Journal of neurosurgery
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Journal of neurosurgery · Jul 2017
Bone marrow response as a potential biomarker of outcomes in glioblastoma patients.
OBJECTIVE Glioblastoma (GBM) is a highly aggressive malignancy that requires a multidisciplinary therapeutic approach of surgery, chemotherapy, and radiation therapy, but therapy is frequently limited by side effects. The most common adverse effect of chemotherapy with temozolomide (TMZ) is myelosuppression. It remains unclear whether the degree of bone-marrow suppression might serve as a biomarker for treatment outcome. ⋯ CONCLUSIONS Decreases in white blood cell counts might serve as a potential biomarker for OS and PFS in malignant glioma patients treated with radiation therapy and TMZ. It remains unclear whether treatment-induced changes in white blood cell counts correlate with drug-induced antitumor activity or represent an independent factor of the altered local and systemic tumor environment. Additional studies will be needed to determine dose dependence for chemotherapy based upon peripheral blood counts.
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Journal of neurosurgery · Jul 2017
The force pyramid: a spatial analysis of force application during virtual reality brain tumor resection.
OBJECTIVE Virtual reality simulators allow development of novel methods to analyze neurosurgical performance. The concept of a force pyramid is introduced as a Tier 3 metric with the ability to provide visual and spatial analysis of 3D force application by any instrument used during simulated tumor resection. This study was designed to answer 3 questions: 1) Do study groups have distinct force pyramids? 2) Do handedness and ergonomics influence force pyramid structure? 3) Are force pyramids dependent on the visual and haptic characteristics of simulated tumors? METHODS Using a virtual reality simulator, NeuroVR (formerly NeuroTouch), ultrasonic aspirator force application was continually assessed during resection of simulated brain tumors by neurosurgeons, residents, and medical students. ⋯ Handedness, ergonomics, and visual and haptic tumor characteristics resulted in distinct well-defined 3D force pyramid patterns. CONCLUSIONS Force pyramid fingerprints provide 3D spatial assessment displays of instrument force application during simulated tumor resection. Neurosurgeon force utilization and ergonomic data form a basis for understanding and modulating resident force application and improving patient safety during tumor resection.
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Journal of neurosurgery · Jul 2017
The clinical significance of persistent trigeminal nerve contrast enhancement in patients who undergo repeat radiosurgery.
OBJECTIVE Contrast enhancement of the retrogasserian trigeminal nerve on MRI scans frequently develops after radiosurgical ablation for the management of medically refractory trigeminal neuralgia (TN). The authors sought to evaluate the clinical significance of this imaging finding in patients who underwent a second radiosurgical procedure for recurrent TN. METHODS During a 22-year period, 360 patients underwent Gamma Knife stereotactic radiosurgery (SRS) as their first surgical procedure for TN at the authors' center. ⋯ Dysesthetic pain after repeat SRS was observed for 8 patients with and for 2 patients without contrast enhancement. CONCLUSIONS Trigeminal nerve contrast enhancement on MRI scans observed at the time of a repeat SRS for TN was associated with less satisfactory pain control and more frequently detected facial sensory loss. Residual contrast enhancement at the time of a repeat SRS may warrant consideration of dose reduction or further separation of the radiosurgical targets.
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Journal of neurosurgery · Jul 2017
Improved outcomes for patients with cerebrovascular malformations at high-volume centers: the impact of surgeon and hospital volume in the United States, 2000-2009.
OBJECTIVE Treatment of cerebrovascular malformations has grown in complexity with the development of multimodal approaches, including microsurgery, endovascular treatments, and radiosurgery. In spite of this changing standard of care, the provision of care continues across a variety of settings. The authors sought to determine the risk of adverse outcome after treatment of patients with vascular malformations in the US. ⋯ CONCLUSIONS For patients with vascular malformations who were treated in the US between 2000 and 2009, treatment performed at high-volume centers was associated with significantly lower morbidity and, for high-volume surgeons, with lower mortality rates. These data suggest that treatment by high-volume institutions and surgeons will yield superior outcomes and superior value. The authors therefore advocate the creation of care paradigms that triage patients to high-volume institutions and surgeons, which can serve as cerebrovascular COEs.
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Journal of neurosurgery · Jul 2017
Historical ArticlePerpetuation of errors in illustrations of cranial nerve anatomy.
For more than 230 years, anatomical illustrations have faithfully reproduced the German medical student Thomas Soemmerring's cranial nerve (CN) arrangement. Virtually all contemporary atlases show the abducens, facial, and vestibulocochlear nerves (CNs VI-VIII) all emerging from the pontomedullary groove, as originally depicted by Soemmerring in 1778. Direct observation at microsurgery of the cerebellopontine angle reveals that CN VII emerges caudal to the CN VIII root from the lower lateral pons rather than the pontomedullary groove. ⋯ Others, it could be speculated, chose to depict the CN relationships incorrectly rather than run contrary to long-established dogma. This study is not advocating that a universally recognized numbering scheme be revised, as this would certainly create confusion. The authors do advocate that future depictions of the anatomical arrangements of the brainstem roots of CNs VI, VII, and VIII ought to reflect actual anatomy, rather than be contorted to conform with the classical CN numbering system.