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Biomedical subjects

John A Jane

Publications and source records attributed to John A Jane.

At least 19 recordsLinked to original sources
PubMed2006

Cervical spine injuries in pediatric athletes: mechanisms and management.

Sports-related injuries to the spine, although relatively rare compared with head injuries, contribute to significant morbidity and mortality in children. The reported incidence of traumatic cervical spine injury in pediatric athletes varies, and most studies are limited because of the low prevalence of injury. The anatomical and biomechanical differences between the immature spine of pediatric patients and the mature spine of adults that make pediatric patients more susceptible to injury include a greater mobility of the spine due to ligamentous laxity, shallow angulations of facet joints, immature development of neck musculature, and incomplete ossification of the vertebrae. As a result of these differences, 60 to 80% of all pediatric vertebral injuries occur in the cervical region. Understanding pediatric injury biomechanics in the cervical spine is important to the neurosurgeon, because coaches, parents, and athletes who place themselves in positions known to be associated with spinal cord injury (SCI) run a higher risk of such injury and paralysis. The mechanisms of SCI can be broadly subclassified into five types: axial loading, dislocation, lateral bending, rotation, and hyperflexion/hyperextension, although severe injuries often result from a combination of more than one of these subtypes. The aim of this review was to detail the characteristics and management of pediatric cervical spine injury.

Athletic Injuries↗
PubMed2006

Computer-assisted frameless stereotaxy in transsphenoidal surgery at a single institution: review of 176 cases.

OBJECT: In this study the authors address the efficacy and safety of frameless stereotaxy in transsphenoidal surgery. METHODS: One thousand transsphenoidal operations were performed at the authors' institution between June 2000 and July 2005. This series consists of a retrospective review of 176 patients entered in a prospectively obtained database who underwent frameless stereotactic transsphenoidal surgery in which magnetic resonance (MR) imaging, computerized tomography (CT) scanning, or fluoroscopic guidance was used. Of the 176 patients, 104 (59%) had suprasellar extension of their tumor, 70 (40%) had involvement of the visual apparatus, and 65 (37%) had cavernous sinus involvement. All patients underwent detailed pre- and postoperative neurological, endocrinological, radiographic, and ophthalmological follow-up evaluations. Records were reviewed retrospectively for intraoperative and postoperative complications related to the surgical approach. No instances of visual deterioration, carotid artery (CA) stenosis, or stroke were observed following transsphenoidal surgery. Only one patient sustained damage to the CA intraoperatively, and this was controlled in the operating room. Five patients (3%) required an intensive care unit stay postoperatively. Intraoperative cerebrospinal fluid leakage was encountered in 112 patients (64%) and was more frequently observed in tumors with suprasellar involvement. CONCLUSIONS: Frameless stereotaxy is a safe and effective modality for the treatment of recurrent or invasive sellar masses. All three frameless stereotaxy modalities provided accurate information regarding the anatomical midline and the trajectory to the sella turcica. The MR imaging, CT scanning, and fluoroscopic stereotaxy modalities all have unique advantages as well as specific limitations.

Adenoma↗
PubMed2006

Esthesioneuroblastoma: continued follow-up of a single institution's experience.

OBJECTIVES: To analyze outcomes and to provide follow-up for our increasing patient cohort with esthesioneuroblastoma. DESIGN: Retrospective cohort analysis. SETTING: Patients were examined from September 1, 1976, to May 30, 2004, in a tertiary care academic hospital. PATIENTS: Fifty consecutive patients diagnosed as having esthesioneuroblastoma were treated with a standardized protocol during a 28-year period. Patients with tumors staged Kadish A or B received preoperative radiotherapy followed by craniofacial resection, while patients with Kadish stage C disease were treated with preoperative sequential chemotherapy and radiotherapy followed by a craniofacial resection. The mean follow-up is 93 months (range, 1-330 months). RESULTS: The disease-free survival was 86.5% and 82.6% at 5 and 15 years, respectively. There were 17 patients (34%) who developed recurrent disease, most of which was locoregional (12 patients [71%]). There was a long interval to relapse (mean, 6 years), with the longest time to regional recurrence being 10 years. Distant relapses occurred sooner, with poorer outcomes. Of these 17 patients, 7 (41%) underwent successful salvage surgery, while 3 remain alive with disease. CONCLUSIONS: Excellent outcomes for esthesioneuroblastoma are achievable. Long-term follow-up is necessary because of the extended interval for recurrent disease; unlike most sinonasal malignancies, surgical salvage is possible.

Adolescent↗
PubMed2006

TSH adenomas.

Thyrotropin (TSH) adenomas are uncommon tumors of the anterior pituitary. Clinically, they may present with hyperthyroidism, hypothyroidism, hypopituitarism, or visual loss. Proper diagnosis requires appropriate neuroendocrine evaluation. Although transsphenoidal surgery remains the first-line treatment, adjuvant medical therapy is frequently required for these often invasive tumors. Radiotherapy or radiosurgery should be considered for those patients with persistent TSH hypersecretion following surgery and medical therapy. The clinical evaluation and treatment algorithm for patients with TSH adenomas is discussed.

Adenoma↗
PubMed2006

Craniopharyngioma.

Craniopharyngiomas are benign tumors of the parasellar region. These tumors may be cystic, solid, or combinations of the two. They have a bimodal age distribution and no apparent gender predilection. Patients may present with endocrinopathy or symptoms related to mass effect from the growing tumor. Patients require a multidisciplinary approach during their diagnostic evaluation and subsequent to initiating therapy. Endocrinopathy should be recognized and treated with appropriate hormonal replacement. Surgery is the first-line therapy for most patients. The specific surgical approach must be tailored to the specific clinical situation and depends on the patient age, endocrine status, and the geometry and consistency of the tumor. Whereas most solid tumors will require craniotomy or transsphenoidal surgery, some cystic tumors may be adequately managed with intracavitary therapies. Subtotally resected or residual tumors often require adjuvant radiation therapy or radiosurgery. Long-term multidisciplinary follow-up is necessary for all patients.

Algorithms↗
PubMed2006

Hypophysitis.

Hypophysitis is an uncommon inflammatory condition that may affect the pituitary gland and stalk. Patients often present with varying degrees of hypopituitarism. The diagnosis is often made presumptively based on clinical history and biochemical data but may also be supported by magnetic resonance imaging. Therapy is generally supportive in nature but may require surgery for pathological diagnosis and treatment of mass effect.

Algorithms↗
PubMed2006

Capillary hemangioma of the cauda equina presenting with radiculopathy and papilledema.

A 42-year-old, non-obese man with a three-month history of headache, pulsatile tinnitus, transient visual obscurations, and scintillations later developed low back pain with right lower extremity radiation. Brain MRI and magnetic resonance venography were normal, but spine MRI revealed a mass in the cauda equina. Neuro-ophthalmologic examination disclosed bilateral optic disc edema with normal visual function. During spine surgery, cerebrospinal fluid, released under high pressure despite prior hyperventilation, contained a glucose level of 51 mg/dl and a protein level of 1840 mg/dl. Histologic and immunohistochemical features of the lesion were compatible with a capillary hemangioma. Although spinal cord tumors have been associated with papilledema, this is the first report of a capillary hemangioma of the cauda equina in this context. If papilledema is present, spinal cord imaging should be performed when lumbar puncture discloses unexplained protein elevation and in cases that lack clinical features typical of idiopathic intracranial hypertension.

Adult↗
PubMed2006

Contrast ultrasonographic assessment of cerebral perfusion in patients undergoing decompressive craniectomy for traumatic brain injury.

OBJECT: The aims of this study were to determine whether contrast-enhanced ultrasonography (CEU) could be used for noninvasive evaluation of cerebral perfusion in patients with traumatic brain injury (TBI) and to assess the effect of decompressive surgery on cerebral perfusion as measured by CEU. METHODS: Contrast-enhanced ultrasonography with intravenous administration of a microbubble contrast agent was performed in six patients with TBI undergoing decompressive craniectomy. Contrast-enhanced ultrasonography was performed through a bur hole before craniectomy and through the calvarial defect immediately after craniectomy and on postoperative Days 1 and 2. For the latter two studies, patients were placed in the recumbent position and at a 35 degrees incline to investigate changes in perfusion produced by modulation of intracranial pressure (ICP). Cerebral microvascular blood flow increased by almost threefold immediately after craniectomy, from a mean of 7.5 +/- 6.9 (standard deviation [SD]) to 20.9 +/- 11.6 (p < 0.05), and further improved on postoperative Day 1 (mean 37.1 +/- 13.9 [SD], p < 0.05, compared with postcraniectomy microvascular blood flow) without subsequent change on Day 2. The change in microvascular perfusion correlated inversely with the initial ICP (p < 0.01), indicating less recovery of flow when preoperative ICP was markedly elevated. On postoperative Days 1 and 2, head-of-bed elevation produced an increase in microvascular perfusion on CEU (mean 37 +/- 11 compared with 51 +/- 20, p < 0.05) and a small decrease in ICP (mean 16 +/- 5 mm Hg compared with 12 +/- 4 mm Hg, p < 0.05). In patients with parenchymal hematoma, CEU provided spatial information on perfusion abnormalities in the hemorrhagic core and surrounding tissues. CONCLUSIONS: Contrast-enhanced ultrasonography has potential for the intraoperative and bedside assessment of cerebral perfusion in patients with TBI. The technique may be appropriate for evaluating responses to therapies aimed at preventing secondary ischemia and for assessing regional perfusion abnormalities.

Adolescent↗
PubMed2006

Primary disseminated leptomeningeal oligodendroglioma with 1p deletion. Case report.

The authors report the case of a 2-year-old boy with a primary, diffuse leptomeningeal oligodendroglioma in which the deletion of chromosome arm lp was identified by performing a fluorescence in situ hybridization (FISH) analysis. This previously healthy child initially presented with malaise, anorexia, nausea, vomiting, and macrocephaly. Imaging studies confirmed the presence of hydrocephalus, and a ventriculoperitoneal shunt was placed. The postoperative course was complicated by emesis, continued weight loss, and numerous seizurelike episodes. A contrast-enhanced magnetic resonance imaging study performed approximately 10 weeks postoperatively showed diffuse leptomeningeal thickening and enhancement without evidence of an intraparenchymal mass lesion. A right frontal lobe brain biopsy revealed a hypercellular proliferation of small oligodendroglioma-like cells, which occupied the leptomeninges diffusely and spared the underlying cortical gray matter. The tumor cells displayed prominent perinuclear clearing and had evenly spaced, uniformly round nuclei. Occasional mitotic figures were observed. Background vessels were thin and delicate, and there was no evidence of necrosis. The tumor cells showed strong immunoreactivity for S100 protein; the results of immunohistochemical staining were negative for glial fibrillary acidic protein, vimentin, epithelial membrane antigen, NeuN, and synaptophysin. The deletion of lp was demonstrated by FISH analysis; lq, 19p, and 19q were intact. This appears to be the first reported case of a primary diffuse leptomeningeal oligodendroglioma in which a lp deletion was identified.

Biopsy↗
PubMed2006

Retraction.

Explore the source record for details and available documents.

Retraction Notice↗
PubMed2005

Perspectives on endoscopic transsphenoidal surgery.

Sellar tumors are most commonly approached through the transsphenoidal corridor, and tumor resection is most often performed using the operating microscope. More recently the endoscope has been introduced for use either as an adjunct to or in lieu of the microscope. Both the microscopic and endoscopic transsphenoidal approaches to sellar tumors allow safe and effective tumor resection. The authors describe their current endoscopic technique and elucidate the advantages and disadvantages of the pure endoscopic adenomectomy compared with the standard microscopic approach.

Endoscopy↗
PubMed2005

Brief history of endoscopic transsphenoidal surgery--from Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery.

Since its inception, one of the major issues in transsphenoidal surgery has been the adequate visualization of anatomical structures. As transsphenoidal surgery evolved, technical advancements improved the surgical view of the operative field and the orientation. The operating microscope replaced Cushing's headlight and Dott's lighted speculum retractor, and fluoroscopy provided intraoperative imaging. These advances led to the modern concept of microsurgical transsphenoidal procedures in the early 1970s. For the past 30 years the endoscope has been used for the treatment of diseases of the sinus and, more recently, in the surgical treatment of pituitary tumors. The collaboration between neurological and otorhinolaryngological surgeons has led to the development of novel surgical procedures for the treatment of various pathological conditions in the skull base. In this paper the authors review the history of the endoscope--its technical development and its application--from the first endoscope described by Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery held in 2005 in Pittsburgh, Pennsylvania. Specifically, in this review the history of endoscopy and its application in endonasal neurosurgery are presented.

Congresses as Topic↗
PubMed2005

Relevance of high Ki-67 in pituitary adenomas. Case report and review of the literature.

Pituitary adenomas are heterogeneous in growth rate, invasiveness, and recurrence. To understand the biological behavior of the individual adenoma more fully, cell proliferation markers such as monoclonal antibodies targeted against the Ki-67 antigen have been applied. The Ki-67 antigen is a protein related to cell proliferation and is expressed in cell nuclei throughout the entire cell cycle. The authors report the case of an extremely rapidly growing pituitary adenoma with cavernous sinus invasion. The lesion, which displayed a high Ki-67 labeling index (LI; 22%), was found in a 54-year-old woman who presented with diplopia and headaches. The patient underwent three transsphenoidal operations in less than 6 months and, ultimately, was treated with fractionated intensity-modulated radiation therapy. The relationships between high Ki-67 LIs and tumor recurrence, invasiveness, and growth velocity in pituitary adenomas are reviewed.

Adenoma↗
PubMed2005

Genetics of pituitary adenomas: current theories and future implications.

Pituitary tumors are often viewed as benign entities that are rarely associated with significant rates of mortality or morbidity. These tumors can still be extremely difficult to manage, however, and can cause significant morbidity to the patient, both from tumor mass effect and secondary to hormonal imbalances.

Adenoma↗
PubMed2005

Pediatric sellar tumors: diagnostic procedures and management.

The diagnosis and management of pediatric sellar lesions is discussed in this paper. Craniopharyngiomas account for the majority of pediatric sellar masses, and pituitary adenomas are extremely uncommon during childhood. The diagnosis of sellar lesions involves a multidisciplinary effort, and detailed endocrinological, ophthalmological, and neurological testing is critical in the evaluation of a new sellar mass. The management of pituitary adenomas varies depending on the entity. For most tumors other than prolactinomas, transsphenoidal resection remains the mainstay of treatment. Less invasive methods, such as endoscopic transsphenoidal surgery and stereotactic radiosurgery, have shown promise as primary and adjuvant treatment modalities, respectively.

Child↗
PubMed2005

The transsphenoidal approach. A historical perspective.

Over the last century, the transsphenoidal approach has evolved into the first-line method of treatment for sellar as well as select groups of parasellar and suprasellar lesions. The journey to its current popularity has been marked by controversy and near abandonment in the late 1920s, followed by its renaissance in the late 1960s. Despite the profound skepticism with which this procedure was viewed, several visionary neurosurgeons persevered through its nadir in popularity, preserving this surgical corridor to the skull base. Advances in medical and surgical techniques, paralleling an improved understanding of pituitary pathophysiology, contributed to its resurgence. The transsphenoidal procedures now performed stem from an array of modifications and refinements accumulated through nearly 100 years of medical and surgical evolution. This era's critical innovations and neurosurgical personalities are the topic of this historical overview.

Brain Neoplasms↗
PubMed2005

Neurosurgical approach to treating pituitary adenomas.

The transsphenoidal route remains the dominant surgical approach to the management of pituitary adenomas. These tumors may present clinically with signs or symptoms related to hypersecretion, hypopituitarism, or mass effect; or they may be identified incidentally during neuroimaging for management of other disorders. Diagnostic and treatment strategies for pituitary adenomas are reviewed. In addition, we present outcomes data from a large number of patients treated over a 30-year period by a single neurosurgeon. In our experience, transsphenoidal surgery for pituitary adenomas is associated with low rates of morbidity, mortality, and disease recurrence.

Adenoma↗