Delayed diagnosis of large cerebello-pontine angle tumors, despite hearing conservation training.

Recently, at the National Naval Medical Center in Bethesda, Maryland, we have encountered several patients with large cerebello-pontine angle tumors. All were active duty and had evaded the military's stringent hearing screening program until the tumors were of life-threatening size. Early detection of these tumors can reduce overall morbidity and improve the patient's chances of returning to a normal lifestyle. We have analyzed each of these cases and discovered weaknesses in the program. The primary difficulty was in accurately following the algorithms set forth by military regulations. To that end we recommend: (1) establishing a cutoff for identification of those who should be evaluated after they obtain their enlistment/annual physical examinations; (2) specific training for hearing conservation program managers in the algorithms for hearing screening; (3) establishment of specific guidelines for primary care physicians for further evaluation of abnormal audiograms; and (4) reevaluation of form DD 2216.

Current management of carotid atherosclerosis.

Carotid atherosclerosis affects thousands of individuals each year. A history of transient ischemic attacks should alert the clinician to the possibility of carotid artery disease. Carotid endarterectomy is of proven benefit in both symptomatic and asymptomatic individuals, with angiographically confirmed carotid stenosis of from 70 to 99%, respectively. Guidelines for the diagnostic and preoperative screening procedures as well as the surgical technique used by the Department of Neurosurgery at the National Naval Medical Center are reviewed.

Relationship of perfusion pressure and size to risk of hemorrhage from arteriovenous malformations.

The relationship between the size of an arteriovenous malformation (AVM) and its propensity to hemorrhage is unclear. Although nidus volume increases geometrically with respect to AVM diameter, hemorrhages are at least as common, in small AVM's compared to large AVM's. The authors prospectively evaluated 92 AVM's for nidus size, hematoma size, and arterial feeding pressure to determine if these variables influence the tendency to hemorrhage. Small AVM's (diameter less than or equal to 3 cm) presented with hemorrhage significantly more often (p less than 0.001) than large AVM's (diameter greater than 6 cm), the incidence being 82% versus 21%. Intraoperative arterial pressures were recorded from the main feeding vessel(s) in 24 of the 92 patients in this series: 10 presented with hemorrhage and 14 presented with other neurological symptoms. In the AVM's that had hemorrhaged, the mean difference between mean arterial blood pressure and the feeding artery pressure was 6.5 mm Hg (range 2 to 15 mm Hg). In the AVM's that did not rupture, this difference was 40 mm Hg (range 17 to 63 mm Hg). Smaller AVM's had significantly higher feeding artery pressures (p less than 0.05) than did larger AVM's, and they were associated with large hemorrhages. It is suggested that differences in arterial feeding pressure may be responsible for the observed relationship between the size of AVM's and the frequency and severity of hemorrhage.

Cavernous malformations of the brain stem.

Once they become symptomatic, cavernous malformations of the brain stem appear to cause progressive morbidity from repetitive hemorrhage, and can even be fatal. Twenty-four patients with long-tract and/or cranial nerve findings from their cavernous malformations of the brain stem were seen for initial evaluation or surgical consultation and thereafter received either surgical or continued conservative treatment. The decision to operate was based on the proximity of the cavernous malformation to the pial surface of the brain stem, the patient's neurological status, and the number of symptomatic episodes. Sixteen patients were treated by definitive surgery directed at excision of their malformation. In four patients, associated venous malformations influenced the surgical approach and their recognition avoided the risk of inappropriate excision of the venous malformation. Although some of the 16 patients had transient, immediate, postoperative worsening of their neurological deficits, the outcome of all except one was the same or improved. Only one patient developed recurrent symptoms: a new deficit 2 1/2 years after surgery required reoperation after regrowth of the cavernous malformation. She has been neurologically stable since the second surgery. One patient died 6 months postoperatively from a shunt infection and sepsis. The eight conservatively treated patients are followed with annual magnetic resonance imaging studies. One has a dramatic associated venous malformation. Seven patients have either minor intermittent or no symptoms, and the eighth died from a hemorrhage 1 year after his initial presentation. Based on these results, surgical extirpation of symptomatic cavernous malformations of the brain stem appears to be the treatment of choice when a patient is symptomatic, the lesion is located superficially, and an operative approach can spare eloquent tissue. When cavernous malformations of the brain stem are completely excised, cure appears permanent.

Coagulopathy and warfarin-associated breast necrosis in a patient with a primary brain tumor.

Although the association of coagulopathy and neoplastic disease is well documented, there have been few reports of patients with primary central nervous system tumors who exhibited hypercoagulable states. We report the case of a 58-year-old woman with a recurrent falcine meningioma and repeated episodes of venous thrombosis who developed warfarin-associated breast necrosis on the fifth day of coumadin therapy. Laboratory evaluation at that time demonstrated an elevated prothrombin time and normal activated partial thromboplastin time. Of the 24 cases of warfarin-associated massive necrosis of the breast described in the literature, only one other case was associated with a neoplasm, a resected craniopharyngioma.

Unusual metastasis to the cauda equina: case report.

A case of intradural metastasis from endometrial carcinoma to the cauda equina is presented. The clinical presentation and radiographic findings were misleading and suggested a herniated nucleus pulposus. Findings at operation were most suggestive of an ependymoma, but final pathological diagnosis revealed endometrial carcinoma. This has never been reported. Once again it demonstrates that surgeons managing lumbar disc disease must be prepared for possible intradural exploration with an appropriate team.