x-ray films and computerized tomography (CT) scans demonstrated solid fusion in 98% of 41 patients. Improvement from the baseline Oswestry Disability Rating was demonstrated at 6 months postoperatively in 68% of the patients, based on the Oswestry Disability Questionnaire. At 12 months all 11 patients in whom CT scans were obtained showed complete bridging of bone; there were no device-related complications.

Conclusions
Results in this series provide evidence of the feasibility of using HYDROSORB Telamon biore-sorbable spacers in combination with Infuse bone graft for lumbar spine fusion.
Porous polyethylene implant for cranioplasty and skull base reconstruction
Authors: Liu James K. , Gottfried Oren N. , Cole Chad D. , Dougherty William R. , Couldwell William T. 
Published: January 2008

Object
Cranial reconstruction after skull base surgery is important for restoration of function and cosmesis. The authors describe their experience with the Medpor porous polyethylene implant for cosmetic cranioplasty and reconstruction after skull base surgery.

Methods
Medpor, a biocompatible implant, is flexible and can be contoured to facilitate surgical reconstruction of small to medium (< 8 cm) convexity or cranial base defects resulting from a variety of skull base approaches. This method provides similar cosmetic results to standard alloplast cranioplasty while decreasing operating time. The porous nature of the material allows ingrowth of soft tissue and bone to increase implant strength and decrease the risk of infection. This material can also be used safely in reconstruction of the cranium and skull base adjacent to the paranasal sinuses.

Conclusions
The authors have used the Medpor porous polyethylene implant in 611 standard cranial and skull base procedures and have achieved excellent cosmetic results and no implant-related complications.
Use of polylactide resorbable film as a barrier to postoperative peridural adhesion in an ovine dorsal laminectomy model
Authors: Klopp Lisa S. , Welch William C. , Tai Joseph W. , Toth Jeffery M. , Cornwall G. Bryan , Turner A. Simon 
Published: January 2008

Object
The purpose of this study was to evaluate the performance of a resorbable polylactide film in the sheep posterior spine in the presence of a combined laminectomy and durotomy defect.

Methods
A resorbable polylactide film was used to cover the combined defects in the eight sheep used in this study. Two surgical levels were performed in each animal, with randomly assigned control and treated sites. Each surgical level consisted of a full laminectomy followed by a needle-induced durotomy. The treated levels received a resorbable polylactide film cut to size and tucked in under the laminar defect. At 8 to 10 weeks postoperatively, results of myelography and visual dye infiltration showed complete healing of the durotomies for all sites. In addition, evaluation of gross dissection based on volume and tenacity scores as well as histological findings indicates decreased posterior dural adhesions for sites treated with resorbable polylactide film.

Conclusions
The results of this investigation support previous studies in which the use of a resorbable polylactide film was found to be effective in reducing posterior dural adhesions in the spine with no apparent safety issues related to impaired dural healing.
Cervical spine fusion with bioabsorbable cages
Authors: Lippman Caleb R. , Hajjar Michael , Abshire Bret , Martin George , Engelman Robert W. , Cahill David W. 
Published: January 2008

Object
Although it improves rates of fusion in surgical arthrodesis, conventional spinal instrumentation is associated with several risks, including hardware extrusion that injures adjacent anatomical structures, and disuse osteopenia as a result of stress shielding. The long-term effects of indwelling spinal instrumentation, although incompletely documented, may be detrimental. One way to avoid such problems would be to use bioabsorbable implantation devices. In this pilot study, performed in 1998 and 1999, the authors evaluated the use of a bioabsorbable interbody fusion device in a goat cervical spine model.

Methods
Forty-two goats underwent two-level anterior cervical discectomy and fusion: eight received iliac crest autograft; 16 received a cage implant composed of 70:30 poly(L-lactide-co-D,L-lactide)/polyglycolic acid (70:30 PLDLLA/PGA) filled with either autograft or recombinant human bone morphogenetic protein–2 (rhBMP-2); and 18 received a cage implant composed of 85:15 PLDLLA/PGA filled with either autograft or rhBMP-2. Animals were killed at 3, 6, and 12 months postsurgery, and their cervical spines were evaluated histologically, radiographically, and physically for fusion.
A primarily fibrous union was demonstrated in all animals killed at 3 months. At 6 months, bone trabeculae had become more prominent and the fibrous response less so in all cohorts. This occurred most frequently in the animals that underwent fusion with the 70:30 PLDLLA/PGA cages filled with rhBMP-2, in which 63% attained a histologically confirmed union that contained quantitatively more bone and less fibrous tissue than in the other cohorts; 63% of the unions in the aforementioned cohort were graded quantitatively as being stable.

Conclusions
In this study the authors have established that the 85:15 PLDLLA/PGA cages are absorbed too quickly to be functionally useful in this model. The 70:30 PLDLLA/PGA cages worked as well as tricortical autograft when filled with cancellous autograft, and better when filled with rhBMP-2. At 6- and 12-month follow-up review, the 70:30 PLDLLA/PGA cages had not yet begun to be absorbed. There was little if any inflammatory response to these cages at 6 months. Future studies should include biomechanical and microradiographic testing, and a longer follow-up period is necessary in this model to determine when the 70:30 PLDLLA/PGA cages are absorbed.
Early findings in a pilot study of anterior cervical interbody fusion in which recombinant human bone morphogenetic protein–2 was used with poly(L-lactide-co-D,L-lactide) bioabsorbable implants
Authors: Lanman Todd H. , Hopkins Thomas J. 
Published: January 2008

Object
The goal of this study was to assess the efficacy of bioabsorbable interbody spacers in cervical spine fusion.

Methods
The authors report on a prospective examination of 20 patients with degenerative cervical disc disease who underwent anterior cervical fusion at 28 total levels. The authors used Infuse bone graft (that is, recombinant human bone morphogenetic protein–2 applied to an absorbable collagen sponge and contained within a Cornerstone-HSR bioabsorbable spacer. Multiple-level fusions were performed in 30% of these patients. At 3 months postfusion, radiographs and computerized tomography scans demonstrated bridging bone in 100% of the patients. Improvement from baseline scores in physical functioning, mental health, and bodily pain was demonstrated at 3 months postoperatively according to results of the Short Form–36 Version 2 health survey. There were no device-related complications.

Conclusions
The results in this series indicate that the use of Cornerstone-HSR as a bioabsorbable interbody spacer in combination with Infuse bone graft may be an alternative treatment for cervical spine fusion.
Posterior lumbar interbody fusion with bioabsorbable spacers and local autograft in a series of 27 patients
Authors: Couture Daniel E. , Branch Charles L. 
Published: January 2008

Object
The goal of this prospective study was to review a series of 27 patients who underwent bilateral posterior lumbar interbody fusion with instrumented pedicle fixation and two HYDROSORB (known generically as 70:30 poly[L-lactide-co-D,L-lactide]) rectangular cages packed with locally harvested autograft at a total of 48 levels, and to assess the safety and efficacy of this novel technique. This analysis, conducted at a mean of 26 months of follow up, is the first report of a long-term evaluation of this technique. Fusion rates and clinical outcomes are presented.

Methods
A prospective clinical and radiographic review of findings in 27 consecutive patients was performed. Fusion rates and clinical outcome were assessed at 6-month intervals up to the 32-month follow-up end point. Two patients with four corresponding fusion levels were lost to follow up.
Radiographic evidence of satisfactory fusion was achieved in 42 (95.5%) of 44 levels fused. Satisfactory fusion at all levels was achieved in 23 (92%) of 25 patients. Two patients required repeated operations for treatment of symptomatic pseudarthrosis during the study period. The likelihood of all levels attaining fusion in a given patient decreased as the number of levels treated increased, which is consistent with previously published studies. Nonetheless, fusion rates per treated level were similar for patients in whom one to three levels were treated. No significant surgical complication occurred.

Conclusions
Posterior lumbar interbody fusion in which the HYDROSORB bioabsorbable implant packed with locally harvested autograft and segmental internal fixation are used appears to be an interbody fusion alternative whose efficacy is comparable with previously reported procedures.
Stereotactic radiosurgery for Cushing disease
Authors: Hentschel Stephen J. , McCutcheon Ian E. 
Published: January 2008

The most common cause of Cushing syndrome is Cushing disease, in which hypercortisolism is produced by a functional adrenocorticotropic hormone–producing adenoma of the anterior pituitary gland. The common therapies available include microsurgical resection, conventional fractionated radiotherapy, and stereotactic radiosurgery (SRS). In this article the authors review the indications, results, and complications associated with SRS in the treatment of Cushing disease.
In as many as 90% of patients SRS results in disease remission, which is defined as a normal 24-hour urinary free cortisol level and a normal or subnormal morning serum cortisol level. Although in most patients who are subsequently cured a marked decrease in the serum cortisol level is demonstrated within 3 months after treatment, a biochemical cure may be delayed up to 3 years in some cases. Complications following SRS for pituitary adenomas are uncommon, particularly in patients with microadenomas, which are most commonly seen in Cushing disease. The most common complication is hypopituitarism, which occurs in up to 50% of patients with a mean latency period of 5 years. Radiation-induced optic neuropathy has been reported in less than 2% of cases and induction of a secondary neoplasm in less than 1% of cases.
For patients with Cushing disease, the rate of endocrinological cure following SRS appears to be similar to that attained using microsurgical resection. In contrast to surgery, SRS has the benefit of being noninvasive and associated with a very low incidence of diabetes insipidus, although hypopituitarism may be more common with SRS. With continued follow-up patient reviews and additional experience with SRS, it may become possible to make more definitive statements regarding SRS as the initial treatment for patients with Cushing disease.
Metastases to the pituitary gland
Authors: Fassett Daniel R. , Couldwell William T. 
Published: January 2008

Only 1% of all pituitary surgeries are performed to treat tumors that have metastasized to the pituitary gland; however, in certain cases of malignant neoplasms pituitary metastases do occur. Breast and lung cancers are the most common diseases that metastasize to the pituitary. Breast cancer metastasizes to the pituitary especially frequently, with reported rates ranging between 6 and 8% of cases.
Most pituitary metastases are asymptomatic, with only 7% reported to be symptomatic. Diabetes insipidus, anterior pituitary dysfunction, visual field defects, headache/pain, and ophthalmoplegia are the most commonly reported symptoms. Diabetes insipidus is especially common in this population, occurring in between 29 and 71% of patients who experience symptoms.
Differentiation of pituitary metastasis from other pituitary tumors based on neuroimaging alone can be difficult, although certain features, such as thickening of the pituitary stalk, invasion of the cavernous sinus, and sclerosis of the surrounding sella turcica, can indicate metastasis to the pituitary gland. Overall, neurohypophysial involvement seems to be most prevalent, but breast metastases appear to have an affinity for the adenohypophysis. Differentiating metastasis to the pituitary gland from bone metastasis to the skull base, which invades the sella turcica, can also be difficult. In metastasis to the pituitary gland, surrounding sclerosis in the sella turcica is usually minimal compared with metastasis to the skull base.
Treatment for these tumors is often multimodal and includes surgery, radiation therapy, and chemotherapy. Tumor invasiveness can make resection difficult. Although surgical series have not shown any significant survival benefits given by tumor resection, the patient's quality of life may be improved. Survival among these patients is poor with mean survival rates reported to range between 6 and 22 months.
Primary brachial plexus tumors: imaging, surgical, and pathological findings in 25 patients
Authors: Binder Devin K. , Smith Justin S. , Barbaro Nicholas M. 
Published: January 2008

Object
The authors report on the treatment of primary brachial plexus tumors in 25 patients at the University of California, San Francisco. They compare their findings with those obtained in similar series.

Methods
The authors reviewed the electronic and medical records, radiological images, operative reports, and pathological findings in 25 consecutive cases of primary brachial plexus tumors. Cases of metastatic lesions or adjacent neoplasms extending into and involving the brachial plexus were excluded.
At presentation patients ranged in age from 19 to 71 years (mean 47 ±15 years), and neurofibromatosis was present in eight patients (32%). Presenting signs and symptoms included palpable mass (60%), numbness/paresthesias (44%), radiating pain (44%), local pain (16%), and weakness (12%). Duration of symptoms ranged from 2 months to 10 years. Neuroimaging revealed lesions ranging widely in size (volume ~1 to >100 ml). Pathological diagnoses included schwannoma (15 [60%]), neurofibroma (five [20%]), malignant peripheral nerve sheath tumor (four [16%]), and desmoid tumor (one [4%]).

Conclusions
Primary tumors arising in the brachial plexus are rare. Careful workup, surgical technique, and attention to pathological diagnosis optimize management.
Infraclavicular brachial plexus stretch injury
Authors: Kim Daniel H. , Murovic Judith A. , Tiel Robert L. , Kline David G. 
Published: January 2008

Object
The authors report the surgery-related results obtained in 143 patients with stretch-induced infraclavicular brachial plexus injuries (BPIs). The entire series comprised 1019 operative BPIs managed at the Louisiana State University Health Sciences Center between 1968 and 1998.

Methods
Infraclavicular lesions represented 143 (28%) of the total of 509 stretch injuries involving both the infra-and supraclavicular brachial plexus, of which 366 (72%) were supraclavicular lesions. The operative approach is thoroughly outlined, and common patterns and combinations of involvement of nerves peculiar to the infraclavicular area are presented. Overall, the results of suture and graft repair were favorable for the lateral and posterior cord and their outflows. Repair of medial cord–median nerve also yielded acceptable results. The results of medial cord and medial cord–ulnar nerve, however, were poor. The incidence of associated injuries in the infraclavicular as opposed to the supraclavicular area, including shoulder dislocation and fracture and humeral fractures as well as vascular injuries including axillary artery injury was higher. Results of a literature search supported the finding that vascular injuries were increased due to the juxtaposition of vessels among the brachial plexus elements.

Conclusions
Thus, although less common than their supraclavicular counterpart, infraclavicular stretch injury lesions when they occur are technically more difficult to treat and are associated with a higher incidence of vascular and dislocation/fraction injuries. Favorable results were obtained for lateral and posterior cord lesions and their outflows, with acceptable outcome after medial cord–median nerve stretch injury repair. The results of medial cord and medial cord to ulnar nerve, however, were poor.
Gracilis free muscle transfer for restoration of function after complete brachial plexus avulsion
Authors: Barrie Kimberly A. , Steinmann Scott P. , Shin Alexander Y. , Spinner Robert J. , Bishop Allen T. 
Published: January 2008

Object
The authors report the functional outcomes after functioning free muscle transfer (FFMT) for restoration of the upper-extremity movement after brachial plexus injury (BPI).

Methods
The authors conducted a retrospective review of 36 gracilis FFMT procedures performed in 27 patients with BPI between 1990 and 2000. Eighteen patients underwent a single gracilis FFMT procedure for restoration of either elbow flexion (17 cases) or finger flexion (one case). Nine patients underwent a double free muscle transfer for simultaneous restoration of elbow flexion and wrist extension (first muscle) and finger flexion (second muscle), combined with direct triceps neurotization. The results obtained in 29 cases of FFMT in which the follow-up period was 1 year are reported.
Neurotization of the donor muscle was performed using the musculocutaneous nerve (one case), spinal accessory nerve (12 cases), or multiple intercostal motor nerves (16 cases). Two second-stage muscle flaps failed secondary to vascular insufficiency. Mean electromyography-measured reinnervation time was 5 months. At a minimum follow-up period of 1 year, five muscles achieved less than or equal to Grade M2, eight Grade M3, four Grade M4, and 12 Grade M5. Transfer for combined elbow flexion and wrist extension compared with elbow flexion alone lowered the overall results for elbow flexion strength. Seventy-nine percent of the FFMTs for elbow flexion alone (single transfer) and 63% of similarly innervated muscles transferred for combined motion achieved at least Grade M4 elbow flexion strength.

Conclusions
Functioning free muscle transfer is a viable reconstructive option for restoration of upper-extremity function in the setting of severe BPI. It is possible to achieve good to excellent outcomes in terms of muscle grades with the simultaneous reconstruction of two functions by one FFMT, making restoration of basic hand function possible. More reliable results are obtained when a single FFMT is performed for a single function.
The Canadian multicenter trial of pallidal deep brain stimulation for cervical dystonia: preliminary results in three patients
Authors: Kiss Zelma H. T. , Doig Kristina , Eliasziw Michael , Ranawaya Ranjiit , Suchowersky Oksana 
Published: January 2008

Object
Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is beneficial for generalized dystonia and has been proposed as a treatment for cervical dystonia. The Canadian Stereotactic/Functional and Movement Disorders Groups designed a pilot project to investigate the following hypothesis: that bilateral DBS of the GPi will reduce the severity of cervical dystonia at 1 year of follow up, as scored in a blinded fashion by two neurologists using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Secondary outcome measures included pain and disability subscores of the TWSTRS, Short Form–36 quality of life index, and the Beck Depression Inventory.

Methods
Three patients have undergone surgery in Calgary with a followup duration of 7.4 ± 5.9 months (mean ± standard deviation). One patient underwent inadvertent ineffective stimulation for the first 3 months and did not experience a benefit until DBS programming was corrected. All three patients had rapid response to stimulation, with the muscles relaxing immediately and abnormal movements improving within days. Total TWSTRS scores improved by 79%, and severity subscores improved significantly, from 15.7 ± 2.1 to 7.7 ± 2.9 (paired ttest, p = 0.02). Pain and disability subscores improved from 25.5 ± 4.1 to 3.3 ± 3.1 (paired ttest, p = 0.002) and from 13.3 ± 4.9 to 3.3 ± 4.2 (paired ttest, p = 0.06), respectively.

Conclusions
Although it is too early to reach broad conclusions, this report of preliminary results confirms the efficacy of DBS of the GPi for cervical dystonia.