Spontaneous thrombosis of posterior cerebral artery aneurysm with angiographic reappearance. Case report.

The case is presented of a 23-year-old man suffering ischemic brain infarction from spontaneous thrombosis of a left posterior cerebral artery P1-P2 junction aneurysm. Vasospasm and/or partial parent vessel occlusion were documented by magnetic resonance (MR) imaging and angiography. Repeat cerebral angiography and MR imaging 3 months later revealed patency of the posterior cerebral artery and luminal filling of a 1-cm fusiform aneurysm, which was successfully trapped at surgery.

Modification of acute focal ischemia in rabbits by poloxamer 188.

We studied the effect of a synthetic copolymer surfactant, poloxamer 188, on cerebral blood flow in a rabbit model of focal cerebral ischemia. Following retro-orbital craniectomy, the parietal branch of the middle cerebral artery was occluded with bipolar current. Cerebral blood flow was measured by the hydrogen clearance technique using platinum-iridium electrodes placed within the parietal cortex. Ten rabbits were infused with 50 mg/kg poloxamer 188 in saline beginning 30 minutes after occlusion; 12 control rabbits received an equal volume of saline. Poloxamer 188 increased blood flow significantly in areas of severe or moderate ischemia but had little effect in areas with mild or no ischemia. The improvement in blood flow could not be accounted for by hemodilution, and the copolymer did not affect blood viscosity at any shear rate from 1 to 100 sec-1. We hypothesize that poloxamer 188 increases circulation in ischemic tissue by inhibiting adhesive interactions among proteins (fibrin and fibrinogen) and cells in the microcirculation.

CT-assisted stereotactic brain biopsy: value of intraoperative frozen section diagnosis.

In 100 recent CT-guided brain biopsies, the value of intraoperative histologic examination using frozen section technique was evaluated. In 87 of these cases, the biopsy was performed stereotactically. In the remaining 13 cases, a CT-guided free hand technique was used. Of the 100 biopsies performed, adequate tissue for histopathologic diagnosis was obtained in 97, and in three the biopsy was nondiagnostic. In 61 procedures the initial biopsy specimen was adequate for diagnosis. Two specimens were required in 25 and in the remaining cases it was necessary to obtain three to four biopsy specimens before a definitive diagnosis could be made. Ultimately, the histologic diagnosis was made on frozen section examination in 93 of the cases. The lesions identified were neoplastic disease in 83 cases, vascular disease in seven, infectious disease in five, demyelinating disease in one, and radiation necrosis in one. Comparison between the frozen section diagnosis and the final diagnosis based on the permanent sections revealed that they matched in 89 cases (92%). Of the 83 cases of neoplasms the exact grade of malignancy was determined by frozen section to make a final diagnosis revealed that even if the specimen volume was less than 2 mm3, the biopsy was generally successful. The disadvantages of the small sample size obtained through needle biopsy are best overcome by careful targeting and assessment of sample quality by intraoperative frozen section examinations, which will give the definitive diagnosis in most of the cases without paraffin-embedded sections.

Management of spasmodic torticollis.

Based on a review of the literature, the management of spasmodic torticollis may begin with the conservative measures of pharmacotherapy, sensory feedback, or percutaneous dorsal column stimulation. Approximately 50% of patients will benefit from an adequate trial of these modalities. With particularly resistant and disabling torticollis, the ablative procedures of microsurgical cervical rhizotomy or stereotaxic thalamotomy have offered significant relief in about 74% and 56%, respectively, of properly selected cases. Nevertheless, the variability in the duration of response to all forms of therapy has made the treatment of spasmodic torticollis a difficult and often frustrating undertaking.

Mammographic and pathologic correlation of microcalcification in disease of the breast.

Fifty-five patients with isolated microcalcification clusters and no palpable tumor of the breast were studied. All patients underwent appropriate localization biopsies and had roentgenographic, specimen roentgenographic examination of histologic confirmation that the area of microcalcification was removed. Fifteen patients proved to have a malignant lesion at biopsy and in 40 patients, it proved to be benign. Of the proved cancers, ten were noninvasive. Fourteen of the patients with cancer were free of axillary metastases. The results of the follow-up study, with a mean time of four years, revealed a 100 per cent survival rate and no recurrence of disease. Careful study of the microcalcification clusters, at preoperative mammographic examination, did not show significant differences between the malignant and benign group that could be helpful to the clinician, in predicting the nature of the lesion. Due to the reasonably high, 27 per cent, rate of malignant disease, we believe all patients with isolated microcalcification clusters at preoperative mammographic examination should have a localization biopsy.