Neuroimaging in Pineal Tumors

BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.     

Contribution of peripheral N-methyl-D-aspartate receptors to c-fos expression in the trigeminal spinal nucleus following acute masseteric inflammation

In this study, we examined the contribution of N-methyl-D-aspartate (NMDA) receptors on c-fos expression in the trigeminal brainstem nuclei following acute muscle inflammation. Mustard oil (MO; 20%, 30 microL) injected into the masseter muscle induced extensive peripheral edema and Fos-like immunoreactivity (Fos-LI) in several trigeminal brainstem areas including the subnucleus caudalis of the trigeminal spinal nucleus (Vc), the ventral and dorsal regions of the Vc/subnucleus interpolaris transition zone, and the paratrigeminal nucleus. In order to assess the effect of antagonizing NMDA receptors on MO-induced Fos-LI, rats were pre-treated with two different doses of i.v. MK-801 (0.3 mg/kg, 3 mg/kg), a non-competitive NMDA receptor antagonist, 30 min prior to MO injection. Additional groups of rats received MK-801 (0.3 mg/kg) directly in the masseter muscle or in the biceps muscle 5 min prior to MO injection. A higher dose of i.v. MK-801 (3 mg/kg) and MK-801 given locally into the masseter muscle (0.3 mg/kg) produced a significant reduction in total number of MO-induced Fos-LI. Further analyses revealed that pre-treatment with MK-801 (3 mg/kg i.v.) significantly reduced the Fos-LI all throughout the Vc. Only at the caudal Vc, there was a dose-dependent reduction of MO induced Fos-LI. Pre-treatment with masseteric MK-801 also significantly reduced the Fos-LI in the caudal Vc, with the effect greater than that produced by the same dose of MK-801 given intravenously. These results suggest that peripheral NMDA receptors contribute to nociceptive processing from craniofacial muscles.     

Malignant clinical behavior of cardiac myxomas and "myxoid imitators"

The clinical experience with cardiac myxomas and "myxoid imitators" at the Humana Heart Institute International is reviewed and contrasted with a comprehensive review of the world literature. Twenty-two patients with primary cardiac tumors have been treated at our institution. Three (13.6%) of them had myxoid imitators, and 19 had classic myxomas. One of the 19 patients with a classic myxoma had recurrence on two occasions (recurrence rate, 5.3%). The cases of 57 patients from the world literature are reviewed. Recurrence and/or metastases (including formation of mycotic aneurysm) occurred in approximately 50% of these patients. The overall mortality in these patients was 47%. This review provides documentation of the malignant clinical behavior of cardiac myxomas and myxoid imitators. Neither local recurrence nor regrowth of the tumor in a new location, whether intracardiac or extracardiac, can be predicted from the microscopic appearance of the primary tumor. Resection of the myxoma with a wide margin is the recommended surgical procedure but does not ensure a cure. Therefore, long-term follow-up is mandatory.     

Temporary antibiotic loaded acrylic hip replacement: a novel method for management of the infected THA

Postoperative infection after hip joint replacement is an uncommon but potentially devastating complication in contemporary orthopaedics. Management in two stages is the more favored approach in North America. This introduces difficulty with patient management in the interval between stages, delays rehabilitation, and introduces technical difficulty during the second stage. A method has been developed whereby a temporary antibiotic-loaded facsimile of the hip is introduced at the first stage, designed to maintain stability of the joint, length of the limb, and mobility of the patient. It has been used in a total of 86 cases to date. The results in 46 cases with a minimum follow-up of 2 years are reviewed in this article. The infection was controlled in 93.5% of cases.     

The treatment of periprosthetic fractures of the femur using cortical onlay allograft struts

Periprosthetic fractures of the femur are a complex problem to treat. Careful planning is essential before embarking on such a technically demanding procedure. There are many factors to be considered, including the premorbid condition of the patient and previous experience and training of the surgeon. Important factors relating directly to the fracture include the site, stability of the implant, and the state of the surrounding bone stock.