Publications by authors named "Lansen T"

The activity of didemnin B, a natural product derived from the Caribbean Tunic was assessed in 16 patients with Glioblastoma multiforme. Didemnin B was administered intravenously by a short infusion at a dose of 4.3 mg/m2 and subsequently escalated to 6.

View Article and Find Full Text PDF

The authors report two cases of Erdheim-Chester disease (ECD), an illness of unknown pathogenesis. Generally, this disease process involves the metaphyseal and diaphyseal portions of the long bones, the lungs, and the retroperitoneum; however, other tissues may be involved including the central nervous system (CNS). To date only two cases of CNS-related ECD have been reported.

View Article and Find Full Text PDF

To report a case in which triphasic waves developed during pentobarbital treatment. Pentobarbital coma is indicated in status epilepticus, refractory to other anticonvulsants, and in certain neurologic conditions in order to decrease brain metabolism. At high doses of pentobarbital, the EEG shows a typical burst-suppression pattern, while at low doses, diffuse slowing.

View Article and Find Full Text PDF

Background And Purpose: It is not known what fraction of patients with symptomatic cerebral aneurysms are misdiagnosed at initial medical presentation. It is also not clear whether misdiagnosed patients more frequently deteriorate before definitive aneurysm diagnosis and therapy or achieve a poorer outcome than correctly diagnosed patients.

Methods: We reviewed records of consecutive patients with symptomatic cerebral aneurysms managed by four tertiary-care neurosurgical services during a recent 19-month period.

View Article and Find Full Text PDF

Rationale And Objectives: Resected meningiomas were examined by relaxometry and light microscopy to evaluate the potential of magnetic resonance imaging (MRI) for identifying histologic subtypes and for discriminating among benign, radiation therapy-induced, and malignant meningiomas.

Methods: The magnetic field dependence of 1/T1 of water protons (nuclear magnetic relaxation dispersion [NMRD] profile) and the water content (dry weight) were measured for 67 specimens, and the data were compared with histology. Only noncalcified, nonhemorrhagic meningiomas are reported.

View Article and Find Full Text PDF

Purpose: To investigate the usefulness of transcranial Doppler ultrasonography in the evaluation of intracranial pressure changes after head injury.

Methods: Transcranial Doppler examinations and intracranial pressure measurements using intraparenchymal monitors were performed in 12 cases of closed head injury. Twenty-four sets of data, including the Glasgow Coma Scale, intracranial pressure, transcranial Doppler, and carbon dioxide pressure were compared.

View Article and Find Full Text PDF

The magnetic relaxation rate 1/T1 of tissue water protons was measured over a wide range of magnetic field strengths (NMRD profile) for 92 fresh surgical specimens of astrocytomas to search for correlations of 1/T1 with tumor histology, as determined by light microscopy, and to assess the diagnostic potential of NMRD profiles for grading astrocytomas. A third goal was to elucidate the molecular determinants of 1/T1. Each specimen was histologically graded and inspected for evidence of mineral deposits (Ca, Fe); its dry weight was determined and expressed in % of original wet weight.

View Article and Find Full Text PDF

To investigate the nature of the headache accompanying aneurysmal subarachnoid hemorrhage, a retrospective study was conducted. Fifty-four patients and 54 controls completed questionnaires regarding headache, medical history, and family history, in an attempt to derive further information regarding symptoms and factors that might be predictive of aneurysmal subarachnoid hemorrhage. Factors that appear to be of importance in evaluating headache caused by subarachnoid hemorrhage include ominously severe headache, a history of vigorous physical activity precipitating headache, syncope or transient lethargy accompanying headache, previous medical attention for headache, a family history of aneurysmal subarachnoid hemorrhage, or catastrophic central nervous system event at an early age.

View Article and Find Full Text PDF

We report two cases of Creutzfeld-Jakob disease with clusters of giant collagen fibers. To our knowledge, these abnormally large collagen fibers have never been described in patients with degenerative diseases of the central nervous system. The significance of the formation of such plaque-like large collagen fibers has as yet not been elucidated.

View Article and Find Full Text PDF

The authors have measured the magnetic field dependence of 1/T1 (nuclear magnetic relaxation dispersion, or NMRD profiles) of water protons of histologically characterized samples of astrocytomas, meningiomas, and lymphomas. The goal was to elucidate the determinants of 1/T1 of brain tumors at the cellular level and, in particular, to search for a possible correlation of the profiles with neoplastic properties, including degree of malignancy. Because of the recently demonstrated contribution of myelin to 1/T1 of white matter, careful histologic analyses were performed to correct for its presence.

View Article and Find Full Text PDF

Periodontoid hypertrophic cicatrix resulting from trauma, as demonstrated by magnetic resonance (MR) imaging, is essentially the same as that seen in rheumatoid arthritis. Recent reports suggest that, in rheumatoid arthritis, occipitocervical fusion without transoral decompression of the pannus is adequate for resolution of this anterior lesion. A case of traumatic periodontoid cicatrix is presented in which posterior fusion resulted in reduction of the anterior mass lesion, clearly demonstrated by MR imaging.

View Article and Find Full Text PDF

Saccular intracranial aneurysms occur infrequently in children, and the incidence of pediatric giant aneurysms is statistically in the same proportion as in adults. The management of these giant aneurysms can be treacherous. This paper presents a case of a 9-year-old boy with a giant aneurysm of the right middle cerebral artery that was successfully managed by ligation of the middle cerebral artery using a Drake tourniquet with the patient awake and by augmentation of the middle cerebral artery circulation with superficial temporal artery-middle cerebral artery anastomosis without excision of the lesion.

View Article and Find Full Text PDF

The management of pediatric patients with severe head trauma often requires aggressive physiologic monitoring and treatment. As intracranial pressure (ICP) increases, so does mortality. Yet attempts to decrease elevated ICP can cause physiologic and hemodynamic problems.

View Article and Find Full Text PDF

In the summer of 1978, two children who had recently been swimming in freshwater lakes in Florida died from primary amoebic meningoencephalitis. Despite early and intensive treatment with amphotericin B, both patients died three to five days after the onset of illness. Amoebae were observed in wet preparations of cerebrospinal fluid and in sections of cerebral tissue and were identified as Naegleria fowleri by the indirect immunofluorescent antibody technique.

View Article and Find Full Text PDF