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Beagle puppy model of intraventricular hemorrhage

Effect of indomethacin on cerebral blood flow

Laura R. Ment, William B. Stewart, Charles C. Duncan, David T. Scott and Richard Lambrecht

✓ The newborn beagle puppy has been demonstrated to provide a good model for neonatal intraventricular hemorrhage (IVH). A study was designed to determine if indomethacin can prevent IVH and if indomethacin would produce changes in cerebral blood flow (CBF). Newborn beagle puppies were randomized by computer into two groups: one was pretreated with indomethacin, a known inhibitor of prostaglandin synthetase, and the other was saline. The dogs in both groups were then assigned either to undergo hemorrhagic hypotension/volume reexpansion insult or to receive no insult. Twenty percent of all pups receiving indomethacin and undergoing the insult experienced IVH, compared to 71% of the pups undergoing insult that had been pretreated with saline. Significant alterations in the blood pressure responses to the hemorrhagic hypotension/volume reexpansion insult were noted in the former group compared to the saline-pretreated pups subjected to insult. Finally, employing carbon-14 autoradiography for the determination of CBF, it was demonstrated that indomethacin decreases resting CBF of the newborn beagle pups and, in indomethacin-pretreated animals subjected to insult, prevents the increases in CBF seen in the saline-pretreated traumatized pups.

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Beagle puppy model of intraventricular hemorrhage

Effect of indomethacin on local cerebral glucose utilization

Laura R. Ment, William B. Stewart, Charles C. Duncan, David T. Scott and Richard Lambrecht

✓ The newborn beagle puppy has been demonstrated to provide a good model for neonatal intraventricular hemorrhage (IVH). A study was designed to determine if indomethacin can prevent IVH, and if indomethacin would produce changes in local cerebral glucose utilization (LCGU). By computerized random design, newborn beagle puppies were pretreated with either indomethacin (a known inhibitor of prostaglandin synthetase) or saline, and then assigned either to receive a hemorrhagic hypotension/volume reexpansion insult or to receive no insult. Pretreatment with indomethacin produced a marked drop in the incidence of IVH as well as significant alterations in the blood pressure responses to the hemorrhagic hypotension/volume reexpansion insult. Carbon-14 autoradiography was used to determine LCGU: no alterations were demonstrated in cerebral metabolism in uninjured pups pretreated with indomethacin compared to saline-pretreated animals. In addition, although the hemorrhagic hypotension/volume reexpansion insult produced marked alterations in LCGU in both groups of traumatized pups, indomethacin prevented the changes in LCGU in the germinal matrix and white matter that were found in the saline-pretreated animals.

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Cynthia S. Kretschmar, Nancy J. Tarbell, William Kupsky, Beverly L. Lavally, Jay S. Loeffler, Lawrence Wolfe, Roy Strand, R. Michael Scott and Stephen E. Sallan

✓ From March, 1984, through June, 1987, 21 newly diagnosed children with high-risk medulloblastoma (Chang Stage T3 to T4) were treated on a 9-week postoperative, pre-irradiation chemotherapy regimen consisting of vincristine and cisplatin. The children over 2 years old then received radiation therapy. Six infants (aged 6 to 18 months) were maintained on chemotherapy consisting of MOP (nitrogen mustard, vincristine, and procarbazine) until the age of 2 years, at which time they were referred for irradiation. Of 13 children with measurable disease following surgery, five showed a definite response on computerized tomography scans to vincristine and cisplatin (one complete response and four partial responses) and five others showed clear marginal responses. Four of the six infants were disease-free at 19, 32, 35, and 57 months from diagnosis. One infant developed progressive disease at the completion of the vincristine and cisplatin course, and a second infant had progression during MOP administration. Three of the 21 children developed hearing loss within the speech frequencies during cisplatin treatments, but there were no other major toxicities. Fifteen children remained disease-free with a median follow-up period of 35 months (range 19 to 57 months). Chemotherapy given between surgery and radiotherapy may allow for the direct evaluation of a specific drug regimen and permit the postponement of radiation therapy in infants. Pre-irradiation vincristine and cisplatin was well tolerated and effective in shrinking the tumor in most children with medulloblastoma. Such chemotherapy regimens have the potential for extending long-term survival in high-risk children.

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R. Michael Scott, Patrick Barnes, William Kupsky and Lester S. Adelman

✓ A surgical series of 19 patients under the age of 18 years with pathologically verified cavernous angioma is presented. Most lesions were located in the cerebral hemispheres, but four were in the pons or midbrain, two in the diencephalon, and one in the spinal cord. Fourteen patients presented with an acute or progressing neurological deficit, three with seizures, one infant with irritability, and one with headache alone. Five patients had family histories of vascular malformations of the central nervous system, and five had multiple lesions. Surgery for small or deep lesions was aided considerably by intraoperative ultrasonographic or stereotactic localization techniques. Pathological examination of the resected malformations revealed a complex histology containing not only typical closely approximated cavernous vessels, but also areas of marked proliferation of granulation tissue and partially re-endothelialized hemorrhage, suggesting a mechanism for the apparent growth of certain cavernous angiomas. The postoperative results were good, with only one patient suffering a permanent worsening of neurological status after surgery. Incomplete resection was initially carried out in five patients, two of whom rebled within 1 year after operation. Long-term follow-up findings in these patients have emphasized the unusual history of certain of these malformations.

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Intracranial extension of an eccrine porocarcinoma

Case report and review of the literature

Ann M. Ritter, R. Scott Graham, Barbara Amaker, William C. Broaddus and Harold F. Young

✓ Eccrine porocarcinoma is a rare malignant tumor of the true sweat gland. It commonly presents in the lower extremities with lymphatic metastasis. The authors describe the clinical presentation, radiographic evidence, operative discoveries, and pathological findings in a patient with an eccrine porocarcinoma involving the soft tissue of the occiput, which had eroded through the cranium. A review of the literature failed to reveal any other such case. The discussion includes the epidemiology, pathogenesis, treatment, and outcome of eccrine porocarcinomas. The six reported cases of scalp eccrine tumors are reviewed.

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Scott Shapiro, William Snyder, Kevin Kaufman and Todd Abel

Object. To increase knowledge about unilateral facet dislocation, including presentation, radiological findings, management, and outcome, the authors reviewed the cases of 51 consecutive patients with unilateral locked facets of the cervical spine who underwent treatment over an 11-year period. With the development of internal fixation devices, the authors compared the procedure of using interspinous wire and facet wiring of iliac crest to fix unilateral locked facets with that in which interspinous braided cable and lateral mass plates were used.

Methods. Thirty-seven patients (73%) presented with radiculopathy, eight (16%) with neck pain only, and six (12%) with spinal cord injuries (SCIs). Plain x-ray films demonstrated subluxation in only 44 (86%) of 51 cases. All patients underwent cervical computerized tomography (CT) scanning, and in all patients with SCI, a magnetic resonance (MR) image was obtained. Fracture in addition to facet locking was seen on 24 (47%) of 51 CT scans. Disc disruption with cord compression was seen in five cases (10%). Based on CT and/or MR imaging findings, a closed reduction procedure was believed to be contraindicated in 11 cases (22%). Of the remaining 40 patients, 13 (33%) underwent closed reduction procedures. Two patients who underwent a closed reduction procedure were placed in a halo brace but experienced resubluxation. Thus, all cases were surgically treated. Forty-six patients underwent posterior reduction and/or internal fixation alone (in 24 cases spinous process fixation with facet wiring was connected to struts of iliac crest, and in 22 cases interspinous braided cable for lateral mass plating was used). Initial surgery, regardless of technique, was successful in 45 (98%) of 46 cases. One patient experienced a resubluxation and underwent reoperation in which anterior cervical fusion and plating were performed. Four of six patients with SCI underwent an emergency combined anterior—posterior decompressive procedure in which internal fixation was performed, and the patients experienced immediate neurological improvement. Overall there were no cases of neurological worsening or death, and there were three cases of wound infection. At 1 year postsurgery, all deficits had improved. Of 37 cases of radiculopathy, three patients (8%) experienced persistent 4/5 weakness, and the remaining patients were normal, including four patients in whom diagnosis was delayed. The six patients with SCI all improved significantly by 1 year. Persistent neck pain was seen in nine cases (18%). Although the lateral mass plates and interspinous cable are stronger, easier to place, and significantly lessened the amount of resultant kyphosis (p < 0.02), the results of chi-square analysis demonstrated only a slight trend for improved clinical outcome compared with the use of wire and iliac crest (p = 0.1).

Conclusions. Cervical CT and MR imaging provide information that aids in the diagnosis and management of patients with unilateral locked facets of the cervical spine. The authors' experience strongly suggests that a reduction procedure in which internal fixation and bone fusion are performed will be the most successful treatment for this injury.

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Ann M. Ritter, Barbara H. Amaker, R. Scott Graham, William C. Broaddus and John D. Ward

✓ Leiomyosarcomas (LMSs) of the central nervous system are extremely rare; however, they are becoming more prevalent in immunocompromised patients. The authors present the cases of two patients with acquired immunodeficiency syndrome: one with LMS of the thoracic vertebral body and the other with LMS originating from the region of the cavernous sinus. The epidemiological and histological characteristics of LMS and its association with latent Epstein—Barr virus are discussed, as well as the treatments for this neoplasm.