Biomedical subjects

G I Jallo

Publications and source records attributed to G I Jallo.

27 records · Page 2Linked to original sources

PubMed1997

Intraspinal sarcoidosis: diagnosis and management.

OBJECTIVE: Isolated intramedullary spinal cord or cauda equina involvement by sarcoidosis is quite rare. We report three patients with intraspinal sarcoidosis and absent systemic manifestations of the disease. The clinical presentation, operative management, electrophysiologic studies, pathology, laboratory investigations, and current therapy are discussed with attention to the previous literature. METHODS: Two of the three patients had a preoperative diagnosis of a cervical intramedullary spinal cord tumor. The third patient had the preoperative diagnosis of an infectious process involving the cauda equina. Magnetic resonance imaging (MRI) with gadolinium did not suggest an inflammatory process. Intraoperative somatosensory evoked potential performed in two patients exhibited normal amplitudes, but a prolonged latency in seven out of eight extremities; with normal central conduction time suggesting a peripheral or radicular involvement. All three patients underwent laminectomy and biopsy of the intraspinal pathology. RESULTS: Pathologic examination demonstrated sarcoidosis in all three patients. Intraoperative observations, intramedullary nodules, and thickening of the meninges were inconsistent with neoplasm and limited the surgical procedure to a biopsy. Frozen sections performed at two of the operations revealed an inflammatory process that confirmed the intraoperative observations. Postoperatively, the diagnostic work-up for all patients was negative for systemic manifestations. CONCLUSIONS: Isolated intraspinal sarcoidosis is a rare process. The current management for intramedullary spinal cord or cauda equina sarcoidosis is prolonged corticosteroids. The surgeon should not attempt complete resection if this granulomatous process is suspected.

Adult↗

PubMed1997

Neurosurgical management of penetrating spinal injury.

BACKGROUND: Penetrating spinal injuries are the third most common cause of spinal cord injury, exceeded only by motor vehicle accidents and falls. The spinal cord can vary from complete destruction to a normal appearing cord. There remains much controversy regarding the neurosurgical management of patients who sustain penetrating injuries of the spine. METHODS: Penetrating spinal injuries account for four to seven new cases of penetrating injury per million persons per annum. The initial management of penetrating spinal injury follows the principles of standard trauma care. Once the patient is hemodynamically stabilized and concomitant life-threatening injuries have been addressed, care can be directed toward the spinal injury. RESULTS: A meticulous neurological examination should be performed, including individual assessment of all muscle groups and sensory dermatomes. This examination becomes the baseline with which all subsequent examinations will be compared. The radiologic examination of the patient begins after all radiographs of higher priority have been obtained. CONCLUSIONS: Penetrating spinal cord injury is associated with significant morbidity. The optimal management for these patients has not been determined, however, spinal instability resulting from the initial missile injury is rare.

Humans↗

PubMed1997

Arachnoid cysts of the cerebellopontine angle: diagnosis and surgery.

OBJECTIVE: The optimal surgical management of arachnoid cysts remains controversial. The cerebellopontine angle (CPA) is a rare location for arachnoid cysts, and only 28 cases of arachnoid cysts occurring in the CPA have been reported in the literature. We discuss the diagnosis, radiographic imaging, and surgical management of CPA arachnoid cysts. METHODS: Five patients (three male and two female patients) with a mean age of 5.6 years have been operated on at our institution since 1980. Magnetic resonance imaging allows for the accurate diagnosis of these arachnoid cysts, which can present with only discrete symptoms, such as headache or ataxia. All five arachnoid cysts compressed the cerebellum or brain stem. One patient had associated hydrocephalus. Three patients presented with refractory headaches associated with nausea and vomiting. The remaining two patients presented with cerebellar signs. No patient had an initial cranial neuropathy. RESULTS: All patients underwent a retrosigmoid suboccipital craniotomy and microsurgical resection and fenestration of the cyst walls. One patient underwent two procedures. A cystoperitoneal shunt was inserted at the first operation. After the shunting procedure, the patient's condition deteriorated; however, after the microsurgical resection and fenestration, his symptoms improved. With a mean 5.2-year follow-up, there has been no evidence of clinical or radiographic recurrence. CONCLUSION: Although CPA arachnoid cysts represent a small number of total arachnoid cysts, the CPA is the second most common location for arachnoid cysts to occur. CPA cysts are congenital lesions found in children who present with subtle signs or symptoms. The definitive treatment for these arachnoid cysts is a retrosigmoid suboccipital craniotomy and microsurgical resection and fenestration of the cyst walls.

Adolescent↗

PubMed1997

Tenascin-C expression in the cyst wall and fluid of human brain tumors correlates with angiogenesis.

OBJECTIVE: Tenascin-C (TN) is an extracellular matrix glycoprotein with a characteristic six-armed structure. The aim of this study was to determine whether the concentration of TN in the cyst fluid of brain tumors can be used as a marker for angiogenesis and glioma grade. METHODS: We investigated the expression of TN in the cyst wall and cyst fluid of human brain tumors by immunohistochemistry, immunoprecipitation, and immunoblotting. The tumors included 12 astrocytomas (5 glioblastoma multiforme tumors, 1 anaplastic astrocytoma, 1 low-grade astrocytoma, 4 juvenile pilocytic astrocytomas, and 1 mixed glioma), 2 dysembryoplastic neuroepithelial tumors, 3 craniopharyngiomas, 2 ependymomas, 2 metastatic carcinomas, 3 arachnoid cysts, 1 glial ependymal cyst, and 1 inflammatory cyst. RESULTS: We detected no expression of TN in the cyst fluids of the ependymomas, craniopharyngiomas, and nonpilocytic low-grade astrocytoma. By contrast, TN was detected in the cyst fluids of all the other tumors. Results of quantitative immunoblotting using a PhosphorImager unit (Molecular Dynamics, Sunnyvale, CA) revealed that, on average, a 5-fold higher signal was observed in the glioblastoma multiforme tumors as compared with the anaplastic astrocytoma, and a 10-fold higher signal as compared with the mixed glioma, juvenile pilocytic astrocytomas, and dysembryoplastic neuroepithelial tumors. Results of TN immunohistochemistry in the astrocytomas correlated with glioma grade, with stronger staining of the hyperplastic vessels and tumor cells being observed in higher grade gliomas. No TN immunoreactivity was detected in the walls of the ependymomas, arachnoid cysts, and glial ependymal cyst that lack hyperplastic vessels, and minimal TN immunoreactivity was observed in the perivascular gliotic rim of the craniopharyngiomas. No TN was detected in the cyst fluid of these cystic processes. CONCLUSION: The presence of TN in and around the hyperplastic vessels and tumor cells present in the cyst walls of astrocytomas and its deposition in the intratumoral cyst fluid in which angiogenic factors have been detected further suggests a role for TN as an angiogenic modulator. These preliminary results suggest that immunodetection of TN in the tumor cyst fluid may indicate tumor type and grade.

Adolescent↗

PubMed1996

Intramedullary subependymoma of the spinal cord.

A consecutive series of six patients underwent operative resection of intramedullary spinal cord subependymomas between January 1981 and August 1993. Three men and three women between the ages of 26 and 66 years experienced symptoms for a mean of 50 months preceding diagnosis. The locations of the tumors were predominantly cervical or cervicothoracic, except in one patient. At operation, a complete extirpation was achieved in each patient. No patient received further adjunct therapy. There has been no tumor recurrence in any patient after a mean follow-up period of 39 months. Most of the intramedullary spinal cord tumors are either ependymomas or astrocytomas. Clinical histories, physical examinations, and radiographic investigations are not conclusive for absolute diagnosis of subependymomas; however, intraoperative gross observations have shown these well-demarcated tumors to be located eccentrically within the spinal cord. Pathological examinations demonstrate tumors with sparse cellularity, clustering of cells, and dense fibrillary stroma. Proliferation studies with the mouse monoclonal antibody MIB-1 reconfirm the slow growth potential of these benign tumors.

Adult↗

PubMed1996

Introduction of a second working portal for neuroendoscopy. A technical note.

The introduction of a second portal during endoscopic procedures in presented. This second portal allows passage of larger instruments while the surgical field is viewed with an endoscope placed through the first portal. This dual portal technique provides an angled view of the operative site, thus avoiding optical obstruction by tissue being pulled toward the endoscope. We report the use of this technique in 6 endoscopic cases.

Adolescent↗

PubMed1995

Ventral intermediate thalamotomy for hemiballismus.

Stereotactic thalamotomy in an unusual case of hemiballismus is reported. This 13-year-old female developed constant left upper and lower extremity flinging movements shortly after cardiac bypass surgery for congenital heart disease at the age of 8. Numerous medications were unsuccessful in controlling these abnormal movements, hence, she stopped attending elementary school for 1 year prior to admission. Under local anesthesia, a stereotactic right ventral intermediate thalamotomy was performed to assist in making precise lesions. There was no postoperative complication. There was an immediate significant improvement. Her ballistic movements in all muscle groups disappeared from both upper and lower extremity, except for residual involuntary movements of her fingers and wrist.

Adolescent↗

PubMed1991

Development of D1 and D2 dopamine receptors and associated second messenger systems in fetal striatal transplants.

Stereotactic implantation of fetal brain regional anlage into adult host brain ("brain transplantation") appears to be an increasingly viable strategy for therapy of neurodegenerative diseases. We have studied implantation of fetal striatum into adult striatum, previously lesioned by neurotoxic amino acid injection, as a model for transplantation therapy of Huntington's disease. The beginning of behavioral recovery to apomorphine is not apparent until 6.5 months after implantation. By 4 months after implantation cerebral blood flow through the implants appears equal to that in the intact contralateral striatum. At this time, cerebral glucose utilization is reduced in the implants but increases following apomorphine treatment. The development of D1 and D2 dopamine (DA) receptors is markedly deficient in the striatal grafts at both 4 and 6.5 months after implantation. Very little D2 radioligand binding was observed in the grafts at either time point; D1 receptors appeared in a patchy fashion by 6.5 months at densities approaching normal striatum. In situ hybridization of D2 dopamine receptor mRNA demonstrated robust hybridization signal in normal striatum and accumbens but no signal in 6.5-month-old striatal grafts. Adenylate cyclase (AC) activity, examined with high-affinity [3H]forskolin binding, also appeared in patches similar to D1 receptors at 6.5 months. In contrast, protein kinase C activity, labeled with [3H]phorbol ester, was very apparent in the grafts at both time points. Higher and generally homogenous densities of muscarinic cholinergic receptors, assessed with [3H]QNB binding, develop in the grafts, but there appear to be few functioning cholinergic terminals, as measured by [3H]hemicholinium binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMedDate not supplied

Ototoxicity of carboplatin delivered locally in a monkey brainstem.

Ototoxicity is a common side effect of platinum-based chemotherapy. Intratumoral drug delivery theoretically could reduce the ototoxic effects of systemic drug infusions. However, local delivery to central nervous system (CNS) tumors might promote ototoxicity through drug release into cerebrospinal fluid (CSF). This report describes an examination of the cytoarchitecture of vestibular cells of cynomolgus monkeys that had chronic brainstem infusions with the maximum tolerated dose (MTD) of carboplatin. The brainstems of adult monkeys were infused for 30 days at 0.42 mu l/h with 0.025 to 0.25 mg/kg (MTD) of carboplatin. The vestibular sensory epithelia of eight drug-treated animals were isolated for microscopic examination of vestibular hair cells and support cells. Local infusions produced chronic elevated CSF levels of platinum, neurological symptoms, and radiographic evidence of pontine injury. Histology revealed significant cell damage at the infusion sites. Microscopic examinations of vestibular support cells and hair cells demonstrate a small reduction in cell counts in the drug-treated monkeys compared to a noninfused control animal. Parametric and nonparametric tests show no effect of dose in predicting the vestibular cell counts. In this single study of eight monkeys, a dose-dependent reduction of vestibular hair cells or support cells was not observed in animals infused with brainstem infusions of 0.025 to 0.25 mg/kg of carboplatin.

Animals↗