摘要:

A HISTORY OF Arctic and Antarctic exploration, whether to find a Northwest Passage, North Pole, or South Pole, is a history of triumph and tribulation. The hardship experienced by polar explorers in the last 1000 years permeates the tales of achievement. Physicians and surgeons have played prominent roles in all major polar explorations. No significant Arctic voyage, particularly in the last 300 years, was made without a member of the party trained in the management of medical emergencies and in basic surgery. During times of health, surgeons functioned as the voyage naturalists with expertise in biology, botany, zoology, and the writing of scientific catalogs. Spurred by our interest and fascination with the history of polar exploration, we reviewed the roles of physicians and natural scientists in Arctic and Antarctic adventures.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVE:Acute pupillary dilation in a head-injured patient is a neurological emergency. Pupil dilation is thought to be the result of uncal herniation causing mechanical compression of the IIIrd cranial nerve and subsequent brain stem compromise. However, not all patients with herniation have fixed and dilated pupils, and not all patients with nonreactive, enlarged pupils have uncal herniation. Therefore, we have tested an alternative hypothesis that a decrease in brain stem blood flow (BBF) is a more frequent cause of mydriasis and brain stem symptomatology after severe head injury. We determined the relation of BBF to outcome and pupillary response in patients with severe head injuries.METHODS:One hundred sixty-two patients with a Glasgow Coma Scale score of 8 or less underwent stable xenon computed tomographic blood flow determination at the level of the superior colliculus, and this blood flow was correlated with pupillary features, intracranial pressure, computed tomographic scan pathology, and outcome.RESULTS:A BBF of less than 40 ml/100 g/min was significantly associated with poor outcome (P< 0.009). In patients with bilaterally nonreactive pupils, the BBF was 30.5 ± 16.8 ml/100 g/min, and in those with normally reactive pupils, the BBF was 43.8 ± 18.7 ml/100 g/min (P< 0.001). Intracranial pressure and the presence of a brain stem lesion observed on the computed tomographic scan did not correlate with BBF, pupillary size, or reactivity. Unfavorable outcome at 12 months was directly related to age (P= 0.062) and inversely related to pupillary responsiveness (P= 0.0006), pupil size (P= 0.005), and BBF of less than 40 ml/100 g/min (P= 0.009).CONCLUSION:These findings suggest that pupillary dilation is associated with decreased BBF and that ischemia, rather than mechanical compression of the IIIrd cranial nerve, is an important causal factor. More important, pupil dilation may be an indicator of ischemia of the brain stem. If cerebral blood flow and cerebral perfusion pressure can be rapidly restored in the patient with severe head injury who has dilated pupils, the prognosis may be good.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVE:Resection of benign cavernous sinus tumors with minimum morbidity and mortality is increasingly more common. Although meningiomas have dominated most discussions, numerous nonmeningeal tumors also deserve attention because they are generally more amenable to radical surgical resection.METHODS:We reviewed the records of 40 patients (19 female and 21 male patients) who were treated surgically during a 15-year period for benign, nonmeningeal tumors of the cavernous sinus. Invasive pituitary adenomas (14 cases) and trigeminal schwannomas (13 cases) comprised the majority of tumors; the remaining tumor types were hemangioma, neurofibroma, juvenile angiofibroma, dermoid tumor, giant cell tumor, chondromyxofibroma, and chondroma. Patient age ranged from 7 to 65 years (mean, 37 yr).RESULTS:All patients underwent surgery, the intent being total resection. Total resection was achieved in 33 (82.5%) of the 40 patients. Follow-up was achieved via a combination of direct patient visit or phone interview or via the referring physician. Eight patients had undergone previous surgery elsewhere, which correlated closely with complications and neurophthalmological outcomes but did not affect resectability. Postoperatively, 89.7% of the patients had either stable or improved extraocular muscle function compared with their preoperative statuses. Forty percent of the patients experienced improvement of their preoperative extraocular muscle deficits. Complications included cerebrospinal fluid leak (three cases), postoperative hemorrhage (one case), fat embolism (one case), perforator distribution infarct (one case), hydrocephalus requiring ventriculoperitoneal shunting (two cases), transient hemiparesis (one case), and diabetes insipidus (one case).CONCLUSION:We conclude that benign nonmeningeal tumors of the cavernous sinus can be safely and radically removed and result in good long-term neuro-ophthalmological function and low morbidity and mortality. Furthermore, when compared with our previously reported results for cavernous sinus meningiomas, benign nonmeningeal tumors of the cavernous sinus carry a better chance of total removal, a lower incidence of postoperative ocular dysfunction, and a higher rate of recovery of preoperative cranial nerve deficits(7).

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

OBJECTIVE:Transnasal surgery has been performed in only a small number of cases of pediatric craniopharyngiomas, and its efficacy is still a matter of debate.METHODS:We analyzed the results of transnasal surgery performed in 11 pediatric patients (6 male and 5 female patients) with infradiaphragmatic craniopharyngiomas who were younger than 15 years at the time of surgery (age range, 7.7-14.9 yr) and who were treated between 1985 and 1996, when more refined diagnostic and surgical techniques were available. Two of the patients had undergone primary surgery elsewhere. The transnasal approach was chosen because of sellar enlargement and the presence of an infradiaphragmatic tumor. The duration of the clinical follow-up period was at least 1 year.RESULTS:Five patients required drilling of incompletely pneumatized sphenoid sinuses to reach the sella, but in no cases were the anatomic differences related to patient age or size thought to be a limiting factor in the transnasal procedure. The normal pituitary gland was incised to expose a dorsally located tumor in each of eight patients (72.7%). This surgical procedure has never provoked any major functional damage to the anterior pituitary gland. Complete tumor resection was achieved in three patients (27.3%) and subtotal removal in eight (72.7%). Twenty-two (95.7%) of 23 normal functions were preserved after subtotal tumor removal. In contrast, only one of four normal functions was maintained after complete tumor resection. Persistent diabetes insipidus occurred after total tumor resection in one patient. Tumor regrowth occurred in two patients. No tumor recurrence was observed during the follow-up period.CONCLUSION:Based on the present findings, transnasal surgery seems to be indicated for most infradiaphragmatic craniopharyngiomas occurring in pediatric patients. Transnasal surgery is as safe to perform in pediatric patients as it is in adult patients. The concept of subtotal tumor removal with preservation of pituitary function, avoiding damage to hypothalamic structures and excessive cerebrospinal fluid leakage, seems to be justified in pediatric patients.

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1999

数据来源: OVID