The spectrum of neurological disease in patients with systemic cancer.

To ascertain the range of neurological problems in patients with systemic cancer, we prospectively evaluated neurological symptoms, neurological diagnoses, and primary tumors in all patients with a history of systemic cancer examined by the Department of Neurology at the Memorial Sloan-Kettering Cancer Center, from Jul 1, 1990, to Dec 31, 1990. Of the 815 patients seen for neurological symptoms, less than half (45.2%) had metastatic involvement of the nervous system. The three most common symptoms were back pain (18.2%), altered mental status (17.1%), and headache (15.4%). The most common neurological diagnosis was brain metastasis (15.9%), followed by metabolic encephalopathy (10.2%), pain associated with bone metastases only (9.9%), and epidural extension or metastasis of tumor (8.4%). Of 133 patients with undiagnosed back or neck pain, 44 (33%) had epidural extension or metastases from tumor and 40 (30%) had pain associated with vertebral metastases only. In 15 (11%) the cause for the back pain was unrelated to metastatic disease. Of 132 patients seen on initial consultation for altered mental status, metabolic encephalopathy was the major neurological diagnosis (80; 61%); 20 (15%) had intracranial metastases. Of 97 patients with undiagnosed headache, 59 (61%) had a nonstructural cause. Fifty-three of these patients had either migraine, tension headache, or headache related to systemic illness (e.g., fever, sepsis). These results indicate that even in patients with systemic cancer, a group particularly prone to developing neurological disease that can be diagnosed radiologically, the role of clinicians remains important in helping distinguish noncancer-related and nonmetastatic neurological problems.     

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.      

An integrated functional magnetic resonance imaging procedure for preoperative mapping of cortical areas associated with tactile, motor, language, and visual functions

OBJECTIVE: To evaluate an integrated battery of preoperative functional magnetic resonance imaging (fMRI) tasks developed to identify cortical areas associated with tactile, motor, language, and visual functions. METHODS: Sensitivity of each task was determined by the probability that a targeted region was activated for both healthy volunteers (n = 63) and surgical patients with lesions in these critical areas (n = 125). Accuracy of each task was determined by the correspondence between the fMRI maps and intraoperative electrophysiological measurements, including somatosensory evoked potentials (n = 16), direct cortical stimulation (n = 9), and language mapping (n = 5), and by preoperative Wada tests (n = 13) and visual field examinations (n = 6). RESULTS: For healthy volunteers, the overall sensitivity was 100% for identification of the central sulcus, visual cortex, and putative Wernicke's area, and 93% for the putative Broca's area (dominant hemisphere). For patients with tumors affecting these regions of interest, task sensitivity was 97% for identification of the central sulcus, 100% for the visual cortex, 91% for the putative Wernicke's area, and 77% for the putative Broca's area. These sensitivities were enhanced by the use of multiple tasks to target related functions. Concordance of the fMRI maps and intraoperative electrophysiological measurements was observed whenever both techniques yielded maps and Wada and visual field examinations were consistent with fMRI results. CONCLUSION: This integrated fMRI task battery offers standardized and noninvasive preoperative maps of multiple critical functions to facilitate assessment of surgical risk, planning of surgical routes, and direction of conventional, intraoperative electrophysiological procedures. Thus, a greater range of structural and functional relationships is brought to bear in the service of optimal outcomes for neurosurgery.