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Biomedical subjects

N Sundaresan

Publications and source records attributed to N Sundaresan.

14 recordsLinked to original sources

Pediatric spinal axis tumors.

Pediatric spinal cord tumors occur in the intramedullary or extramedullary spaces. The extramedullary tumors are further divided into those in intradural-extramedullary or extradural locations. Tumors in the intradural-extramedullary region include nerve sheath tumors, meningiomas, and "embryonal" tumors. In the extradural space are neuroblastomas, sarcomas, and other primary tumors of bone. The radiographic findings, histology, and management of each type of tumor are included in this article, which focuses on extramedullary tumors.

Biomarkers, Tumor

Treatment of neoplastic spinal cord compression: results of a prospective study.

Currently, external radiation and steroid therapy are used in most patients with neoplastic spinal cord compression. Surgery is generally used to treat those who do not respond to radiation therapy. To determine the role of de novo surgery in patients with spinal metastases, a prospective study was undertaken. Over a 4 1/2-year period, the cases of 54 patients with radiologically documented spinal metastases were studied. The sites of tumor origin included soft tissue sarcoma (8 patients), kidney (6 patients), lung (5 patients), breast (5 patients), spine (6 patients), unknown primary site (6 patients), and others (18 patients). Sites of compression included the cervical spine segments in 15 patients, thoracic segments in 23, lumbar in 14, and sacral in 2. Before surgery, 24 patients (44%) were nonambulatory. Three surgical approaches were used: anterior vertebral body resection in 45 patients, laminectomy in 7, and lateral osteotomy in 2. After surgery, 37 patients received external radiation therapy. All patients improved (became ambulatory) after surgery, with 23 of 25 patients surviving at 2 years continuing to be ambulatory. The 30-day mortality rate was 6% (three patients); eight patients (15%) sustained various surgical complications. These results are superior to those reported after external radiation therapy and steroids alone, and they support the concept that de novo surgery be considered in selected patients with spinal metastases.

Adolescent

Spinal instrumentation for degenerative disease of the lumbar spine.

Instrumentation for spinal implant is currently changing more rapidly than at any previous period in its 100-year history. At present, the most common indication for spinal instrumentation is degenerative disease of the lumbar spine, which can be roughly categorized as of three kinds: herniated lumbar disks, spondylolisthesis, and spinal stenosis. The literature on indications for arthrodesis is reviewed. A brief summary of the approach and type of instrumentation available for the lumbar spine is presented.

Humans

Cerebrospinal fluid markers in central nervous system metastases from testicular carcinoma.

Serum values of alpha-fetoprotein (AFP) and human chorionic gonadotrophin (HCG) have been used to monitor disseminated testicular carcinoma. Serial measurements of these markers have been used to monitor the response to therapy, to follow the progress of disease, and to detect subclinical recurrences. With increasingly effective chemotherapy for systemic disease, central nervous system (CNS) metastases in testicular carcinoma are becoming increasingly important as a cause of treatment failure. Cerebrospinal fluid (CSF) values of AFP and HCG seem to be important ancillary acids in the neurosurgical management of CNS metastases from testicular cancer. Our preliminary experience with three cases suggests that these CSF markers (plus computerized tomograhic scanning) should be evaluated in patients with this disease.

Adult

Spinal chordomas.

A series of 54 patients with spinal chordomas were treated at Memorial Sloan-Kettering Cancer Center between 1949 and 1976. Thirty-six lesions were located in the sacrococcygeal region and 18 involved the vertebral column at a higher level. The male to female ratio was 35:19. Vertebral chordomas generally occurred in a younger age group. Our radiological findings suggest that there is marked soft-tissue extension anterior to the vertebral column at the time of initial diagnosis. Eleven of 18 vertebral chordomas and 10 of 36 sacral chordomas were found to have disseminated metastases during their course. Analysis of the various modes of therapy reveals that the median survival for both groups is approximately 6 years. However, the 5-year survival for the sacrococcygeal group was 66% as opposed to 50% for the vertebral group. Radiation therapy produced significant palliation but objective evidence of tumor regression was difficult to assess. Chemotherapy in a small number of patients did not have any effect on the tumor. With the advent of computerized tomography scanning, further studies should be done to document the response of this tumor to radiation therapy.

Adolescent

Radiation myelopathy in children.

Three children, 1 with medulloblastoma, 1 with anaplastic cerebellar tumor, and 1 with acute lymphocytic leukemia, received craniospinal irradiation with an estimated cord dose between 1,100 and 1,200 rets. All 3 patients after a latent period of seven to eight months developed subacute transverse myelopathy. The myelopathy was cervical in 2 patients and thoracic in 1. Spinal fluid examination showed high protein levels in 2 patients. Myelography demonstrated a swollen cord in 2 patients and normal appearance in 1. Autopsy in 1 patient disclosed a necrotizing myelopathy. The findings suggest that children tolerate less well than adults what previously have been considered safe doses of radiation to the spinal cord.

Adolescent

Acute hemorrhagic cerebellar infarction following angiography.

Cerebellar infarction following cerebral angiography is an unusual complication. A case is reported. The patient's condition deteriorated with each diagnostic study. Improvement occurred after cerebellar decompression and evacuation of an intracerebellar hematoma.

Cerebellar Diseases

Hemangiomas of the internal auditory canal.

Three patients who presented with symptoms and signs of acoustic tumors are described: one of them had an arteriovenous malformation and the other two had cavernous hemangiomas. The common feature in all these patients was the presence of marked facial weakness with or without fasciculations and a complete loss of hearing in the presence of a small tumor. The cerebrospinal fluid protein was normal in these patients. Polytomography and Pantopaque cisternograms were used to make the diagnosis. Since these lesions are circumscribed, they are suitable for removal using microneurosurgical techniques.

Adult

Endodermal sinus tumor of the pineal region: case report.

A 13-year-old boy presented with symptoms and signs of a posterior 3rd ventricle tumor associated with raised levels of serum and cerebrospinal alpha-fetoprotein. The patient underwent subtotal resection of the tumor followed by craniospinal radiation. Histopathological examination revealed a pure endodermal sinus tumor. Endodermal sinus tumors represent a rare type of germ cell tumor, only 13 intracranial cases having been reported in the literature.

Adolescent