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Intraoperative mapping and neuromonitoring is an established technique to maximise tumour resection while minimising the risk of inducing permanent postoperative deficit. However, very little is known on how many patients require brain mapping within a general adult neuro-oncology service. A prospective study of all neuro-oncology patients operated over a 12 months’ period (January–December 2017) was performed. All patients were seen in a dedicated neuro-oncology pre-assessment clinic after discussion in a neuro-oncology multidisciplinary team meeting. Inclusion criteria for brain mapping were age more than 18, performance status less than 2, tumour location in an eloquent area. Age, sex, histology, surgical technique, extent of resection and operative complications were analysed. Two hundred thirty-five craniotomies were performed in the study period. Intraoperative mapping was used for 57 (24%) cases. There were 22 females and 35 males; median age was 52 years (22–73).17 (30%) patients were operated awake for speech and 40 (70%) asleep for motor mapping. One hundred fifteen patients had a diagnosis of glioma; of these, 48 (42%) were operated with intraoperative mapping. Age (48.92 ± 2.18versus 58.43 ± 1.63, p = 0.001) and WHO grading were significantly lower in the mapping group and the extent of resection was significantly higher (GTR—81.25% versus 37.3%, p < .001). Within the mapping group, the awake subgroup had a better performance status (p = 0.039), less glioblastomas as histological diagnosis (p < 0.05) and an increased proportion of tumours in both temporal and insular locations (p < 0.05). Intraoperative mapping was employed in almost one quarter of our general adult neuro-oncology population. Four in 10 gliomas were operated with intraoperative mapping. This percentage reflects the need for specialised training in brain mapping and budget allocation within the neuro-oncology department.
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ORIGINAL ARTICLE
How many patients require brain mapping in an adult
neuro-oncology service?
Anastasios Giamouriadis
1
&Jose Pedro Lavrador
1
&Ranjeev Bhangoo
1
&Keyoumars Ashkan
1
&Francesco Vergani
1
Received: 11 December 2018 /Revised: 15 April 2019 / Accepted: 6 May 2019
#Springer-Verlag GmbH Germany, part of Springer Nature 2019
Abstract
Intraoperative mapping and neuromonitoring is an established technique to maximise tumour resection while minimising the risk of
inducing permanent postoperative deficit. However, very little is known on how many patients require brain mapping within a general
adult neuro-oncology service. A prospective study of all neuro-oncology patients operated over a 12 monthsperiod (January
December 2017) was performed. All patients were seen in a dedicated neuro-oncology pre-assessment clinic after discussion in a
neuro-oncology multidisciplinary team meeting. Inclusion criteria for brain mapping were age more than 18, performance status less
than 2, tumour location in an eloquent area. Age, sex, histology, surgical technique, extent of resection and operative complications
were analysed. Two hundred thirty-five craniotomies were performed in the study period. Intraoperative mapping was used for 57
(24%) cases. There were 22 females and 35 males; median age was 52 years (2273).17 (30%) patients were operated awake for
speech and 40 (70%) asleep for motor mapping. One hundred fifteen patients had a diagnosis of glioma; of these, 48 (42%) were
operated with intraoperative mapping. Age (48.92 ± 2.18versus 58.43 ± 1.63, p= 0.001) and WHO grading were significantly lower in
the mapping group and the extent of resection was significantly higher (GTR81.25% versus 37.3%, p< .001). Within the mapping
group, the awake subgroup had a better performance status (p= 0.039), less glioblastomas as histological diagnosis (p< 0.05) and an
increased proportion of tumours in both temporal and insular locations (p< 0.05). Intraoperative mapping was employed in almost one
quarter of our general adult neuro-oncology population. Four in 10 gliomas were operated with intraoperative mapping. This
percentage reflects the need for specialised training in brain mapping and budget allocation within the neuro-oncology department.
Keywords Brain tumour .Brain mapping .Neuromonitoring .Neuro-oncology .Glioma
Introduction
Tumoursin eloquent areas of the brain represent a challenge to
neurosurgeons due to the risk of inducing permanent neuro-
logical deficits. In glioma patients, postoperative deficits have
also been linked to a decrease in overall survival [6,7,14,21,
22,25,32,39,40,4244]. In order to maximise the extent of
resection while minimising the risk of inducing permanent
deficits, techniques of intraoperative mapping and monitoring
with direct electrical stimulation (DES) have been developed
[35,28,33,38,45,55]. Large series employing intraopera-
tive mapping have been reported in the literature, particularly
by centres with a high volume of low-grade glioma referrals
[5,16,21,26,31,40,51]. It remains to be established what the
percentage of cases is requiring the use of DES out of the total
of cases referred to a general neuro-oncology centre.
In the present paper, we prospectively assessed the number
of patients operated with DES at the Neurosurgical
Department of Kings College Hospital, in order to evaluate
the proportion of patients requiring brain mapping in an unse-
lected neuro-oncology population.
Material and methods
Preoperative evaluation
The neuro-oncology multidisciplinary team (MDT) of Kings
College Hospital covers south-east London and Kent
(England), corresponding to a population of approximately 3
Presentation at a conference
Poster presentation at SBNS/Hellenic Neurosurgical Society Meeting,
Crete, May 2018
Poster presentation at EANS, Brussels, October 2018
*Anastasios Giamouriadis
agiamouriadis@nhs.net
1
Department of Neurosurgery, Kings College Hospital NHS
Foundation Trust, Denmark Hill, London SE5 9RS, UK
https://doi.org/10.1007/s10143-019-01112-5
Neurosurgical Review (2020) 43:729738
/Published online: 19 2019
May
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... This approach is commonly employed in surgeries where there is a risk to the motor cortex or corticospinal tract and is often conducted with patients under general anesthesia. Bipolar stimulation is frequently used in patients who are required to undergo language testing during awake surgery, which is a practice commonly described as the standard procedure in the existing literature [16,18,35]. In our cohort, bipolar mapping was also mainly employed for language mapping procedures. ...
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Background: Patients with eloquently located cerebral lesions require surgery that usually employs mapping and monitoring techniques for the preservation of motor and language function. However, in many cases, mapping only might be sufficient, reducing the need for technical and personnel logistics. Here, we report our experiences using a device that can be operated by the surgeon independently, providing mapping techniques but omitting monitoring techniques. Methods: For monopolar and bipolar cortical/subcortical stimulation, pre-set programs were available and intraoperatively used—two enabling EMG real-time tracking of eight muscles for monopolar (cortical/subcortical) mapping, and two programs for 60 Hz stimulation, one with EMG and one without. Motor mapping was performed under continuous observation of the screened EMG signal and acoustic feedback by the surgeon. For the 60 Hz stimulation, a standard bipolar stimulation probe was connected through a second port. The preoperative application of the subdermal EMG needles, as well as the intraoperative handling of the device, were performed by the surgeons independently. Postoperatively, an evaluation of the autonomous handling and feasibility of the device for the chosen test parameters was conducted. Results: From 04/19–09/21, 136 procedures in patients with eloquently located cerebral lesions were performed by using the “mapping-only” device. Mapping was performed in 82% of the monopolar cases and in 42% of the bipolar cases. Regarding the setup and sufficiency for the cortical/subcortical mapping, the device was evaluated as independently usable for motor and language mapping in 129 procedures (95%). Gross total resection was achieved, or functional limit throughout resection was reached, in 79% of the patients. 13 patients postoperatively suffered from a new neurological deficit. At the 3–6-month follow-up, three patients showed persistent deficit (2%). All of them had language disturbances. The setup time for the device was less than 7 min. Conclusions: The device was evaluated as sufficient in over 90% of cases concerning monopolar and bipolar mapping, and the setup and handling was sufficient in all patients. With the present data we show that in well-selected cases, a very simple system providing mapping only is sufficient to achieve gross total resection with the preservation of functionality.
... Although intracerebral tumors of critical regions, especially gliomas, are the object of many studies in the world literature, the problem of meningiomas of the rolandic region is less debated. Most studies [1, 9, 13-15, 19, 26, 27, 32, 34] include all meningiomas of the brain convexity, parasagittal region and falx without focusing on the rolandic location; others [8,11,16,20] include tumors of the rolandic region of different origin (both intracerebral and extracerebral) without providing separate data on meningiomas. ...
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Objective Meningiomas of the rolandic region are associated to high risk of postoperative motor deficits. This study discusses the factors affecting motor outcome and recurrences from the analysis of a monoinstitutional case series and eight studies from a literature review. Methods Data of 75 patients who underwent surgery for meningioma of the rolandic region were retrospectively reviewed. The analyzed factors included tumor location and size, clinical presentation, magnetic resonance imaging (MRI) and surgical findings, brain-tumor interface, extent of resection, postoperative outcome and recurrence. Eight studies from literature on rolandic meningiomas treated with or without intraoperative monitoring (IOM) were reviewed with the aim to define the impact of IOM on the extent of resection and motor outcome. Results Among the 75 patients of the personal series, the meningioma was on the brain convexity in 34 (46%), at the parasagittal region in 28 (37%) and at the falx in 13 (17%). The brain-tumor interface was preserved in 53 cases (71%) at MRI and in 56 (75%) at surgical exploration. Simpson grade I resection was obtained in 43% of patients, grade II in 33%, grade III in 15% and grade IV in 9%. The motor function worsened postoperatively in 9 among 32 cases with preoperative deficit (28%) and in 5 among 43 with no preoperative deficit (11.5%); definitive motor deficit was evidenced in overall series at follow-up in 7 (9.3%). Patients with meningioma with lost arachnoid interface had significant higher rates of worsened postoperative motor deficit (p = 0.01) and seizures (p = 0.033). Recurrence occurred in 8 patients (11%). The analysis of the 8 reviewed studies (4 with and 4 without IOM) shows in the group without IOM higher rates of Simpson grades I and II resection (p = 0.02) and lower rates of grades IV resection (p = 0.002); no significant differences in postoperative immediate and long-term motor deficits were evidenced between the two groups. Conclusions Data from literature review show that the use of IOM does not affect the postoperative motor deficit Therefore, its role in rolandic meningiomas resection remains to be determined and will be defined in further studies.
... Intraoperative neurophysiological monitoring (IOM) remains across time in the first line and have gotten the title of the golden standard procedure for lesion located in functional areas, even though we are witnessing a high development of functional imaging techniques especially 3D diffusion tractography and functional magnetic resonance imaging [1,9,11]. ...
Article
Introduction: Intraoperative neurophysiological monitoring is the golden standard for lesions located in eloquent areas of the brain. On the one hand, positive mapping offers a view of the relationship between the anatomo-functional cortical organisation of the patient and the lesion, facilitating the choice of the cerebrotomy entry point and the resection until the functional borders are found. On the other hand, negative mapping does not offer certainty that the absence of the motor response, from the operative field, is the real feedback or is the result of the false-negative response. In such a situation, a differentiation between those two must be done. Materials and methods: We evaluated the results of direct cortical stimulation of lesion located in or near the primary motor area, which were diagnosticated with contrast-enhancement head MRI and admitted to the Third Department of Neurosurgery, "Prof. Dr N. Oblu” Emergency Clinical Hospital, Iasi, Romania, between January 2014 and July 2018. Special attention was given especially to the negative mapping cases, regarding the histological type, imagistic localisation, symptoms and neurological outcome immediate postoperative, at 6 months and one-year follow-up. Results: From all 66 patients meeting the inclusion and exclusion criteria in 9,09% (6 cases) we did not obtain any motor response after direct cortical stimulation. The imagistic localisations of those cases were: 3 – Rolandic, 2 – pre-Rolandic and one retro-Rolandic. Tumors histological types were: glioblastoma, anaplastic astrocytoma, oligoastrocytoma and oligodendroglioma each one case and two cases of fibrillary astrocytoma. The intensity range was between 6 – 18mA, the mode – 12mA and the median – 10mA. Postoperatively the neurological condition of 3 patients worsened (4,54% from all the cases), while 3 had a favourable evolution with symptom remission. At 6monts and one-year follow-up in one case (1,51%), we observed no improvement in contrast with the other two, where dysfunction remission was highlighted. Conclusion: The possible technical, surgical and anesthesiologic causes of false-negative motor response must be eliminated to be able to differentiate from the real absence of the functional area from the operative field. In the first scenario, the resection may be associated with permanent postoperative neurologic deficit and major life quality alteration while in the second one the patient presents no motor dysfunction after surgery and the resection may be extensive with multiple oncological benefits.
... Nowadays tumors located in functional areas of the brain, brainstem and medullary lesions still represents a challenge for many neurosurgeons because of the high risk of postoperatively permanent neurological deficits, but the technological development comes in our aid and the golden standard of maximal resection with minimal neurological disfunction can be reached more often using functional technique perioperatively [12,34,35,41,46]. ...
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Intraoperative neurophysiological monitoring (IOM) and especially motor evoked potentials represents an important tool in the evaluation of the nervous system integrity and particularly of the motor tracts. A real and correct registration of the potentials with a proper interpretation of the modification is mandatory for an optimal outcome in eloquent areas, tumours, brainstem and medullary lesions. For all this to happen a suitable anaesthetic protocol must be used. Even though there is a large spectrum of anaesthetic agents at our disposal it is imperative to know their effect on the IOM signals recordings and the fact that some of them are dose-dependent. Drugs effects and physiological changes produced intraoperatively must be corrected before a shift in the direction of the surgical lesion resection it is taken. We present an overview of the action of the anaesthetic agents, most used protocols and the physiological alteration encountered in the operative theatre.
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We read with great enthusiasm the paper by Peabody et al 1 discussing the challenges of the informed consent for clinical research in the context of intraoperative brain research. This is a crucial ethical challenge requiring deep reflexion in the current environment within the neurosurgical practice. The authors highlight the heterogeneous impact and retention of the information provided during the consent process as well the unique place occupied by the relational dimension between the surgeon and the patient during this process. They suggest the involvement of a patient's advocate and reconsent during awake craniotomy (if applied) to overcome some of the abovementioned limitations. At our center, we have established a dedicated neuro-oncology preoperative assessment clinic for discussing the diagnosis and the treatment plan with both patients and their relatives. 2 We strongly agree that patient's relatives should be involved in the decision-making process from very early stages to support the patient to take the best informed decisions for himself. The introduction to potential research programs is performed by the responsible neurosurgeon although the research consent process is independent and performed by the research team. Nevertheless, the responsible neurosurgeon is at the center of the consent process given the personalized relational dimension outlined by Peabody et al 1 and unique relationship between the surgeon and the patient , particularly in the setting of the awake craniotomy. A point that is worthwhile mentioning is how the research-derived information can help the clinical consent process. At our institution, we performed extensive preoperative mapping that is explained to the patients as part of their consent process. 3,4 This significantly improves their understanding about the procedure, particularly the benefits and risks involved. 5 Therefore, there is an active interaction between the clinical and research consent processes. Although they are independent in their nature, the information provided by one can facilitate the understanding of the other and promote a more informed decision and potential involvement in both treatment and research processes. Patient information for patients with cancer is a vital part to personalized informed consent 6 and forms a national measure to hold UK oncology centers accountable. According to the National Cancer Patient Experience Survey in the United Kingdom, 7 89.4% of patients, who underwent surgery for cancer, said that before their treatment started, they had the information they needed in a way they could understand. It demonstrated that although the experience was good, we still had more room for improvement and innovation in the way we educate patients and make them understand regarding their disease process. Different strategies have been used to improve the consent form process, such as personalized 2-dimensional and 3-dimensional imaging available during consent process 8 which is aligned with the General Medical Council in UK recommendations in their principles of decision making and consent. 9 Thus, pushing the boundaries with innovative technology that is patient friendly promoting positive patient experience would act as an important process in the armamentarium for the current and future neurosurgeons. The increase utilization 10 and recent advances in intraoperative neuromonitoring and mapping paved the way to a better understanding of the mechanisms underlying the brain function. Despite being independent processes, clinical treatment and research have a dynamic interaction where the neurosurgical team has a pivotal role in integrating the information provided. We could not agree more that the patient is at the center of all the decisions made even at the time of surgery during awake procedures. 1 The challenge to the surgical teams is to provide constantly updated information to allow the best decision-making process to the patients and their advocates before surgery and to the patient himself during the awake procedure. Funding This study did not receive any funding or financial support.
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Surgery remains the mainstay treatment of gliomas, with maximal resection of the tumour being central to achieving long-term disease control; growing evidence supports efforts to undertake more-extensive 'supratotal' resection The real clinical benefit of glioma surgery depends, however, on the balance between the extent of cytoreduction and neurological morbidity; novel surgical techniques and technologies can be leveraged to improve both of these determinants of patient outcomes Advanced intraoperative imaging methods (such as intraoperative neuronavigation, MRI, and ultrasonography), fluorescence-based tumour biomarkers, and real-time mutational analyses can be exploited to maximize tumour resection In parallel, the risk of perioperative morbidity can be minimized through the combined use of corticospinal tract imaging (MRI-based diffusion tensor imaging tractography and transcranial magnetic stimulation), stimulation mapping, and/or somatosensory-evoked potential techniques Together, these technological advances and modern principles of neurosurgical oncology have dramatically altered the approach to the treatment of patients with glioma and have enabled improvements in clinical outcomes
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Introduction: Intraoperative application of electrical current to the brain is a standard technique during brain surgery for inferring the function of the underlying brain. The purpose of intraoperative functional mapping is to reliably identify cortical areas and subcortical pathways involved in eloquent functions, especially motor, sensory, language and cognitive functions. Material and methods: The aim of this article is to review the rationale and the electrophysiological principles of the use of direct bipolar electrostimulation for cortical and subcortical mapping under awake conditions. Results: Direct electrical stimulation is a window into the whole functional network that sustains a particular function. It is an accurate (spatial resolution of about 5mm) and a reproducible technique particularly adapted to clinical practice for brain resection in eloquent areas. If the procedure is rigorously applied, the sensitivity of direct electrical stimulation for the detection of cortical and subcortical eloquent areas is nearly 100%. The main disadvantage of this technique is its suboptimal specificity. Another limitation is the identification of eloquent areas during surgery, which, however, could have been functionally compensated postoperatively if removed surgically. Conclusion: Direct electrical stimulation is an easy, accurate, reliable and safe invasive technique for the intraoperative detection of both cortical and subcortical functional brain connectivity for clinical purpose. In our opinion, it is the optimal technique for minimizing the risk of neurological sequelae when resecting in eloquent brain areas.
Article
For a long time, the right hemisphere (RH) was considered as "non-dominant", especially in right-handers. In neurosurgical practice, this dogma resulted in the selection of awake procedure with language mapping only for lesions of the left "dominant" hemisphere. Conversely, surgery under general anesthesia (possibly with motor mapping) was usually proposed for right lesions. However, when objective neuropsychological assessments were performed, they frequently revealed cognitive and behavioral deficits following brain surgery, even in the RH. Therefore, to preserve an optimal quality of life, especially in patients with a long survival expectancy (as in low-grade gliomas), awake surgery with cortical and axonal electrostimulation mapping has recently been proposed for right tumors resection. Here, we review new insights gained from intraoperative stimulation into the pivotal role of the RH in movement execution and control, visual processes and spatial cognition, language and non-verbal semantic processing, executive functions (e.g. attention), and social cognition (mentalizing and emotion recognition). Such original findings, that break with the myth of a "non-dominant" RH, may have important implications in cognitive neurosciences, by improving our knowledge of the functional connectivity of the RH, as well as for the clinical management of patients with a right lesion. Indeed, in brain surgery, awake mapping should be considered more systematically in the RH. Moreover, neuropsychological examination must be achieved in a more systematic manner before and after surgery within the RH, to optimize the care by predicting the likelihood of functional recovery and by elaborating specific programs of rehabilitation.