Advanced Insights into Human Uterine Innervation: Implications for Endometriosis and Pelvic Pain

(1) Background: Understanding uterine innervation, an essential aspect of female reproductive biology, has often been overlooked. Nevertheless, the complex architecture of uterine innervation plays a significant role in conditions such as endometriosis. Recently, advances in histological techniques have provided unprecedented details about uterine innervation, highlighting its intricate structure, distribution, and density. The intricate nature of uterine innervation and its influence on pathologies such as endometriosis has garnered increasing attention. (2) Objectives: This review aims to compile, analyze, and summarize the existing research on uterine innervation, and investigate its implications for the pathogenesis of endometriosis and associated pain. (3) Methods: A systematic review was conducted in line with PRISMA guidelines. Using the PubMed database, we searched relevant keywords such as "uterine innervation", "endometriosis", and "pain association". (4) Results: The initial literature search yielded a total of 3300 potential studies. Of these, 45 studies met our inclusion criteria and were included in the final review. The analyzed studies consistently demonstrated that the majority of studies focused on macroscopic dissection of uterine innervation for surgical purposes. Fewer studies focused on micro-innervation for uterine innervation. For endometriosis, few studies focused on neural pain pathways whereas many studies underlined an increase in nerve fiber density within ectopic endometrial tissue. This heightened innervation is suggested as a key contributor to the chronic pain experienced by endometriosis patients. (5) Conclusions: The understanding of uterine innervation, and its alterations in endometriosis, offer promising avenues for research and potential treatment.

A reappraisal of the deep uterine vein: a multimodal exploration with implications for pelvic surgery

PURPOSE

Pelvic gynecological surgeries, whether for malignant or benign conditions, frequently result in functional complications due to injuries to the autonomic nervous system. Recognizing the deep uterine vein (DUV) as an essential anatomical reference can aid in preserving these structures. Despite its significance, the DUV is infrequently studied and lacks comprehensive documentation in Terminologia Anatomica. This research endeavors to elucidate a detailed characterization of the DUV.

METHODS

We undertook a systematic literature review aligning with the "PRISMA" guidelines, sourcing from PUBMED and EMBASE. Our comprehensive anatomical examination encompassed cadaveric dissections and radio-anatomical evaluations utilizing the Anatomage® Table.

RESULTS

The literary exploration revealed a consensus on the DUV's description based on both anatomical and surgical observations. It arises from the merger of cervical, vesical, and vaginal veins, coursing through the paracervix in a descending and rearward direction before culminating in the internal iliac vein. The hands-on anatomical study further delineated the DUV's associations throughout its course, highlighting its role in bifurcating the uterus's lateral aspect into two distinct zones: a superior vascular zone housing the uterine artery and ureter and an inferior nervous segment below the DUV representing the autonomic nerve pathway.

CONCLUSION

A profound understanding of the subperitoneal space anatomy is paramount for pelvic surgeons to mitigate postoperative complications. The DUV's intricate neurovascular interplays underscore its significance as an indispensable surgical guide for safeguarding nerves and the ureter.

Behavioural disinhibition in frontotemporal dementia investigated within an ecological framework

Disinhibition is a core symptom in behavioural variant frontotemporal dementia (bvFTD) particularly affecting the daily lives of both patients and caregivers. Yet, characterisation of inhibition disorders is still unclear and management options of these disorders are limited. Questionnaires currently used to investigate behavioural disinhibition do not differentiate between several subtypes of disinhibition, encompass observation biases and lack of ecological validity. In the present work, we explored disinhibition in an original semi-ecological situation, by distinguishing three categories of disinhibition: compulsivity, impulsivity and social disinhibition. First, we measured prevalence and frequency of these disorders in 23 bvFTD patients and 24 healthy controls (HC) in order to identify the phenotypical heterogeneity of disinhibition. Then, we examined the relationships between these metrics, the neuropsychological scores and the behavioural states to propose a more comprehensive view of these neuropsychiatric manifestations. Finally, we studied the context of occurrence of these disorders by investigating environmental factors potentially promoting or reducing them. As expected, we found that patients were more compulsive, impulsive and socially disinhibited than HC. We found that 48% of patients presented compulsivity (e.g., repetitive actions), 48% impulsivity (e.g., oral production) and 100% of the patients group showed social disinhibition (e.g., disregards for rules or investigator). Compulsivity was negatively related with emotions recognition. BvFTD patients were less active if not encouraged in an activity, and their social disinhibition decreased as activity increased. Finally, impulsivity and social disinhibition decreased when patients were asked to focus on a task. Summarising, this study underlines the importance to differentiate subtypes of disinhibition as well as the setting in which they are exhibited, and points to stimulating area for non-pharmacological management.

Multidisciplinary management of posterior fossa dural arteriovenous fistula: A single-center experience

PURPOSE

The management of posterior fossa dural arteriovenous fistulas (pfDAVFs) is challenging. Here, we show how multidisciplinarity leads to their successful management, even in complex cases.

METHODS

All pfDAVFs managed from 2010 to 2019 at our center were reviewed. The preoperative clinical and radiological characteristics, their management and the occlusion rate were retrieved. The radiological and functional outcomes were retrieved at discharge and last follow-up (FU).

RESULTS

n=27 patients were included (6 females, mean age: 61-years-old, mean FU: 22.5 months). n=8 patients presented with cerebral hemorrhage. Among patients with ruptured pfDAVFs, n=7 had headache, n=4 had ataxia, and n=2 had impaired level of consciousness. In the unruptured group N (n=19), n=7 patients had headache, n=6 patients had focal neurological deficit, n=4 patients had tinnitus, n=3 (had ataxia, and one presented with seizure. n=24 patients were treated by endovascular therapy (EVT), n=2 patients were treated by microsurgery (MS) and n=1 patient was managed with a combined approach. Re-treatment was necessary in n=6 patients. n=24 patients showed total exclusion at last FU. n=2 patients died during the first 30 days; n=1 patient died during FU.

CONCLUSIONS

While EVT should be advocated as the first line therapy whenever possible, MS should not be banned from the treatment armamentarium. Neurosurgeons must be able to achieve direct surgical occlusion when the angioarchitecture speaks against EVT.

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial

OBJECTIVE

The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries.

METHODS

Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2.

RESULTS

From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%–22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%–28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%–25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%–21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%–37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%–20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%–40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%–21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%–35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%–29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%–33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%–34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%–26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%–34%).

CONCLUSIONS

Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.

Surgical treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial

OBJECTIVE

The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is a pragmatic study that includes 2 randomized trials and registries of treated or conservatively managed patients. The authors report the results of the surgical registry.

METHODS

TOBAS patients are managed according to an algorithm that combines clinical judgment and randomized allocation. For patients considered for curative treatment, clinicians selected from surgery, endovascular therapy, or radiation therapy as the primary curative method, and whether observation was a reasonable alternative. When surgery was selected and observation was deemed unreasonable, the patient was not included in the randomized controlled trial but placed in the surgical registry. The primary outcome of the trial was mRS score > 2 at 10 years (at last follow-up for the current report). Secondary outcomes include angiographic results, perioperative serious adverse events, and permanent treatment-related complications leading to mRS score > 2.

RESULTS

From June 2014 to May 2021, 1010 patients were recruited at 30 TOBAS centers. Surgery was selected for 229/512 patients (44%) considered for curative treatment; 77 (34%) were included in the surgery versus observation randomized trial and 152 (66%) were placed in the surgical registry. Surgical registry patients had 124/152 (82%) ruptured and 28/152 (18%) unruptured arteriovenous malformations (AVMs), with the majority categorized as low-grade Spetzler-Martin grade I-II AVM (118/152 [78%]). Thirteen patients were excluded, leaving 139 patients for analysis. Embolization was performed prior to surgery in 78/139 (56%) patients. Surgical angiographic cure was obtained in 123/139 all-grade (89%, 95% CI 82%-93%) and 105/110 low-grade (95%, 95% CI 90%-98%) AVM patients. At the mean follow-up of 18.1 months, 16 patients (12%, 95% CI 7%-18%) had reached the primary safety outcome of mRS score > 2, including 11/16 who had a baseline mRS score ≥ 3 due to previous AVM rupture. Serious adverse events occurred in 29 patients (21%, 95% CI 15%-28%). Permanent treatment-related complications leading to mRS score > 2 occurred in 6/139 patients (4%, 95% CI 2%-9%), 5 (83%) of whom had complications due to preoperative embolization.

CONCLUSIONS

The surgical treatment of brain AVMs in the TOBAS registry was curative in 88% of patients. The participation of more patients, surgeons, and centers in randomized trials is needed to definitively establish the role of surgery in the treatment of unruptured brain AVMs. Clinical trial registration no.: NCT02098252 (ClinicalTrials.gov).

An ecological approach to identify distinct neural correlates of disinhibition in frontotemporal dementia

Disinhibition is a core symptom of many neurodegenerative diseases, particularly frontotemporal dementia, and is a major cause of stress for caregivers. While a distinction between behavioural and cognitive disinhibition is common, an operational definition of behavioural disinhibition is still missing. Furthermore, conventional assessment of behavioural disinhibition, based on questionnaires completed by the caregivers, often lacks ecological validity. Therefore, their neuroanatomical correlates are non-univocal. In the present work, we used an original behavioural approach in a semi-ecological situation to assess two specific dimensions of behavioural disinhibition: compulsivity and social disinhibition. First, we investigated disinhibition profile in patients compared to controls. Then, to validate our approach, compulsivity and social disinhibition scores were correlated with classic cognitive tests measuring disinhibition (Hayling Test) and social cognition (mini-Social cognition & Emotional Assessment). Finally, we disentangled the anatomical networks underlying these two subtypes of behavioural disinhibition, taking in account the grey (voxel-based morphometry) and white matter (diffusion tensor imaging tractography). We included 17 behavioural variant frontotemporal dementia patients and 18 healthy controls. We identified patients as more compulsive and socially disinhibited than controls. We found that behavioural metrics in the semi-ecological task were related to cognitive performance: compulsivity correlated with the Hayling test and both compulsivity and social disinhibition were associated with the emotion recognition test. Based on voxel-based morphometry and tractography, compulsivity correlated with atrophy in the bilateral orbitofrontal cortex, the right temporal region and subcortical structures, as well as with alterations of the bilateral cingulum and uncinate fasciculus, the right inferior longitudinal fasciculus and the right arcuate fasciculus. Thus, the network of regions related to compulsivity matched the "semantic appraisal" network. Social disinhibition was associated with bilateral frontal atrophy and impairments in the forceps minor, the bilateral cingulum and the left uncinate fasciculus, regions corresponding to the frontal component of the "salience" network. Summarizing, this study validates our semi-ecological approach, through the identification of two subtypes of behavioural disinhibition, and highlights different neural networks underlying compulsivity and social disinhibition. Taken together, these findings are promising for clinical practice by providing a better characterisation of inhibition disorders, promoting their detection and consequently a more adapted management of patients.

Anatomic and functional mapping of human uterine innervation

OBJECTIVE

To better understand the physiology of pain in pelvic pain pathological conditions, such as endometriosis, in which alterations of uterine innervation have been highlighted, we performed an anatomic and functional mapping of the macro- and microinnervation of the human uterus. Our aim was to provide a 3-dimensional reconstruction model of uterine innervation.

DESIGN

This was an experimental study. We dissected the pelvises of 4 human female fetuses into serial sections, and treated them with hematoxylin and eosin staining before immunostaining.

SETTING

Academic Research Unit.

PATIENTS

None.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Detection of nerves (S100 +) and characterization of the types of nerves. The slices obtained were aligned to construct a 3-dimensional model.

RESULTS

A 3-dimensional model of uterine innervation was constructed. The nerve fibers appeared to have a centripetal path from the uterine serosa to the endometrium. Within the myometrium, innervation was dense. Endometrial innervation was sparse but present in the functional layer of the endometrium. Overall innervation was richest in the supravaginal cervix and rarer in the body of the uterus. Innervation was rich particularly laterally to the cervix next to the parametrium and paracervix. Four types of nerve fibers were identified: autonomic sympathetic (TH+), parasympathetic (VIP+), and sensitive (NPY+, CGRP1+ and VIP+). They were found in the 3 portions and the 3 layers of the uterus.

CONCLUSIONS

We constructed a 3-dimensional model of the human uterine innervation. This model could provide a solid base for studying uterine innervation in pathologic situations, in order to find new therapeutic approaches.

Relationship between uterine veins, ureter and hypogastric nerves for uterine transplantation: an anatomic study

BACKGROUND

Uterine transplantation is on the rise worldwide. In contrast to its arterial anatomy, venous drainage of the uterus is poorly defined in the literature. Our aim was to provide a standardized description of uterine veins through a multimodal approach to establish anatomical landmarks for the uterine transplantation surgeon.

METHODS

Data were obtained from: (1) an anatomical study of eight fresh female cadavers (16 hemipelves) studied separately by an extrafascial dissection from the iliac bifurcation to the uterine pedicle, with analysis of the urinary tract and nerve structures; and (2) a virtual anatomical study from the Anatomage® Table comprising a high-fidelity virtual reconstruction of two deceased female subjects by imaging and anatomical methods.

RESULTS

An inconstant duality of uterine veins was identified: a deep uterine vein of larger caliber, and a superficial uterine vein observed in 25% of cases. A close relationship of the ureter passing posterior to the superficial uterine vein and anterior to the deep uterine vein was evident in the parametrium. The inferior hypogastric plexus was identified in all cases immediately behind the deep uterine vein. The data obtained from the fresh female cadavers were validated by the Anatomage® Table.

CONCLUSIONS

We describe the close relationship of the uterine veins with the ureter and the inferior hypogastric plexus. This knowledge represents a surgical landmark to support the success of uterine transplantation by respecting both the graft and the safety of the living donor by limiting the risk of injuries during uterus procurement. This article is protected by copyright. All rights reserved.

Frontotemporal dementia subtypes based on behavioral inhibition deficits

INTRODUCTION

We aimed to investigate phenotypic heterogeneity in the behavioral variant of frontotemporal dementia (bvFTD) through assessment of inhibition deficits.

METHODS

We assessed occurrences of 16 behavioral inhibition deficits from video recordings of 15 bvFTD patients (early stage) and 15 healthy controls (HC) in an ecological setting. We extracted dimensions of inhibition deficit and analyzed their correlations with cognitive and clinical measures. Using these dimensions, we isolated patient clusters whose atrophy patterns were explored.

RESULTS

After identifying two patterns of inhibition deficit (compulsive automatic behaviors and socially unconventional behaviors), we isolated three behavioral clusters with distinct atrophy patterns. BvFTD-G0 (N = 3), an outlier group, showed severe behavioral disturbances and more severe ventromedial prefrontal cortex/orbitofrontal cortex atrophy. Compared to bvFTD-G1 (N = 6), bvFTD-G2 (N = 6) presented higher anxiety and depression along with less diffuse atrophy especially in midline regions.

DISCUSSION

Identifying clinico-anatomical profiles through behavior observation could help to stratify bvFTD patients for adapted treatments.

Ruptured intracranial arachnoid cysts in the subdural space: evaluation of subduro-peritoneal shunts in a pediatric population

PURPOSE

Rupture of arachnoid cysts (AC) in the subdural space after trauma may cause a subacute/chronic subdural hematoma or a hygroma. Treatment of this complication still remains controversial, and no consensual strategy is to date clearly proposed. In this study, the authors evaluated the clinical and radiological evolution of patients treated by a subduro-peritoneal shunt for symptomatic subdural collections complicating ruptured AC.

METHODS

Medical records of the 10 patients treated at our institution between January 2005 and December 2018 for a subdural collection associated with an intracranial AC were reviewed. Subduro-peritoneal shunts consisted of low-pressure valves from 2005 to 2012 (6 cases) and medium-pressure valves after 2012 (4 cases).

RESULTS

A benign head trauma was retrospectively found in the history of 8 patients. The mean time to diagnosis ranged from 15 days to 5 months. Symptoms resulted mainly from intracranial hypertension. Six patients had an ipsilateral hygroma to the AC, 2 patients had a bilateral hygroma predominantly to the AC side, and 2 patients presented an ipsilateral chronic subdural hematoma. Arachnoid cysts were classified as Galassi I in 5 cases and Galassi II in 5 cases. Patients with chronic subdural hematoma were given a medium-pressure valve. Patients with subdural hygroma received a low-pressure valve in 6 cases and a medium-pressure valve in 2 cases. There were no complications during surgical procedures. All patients were rapidly free of symptoms after surgery and were discharged from hospital 1 to 4 days postoperatively. The subdural collection completely disappeared in all cases. In the long term, only 2 patients with low-pressure valves underwent shunt removal without any consequences, while a second surgical procedure was necessary to treat recurrence of intracranial hypertension in the 4 remaining cases. All the medium-pressure valves were removed without problems. The size of the AC was reduced in 3 cases, remained stable in 4 cases, and increased in 3 cases. No patients experienced recurrence of subdural collection during follow-up.

CONCLUSIONS

Medium-pressure subduro-peritoneal shunts should be considered as part of the arsenal of surgical strategy in symptomatic ruptured AC in the subdural space. The procedure is simple with a very low morbidity, and it allows rapid improvement of symptoms. Although the shunt is located in the subdural space, we strongly recommend avoiding devices which may create an overdrainage and expose the patient to shunt dependency such as low-pressure shunts.

Impact of the complexity of surgical procedures and intraoperative interruptions on neurosurgical team workload

BACKGROUND

Neurosurgical teams are exposed to various stressors: complexity of surgical procedures, environment, time pressure and interruptions contribute to increasing the perceived workload.

OBJECTIVE

This study aimed to evaluate the impact of interruptions and surgical complexity on neurosurgical team workload.

METHODS

A prospective observational study was conducted on thirty surgical procedures of graduated complexity recorded in our Department of Neurosurgery. A scale was created and used by neurosurgeons to evaluate the perceived complexity of the surgical procedure. Interruptions and severity of interruptions were noted. The workloads of the neurosurgeon, surgical assistant, scrub nurse and circulating nurse were measured on the Surgery Task Load Index (SURG-TLX) at the end of the procedure.

RESULTS

A mean 24.6 interruptions per hour were recorded. The mean interference level of the interruptions was 3.5/7. Mean surgical complexity was 4.3/10. Mean sterile team workload was 43.4/100. The multiple linear regression model showed that sterile team workload increased with surgical complexity (β=6.692, P=.0002) but decreased in spite of increases in the number of interruptions per hour (β=-0.855, P=.027). Neurosurgeon and surgical assistant workload increased with surgical complexity (β=11.53, P<0.0001 and β=7.42, P=0.0007, respectively). Scrub nurse workload decreased in spite of increases in the number of interruptions per hour (β=-1.11, P=.026).

CONCLUSION

Our study suggests positive effects of some interruptions during elective neurosurgical procedures with strong team familiarity.

Functional outcome 1 year after aneurysmal subarachnoid hemorrhage due to ruptured intracranial aneurysm in elderly patients

BACKGROUND

Population aging raises questions about extending treatment indications in elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). We therefore assessed functional status 1 year after treatment.

METHODS

This study involved 310 patients, aged over 70 years, with ruptured brain aneurysm, enrolled between 2008 and 2014 in a prospective multicentre trial (FASHE study: NCT00692744) but considered unsuitable for randomisation and therefore analysed in the observational arms of the study: endovascular occlusion (EV), microsurgical exclusion (MS) and conservative treatment. The aims were to assess independence, cognition, autonomy and quality of life (QOL) at 1 year post-treatment, using questionnaires (MMSE, ADLI, IADL, EORTC-QLQ-C30) filled in by independent nurses after discharge.

RESULTS

The 310 patients received the following treatments: 208 underwent EV (67.1%), 54 MS (17.4%) and 48 were conservatively managed (15.5%). At 1 year, independence rates for patients admitted with good clinical status (WFNS I-III) were, according to the aneurysm exclusion procedure (EV, MS or conservative), 58.9%, 50% and 12.1% respectively. MMSE score was pathological in 26 of the 112 EV patients (23.2%), 10 of the 25 MS patients (40%) and 4 of the 9 patients treated conservatively (44%), without any statistically significant difference [Pearson's Chi² test, F ratio=4.29; P=0.11]. Regarding QoL, overall score was similar between the EV and MS cohorts, but significantly lower with conservative treatment.

CONCLUSION

Elderly patients in good clinical condition with aSAH should be treated regardless of associated comorbidities. Curative treatment (EV or MS) reduced mortality without increasing dependence, in comparison with conservative treatment.

Interruptions in Surgery: A Comprehensive Review

BACKGROUND

Recent literature showed that analysis of interruptions can contribute to evaluating the care process in the operating room, and thus, understanding potential errors that may occur during surgical procedures. The aim of this comprehensive review was to summarize current knowledge on the description and impact of interruptions in surgery.

MATERIAL AND METHODS

A literature search was conducted according to a set of criteria in the databases MEDLINE, BASE, Cochrane's Library, and PsycINFO.

RESULTS

41 articles were included. Two main methodological approaches were found, observational in the OR, or controlled in an experimental simulated environment. Interruptions in the OR were manifold, and several classifications were used. The severity of interruptions differed according to the category of the interruptions. Interruptions were influenced by team familiarity and the expertise of the surgical team; high team familiarity and a high level of expertise decreased the frequency of interruptions. However, our literature search lacked controlled studies carried out in the OR. Interruptions seemed to increase the workload and stress of the surgical team and impair nontechnical skills, but no clear evidence of this was advanced.

CONCLUSIONS

Interruptions are probably risk factors for errors in the operating room. However, there is as yet no clear evidence of the association of interruption frequency with errors in the operating room. There is a need to define and target interruptions, which should be reduced by putting safeguards in place, thereby allowing those which could be beneficial and neglecting those with no potential consequences.

Selective neurotomy of the sciatic nerve branches to the hamstring muscles: An anatomical study

BACKGROUND

Hamstring spasticity can bring about a flexion deformity of the knee, liable to cause disability. Surgical treatment by selective neurotomies of the sciatic nerve branches leading to the hamstring muscles may then be indicated. Few studies have investigated the precise origin of these branches on the sciatic nerve, describing the innervation pattern of the hamstring muscles. Further anatomical data are needed to enhance surgical techniques in neurotomies of the sciatic nerve branches, to define the best incision and surgical approach and what section and length of the SN need to be exposed. Therefore, we performed an anatomical study to: (1) define a surgical approach to perform selective neurotomies of the sciatic nerve branches for hamstring spasticity?(2) whether the anatomical variants of the hamstring innervation have been identified?

HYPOTHESIS

Our anatomical data could lead to the definition of an approach to the sciatic nerve for the purpose of selective neurotomy.

MATERIAL AND METHODS

Twenty posterior compartments of the thigh were dissected. We counted each branch of the sciatic nerve leading to the hamstring and described their arising point using the centre of the lateral surface of the great trochanter and the lower edge of the gluteus maximus muscle as main anatomical landmarks. We also described the presence of branch divisions and their muscular penetrating points.

RESULTS

The mean distances between the center of the lateral surface of the great trochanter and the emergence of branches from the SN were: 2.2±3.6cm (-5 to 9cm) for the long head of the biceps femoris muscle, 2.3±3cm (-4 to 10cm) for the semitendinosus muscle, and 2.2±3cm (-5 to 8cm) for the semimembranosus muscle. No branches originated from the sciatic nerve below the lower edge of the gluteus maximus muscle. In summary the branches innervating the hamstrings originated from the SN within an interval of 15cm (5cm above and 10cm below the centre of the lateral surface of great trochanter). The average number of sciatic nerve branches for the hamstring muscles was 4.7 (minimum: 3; maximum: 6) with 1.8 branches for the long head of the biceps [1 in 7/20 (35%), 2 in 10/20 (50%), and 3 in 3/20 (15%)], 1.5 branches for the semitendinosus [1 in 11/20 (55%) and 2 in 9/20 (45%)], 1.4 branches for the semimembranosus [1 in 12/20 (60%) and 2 in 8/20 (40%)]. No branches had a common origin with cutaneous nerves.

DISCUSSION

This anatomical study enabled us to propose an approach to exposing the sciatic nerve in order to perform a selective neurotomy: horizontal cutaneous incision on the gluteal fold, incision of the lower edge of the gluteus maximus, exposure of the sciatic nerve to a distance of 10cm below the great trochanter, and visualization of the nerve branches to the hamstring muscles. Exposure of the nerve above the great trochanter is not necessary because the branches which emerge from the SN above the great trochanter are still contiguous with the SN.

LEVEL OF EVIDENCE

IV: prospective study without control.

Spinal Dural Arteriovenous Fistulas: Clinical Outcome After Surgery Versus Embolization: A Retrospective Study

OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) are rare vascular spinal malformations. According to the reported data, surgery seems to result in better occlusion rates than endovascular treatment. However, the post-treatment evolution of neurological symptoms stratified by the treatment remains unknown. The main objective of the present study was to compare the clinical outcomes for patients according to the treatment method.

METHODS

The data from 63 patients with SDAVFs from 2000 to 2017 at 4 academic neurosurgical departments were retrospectively analyzed. Preoperative and postoperative examination neurological status was assessed using the Aminoff-Logue scale (ALS), which evaluates gait and micturition disturbances. Initial occlusion, late recurrence, and complications of the 2 techniques were also reviewed.

RESULTS

Patients who had undergone surgery and embolization improved clinically on the ALS (P = 0.0009), and no significant differences were found between the 2 techniques. Subgroup analysis using the ALS showed that patients who had undergone surgery and embolization without late recurrence improved (P < 0.0001 and P = 0.0334, respectively) and that patients who had undergone surgery or embolization with late recurrence did not improve. The initial occlusion rate was in favor of surgery, with 91.3% versus 70% for endovascular treatment (P = 0.050). The late recurrence rate was higher for embolization (21.4% vs. 9.1% for surgery; P = 0.28).

CONCLUSIONS

Surgery can be proposed as first-line treatment of SDAVFs after multidisciplinary discussion between neurosurgeons and neuroradiologists. The development of late recurrence negatively affects the neurological outcome of patients.

Quality of life in the management of small vestibular schwannomas: Observation, radiotherapy and microsurgery

OBJECTIVE

The aim of this study was to compare quality of life (QOL) in small unilateral vestibular schwannoma (VS) patients managed by microsurgery, radiotherapy or observation.

STUDY DESIGN

A retrospective chart review.

METHODS

The study included a total of 142 patients with VS stage 1 or 2 according to the Koos classification and treated between January 2004 and December 2015. Microsurgery, radiotherapy and observation groups comprised 43, 46 and 53 patients, respectively. All patients completed four QOL (questionnaires: Short-Form Health Survey 36, Hearing Handicap Inventory, Tinnitus Handicap Inventory and Dizziness Handicap Inventory Short-Form). Clinical symptoms and QOL were compared among groups.

RESULTS

The average time interval between management and filling in the questionnaires was 66 months. There was no difference in QOL between the three groups on any of the four questionnaires. The most debilitating symptom was vertigo for all three groups. Tinnitus was a pejorative factor in the surgery group. Hearing level was deteriorated after microsurgery but there was no significant difference between the radiotherapy group and the middle fossa approach.

CONCLUSION

Patients with small VS stage 1 and 2 had similar QOL, irrespective of management by observation, radiotherapy or microsurgery. The overall predictor for long-term reduced QOL was vertigo. Vestibular rehabilitation could improve QOL in symptomatic patients.

Functional atlases for analysis of motor and neuropsychological outcomes after medial globus pallidus and subthalamic stimulation

Anatomical atlases have been developed to improve the targeting of basal ganglia in deep brain stimulation. However, the sole anatomy cannot predict the functional outcome of this surgery. Deep brain stimulation is often a compromise between several functional outcomes: motor, fluency and neuropsychological outcomes in particular. In this study, we have developed anatomo-clinical atlases for the targeting of subthalamic and medial globus pallidus deep brain stimulation. The activated electrode coordinates of 42 patients implanted in the subthalamic nucleus and 29 patients in the medial globus pallidus were studied. The atlas was built using the representation of the volume of tissue theoretically activated by the stimulation. The UPDRS score was used to represent the motor outcome. The Stroop test was represented as well as semantic and phonemic fluencies. For the subthalamic nucleus, best motor outcomes were obtained when the supero-lateral part of the nucleus was stimulated whereas the semantic fluency was impaired in this same region. For the medial globus pallidus, best outcomes were obtained when the postero ventral part of the nucleus was stimulated whereas the phonemic fluency was impaired in this same region. There was no significant neuropsychological impairment. We have proposed new anatomo-clinical atlases to visualize the motor and neuropsychological consequences at 6 months of subthalamic nucleus and pallidal stimulation in patients with Parkinson's disease.

Knowledge transfer for surgical activity prediction

PURPOSE

Lack of annotated training data hinders automatic recognition and prediction of surgical activities necessary for situation-aware operating rooms. We propose using knowledge transfer to compensate for data deficit and improve prediction.

METHODS

We used two approaches to extract and transfer surgical process knowledge. First, we encoded semantic information about surgical terms using word embedding. Secondly, we passed knowledge between different clinical datasets of neurosurgical procedures using transfer learning.

RESULTS

The combination of two methods provided 22% improvement of activity prediction. We also made several pertinent observations about surgical practices based on the results of the performed transfer.

CONCLUSION

Word embedding boosts learning process. Transfer learning was shown to be more effective than a simple combination of data, especially for less similar procedures.

Steroids in chronic subdural hematomas (SUCRE trial): study protocol for a randomized controlled trial

BACKGROUND

Chronic subdural hematoma (CSDH) is a common neurological pathology, especially in older patients. The actual "gold standard" of treatment is surgical evacuation, with various techniques used across neurosurgical teams. Over the years, there has been growing evidence that inflammatory processes play a major role in the pathogenesis of CSDH. In that context, the use of corticosteroids has been proposed alone or as an adjuvant treatment to surgery. However, this practice remains very empirical and there is a need for high-quality-of-evidence studies to clarify the role of corticosteroids in the management of CSDH.

METHODS/DESIGN

We propose a double-blind, randomized controlled trial comparing methylprednisolone versus placebo in the treatment of CSDH without clinical and/or radiological signs of severity. The treatment will be administered daily for a duration of 3 weeks, at a dose of 1 mg/kg. The primary endpoint will be the delay of occurrence of surgical treatment at 1 month following the introduction of the treatment. Secondary endpoints will include the rate of recourse to surgery, survival rate, quality of life and functional assessments, occurrence of systemic secondary effects and radiological assessment of the response to treatment. This multimodal assessment will be done at 1, 3 and 6 months. Two hundred and two patients (101 per arm) are expected to be included considering our primary hypotheses.

DISCUSSION

This trial started in June 2016; its results may open interesting alternatives to surgery in the management of patients harboring a CSDH, and may provide insights into the natural history of this common pathology.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02650609 . Registered on 4 January 2016. Graphical output of the OBF boundaries.

Anterior cervical interbody fusion using polyetheretherketone cage filled with synthetic bone graft in acute cervical spine injury

PURPOSE

The aim of this study was to assess the interbody fusion rate for patients treated by anterior cervical interbody fusion (ACIF) using polyetheretherketone (PEEK) cages filled with synthetic bone graft in acute cervical spine injury.

MATERIALS AND METHODS

Twenty-nine patients (mean age: 49 years) with monosegmental instability due to cervical spine injury were followed. We assessed the rate of and time to interbody fusion at 1-year follow-up. In case of secondary displacement, we analysed its causes and surgical management.

RESULTS

The rate of fusion was 86.2%. The mean time to fusion was 7.2 months. Interbody fusion was observed at 3 months in 4 patients, at 6 months in 14 and at 1 year in 7. Four patients had secondary displacement within 3 months.

CONCLUSION

ACIF with a PEEK cage filled with synthetic bone graft seems to be an alternative to iliac crest bone graft with no morbidity related to the harvest site.

Acquisition models in intraoperative positron surface imaging

PURPOSE

Intraoperative imaging aims at identifying residual tumor during surgery. Positron Surface Imaging (PSI) is one of the solutions to help surgeons in a better detection of resection margins of brain tumor, leading to an improved patient outcome. This system relies on a tracked freehand beta probe, using [Formula: see text]F-based radiotracer. Some acquisition models have been proposed in the literature in order to enhance image quality, but no comparative validation study has been performed for PSI.

METHODS

In this study, we investigated the performance of different acquisition models by considering validation criteria and normalized metrics. We proposed a reference-based validation framework to perform the comparative study between acquisition models and a basic method. We estimated the performance of several acquisition models in light of four validation criteria: efficiency, computational speed, spatial accuracy and tumor contrast.

RESULTS

Selected acquisition models outperformed the basic method, albeit with the real-time aspect compromised. One acquisition model yielded the best performance among all according to the validation criteria: efficiency (1-Spe: 0.1, Se: 0.94), spatial accuracy (max Dice: 0.77) and tumor contrast (max T/B: 5.2). We also found out that above a minimum threshold value of the sampling rate, the reconstruction quality does not vary significantly.

CONCLUSION

Our method allowed the comparison of different acquisition models and highlighted one of them according to our validation criteria. This novel approach can be extended to 3D datasets, for validation of future acquisition models dedicated to intraoperative guidance of brain surgery.

Reprint of: Signaling the Unfolded Protein Response in primary brain cancers

The Unfolded Protein Response (UPR) is an adaptive cellular program used by eukaryotic cells to cope with protein misfolding stress in the Endoplasmic Reticulum (ER). During tumor development, cancer cells are facing intrinsic (oncogene activation) and extrinsic (limiting nutrient or oxygen supply; exposure to chemotherapies) challenges, with which they must cope to survive. Primary brain tumors are relatively rare but deadly and present a significant challenge in the determination of risk factors in the population. These tumors are inherently difficult to cure because of their protected location in the brain. As such surgery, radiation and chemotherapy options carry potentially lasting patient morbidity and incomplete tumor cure. Some of these tumors, such as glioblastoma, were reported to present features of ER stress and to depend on UPR activation to sustain growth, but to date there is no clear general representation of the ER stress status in primary brain tumors. In this review, we describe the key molecular mechanisms controlling the UPR and their implication in cancers. Then we extensively review the literature reporting the status of ER stress in various primary brain tumors and discuss the potential impact of such observation on patient stratification and on the possibility of developing appropriate targeted therapies using the UPR as therapeutic target. This article is part of a Special Issue entitled SI:ER stress.

Signaling the Unfolded Protein Response in primary brain cancers

The Unfolded Protein Response (UPR) is an adaptive cellular program used by eukaryotic cells to cope with protein misfolding stress in the Endoplasmic Reticulum (ER). During tumor development, cancer cells are facing intrinsic (oncogene activation) and extrinsic (limiting nutrient or oxygen supply; exposure to chemotherapies) challenges, with which they must cope to survive. Primary brain tumors are relatively rare but deadly and present a significant challenge in the determination of risk factors in the population. These tumors are inherently difficult to cure because of their protected location in the brain. As such surgery, radiation and chemotherapy options carry potentially lasting patient morbidity and incomplete tumor cure. Some of these tumors, such as glioblastoma, were reported to present features of ER stress and to depend on UPR activation to sustain growth, but to date there is no clear general representation of the ER stress status in primary brain tumors. In this review, we describe the key molecular mechanisms controlling the UPR and their implication in cancers. Then we extensively review the literature reporting the status of ER stress in various primary brain tumors and discuss the potential impact of such observation on patient stratification and on the possibility of developing appropriate targeted therapies using the UPR as therapeutic target.

Automatic data-driven real-time segmentation and recognition of surgical workflow

PURPOSE

With the intention of extending the perception and action of surgical staff inside the operating room, the medical community has expressed a growing interest towards context-aware systems. Requiring an accurate identification of the surgical workflow, such systems make use of data from a diverse set of available sensors. In this paper, we propose a fully data-driven and real-time method for segmentation and recognition of surgical phases using a combination of video data and instrument usage signals, exploiting no prior knowledge. We also introduce new validation metrics for assessment of workflow detection.

METHODS

The segmentation and recognition are based on a four-stage process. Firstly, during the learning time, a Surgical Process Model is automatically constructed from data annotations to guide the following process. Secondly, data samples are described using a combination of low-level visual cues and instrument information. Then, in the third stage, these descriptions are employed to train a set of AdaBoost classifiers capable of distinguishing one surgical phase from others. Finally, AdaBoost responses are used as input to a Hidden semi-Markov Model in order to obtain a final decision.

RESULTS

On the MICCAI EndoVis challenge laparoscopic dataset we achieved a precision and a recall of 91 % in classification of 7 phases.

CONCLUSION

Compared to the analysis based on one data type only, a combination of visual features and instrument signals allows better segmentation, reduction of the detection delay and discovery of the correct phase order.

Spinal cord hemorrhage in a patient with neurosarcoidosis on long-term corticosteroid therapy: case report

BACKGROUND

Central nervous system bleeding is a rare complication of neurosarcoidosis: only 18 cases of spontaneous cerebral hematoma have been reported. We present the first recorded case of spinal cord hemorrhage in neurosarcoidosis.

CASE PRESENTATION

A 48-year-old Caucasian woman had relapsing neurosarcoidosis for 5 years, with inflammatory spinal and cerebral lesions. While on 20 mg corticosteroids, she experienced subacute paraparesia with right leg pain. A spine MRI revealed a low thoracic hematomyelia at the T10-T11 level. Despite high doses of corticosteroids, her condition continued to worsen. Surgical evacuation of the hematoma was performed 10 days after the onset of bleeding, and she partially recovered.

CONCLUSION

This report highlights the possibility of spinal cord hemorrhage secondary to sarcoid vasculitis. The patient improved after surgical evacuation of the intramedullary hematoma. Immuno-modulating agents must be envisaged in severe neurosarcoidosis, to prevent complications.

Work domain constraints for modelling surgical performance

PURPOSE

Three main approaches can be identified for modelling surgical performance: a competency-based approach, a task-based approach, both largely explored in the literature, and a less known work domain-based approach. The work domain-based approach first describes the work domain properties that constrain the agent's actions and shape the performance. This paper presents a work domain-based approach for modelling performance during cervical spine surgery, based on the idea that anatomical structures delineate the surgical performance. This model was evaluated through an analysis of junior and senior surgeons' actions.

METHOD

Twenty-four cervical spine surgeries performed by two junior and two senior surgeons were recorded in real time by an expert surgeon. According to a work domain-based model describing an optimal progression through anatomical structures, the degree of adjustment of each surgical procedure to a statistical polynomial function was assessed.

RESULTS

Each surgical procedure showed a significant suitability with the model and regression coefficient values around 0.9. However, the surgeries performed by senior surgeons fitted this model significantly better than those performed by junior surgeons. Analysis of the relative frequencies of actions on anatomical structures showed that some specific anatomical structures discriminate senior from junior performances.

CONCLUSION

The work domain-based modelling approach can provide an overall statistical indicator of surgical performance, but in particular, it can highlight specific points of interest among anatomical structures that the surgeons dwelled on according to their level of expertise.

Influence of cumulative surgical experience on the outcome of poor-grade patients with ruptured intracranial aneurysm

BACKGROUND

The expansion of endovascular techniques for intracranial aneurysms has led to a global decrease in vascular neurosurgery activity. This situation might impact neurosurgeons' level of expertise, even though they all might have to deal with this surgically challenging pathology. In that context, we wanted to assess the impact of cumulative surgical experience on the outcome of patients with poor-grade subarachnoid haemorrhage (SAH) and intracerebral haemorrhage (ICH) treated by microsurgery.

METHODS

Sixty-seven patients who underwent surgery for a ruptured aneurysm with SAH and ICH, and a WFNS scale of IV/V, were included. Surgeries were performed by five surgeons, whose experience was judged by the total number of aneurysm surgeries performed. The outcome was assessed by three indicators: intraoperative rupture (IOR), early mortality, and the modified Rankin Scale at last follow-up. The time of IOR was reported on an IOR score. The correlation between surgical experience and outcome was assessed by linear regression. Nonlinear regression was used to assess the correlation of the data with a learning curve model.

RESULTS

The analysis showed an influence of surgical experience on intraoperative rupture, with no effect on long-term outcome. No influence was found on early mortality. Increased surgical experience seems to reduce IOR during aneurysm dissection and clip repositioning. Intraoperative rupture data fit Wright's learning curve model.

CONCLUSION

This study suggests a direct impact of cumulative experience on the course of ruptured aneurysm surgery and pleads for the use of training and simulation programmes dedicated to neurovascular surgery.

Dynamic cervical myelopathy in young adults

PURPOSE

Non-traumatic cervical chronic joint instability in young adults is a rare and underexplored entity. We assessed the diagnostic relevance of dynamic MRI, and the clinical and radiological outcome after anterior cervical interbody fusion (ACIF) in these cases.

METHODS

Six young patients (mean age 34 years) with cervical myelopathy without compression on static imaging had a dynamic MRI. Joint instability was defined by a reduction of the canal diameter on dynamic sequences. Clinical and radiological outcomes were assessed after surgery by examination, cervical X-rays, static and dynamic MRI.

RESULTS

All the patients had joint instability. Four patients underwent surgery. Clinical status improved 1 year after surgery. All patients had a satisfactory fusion at 6-month follow-up and no residual compression at 1 year.

CONCLUSION

Dynamic MRI can help detect a joint instability in young patients with cervical myelopathy without compression. ACIF seems to be efficient in these cases.

How can we optimize anterior iliac crest bone harvesting? An anatomical and radiological study

PURPOSE

Anterior iliac crest bone is a widely used donor site for bone harvesting. It provides an autologous bone graft consisting of cancellous bone that can be packed or cortical bone with greater structural support. Uses include spinal fusion and fracture non-union surgery. Although its use is common, dedicated anatomical and radiological studies analysing graft dimensions and optimal harvesting site in relation to local anatomical landmarks [anterior superior iliac spine (ASIS), anterior iliac tubercle (AIT) and lateral femoral cutaneous nerve (LFCN)] have not been described.

METHODS

Twenty-eight female hemipelvises were dissected for this study. The LFCN, ASIS and AIT were identified. Calliper measurements and CT scan analysis were undertaken to determine the optimum positions in obtaining a 5-mm-thickness tricortical graft whilst remaining safe for the LFCN.

RESULTS

According to our measurements, the optimal location for harvesting a 5-mm-thick tricortical graft with 35-mm height and 47-mm width is situated anterior to a line passing at the level of the thickest point of the AIT. This thickest point was situated at a mean 67 mm from the centre of the EIAS in our study.

CONCLUSION

This anatomical and radiographic study determined the anatomical iliac crest landmarks to avoid neurological injury when taking an optimal 5-mm-width tricortical bone graft.

Connectivity within the primary motor cortex: a DTI tractography study

PURPOSE

Because of the motor function of the precentral area, the connections of the primary motor cortex by white matter fiber bundles have been widely studied in diffusion tensor imaging (DTI). Nevertheless, the connections within the primary motor cortex have yet to be explored. We have studied the connectivity between the different regions of the precentral gyrus in a population of subjects.

METHODS

Based on T1 magnetic resonance imaging (MRI) and on individual sulco-gyral anatomy, we defined a parcellation of the right and the left precentral gyri in 20 healthy subjects (10 right-handers; 10 left-handers). This parcellation gave us the opportunity to study MRI tracks reconstructed by tractography within the precentral gyrus and to compare these connections across subjects. We also performed a classical dissection of post-mortem brain tissue to isolate this pattern of connectivity.

RESULTS

We showed MRI tracks connecting the different parts of the same precentral gyrus. This result was reproducible and was found in the left and right hemispheres of the 20 subjects. A quantitative description of the bilateral distribution of the MRI tracks was performed, based on statistical analysis and asymmetry indices, to compare asymmetry and handedness.

CONCLUSIONS

To the best of our knowledge, this pattern of connectivity has never before been detailed in the literature. Its functional meaning remains to be determined, which requires further study.

Corticospinal tract asymmetry and handedness in right- and left-handers by diffusion tensor tractography

PURPOSE

Cerebral hemispheres represent both structural and functional asymmetry, which differs among right- and left-handers. The left hemisphere is specialised for language and task execution of the right hand in right-handers. We studied the corticospinal tract in right- and left-handers by diffusion tensor imaging and tractography. The present study aimed at revealing a morphological difference resulting from a region of interest (ROI) obtained by functional MRI (fMRI).

METHODS

Twenty-five healthy participants (right-handed: 15, left-handed: 10) were enrolled in our assessment of morphological, functional and diffusion tensor MRI. Assessment of brain fibre reconstruction (tractography) was done using a deterministic algorithm. Fractional anisotropy (FA) and mean diffusivity (MD) were studied on the tractography traces of the reference slices.

RESULTS

We observed a significant difference in number of leftward fibres based on laterality. The significant difference in regard to FA and MD was based on the slices obtained at different levels and the laterality index. We found left-hand asymmetry and right-hand asymmetry, respectively, for the MD and FA.

CONCLUSIONS

Our study showed the presence of hemispheric asymmetry based on laterality index in right- and left-handers. These results are inconsistent with some studies and consistent with others. The reported difference in hemispheric asymmetry could be related to dexterity (manual skill).

Sporadic intracranial haemangioblastomas: surgical outcome in a single institution series

BACKGROUND

Haemangioblastomas are benign vascular tumours that may appear sporadically or in von Hippel-Lindau disease. Despite their higher incidence, sporadic haemangioblastomas have been less studied than syndromic ones. In this article, we evaluate the specific features, outcome and quality of life of patients with intracranial sporadic haemangioblastomas (ISHs) operated on in our institution.

METHODS

Between 1998 and 2010, 38 patients harbouring 38 ISHs were operated on in our department. Their clinical, biological, radiological and surgical features were retrospectively reviewed. All patients were contacted for a quality-of-life (QOL) survey assessed by the Short Form 36 questionnaire (SF36). The mean duration of follow-up was 40 months (13-108 months).

RESULTS

ISH represented 0.9 % of primary intracranial neoplasms treated in our centre during this period. Patients comprised 23 men and 15 women with a mean age of 47 years. None had polycythaemia. Cerebellar locations accounted for 79 % of ISHs, and brainstem ISH with involvement of the floor of the fourth ventricle represented 11 % of ISHs. At last follow-up, two patients harbouring solid medulla oblongata haemangioblastoma had died following severe bulbar syndrome and five patients had died of unrelated causes. One patient had multiple surgeries for three recurrences. Tumoral control was achieved in all cases at last follow-up. Results of the SF-36 questionnaire were as follows: median physical functioning score 100 (range 0-100), median physical problems score 100 (range 0-100), median bodily pain score 100 (range 45-100), median social functioning score 100 (range 25-100), median general mental health score 84 (range 40-92), median emotional problems score 100 (range 0-100), median vitality score 70 (range 35-80) and median general health perceptions score 70 (range 35-100). Mean QOL scores were similar to the general healthy population.

CONCLUSION

Surgery of ISH provides good QOL and tumoral control except for those located in the medulla oblongata. We recommend considering a careful multimodal therapeutic approach, including radiosurgery for these specific locations.

A cognitive engineering framework for the specification of information requirements in medical imaging: application in image-guided neurosurgery

PURPOSE

This study proposes a framework coming from cognitive engineering, which makes it possible to define what information content has to be displayed or emphasised from medical imaging, for assisting clinicians according to their level of expertise in the domain.

METHOD

We designed a rating scale to assess visualisation systems in image-guided neurosurgery with respect to the depiction of the neurosurgical work domain. This rating scale was based on a neurosurgical work domain analysis. This scale has been used to evaluate visualisation modes among neurosurgeons, residents and engineers. We asked five neurosurgeons, ten medical residents and ten engineers to rate two visualisation modes from the same data (2D MR image vs. 3D computerised image). With this method, the amount of abstract and concrete work domain information displayed by each visualisation mode can be measured.

RESULTS

A global difference in quantities of perceived information between both images was observed. Surgeons and medical residents perceived significantly more information than engineers for both images. Unlike surgeons, however, the amount of information perceived by residents and engineers significantly decreased as information abstraction increased.

CONCLUSIONS

We demonstrated the possibility of measuring the amount of work domain information displayed by different visualisation modes of medical imaging according to different user profiles. Engineers in charge of the design of medical image-guided surgical systems did not perceive the same set of information as surgeons or even medical residents. This framework can constitute a user-oriented approach to evaluate the amount of perceived information from image-guided surgical systems and support their design from a cognitive engineering point of view.

An anthropomorphic polyvinyl alcohol brain phantom based on Colin27 for use in multimodal imaging

PURPOSE

In this paper, the method for the creation of an anatomically and mechanically realistic brain phantom from polyvinyl alcohol cryogel (PVA-C) is proposed for validation of image processing methods such as segmentation, reconstruction, registration, and denoising. PVA-C is material widely used in medical imaging phantoms because of its mechanical similarities to soft tissues.

METHODS

The phantom was cast in a mold designed using the left hemisphere of the Colin27 brain dataset [C. Holmes et al., "Enhancement of MR images using registration for signal averaging," J. Comput. Assist. Tomogr. 22(2), 324 (1998)]. Marker spheres and inflatable catheters were also implanted to enable good registration comparisons and to simulate tissue deformation, respectively.

RESULTS

The phantom contained deep sulci, a complete insular region, and an anatomically accurate left ventricle. It was found to provide good contrast in triple modality imaging, consisting of computed tomography, ultrasound, and magnetic resonance imaging. Multiple sets of multimodal data were acquired from this phantom.

CONCLUSIONS

The methods for building the anatomically accurate, multimodality phantom were described in this work. All multimodal data are made available freely to the image processing community (http://pvabrain.inria.fr). We believe the phantom images could allow for the validation and further aid in the development of novel medical image processing techniques.