Observe without disturbing: tracer particles sense local stresses in cell collectives without affecting the cancer cell dynamics.

Measurements of local stresses on the cancer cells (CCs), inferred by embedding inert compressible tracer particles (TPs) in a growing multicellular spheroid (MCS), show that pressure decreases monotonically as the distance from the core of the MCS increases. How faithfully do the TPs report the local stresses in the CCs is an important question because pressure buildup in the MCS is dynamically generated due to CC division, which implies that the CC dynamics should be minimally altered by the TPs. Here using theory and simulations, we show that although the TP dynamics is unusual, exhibiting sub-diffusive behavior on times less than the CC division times and hyper-diffusive dynamics in the long-time limit, they do not affect the long-time CC dynamics. The CC pressure profile within the MCS, which decays from a high value at the core to the periphery, is almost identical with and without the TPs. That the TPs have a small effect on the local stresses in the MCS implies that they are reasonale reporters of the CC microenvironment.

Adhesion strength between cells regulate nonmonotonic growth by a biomechanical feedback mechanism.

We determine how intercellular interactions and mechanical pressure experienced by single cells regulate cell proliferation using a minimal computational model for three-dimensional multicellular spheroid (MCS) growth. We discover that emergent spatial variations in the cell division rate, depending on the location of the cells either at the core or periphery within the MCS, is regulated by intercellular adhesion strength (fad). Varying fad results in nonmonotonic proliferation of cells in the MCS. A biomechanical feedback mechanism coupling the fad and microenvironment-dependent pressure fluctuations relative to a threshold value (pc) determines the onset of a dormant phase, and explains the nonmonotonic proliferation response. Increasing fad from low values enhances cell proliferation because pressure on individual cells is smaller compared with pc. However, at high fad, cells readily become dormant and cannot rearrange effectively in spacetime, leading to arrested cell proliferation. Utilizing our theoretical predictions, we explain experimental data on the impact of adhesion strength on cell proliferation and find good agreement. Our work, which shows that proliferation is regulated by pressure-adhesion feedback mechanism, may be a general feature of multicellular growth.

Mechanical feedback controls the emergence of dynamical memory in growing tissue monolayers.

The growth of a tissue, which depends on cell-cell interactions and biologically relevant processes such as cell division and apoptosis, is regulated by a mechanical feedback mechanism. We account for these effects in a minimal two-dimensional model in order to investigate the consequences of mechanical feedback, which is controlled by a critical pressure, pc. A cell can only grow and divide if its pressure, due to interaction with its neighbors, is less than pc. Because temperature is not a relevant variable, the cell dynamics is driven by self-generated active forces (SGAFs) that arise due to cell division. We show that even in the absence of intercellular interactions, cells undergo diffusive behavior. The SGAF-driven diffusion is indistinguishable from the well-known dynamics of a free Brownian particle at a fixed finite temperature. When intercellular interactions are taken into account, we find persistent temporal correlations in the force-force autocorrelation function (FAF) that extends over a timescale of several cell division times. The time-dependence of the FAF reveals memory effects, which increases as pc increases. The observed non-Markovian effects emerge due to the interplay of cell division and mechanical feedback and are inherently a non-equilibrium phenomenon.

Modelling climate change impacts on maize yields under low nitrogen input conditions in sub-Saharan Africa.

Smallholder farmers in sub-Saharan Africa (SSA) currently grow rainfed maize with limited inputs including fertilizer. Climate change may exacerbate current production constraints. Crop models can help quantify the potential impact of climate change on maize yields, but a comprehensive multimodel assessment of simulation accuracy and uncertainty in these low-input systems is currently lacking. We evaluated the impact of varying [CO2 ], temperature and rainfall conditions on maize yield, for different nitrogen (N) inputs (0, 80, 160 kg N/ha) for five environments in SSA, including cool subhumid Ethiopia, cool semi-arid Rwanda, hot subhumid Ghana and hot semi-arid Mali and Benin using an ensemble of 25 maize models. Models were calibrated with measured grain yield, plant biomass, plant N, leaf area index, harvest index and in-season soil water content from 2-year experiments in each country to assess their ability to simulate observed yield. Simulated responses to climate change factors were explored and compared between models. Calibrated models reproduced measured grain yield variations well with average relative root mean square error of 26%, although uncertainty in model prediction was substantial (CV = 28%). Model ensembles gave greater accuracy than any model taken at random. Nitrogen fertilization controlled the response to variations in [CO2 ], temperature and rainfall. Without N fertilizer input, maize (a) benefited less from an increase in atmospheric [CO2 ]; (b) was less affected by higher temperature or decreasing rainfall; and (c) was more affected by increased rainfall because N leaching was more critical. The model intercomparison revealed that simulation of daily soil N supply and N leaching plays a crucial role in simulating climate change impacts for low-input systems. Climate change and N input interactions have strong implications for the design of robust adaptation approaches across SSA, because the impact of climate change in low input systems will be modified if farmers intensify maize production with balanced nutrient management.

Correction: Spatially heterogeneous dynamics of cells in a growing tumor spheroid: comparison between theory and experiments.

Correction for 'Spatially heterogeneous dynamics of cells in a growing tumor spheroid: comparison between theory and experiments' by Sumit Sinha et al., Soft Matter, 2020, 16, 5294-5304, DOI: .

Spatially heterogeneous dynamics of cells in a growing tumor spheroid: comparison between theory and experiments.

Collective cell movement, characterized by multiple cells that are in contact for substantial periods of time and undergo correlated motion, plays a central role in cancer and embryogenesis. Recent imaging experiments have provided time-dependent traces of individual cells, thus providing an unprecedented picture of tumor spheroid growth. By using simulations of a minimal cell model, we analyze the experimental data that map the movement of cells in a fibrosarcoma tumor spheroid embedded in a collagen matrix. Both simulations and experiments show that cells in the core of the spheroid exhibit subdiffusive glassy dynamics (mean square displacement, Δ(t) ≈ tα with α < 1), whereas cells in the periphery exhibit superdiffusive motion, Δ(t) ≈ tα with α > 1. The motion of most of the cells near the periphery is highly persistent and correlated directional motion due to cell doubling and apoptosis rates, thus explaining the observed superdiffusive behavior. The α values for cells in the core and periphery, extracted from simulations and experiments, are in near quantitative agreement with each other, which is surprising given that no parameter in the model was used to fit the measurements. The qualitatively different dynamics of cells in the core and periphery is captured by the fourth order susceptibility, introduced to characterize metastable states in glass forming systems. Analyses of the velocity autocorrelation of individual cells show remarkable spatial heterogeneity with no two cells exhibiting similar behavior. The prediction that α should depend on the location of the cells in the tumor is amenable to experimental testing. The highly heterogeneous dynamics of cells in the tumor spheroid provides a plausible mechanism for the origin of intratumor heterogeneity.

Self-generated persistent random forces drive phase separation in growing tumors.

A single solid tumor, composed of nearly identical cells, exhibits heterogeneous dynamics. Dynamics of cells in the core is glass-like, whereas those in the periphery undergoes diffusive or super-diffusive behavior. Quantification of heterogeneity using the mean square displacement or the self-intermediate scattering function, which involves averaging over the cell population, hides the complexity of the collective movement. Using the t-distributed stochastic neighbor embedding (t-SNE), a popular unsupervised machine learning dimensionality reduction technique, we show that the phase space structure of an evolving colony of cells, driven by cell division and apoptosis, partitions into nearly disjoint sets composed principally of the core and periphery cells. The non-equilibrium phase separation is driven by the differences in the persistence of self-generated active forces induced by cell division. Extensive heterogeneity revealed by t-SNE paves the way toward understanding the origins of intratumor heterogeneity using experimental imaging data.

Damage control surgery in intracerebral hemorrhage in acute leukemia: a review of two cases.

INTRODUCTION: Intracerebral hemorrhage is the second most common cause of mortality (after infections) in acute leukemia and is responsible for approximately 20% of deaths due to acute leukemia. Management of intracerebral hemorrhage (ICH) is mostly conservative but there exist certain patients who need emergent surgery due to the poor Glasgow Coma Scale (GCS) despite their coagulopathic state. CASE REPORT: We present here two such cases which were successfully managed with decompressive craniectomy which was done as a damage control surgery thus stating the importance of surgical intervention in the management of acutely deteriorating patients rather than the commonly employed conservative management due to their coagulopathic state.

A randomized placebo-controlled trial of progesterone with or without hypothermia in patients with acute severe traumatic brain injury.

OBJECTIVE: Among newer neuroprotectant modalities, hypothermia and progesterone have shown a beneficial role in preliminary studies enrolling patients with severe traumatic brain injury (sTBI). The primary objective of this study was to evaluate the efficacy of progesterone with or without prophylactic hypothermia in acute sTBI patients. MATERIALS AND METHODS: This is a prospective, outcome assessor, statistician blinded, randomized, and placebo-controlled phase II trial of progesterone with or without hypothermia (factorial design). All adult patients (18-65 years) with acute sTBI (Glasgow coma score of 4-8) and presenting to trauma center within 8 h after injury were included in the trial. Computer-generated randomization was done after exclusion; sequentially numbered, opaque, sealed envelope technique was used for allocation concealment. The enrollment duration was from January 2012 to October 2014. The primary endpoint was dichotomized Glasgow outcome score (GOS) [poor recovery = GOS 1-3; good recovery = GOS 4-5], and secondary endpoints were functional independence measure (FIM) score and mortality rate at 6 and 12 months follow-up after recruitment. RESULTS: A total of 107 patients were randomized into four groups (placebo [n = 27], progesterone [n = 26], hypothermia alone [n = 27], and progesterone + hypothermia [n = 27]). The study groups were comparable in baseline parameters except for a higher incidence of decompressive craniectomy in the placebo group (P = 0.001). The analysis of GOS at 6 months revealed statistically significant better outcome in the hypothermia group (82%; P = 0.01) and a weaker evidence for progesterone group (74%; P = 0.07) as compared with the placebo group (44%). However, the outcome benefit was marginal at 1-year follow-up for the hypothermia group (82% vs. 58%, P = 0.17). The adjusted odds ratio of poor recovery at 6 months in the hypothermia group was 0.21 (confidence interval = 0.05-0.84, P = 0.03), as compared with the placebo group. Although mean FIM scores at 6 and 12 months respectively were marginally higher in the hypothermia and progesterone groups compared with the placebo group (P = 0.06 and 0.27), the proportion of functionally independent individuals were similar in all the groups (P = 0.79 and 0.51). The mortality rates were similar in all the groups at 6 and 12 months (P = 0.78 and 0.52 respectively). CONCLUSIONS: A strong evidence for prophylactic hypothermia and a weak evidence for progesterone therapy was observed for a better primary outcome at 6 months as compared to the placebo. A similar trend was observed at a 1-year follow-up. Contrary to our hypothesis, prophylactic hypothermia therapy suppressed the beneficial effects of progesterone therapy in sTBI patients. The complex cascades of factors responsible for such interactions are still unknown and need to be further determined.

Adult brachial plexus injuries: Surgical strategies and approaches.

Traumatic brachial plexus injuries are devastating injuries commonly affecting the young population and leading to significant socioeconomic losses to the society. The results of brachial plexus surgery have been severely disappointing in the past. However, several technological advancements and newer surgical techniques, especially the advent of distal nerve transfers over recent years, have led to a paradigm shift in the outcome of patients with these injuries. The best time window for surgery is the first 3 months after injury, and the next best time is the next 3 months. The timing is a crucial factor as the neuromuscular junctions degenerate in 20-24 months. The presence of spontaneous fibrillations in a muscle on electromyography is an indication of denervated yet vital muscle. The restoration of elbow flexion is a priority followed closely by restoration of shoulder abduction and stabilization. The various surgical strategies in brachial plexus injuries should be directed toward accomplishing this goal. The global avulsion injuries have a poor outcome because of very limited source of donors in such types of injury whereas the partial injuries have a remarkable outcome in a majority of cases. This article presents the reader with the guidelines and management algorithms of repair strategy and various surgical approaches utilized in the surgical treatment of brachial plexus injuries.

Bedside computed tomography in traumatic brain injury: Experience of 10,000 consecutive cases in neurosurgery at a level 1 trauma center in India.

INTRODUCTION: Patients with traumatic brain injury (TBI) need frequent computed tomography (CT) of the head for assessment and management. In view of the associated polytrauma, hemodynamic instability, and various in-dwelling catheters and tubes, shifting of patients for CT scans may be difficult. AIMS AND OBJECTIVES: To assess the role of mobile CT (Ceretom®; NeuroLogica Corporation, Boston, MA, USA) in a trauma center with respect to patient management. MATERIALS AND METHODS: In this retrospective study over 67 months (June 2009 to January 2015), the number of CT scans done, the time taken for CT and downtime were evaluated. Also, for the first 1000 mobile CT scans, the clinical and radiological records of all patients with TBI who underwent imaging using the mobile CT scanner in the intensive care units (ICUs) were analyzed. OBSERVATIONS AND RESULTS: A total of 10,000 mobile CT scans were done on the mobile CT scanner till January 5, 2015. Of the first 1000 patients evaluated, 75.3% had severe TBI, 15.1% had moderate TBI, and 9.6% had mild TBI. 78.1% patients were on ventilator, with 80.2% requiring sedation and 8.4%, an inotropic support. An in situ intracranial pressure monitoring was present in 21.1% of patients. In all, 12.4% of patients had long-bone fractures requiring skeletal traction; and, the tube thoracostomy was in-situ in 7.4%. No adverse events related to line malfunction/pullout occurred. The mean time for the performance of imaging using the mobile CT scan was 11.6 minutes compared with 47.8 minutes when patients were shifted to a conventional CT scan suite. The machine was nonfunctional 94 times, with an average downtime of 4.2 hours (range 2-72 hours). The life-cycle cost per mobile CT scan was Rs. 1340. CONCLUSIONS: A mobile CT has considerably changed the management response time in the neurosurgical intensive care unit (ICU) setup and decreased patient transfer times and the associated complications. Inclusion of a mobile CT scanner in the armamentarium of a neurosurgeon as a "bedside tool" can dramatically change decision making and the response time. It should be considered as the standard of care in any large-volume emergency department or neurosurgical facility.

Medial sphenoid wing meningiomas: Experience with microsurgical resection over 5 years and a review of literature.

BACKGROUND: Medial sphenoid wing meningiomas are medially located tumors on the sphenoid wing with attachment over the anterior clinoid process. They represent a distinct entity. These medial sphenoid wing meningiomas present a more difficult problem for the neurosurgeons because in a majority of cases, they involve the anterior visual pathways and arteries of the anterior circulation and may invade the cavernous sinus (CS). Higher morbidity, mortality and recurrence rates have been observed in these tumors compared with meningiomas in other locations. The rate of recurrence for medial sphenoid wing meningiomas is reported as being one of the highest amongst intracranial meningiomas. MATERIAL AND METHODS: The authors retrospectively analyzed 78 consecutive patients with the diagnosis of medial sphenoid wing meningioma who were operated in our department from January 2008 to December 2012. RESULTS: These patients, having a meningioma of the medial sphenoid ridge, were divided into two types depending on the involvement of CS. Diplopia, internal carotid artery encasement, and postoperative visual deterioration were more common in Type 2 tumors. Similarly, extent of resection and postoperative morbidity were greater in Type 2 patients. CONCLUSIONS: CS invasion confers an added risk to the surgical morbidity and outcomes. However, with proper surgical techniques, optimum outcomes can be achieved and overall surgical results at our center are found to be comparable to that of the current literature.

Management of brachial plexus injuries in adults: Clinical evaluation and diagnosis.

Brachial plexus injuries are devastating injuries that usually affect the younger population. The usual modes of injuries are roadside accidents, falls, and assaults. The affected individuals are crippled and may suffer from excruciating peripheral or central deafferentation pain for rest of their lives. The loss of functional capacity accounts for a significant number of man-hours lost at the workplace and consequent financial burden on the family. The results of brachial plexus reconstructive surgery have generally been unsatisfactory in the past. However, in recent decades, the efficacy of surgery has been proven beyond doubt, and there have been various published series in literature that have reported a good outcome after surgical management of these injuries. This has been made possible by the use of operating microscopes, better microsuture techniques for nerve graft and nerve or tendon transfer repair, and advanced perioperative electrophysiological techniques. The key to successful management lies in the proper clinical evaluation, supplemented with electrophysiology, preoperative imaging studies, and planning of surgical strategy. The partial injuries have a better outcome as compared with global palsies, and early referral should be emphasized. Selective combinations of nerve graft and transfers provide a moderate shoulder and elbow control. However, a multispecialty approach involving hand surgeons, plastic surgeons, and physiotherapists is required.

Surgical management of odontoid fractures at level one trauma center: a single-center series of 142 cases.

INTRODUCTION: Odontoid fractures constitute 9-20% of all adult cervical spine fractures. The present study was carried out to focus on the nuances involved in the surgical management of odontoid fractures. MATERIALS AND METHODS: Patients with an odontoid fracture, admitted for surgical stabilization, between January 2008 and March 2014, were included in the study. RESULTS: Among 142 patients [127 male and 15 female patients; median age: 28 years range 4-75 years], type II odontoid fractures were present in 111, type IIA fractures in 8, and type III fractures in 23 patients. 58.5% patients had been involved in a motor vehicular accident while 38.7% had sustained a fall. Eighty-five patients (59.9%) with a well-reduced fracture and an intact transverse ligament underwent anterior odontoid screw (OS) placement; the other 57 patients (40.1%) underwent posterior fixation (PF). The mean follow-up duration was 22 months (range: 6 months-5.4 years). OS placement was successful in 82 patients (96.5%) with a fusion rate of 95% (95.8% in type II, 100% in type III, and 75% in type IIA odontoid fractures). The procedure-related morbidity was 11.7%. One patient died of sub-arachnoid hemorrhage (SAH) that occurred during OS placement. The PF procedures had a better fusion rate (96.5%). The latter patients, however, had significant restriction of their neck movements and an overall morbidity of 8.7%. The revision surgery rates after OS placement and PF fixation were 7% and 3.5%, respectively. CONCLUSIONS: Anterior OS fixation shows excellent fusion rates and should be the first-line management in reduced/non-displaced acute type II (including type IIA) and high type III odontoid fractures as it preserves cervical motion. PF, that has also been associated with an excellent fusion rate, should be reserved for patients where OS fixation has either failed or has not been feasible.

Decompressive craniectomy in traumatic brain injury: A single-center, multivariate analysis of 1,236 patients at a tertiary care hospital in India.

OBJECT: To evaluate the outcome of patients undergoing a decompressive craniectomy (DC) in traumatic brain injury (TBI) and the factors predicting outcome. MATERIALS AND METHODS: A total of 1,236 patients with TBI operated with a DC from January 2008 to December 2013 at a tertiary care hospital were included in the study. The data from the hospital computerized database was retrospectively analyzed and 324 (45%) patients were followed-up for a mean duration of 25.3 months (range 3-42 months) among the cohort of 720 alive patients. The institute's ethical committee clearance was obtained before the start of the study. RESULTS: There were 81% males with a median age [interquartile range (IQR)] of 32 (23-45) years. The mortality rate and median (IQR) Glasgow outcome score (GOS) at discharge in patients presenting with minor, moderate, and severe head injury were 18%, 5 (4-5); 28%, 4 (1-5); and 47.4%, 2 (1-4), respectively. An overall favorable outcome (GOS 4 and 5) at discharge was observed in 46.5% patients and in 39% patients who presented with severe TBI. Only 7.5% patients were in a persistent vegetative state (PVS), while 78% had an overall favorable outcome at the last follow-up of surviving patients (P < 0.001). On multivariate analysis, the factors predictive of a favorable GOS at discharge were: a younger age (odds ratio (OR) 1.03, confidence interval (CI) = 1.02-1.04; P < 0.001), no pupillary abnormalities at admission (OR 2.28, CI = 1.72-3.02; P < 0.001), absence of preoperative hypotension (OR 1.91, CI = 1.08-3.38; P = 0.02), an isolated TBI (OR 1.42, CI = 1.08-1.86; P = 0.01), absence of a preoperative infarct (OR 3.68, CI = 1.74-7.81; P = 0.001), presence of a minor head injury (OR 6.33, CI = 4.07-9.86; P < 0.001), performing a duraplasty (OR 1.86, CI = 1.20-2.87; P = 0.005) rather than a slit durotomy (OR 3.95, CI = 1.67-9.35; P = 0.002), and, avoidance of a contralateral DC (OR 3.58, CI = 1.90-6.73; P < 0.001). CONCLUSIONS: The severity of head injury, performing a duraplasty rather than a slit durotomy, avoidance of a contralateral DC, and the presence of preoperative hypotension, infarct, and/or pupillary asymmetry have the highest odds of predicting the short term GOS at the time of discharge, after a DC in patients with TBI. Although DC carries a high risk of mortality, the probability of the survivors having a favorable outcome is significantly more as compared to those who remain in a PVS.

Microsurgical outcome in posttraumatic brachial plexus injuries in children.

PURPOSE: The purpose of the study was to analyze the surgical outcomes in children (≤18 years) with brachial plexus injury operated between April 2008 and March 2012 at our center. METHODS: All children <18 years of age admitted to our center and surgically treated with a diagnosis of posttraumatic brachial plexus injury were included in the study. The demographic details of these patients were retrieved from the computerized database of our hospital. The results were analyzed in terms of the mode of injury, type of injury, surgical procedure performed, and motor recovery after the surgery (MRC Grading). Motor recovery with MRC >3/5 was termed as good outcome. OBSERVATIONS: A total of 33 patients were surgically treated. The mean age at presentation was 15.1 (range 4-18) years. Boys constituted 79% (n = 26) of our patient population. High-velocity injury was the commonest mode of injury. Panbrachial injury was the commonest seen in 82% (n = 27) of patients. Mean duration between injury and surgical intervention was 6 (range 2-13, SD ± 2.6) months. Majority of patients underwent neurotization procedure. Mean follow-up was 32 (range 6-51) months. CONCLUSIONS: High-velocity trauma is the most common mode on injury. Global palsy involving all the plexal elements was present in 82% of the children. Neurotization was the most commonly performed surgical procedure. Good motor outcome (MRC grade ≥3/5) was seen in 62% of patients.

Pediatric giant pituitary adenomas: are they different from adults? A clinical analysis of a series of 12 patients.

OBJECTIVES: To evaluate clinical presentation and microsurgical outcome of giant pituitary adenomas (GPAs) in pediatric age. METHODS: All patients <18 years, who were operated on at our center for GPA (tumor >40 mm in maximum diameter) were included in study. Clinical features, hormonal profile, radiology, surgical approach, results and complications were analysed. RESULTS: A total of 12 children with GPA were managed microsurgically. Visual deterioration (73 %) was most common presentation. Functioning adenomas were found in 83 % patients, with prolactinomas being most common. Twelve patients underwent a total of 16 microsurgical procedures, with a single surgery done in eight (75 %) patients. Out of the 12 primary surgeries, eight (67 %) were performed trans-sphenoidally. A near-total excision (>90 % tumor removal) could be achieved in six (50 %) patients. Visual improvement was observed in 44 % patients. However, there was no improvement in those where the eye was negative to perception of light prior to surgery. At the last follow-up, all the patients with functioning adenomas were in hormonal remission, and there was no residual/recurrent tumor in patients with non-functional adenomas. 25 % experienced single or multiple perioperative or postoperative complications. There was one perioperative death (8 %). CONCLUSIONS: GPAs are very rare in the pediatric population, with majority being functional and more aggressive in nature as compared to in adults. However, most of them can be approached trans-sphenoidally. The combination of surgery and radiotherapy, as well as medical therapy with bromocriptine, achieves good tumor control, despite a high rate of residual tumor and tumor recurrence.

Brainstem gliomas: surgical indications and technical considerations in a series of 58 cases.

OBJECTIVES. To analyze the indications of surgical treatment, surgical management strategies and post-surgical outcome in patients with brainstem glioma (BSG). METHODS. In this retrospective study conducted from 1998 to 2012, 58 patients of surgically treated intrinsic BSG, meeting the inclusion criterion were enrolled. There were 40 males and 18 females, with age range varying from 3 to 55 years. The most common presentation was gait disturbances, either due to cerebellar involvement or motor weakness, followed by motor weakness, ocular involvement and headache. The posteriorly located tumors were operated by midline suboccipital approach (42 patients) and supracerebellar-infratentorial approach (4 patients). Posterolaterally located tumors were operated by retromastoid (10 patients) and all the ventrolateral tumors by subtemporal approach (4 patients). RESULTS. Above 90% patients improved in their neurological status, while 5% deteriorated. Pilocytic astrocytoma was the most common histopathology (41.4%), followed by Grade II astrocytoma (34.5%) and Grade III astrocytoma (24.1%). Overall, 19% patients had postoperative complications and three patients (5%) died in the perioperative period. CONCLUSIONS. Surgery is advocated for patients with well delineated, posteriorly, posterolaterally and ventrolaterally located tumors having slow progression and relative preservation of motor power. BSG can have excellent surgical results with surgeon's experience and modern surgical facilities.