Impact of World War I on brain mapping.

Although much tragedy was experienced during World War I (WWI), the nature of the war and the advancements of weaponry led to a change in the quality and quantity of injuries which were conducive for study. This paper discusses how trauma during WWI led to advances in brain mapping from occipital injuries. Gordon Holmes was a British neurologist who was able to create a retinotopic map of the visual cortex from studying more than 400 cases of occipital injuries; his work has contributed immensely to our understanding of visual processing. There have been many extensions from Holmes' work in regard to how we analyze other sensory modalities and in researching how the brain processes complex stimuli such as faces. Aside from the scholastic benefit, brain mapping also has functional use and can be used for neurosurgical planning to preserve important structures. With the advent of more advanced modalities for analyzing the brain, there have been initiatives in total brain mapping which has added significantly to the body of work started by Holmes during WWI. This paper reviews the history during WWI that led to advances in brain mapping, the lasting scholastic and functional impact from these advancements, and future improvements.

Minimization of Intraparenchymal Hemorrhagic Stroke Size by Optimization of Serum Lipids.

Introduction Intraparenchymal hemorrhages (IPHs) are the most common type of hemorrhagic stroke. One of the main associated risk factors is total cholesterol (TC) above 200. A severely decreased level of TC potentially interferes with the stabilization of the cell membrane and can potentially lead to a larger hemorrhage. Previous population-based studies have confirmed an association between low TCs and a high incidence of hemorrhagic stroke. It has been established that a TC below 200 decreases the potential for cardiovascular disease. This study suggests that the balance that needs to be achieved between these two extremes presents a unique possibility for an optimal therapeutic range of total cholesterol levels. Materials & methods Inclusion criteria included all adult patients with International Classification of Diseases (ICD)-9/10 code for hemorrhagic stroke, from June 2007 to June 2017. A total of 300 patients met the criteria (N=300). For each patient, the following data were collected: NIH Stroke Scale, TC level, triglyceride level, low-density lipoprotein (LDL) and high-density lipoprotein (HDL), cholesterol reducing medications, size of hemorrhage on computed tomography (CT) of the head, location of hemorrhage, and patient disposition. Statistical analysis was done using the Generalized Linear Modeling with Wald Chi-square as the statistical determinant. Results Intracerebral hemorrhage size is dependent on the intracranial location with brain lobes having larger bleeds. Minimum hemorrhage size was noted in TC 188-196 and this effect was statistically significant independent of location. HDL has a significant independent effect on hemorrhage size with overall minimum bleed occurring in the range of 43-51 mg/dL HDL (98-106 mg/dL for men and 43-51 mg/dL for women). This sex effect within HDL on hemorrhage size is statistically significant. There was a differential effect of HDL dependent on patient race. Asian and black patients had least IPH volume with HDL 70-79 mg/dL, while Hispanic patients had a minimum at 43-51 mg/dL. White patients required a higher HDL, 80-88 mg/dL to minimize the IPH size. The triglyceride level had a statistically significant independent effect on the bleed size with the minimum hemorrhage size occurring in the range of 205-224 mg/dL. This effect was nuanced by patient race with statistically significant minimum IPH size occurring at 144-164 mg/dL for white patients, 124-143 mg/dL for Hispanic and black patients, and 84-103 mg/dL for Asian patients. Post-hospital patient disposition was not significantly affected by any of the above predictor variables. Conclusion This study found TC, HDL and triglycerides in specific ranges are associated with significantly decreased hemorrhage size across all genders and hemorrhage locations. The ranges with the strongest hemorrhage-limiting effect are as follows: TC 188-196 mg/dL, HDL 43-51 mg/dL (98-106 mg/dL for men and 43-51 mg/dL for women), triglycerides 205-224 mg/dL. Lipids both below and above these ranges yield larger bleeds. It also found larger brain areas will have more extensive hemorrhage than smaller brain areas. Future work in this arena should include collaboration with cardiology to determine ideal ranges for both cardio- and neuroprotection as well as a prospective study to validate the applicability of these findings in patient care.

Diagnosis and treatment options for sequelae following radiation treatment of brain tumors.

Radiation serves an important role in the treatment of metastatic and primary brain tumors. Radiation carries a risk of post radiation treatment effects, such as pseudoprogression and radiation necrosis. The ability to differentiate between radiation necrosis, pseudoprogression, and tumor recurrence remains a diagnostic conundrum with varying treatment options. In this review, we will discuss the pathophysiology, diagnostic imaging modalities, and treatments of these post-radiation treatment effects. We focus on the latest developments in magnetic resonance imaging (MRI) modalities including imaging biomarkers and the newest therapeutics such as VEGF inhibitors, Hyperbaric Oxygen Therapy, sensitized cytotoxic T cells, and Laser Interstitial Thermal Therapy (LITT).

Preoperative endovascular embolization of meningiomas: update on therapeutic options.

In this review paper the authors analyze new therapeutic options for the embolization of meningiomas, as well as the future of meningioma treatment through recent relevant cohorts and articles. They investigate various embolic materials, types of meningiomas amenable to embolization, imaging techniques, and potential imaging biomarkers that could aid in the delivery of embolic materials. They also analyze perfusion status, complications, and new technical aspects of endovascular preoperative embolization of meningiomas. A literature search was performed in PubMed using the terms "meningioma" and "embolization" to investigate recent therapeutic options involving embolization in the treatment of meningioma. The authors looked at various cohorts, complications, materials, and timings of meningioma treatment. Liquid embolic materials are preferable to particle agents because particle embolization carries a higher risk of hemorrhage. Liquid agents maximize the effect of devascularization because of deeper penetration into the trunk and distal tumor vessels. The 3 main imaging techniques, MRI, CT, and angiography, can all be used in a complementary fashion to aid in analyzing and treating meningiomas. Intraarterial perfusion MRI and a new imaging modality for identifying biomarkers, susceptibility-weighted principles of echo shifting with a train of observations (SW-PRESTO), can relay information about perfusion status and degrees of ischemia in embolized meningiomas, and they could be very useful in the realm of therapeutics with embolic material delivery. Direct puncture is yet another therapeutic technique that would allow for more accurate embolization and less blood loss during resection.

Materials used in cranioplasty: a history and analysis.

Cranioplasty, one of the oldest surgical procedures used to repair cranial defects, has undergone many revolutions over time to find the ideal material to improve patient prognosis. Cranioplasty offers cosmetic and protective benefits for patients with cranial defects. The first primitive cranioplasty procedures date back to 7000 bc and used metal and gourds to repair cranial defects. Cranioplasty was first documented by Fallopius who described repair using gold plates; the first bone graft was documented by van Meekeren. The first significant improvement for this procedure began with experimentation involving bone grafts in the late 19th century as a more natural approach for repairing cranial defects. The next impetus for advancement came because of wartime injuries incurred during World Wars I and II and involved experimentation with synthetic materials to counter the common complications associated with bone grafts. Methyl methacrylate, hydroxyapatite, ceramics, and polyetheretherketone implants among other materials have since been researched and used. Research now has shifted toward molecular biology to improve the ability of the patient to regenerate bone using bone growth factors. This paper reviews the evolution of materials used over time in addition to the various advantages and pitfalls associated with each change. It is important for neurosurgeons to be mindful of how these techniques have evolved in order to gain a better understanding of this procedure and how it has been adapted.

Tectal pineal cyst in a 1-year-old girl.

Glial cysts of the pineal gland can frequently be found in adults and children, but only rarely do they enlarge to become clinically relevant. We report a unique presentation of a pineal cyst in the midbrain tectum of a 16-month-old girl who initially presented with ptosis and strabismus. Preoperative imaging studies and intraoperative findings revealed no continuity between the tectal cyst and the pineal gland proper. We surmise that this tectal pineal cyst may have arisen from duplicated pineal gland tissue.

Primary spinal germ cell tumors: a case analysis and review of treatment paradigms.

Objective. Primary intramedullary spinal germ cell tumors are exceedingly rare. As such, there are no established treatment paradigms. We describe our management for spinal germ cell tumors and a review of the literature. Clinical Presentation. We describe the case of a 45-year-old man with progressive lower extremity weakness and sensory deficits. He was found to have enhancing intramedullary mass lesions in the thoracic spinal cord, and pathology was consistent with an intramedullary germ cell tumor. A video presentation of the case and surgical approach is provided. Conclusion. As spinal cord germinomas are highly sensitive to radiation and chemotherapy, a patient can be spared radical surgery. Diverse treatment approaches exist across institutions. We advocate biopsy followed by local radiation, with or without adjuvant chemotherapy, as the optimal treatment for these tumors. Histological findings have prognostic value if syncytiotrophoblastic giant cells (STGCs) are found, which are associated with a higher rate of recurrence. The recurrence rate in STGC-positive spinal germinomas is 33% (2/6), whereas it is only 8% in STGC-negative tumors (2/24). We advocate limited volume radiotherapy combined with systemic chemotherapy in patients with high risk of recurrence. To reduce endocrine and neurocognitive side effects, cranio-spinal radiation should be used as a last resort in patients with recurrence.

Dual ipsilateral craniotomies through a single incision for the surgical management of multiple intracranial aneurysms.

OBJECTIVE: To examine whether multiple aneurysms located in the anterior cerebral artery (ACA), middle cerebral artery (MCA), or internal carotid artery (ICA) could be treated through single-stage, ipsilateral dual craniotomies. METHODS: Investigators reviewed records of nine patients who underwent dual ipsilateral craniotomies through one incision for surgical treatment of multiple aneurysms in the anterior circulation at a single institution from 1994-2010. In all cases, a single-stage pterional and frontal interhemispheric approach through two separate, ipsilateral craniotomies under a single, extended pterional incision was used. RESULTS: Dual craniotomies through one incision were performed on nine patients with multiple aneurysms without complications. This series included eight women and one man with an average age of 57 years. The mean number of aneurysms treated was 2.7 (range 2-5 aneurysms). Most patients underwent elective treatment. The pterional craniotomy approach was used to treat MCA and ICA aneurysms, whereas distal ACA aneurysms were treated through the frontal parasagittal craniotomy approach. All aneurysms were successfully treated via clip ablation. There were no perioperative or postoperative complications at an average follow-up of 29 months (range 1-131 months). CONCLUSIONS: Single-stage, ipsilateral dual pterional and frontal craniotomies through one incision constitute a safe approach that can be employed for the effective surgical treatment of multiple aneurysms in joint unilateral and axial locations with excellent clinical results.

Green fluorescent protein variants as ratiometric dual emission pH sensors. 3. Temperature dependence of proton transfer.

In parts 1 and 2 of this series [Hanson, G. T., McAnaney, T. B., Park, E. S., Rendell, M. E. P., Yarbrough, D. K., Chu, S. Y., Xi, L. X., Boxer, S. G., Montrose, M. H., and Remington, S. J. (2002) Biochemistry 41, 15477-15488; McAnaney, T. B., Park, E. S., Hanson, G. T., Remington, S. J., and Boxer, S. G. (2002) Biochemistry 41, 15489-15494], we described the structure, excited-state dynamics, and applications of pH-sensitive, ratiometric dual emission green fluorescent protein (deGFP) variants with fluorescence emission that is modulated between blue (lambda(max) approximately equal 465 nm) and green (lambda(max) approximately equal 515 nm) depending on the pH of the bulk solvent. In this paper, we consider the energetic origin of the dual emission properties of these GFP variants by examining the temperature dependence of the steady-state absorption and fluorescence emission. In most cases, the quantum yield of the green emission decreased as the temperature was lowered, indicating that the excited-state proton transfer (ESPT) which produces the green emitting form is an activated process. The activation energies of ESPT, determined by modeling the quantum yields of both blue and green emissions between 260 and 298 K in the context of a simple photocycle, were found to be larger at low pH than at high pH. These results indicate that the ratiometric dual emission properties of deGFP mutants are due to this pH-sensitive ESPT rate, combined with a modulation of the ground-state neutral and anionic chromophore populations with pH. The time-resolved fluorescence of one of the deGFP mutants was studied in detail. The time-resolved emission spectra of this mutant are the first ultrafast spectra obtained for a GFP. These spectra demonstrate that the rising kinetics for green emission, considered a hallmark of ESPT, is the sum of the contribution from both the neutral and intermediate anionic forms of the chromophore at the probe wavelength and may not be observed in all mutants that undergo ESPT, depending on the relative contributions of the two forms.