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Alexander N. Konovalov, Aldo Spallone, Uvais B. Makhmudov, Jelena A. Kukhlajeva, and Valentina I. Ozerova

✓ Nine patients with brain-stem hematoma were admitted to the authors' institute during the period from 1985 to 1988. Clinical symptoms and signs pointed to pontine involvement in most cases. Progressive clinical deterioration was quite common and usually led to a clinical diagnosis of brain-stem intra-axial tumor. Angiography was noncontributory; computerized tomography (CT) was the main diagnostic test. This gave evidence of different pathological characteristics, including masses showing highly increased density, nonhomogeneous hyperdense lesions, and isodense lesions with peripheral contrast enhancement. No clear correlation was found, however, between the presumed duration of the clinical picture and the CT characteristics of the lesion. In the last four cases, magnetic resonance imaging was performed using a 0.015-tesla resistive system. This examination usually confirmed the presence of a brain-stem mass already shown by previous CT scans. There were, however, no cases in which direct evidence of an intra-axial vascular malformation could be obtained. The patients were all treated surgically with an attempt at total removal of the lesion and thorough inspection of the hematoma cavity and biopsy. Evidence of “cryptic” arteriovenous malformation was obtained in six of the nine cases. There were minor transitory complications in three cases. All of the patients were able to resume their previous activity, and none suffered recurrence of the symptoms following the operation. It may be concluded that surgery is the treatment of choice for brain-stem hematoma.

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David I. Pitskhelauri, Alexander N. Konovalov, Georgy A. Shekutev, Nikolay B. Rojnin, Igor A. Kachkov, Dmitry Y. Samborskiy, Alexander Z. Sanikidze, and Dmitry N. Kopachev

The authors have developed a novel device, which they have named Mari, that allows hands-free utilization of the surgical microscope. The device is attached to the eyepieces of a multifunction counterweight-balanced surgical microscope and consists of a metallic holder with supportive plates that facilitate interaction between the device and surgeon's head. On the holder are installed 1) an electric switch, which allows the surgeon to release the microscope's magnetic clutches, allowing movement of the microscope along the x, y, and z axes as well as the rotational and diagonal ones, and 2) a joystick at the level of the surgeon's mouth for adjustment of focus and zoom. The authors report on the initial experience with the use of the device at the Burdenko Neurosurgery Institute, where the senior author used it in approximately 600 procedures between 2006 and 2012. The surgeries ranged in difficulty and in duration (from 20 minutes to 7 hours, median 2.5 hours). Use of the Mari device resulted in increased accuracy of the surgical manipulations and a reduction in the duration of surgery.

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Marco Cenzato, Davide Colistra, Giorgia Iacopino, Christian Raftopoulos, Ulrich Sure, Marcos Tatagiba, Robert F. Spetzler, Alexander N. Konovalov, Andriy Smolanka, Volodymir Smolanka, Roberto Stefini, Carlo Bortolotti, Paolo Ferroli, Giampietro Pinna, Angelo Franzini, Philipp Dammann, Georgios Naros, Davide Boeris, Paolo Mantovani, Domenico Lizio, Mariangela Piano, and Enrica Fava

OBJECTIVE

In this paper, the authors aimed to illustrate how Holmes tremor (HT) can occur as a delayed complication after brainstem cavernoma resection despite strict adherence to the safe entry zones (SEZs).

METHODS

After operating on 2 patients with brainstem cavernoma at the Great Metropolitan Hospital Niguarda in Milan and noticing a similar pathological pattern postoperatively, the authors asked 10 different neurosurgery centers around the world to identify similar cases, and a total of 20 were gathered from among 1274 cases of brainstem cavernomas. They evaluated the tremor, cavernoma location, surgical approach, and SEZ for every case. For the 2 cases at their center, they also performed electromyographic and accelerometric recordings of the tremor and evaluated the post-operative tractographic representation of the neuronal pathways involved in the tremorigenesis. After gathering data on all 1274 brainstem cavernomas, they performed a statistical analysis to determine if the location of the cavernoma is a potential predicting factor for the onset of HT.

RESULTS

From the analysis of all 20 cases with HT, it emerged that this highly debilitating tremor can occur as a delayed complication in patients whose postoperative clinical course has been excellent and in whom surgical access has strictly adhered to the SEZs. Three of the patients were subsequently effectively treated with deep brain stimulation (DBS), which resulted in complete or almost complete tremor regression. From the statistical analysis of all 1274 brainstem cavernomas, it was determined that a cavernoma location in the midbrain was significantly associated with the onset of HT (p < 0.0005).

CONCLUSIONS

Despite strict adherence to SEZs, the use of intraoperative neurophysiological monitoring, and the immediate success of a resective surgery, HT, a severe neurological disorder, can occur as a delayed complication after resection of brainstem cavernomas. A cavernoma location in the midbrain is a significant predictive factor for the onset of HT. Further anatomical and neurophysiological studies will be necessary to find clues to prevent this complication.