Biomedical subjects

Jay Jagannathan

Publications and source records attributed to Jay Jagannathan.

11 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

Cellular signaling molecules as therapeutic targets in glioblastoma multiforme.

Despite recent advances in operative techniques, chemotherapy, and radiotherapy, the prognosis in patients with glioblastoma multiforme (GBM) remains poor; the majority die within a year of diagnosis. Although often effective at reducing mass effect and tumor burden, surgical debulking and cytotoxic therapies have never demonstrated an unequivocally significant benefit in treating patients with GBM. This shortcoming has led to the development of molecules that target specific steps in the transduction pathways of high-grade glioma cells. In this article the authors review various cellular and extracellular signaling pathways that may prove promising in the treatment of patients with malignant glioma.

Antineoplastic Agents↗

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

Diagnosis and management of pediatric sellar lesions.

Pituitary region tumors in pediatric patients are largely comprised of craniopharyngiomas and pituitary adenomas, each with their unique considerations. Craniopharyngiomas account for the majority of pediatric sellar masses. Pituitary adenomas are relatively uncommon during childhood, although the incidence increases during adolescence. The diagnosis of sellar lesions involves a multidisciplinary effort, and detailed endocrinologic, ophthalmologic and neurologic testing are critical. The management of pituitary tumors varies depending on the entity. For most tumors, other than prolactinomas, transsphenoidal resection remains the mainstay of treatment. Less invasive modalities such as endoscopic transsphenoidal surgery, and stereotactic radiosurgery have shown promise as primary and adjuvant treatment modalities, respectively.

Adolescent↗

PubMed2006

Stereotactic radiosurgery for pituitary adenomas: a review of the literature and our experience.

Pituitary adenomas are not just one of the most common intracranial tumors but also one of the most difficult to cure. Neurosurgeons have adapted their tools to include precise ionizing radiation in the form of the gamma knife to treat pituitary adenomas. The use of the gamma knife in the management of pituitary adenomas following microsurgery or in selected cases as a primary treatment is safe. The combined application of transsphenoidal surgery and Gamma Knife surgery is beneficial in many difficult cases. However in some patients, optimal control of tumor growth and normalization of hypersecretory states are not achieved. Innovative improvements in operative and radiosurgical techniques are required to avoid pituitary insufficiency and to reduce the number of the cases in which optimal radiosurgery is not feasible because of close tumor proximity to the optic pathways.

Acromegaly↗

PubMed2006

Gamma knife radiosurgery for medically and surgically refractory prolactinomas.

OBJECTIVE: Experience with gamma knife radiosurgery (GKRS) for prolactinomas is limited because of the efficacy of medical and surgical intervention. Patients who are refractory to medical and/or surgical therapy may be treated with GKRS. We characterize the efficacy of GKRS for medically and surgically refractory prolactinomas. METHODS: We reviewed our series of patients with prolactinomas who were treated with GKRS after failing medical and surgical intervention who had at least 1 year of follow-up. RESULTS: Twenty-three patients were included in analysis of endocrine outcomes (median and average follow-up of 55 and 58 mo, respectively) and 28 patients were included in analysis of imaging outcomes (median and average follow-up of 48 and 52 mo, respectively). Twenty-six percent of patients achieved a normal serum prolactin (remission) with an average time of 24.5 months. Remission was significantly associated with being off of a dopamine agonist at the time of GKRS and a tumor volume less than 3.0 cm3 (P < 0.05 for both). Long-term image-based volumetric control was achieved in 89% of patients. Complications included new pituitary hormone deficiencies in 28% of patients and cranial nerve palsy in two patients (7%). CONCLUSION: Clinical remission in 26% of treated patients is a modest result. However, because the GKRS treated tumors were refractory to other therapies and because complication rates were low, GKRS should be part of the armamentarium for treating refractory prolactinomas. Patients with tumors smaller than 3.0 cm3 and who are not receiving dopamine agonist at the time of treatment will likely benefit most.

Adolescent↗

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

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↗

PubMed2004

Long-term survival after gamma knife radiosurgery for primary and metastatic brain tumors.

In this paper, we studied factors related to long-term survival after gamma knife radiosurgery (GKS) for primary and metastatic brain tumors. We examined all cases of brain metastases and malignant glioma treated with GKS between September 1994 and December 1998. All patients with survival exceeding 2 years were studied retrospectively using prospectively acquired data. A total of 22 patients, with an average age of 56, were identified, which accounts for 11% of the total patients treated during this time interval. Seventeen of 22 are still alive with a mean follow-up of 48 months. Sixteen patients had metastatic tumors, whereas 6 had a malignant glioma. Thirteen of 15 patients with metastases had a controlled primary site, and the other 2 patients did not have a primary site identified. These 2 patients were among the 3 that died during the follow-up period. Fourteen patients developed symptomatic radiation necrosis by MRI criteria with 4 confirmed by biopsy. Quality-of-life factors were assessed in 20 of 22 patients using a modified Spitzer scale, which showed a high level of functioning in all of the long-term survivors (mean score 8.65 of 10), and only 1 patient had a Karnofsky Performance Score of less than 70. We conclude that radiosurgery provides a noninvasive and effective way of controlling brain tumors, while preserving quality of life.

Adult↗