Transfer of the palmaris brevis motor branch to the thenar motor branch: A cadaveric preliminary study

OBJECTIVE

High median nerve injuries can lead to poor distal recovery, especially poor functioning of median innervated thenar muscles involved in thumb opposition and palmar abduction. The palmaris brevis (PB) is a small subcutaneous muscle innervated by ulnar nerve. Innervation of the PB is in most of cases provided by the ulnar digital nerve to the little finger. The purpose of this study is to assess the feasibility of transferring the PB motor branch (PBMB) to the median nerve thenar motor branch (TMB), in order to allow for early restoration of thumb palmar abduction and opposition, through a preliminary cadaveric study.

METHODS

Twenty-five cadaver upper limbs were dissected under magnification. The length of the PBMB and TMB, and their origin were recorded. Nerve transfer from PBMB to TMB was conducted, and evaluated on 2 parameters: surgical feasibility, and distance from the coaptation site to the recipient nerve muscle entry point. The PBMB and TMB were harvested, fixated in formalin, then embedded in paraffin. They were sectioned transversely, and stained with a combination of hematoxylin-eosin and Luxol fast blue. Myelinated axons were counted in each specimen and the donor-to-recipient axon ratio was recorded.

RESULTS

The PBMB was constant and originated from the ulnar digital nerve of the little finger in all cases. The transfer from PBMB to TMB was feasible in all cases. Mean myelinated axon counts of PBMB and TMB were 253±142 and 356±198, respectively (p=0.06). The donor-to-recipient axon ratio was 1:1.41. The mean distance from coaptation of the PBMB to the recipient thenar muscles was 23.1±3.0mm.

CONCLUSIONS

Based on our results, PBMB to TMB transfer is feasible. The PBMB has the advantage over other distal nerve transfer donors to be constant and superficial, allowing for an easier harvest. Moreover, this procedure does not sacrifice any intrinsic function of the hand, and the proximity of the PBMB with the carpal tunnel allows for a single incision procedure. Therefore, early restoration of the median innervated thenar muscles may be feasible by the PBMB to TMB transfer in cases of high median nerve lesions.

LEVEL OF EVIDENCE

IV.

Mismatch Between Brain MRIs and 18 F-DOPA PET/CT : Impact on the Management of a Long Survivor With EGFR-Mutated Lung Adenocarcinoma

ABSTRACT

After receiving erlotinib for 4 years, a man with advanced lung adenocarcinoma was treated with stereotactic radiotherapy for a left cerebellar brain metastasis. Local relapse of the metastasis was suspected 14 months after and confirmed on 18 F-DOPA PET. Three additional uptakes were described with no unequivocal MRI pathological signal. A second radiotherapy course was delivered. One year later, isolated local recurrence was suspected on a 3 T MRI, with a suspicious 18 F-DOPA uptake. Five additional 18 F-DOPA uptakes were described among which one increased between the 2 PETs. Because of these MRI/PET mismatches, a switch from erlotinib to osimertinib was preferred over surgery.

A national survey to assess the state of anatomy teaching in France across various disciplines and professions

PURPOSE

To investigate the current practices in anatomy teaching at French universities in 2023.

METHODS

On January 10, 2023, a questionnaire was sent to all members of the official list of the French Medical College of Professors of Anatomy. Each Anatomy centre was asked to complete this online form only once. The questionnaire covered several key themes, including broad questions, dissections practices, "virtual" dissections, teaching methods and teaching staff.

RESULTS

The questionnaire was completed by 26/28 anatomy centres. Access to body donor dissection is reported to be mandatory in 15 of the 26 centers (58%), optional in 10 centers (38%), and "tolerated" in one center (4%). Fifteen of 26 centers (58%) reported having a virtual dissection table for teaching anatomy. Concerning the teaching of anatomy via live ultrasound, 10 out of 26 centers (38%) reported providing it. Regarding the teaching methods used for medical students, chalk and board lectures are the most common method, although the intensity of use varies. Most lectures are given with chalk and board in 42% (11/26) of the centers. In about 73% (19/26) of the centers, tablet lectures are used. Regarding anatomy teachers, it was reported that in 24/26 anatomy centres (92%), more than 50% of the courses for medical students are taught by professors holding the chair of anatomy (21/26 professors (81%), 3/26 associate professors (12%)).

CONCLUSION

The present study endeavors to contribute to the existing body of knowledge on anatomy education by offering insights into the current practices in French universities.

Social cognition in adult survivors of brain tumors: studying the relationship between theory of mind and quality of life

OBJECTIVE

The present study is the first to examine theory of mind (ToM) sequelae in a sample of adult survivors of primary brain tumors, and to investigate the assumed relationship between ToM and health-related quality of life (HRQoL).

METHOD

Participants were 40 long-term adult survivors of primary brain tumors and 40 matched healthy controls. They completed ToM tests (Faux-Pas test and Advanced ToM task) and two questionnaires assessing HRQoL (36-Item Short-Form Health Survey and EORTC QLQ-C30/QLQ-BN20). Their relatives also completed an observer-rated version of the SF-36 questionnaire.

RESULTS

Survivors performed worse than controls only on the Advanced ToM task. Overall, patients and caregivers reported more problems than healthy controls and their relatives regarding both global HRQoL and its social/emotional aspects. No relationship was found between ToM and HRQoL scores.

CONCLUSION

Adult survivors of primary brain tumors may exhibit ToM deficits several years after treatment and report more problems on social/emotional HRQoL components. Our findings highlight the need to consider these late effects in survivors' long-term follow-up, even if the clinical involvement of ToM deficits still needs to be elucidated. The assessment of ToM deficits and their potential impact on survivors' everyday life is thoroughly discussed.

Cadaveric study of flexor digitorum profundus and superficialis and flexor pollicis longus innervation patterns for application in selective neurectomy

PURPOSE

Spasticity management in finger flexors (flexor digitorum profundus and superficialis and flexor pollicis longus) is a challenge. Recent studies demonstrated the short- and long-term efficacy of selective and hyperselective neurectomy for the spastic upper limb. However, hyperselective neurectomy of flexor digitorum profundus and flexor digitorum superficialis branches was incomplete, without impairing their muscular body and function. This cadaveric study describes a novel medial approach in the forearm, to reach all the muscular branches: flexor digitorum superficialis and profundus and flexor pollicis longus.

MATERIAL AND METHODS

Fourteen cadaveric fresh frozen upper limbs were used. The feasibility of the medial surgical approach was studied, as well as the number, length and point of emergence of the muscular branches from the median and ulnar nerves to the flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis.

RESULTS

The medial approach to the forearm gave access to all the muscular branches from the median and ulnar nerves to the flexor pollicis longus, flexor digitorum superficialis and flexor digitorum profundus, in all cases. A Martin Gruber communicating branch was found in 7 cases out of 14.

CONCLUSION

The medial approach to the forearm gave access to all the muscular branches from the median and ulnar nerve to the flexor pollicis longus, flexor digitorum superficialis and flexor digitorum profundus, without extensive transmuscular dissection of the pronator teres or flexor digitorum superficialis muscles. This approach opens the way for selective neurectomy of the flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis muscles.

LEVEL OF EVIDENCE

IV.

Associations between Adult Primary Brain Tumor Survivors' Behavioral Executive Functions, Health Related Quality of Life and their Caregivers' Health Related Quality : A cross-sectional study

The present study focused on adult primary brain tumor (PBT) survivors' caregivers. The main objective was to study associations between PBT survivors' health-related quality of life (HRQOL), their behavioral executive functions (EF) and their caregivers' HRQOL. Forty PBT survivors of PBT and 37 caregivers (mostly patient's spouses 81.08%; n = 30) participated in the study. PBT survivors completed a cancer related Quality of Life (QOL) questionnaire. Caregivers completed informant rated HRQOL and behavioral EF reports relating to PBT survivors and a self-rated HRQOL questionnaire relating to themselves. Correlational and multiple regression analyses were conducted. No associations were found between caregivers' physical HRQOL and PBT survivors' HRQOL nor behavioral EF. Analyses yielded several significant correlations between caregivers' mental HRQOL and variables pertaining to PBT survivors' HRQOL and behavioral EF. Multiple regression analyses showed that caregivers' mental HRQOL is predicted by PBT survivors' mental HRQOL, global cancer-related QOL scores and global behavioral EF scores. This study provides evidence suggesting that during the survivorship phase, at an average of 3.67 (SD = 2.31) years following treatment for a PBT, caregivers mental HRQOL is linked to PBT survivors' long-term effects. These findings shed some light regarding post-cancer care for both PBT survivors and their caregivers.

Assessment of using ultrasonography to teach abdominal and cervical anatomy in French medical curricula

PURPOSE

The objective of this work was to assess, in a quantitative and qualitative way, the teaching of cervical and abdominal anatomy via ultrasound for medical students.

METHODS

For several years, tutorials on the study of anatomy through use of ultrasound on the living organism have been given at the Medical School of Brest. These sessions have focused on cervical anatomy and abdominal anatomy. Students were invited to quantitatively assess these lessons by taking two tests containing questions on both cervical and abdominal anatomy and ultrasound technique: a pre-test administered at the beginning of the year and a post-test at the end of the year. In addition, a qualitative assessment was carried out at the end of the year. Ten statements were presented, and students were asked to indicate their agreement or disagreement to a four-point Likert scale.

RESULTS

One hundred and twelve students answered all the questions on the pre-test with an average of 13.4 correct answers out of 20. Forty-eight students answered all the questions on the post-test with an average of 14.6/20. Twenty-six students who benefited from the courses gave positive feedback about the workshops on the qualitative assessment at the end of the year (median scores >  = 3/4).

CONCLUSION

The results of this work suggest that the use of ultrasound makes a positive contribution to the teaching of anatomy. The students interviewed think this type of tutorial should be an integral part of the anatomy curriculum at our university. In addition, this type of instruction can serve to introduce the use of ultrasound itself in a practical learning setting.

A modular system for the synchronized multimodal data acquisition during Awake Surgery: towards the emergence of a dedicated clinical database

Awake Surgery (AS) is considered the best treatment for brain tumors located in or near eloquent areas. During this intervention, Direct Electrical Stimulations (DES) are delivered by the surgeon on the patient's brain in order to obtain an accurate brain mapping of the patient. The patient is asked to perform various tasks (e.g. counting, object naming, emotion recognition) through neuropsychological tests during these stimulations. These DES may cause a reversible lesion inducing deficits on the patient which can be observed during these tasks by the medical staff. The resection is then performed or not according to the patient's response. The intraoperative deficits can take several forms and can be difficult to analyze and identify. The development of new solutions allowing the automatic detection of these deficits could be therefore essential. However, still today, no structured and organized AS dedicated database is available that could be used to train and test these algorithms. We propose a modular system allowing the synchronized multimodal acquisition of various information including physiological measurements, DES signals and parameters, and task-related data to create such database.Clinical relevance- Acquiring synchronized multimodal data during AS will allow the creation of a dedicated database that could then be used to reveal new correlations between DES and the patient's response, and to develop and test new algorithms for the automatic detection of deficits.

Anatomic Study of the Integrity of the Breast Lymphatic Network With Indocyanine Green in Breast Implant Surgery Through the Axillary Approach

INTRODUCTION

The performance of a prosthetic breast augmentation through the axilla always makes the surgeon fear the possibility of damage to the breast lymphatic network. Indocyanine green is a fluorescent marker allowing the analysis of the lymphatic system. This anatomical work aims at demonstrating, thanks to the use of indocyanine green, whether the realization of a prosthetic breast augmentation by axillary way leads to lesions of the breast lymphatic network and also seeks to show the feasibility of detecting the axillary sentinel node after axillary breast augmentation.

MATERIAL AND METHOD

This is an anatomical study. After injection of indocyanine green in the periareolar area, a prosthetic breast augmentation was performed through the axilla. At the end of the procedure, a change in the distribution of indocyanine green in the skin or its abnormal presence was sought: at the level of the skin incision, the prosthetic space, or in contact with the prosthesis itself. The presence of green in these situations was synonymous with a lesion of the lymphatic network. In the opposite case, we considered that the lymphatic system was respected. After sampling, an axillary lymph node we also looked for the presence of indocyanine green at its contact.

RESULTS

We performed 22 breast injections. The lymphatic network could be demonstrated in 15 of them. Among these 15 injections, 12 (80%) were in favor of a preservation of the lymphatic network, whereas 3 (20%) evoked a lesion of the lymphatic network. In all subjects (100%), an axillary lymph node was found with the presence of indocyanine green within it.

CONCLUSION

Our study is in favor of a preservation of the lymphatic network during a prosthetic breast augmentation by axillary way. Furthermore, with the collection of an axillary lymph node containing the dye from each subject, this work demonstrates the feasibility of axillary sentinel node detection with indocyanine green after axillary breast augmentation. Further work on live subjects and on a larger number of subjects would be necessary to confirm these results.

Incidence and characteristics of pseudoprogression in IDH-mutant high-grade gliomas: A POLA network study

BACKGROUND

Incidence and characteristics of pseudoprogression in isocitrate dehydrogenase-mutant high-grade gliomas (IDHmt HGG) remain to be specifically described.

METHODS

We analyzed pseudoprogression characteristics and explored the possibility of pseudoprogression misdiagnosis in IDHmt HGG patients, treated with radiotherapy (RT) (with or without chemotherapy [CT]), included in the French POLA network. Pseudoprogression was analyzed in patients with MRI available for review (reference cohort, n = 200). Pseudoprogression misdiagnosis was estimated in this cohort and in an independent cohort (control cohort, n = 543) based on progression-free survival before and after first progression.

RESULTS

In the reference cohort, 38 patients (19%) presented a pseudoprogression after a median time of 10.5 months after RT. Pseudoprogression characteristics were similar across IDHmt HGG subtypes. In most patients, it consisted of the appearance of one or several infracentimetric, asymptomatic, contrast-enhanced lesions occurring within 2 years after RT. The only factor associated with pseudoprogression occurrence was adjuvant PCV CT. Among patients considered as having a first true progression, 7 out of 41 (17%) in the reference cohort and 35 out of 203 (17%) in the control cohort were retrospectively suspected to have a misdiagnosed pseudoprogression. Patients with a misdiagnosed pseudoprogression were characterized by a time to event and an outcome similar to that of patients with a pseudoprogression but presented with larger and more symptomatic lesions.

CONCLUSION

In patients with an IDHmt HGG, pseudoprogression occurs later than in IDH-wildtype glioblastomas and seems not only frequent but also frequently misdiagnosed. Within the first 2 years after RT, the possibility of a pseudoprogression should be carefully considered.

Natural Course and Prognosis of Primary Spinal Glioblastoma: A Nationwide Study

BACKGROUND AND OBJECTIVES

Primary spinal glioblastoma is extremely rare. The dramatic neurological deterioration and unresectability of primary spinal glioblastoma makes it a particularly disabling malignant neoplasm. Since it is a rare and heterogeneous disease, the assessment of prognostic factors remains limited.

METHODS

Primary spinal glioblastomas were identified from The French Brain Tumor Database and the Club de Neuro-Oncologie of the Société Française de Neurochirurgie retrospectively. Inclusion criteria were age ≥ 18 years at diagnosis, spinal location, histopathological diagnosis of newly glioblastoma according to the 2016 World Health Organization classification, and surgical management between 2004 and 2016. Diagnosis was confirmed by a centralized neuropathological review. The primary outcome was overall survival. Therapeutic interventions and neurological outcomes were also collected.

RESULTS

Thirty-three patients with an histopathologically confirmed primary spinal glioblastoma (median age 50.9 years) were included (27 centers). The median overall survival (OS) was 13.1 months (range 2.5-23.7) and the median progression-free survival was 5.9 months (range 1.6-10.2). In multivariable analyses using Cox model, ECOG PS at 0-1 was the only independent predictor of longer OS [Hazard Ratio: 0.13, 95%CI 0.02-0.801; p=0.02], whereas a Karnofsky PS score <60 [Hazard Ratio: 2.89, 95%CI 1.05-7.92; p=0.03] and a cervical anatomical location [Hazard Ratio: 4.14, 95%CI 1.32-12.98; p=0.01] were independent predictors of shorter OS. The ambulatory status (Frankel D-E) [Hazard Ratio: 0.38, 95%CI 0.07-1.985; p=0.250] was not an independent prognostic factor while the concomitant standard radiochemotherapy with temozolomide (Stupp protocol) [Hazard Ratio: 0.35, 95%CI 0.118-1.05; p=0.06] was at the limit of significance.

DISCUSSION

Preoperative ECOG PS, Karnofsky PS score and the location are independent predictors of overall survival of primary spinal glioblastomas in adults. Further analyses are required to capture the survival benefit of concomitant standard radiochemotherapy with temozolomide.

Feasibility of the abductor pollicis longus hemitendon transfer for thumb opposition: An anatomical study

INTRODUCTION

The abductor pollicis longus (APL) presents two muscle bellies and multiple accessory tendons available for transfer, amongst these an accessory tendon inserting on the thenar aponeurosis (APLTh). Edgerton described an opponensplasty using the whole APL tendon, but its results were limited due to the short size of the donor tendon.

HYPOTHESIS

The purpose of this study is to assess the feasibility of transferring the APLTh for thumb opposition.

MATERIAL AND METHODS

Eleven cadaver upper limbs were dissected to assess the presence of the two heads of the APL as well as their main and accessory tendon insertions. The accessory tendon of the APL inserting on the thenar aponeurosis (APLTh) was harvested with a slip of the thenar aponeurosis. The length of the transplant, the number of tendon slips and their location, as well as pre and postoperative radial and palmar abduction provided by the APL were assessed.

RESULTS

The APL was present in all cadavers whereas its insertion on the thenar aponeurosis was absent in 18% of the cases. When the APLTh was present and could be used for opponensplasty, the mean gain in palmar abduction was 16 degrees, and the mean loss in radial abduction was 21 degrees.

DISCUSSION

Although the experiments revealed a variability in APL anatomy, when present, the APLTh represents a suitable donor for the restoration of thumb opposition. In some cases of high median nerve palsies, thumb opposition can't be restored using median innervated muscles. In these cases, when the APLTh is present, it can be used to restore thumb opposition without functional loss.

LEVEL OF EVIDENCE

IV; anatomical feasibility study.

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.

Relationships between executive functioning and health-related quality of life in adult survivors of brain tumor and matched healthy controls

INTRODUCTION

Few studies have considered health-related quality of life (HRQOL) as a primary outcome measure in adult survivors of primary brain tumor (PBT), and fewer still have studied the cognitive factors that may influence it. Research suggests that executive functions (EFs) are associated with HRQOL, but there is scant evidence to support this. The present study was conducted to (1) extend prior findings about HRQOL limitations in a sample of stable, long-term adult survivors of PBT, (2) investigate the associations between objective/reported EFs and HRQOL, and (3) identify the EFs that contribute most to HRQOL.

METHOD

We recruited 40 survivors of PBT (> 2 years post-treatment) and 40 matched healthy controls. Participants completed an objective EF assessment (inhibition, working memory, shifting, and rule detection) and two self-report questionnaires probing EFs (Behavior Rating Inventory of Executive Function-Adult) and HRQOL (Medical Outcomes Study Short-Form 36). Participants' relatives completed observer-rated versions of these questionnaires.

RESULTS

Patients' objective EF performances were relatively intact. However, patients and caregivers reported significantly more problems than healthy controls and their relatives, for both EFs and HRQOL. There were only negligible links between objective EFs and HRQOL, whereas numerous associations were found between reported EFs and HRQOL components. ANCOVA models revealed that specific reported EF processes contributed to both the physical and mental components of HRQOL, regardless of group.

CONCLUSIONS

From a clinical point of view, this study demonstrates that even several years after end of treatment, adult PBT survivors experience substantial problems across different HRQOL domains. HRQOL assessment should therefore be part of the long-term follow-up of PBT survivors, and clinicians should consider EF limitations when designing appropriate survivorship care plans. These findings indicate that cognitive interventions targeting EFs could improve HRQOL.

NCOG-09. PREDICTIVE GERIATRIC FACTORS IN ELDERLY PATIENTS TREATED FOR IDH-MUTANT HIGH-GRADE GLIOMAS: A FRENCH POLA NETWORK STUDY

We aimed to describe the characteristics, patterns of care and predictive geriatric factors of elderly patients with IDH-mutant (IDHm) high-grade gliomas (HGG) included in the French POLA network, dedicated to HGG (including 68% of IDHm HGG). For IDHm HGG patients over the age of 70 years, geriatric features were collected: G8 score items (appetite, weight loss, mobility, neuropsychological disorders, body mass index, medications, self-rated health, age), Activities and Instrumental Activities of Daily Living (ADL, IADL) scores, Charlson’s comorbidity Index (CCI) and biological markers. Out of the 1433 HGG patients included in the POLA Network, 119 (8.3%) occurred in patients ≥ 70 years. Among them, 39 presented with IDHm HGG. Of these 39 patients, estimated G8 score was ≤ 14/17 for 16 patients (64%), ADL score was &lt; 6 for 33.3%, IADL score was &lt; 4 for 47% and CCI was ≥ 5 for 72%. Regarding treatment feasibility, 6 of the 19 patients treated by temozolomide prematurely discontinued chemotherapy including 2 for toxicity and 4 for progression. Five of the 10 patients treated by PCV prematurely discontinued chemotherapy, all for toxicity. In multivariate analysis, loss of mobility (p=0.018; p=0.008), severe neuropsychological disorders (p=0.005; p=0.047), body mass index &lt; 21 kg/m2 (p=0.002; p=0.006) and ADL score &lt; 6 (p=0.002; p=0.01) were significantly predictive of poor PFS and OS. Then we generated a specific brain geriatric score including these four items with a sensibility, specificity and AUC for long term survivor (≥ 48 months) of 100%, 83% and 0.948 respectively. Using a cutoff of &lt; 10/13, this score was significantly correlated to PFS and OS (p&lt; 0.001 both). In conclusion, geriatric predictive factors may contribute to the elderly management improvement: the brain geriatric score must now be validated in a prospective independent cohort including IDHm and IDHwt elderly patients.

What is the role of neurosurgeons in the current management of intracranial aneurysm in France? An analysis of professional practices

STUDY DESIGN

Retrospective observational survey-based study.

INTRODUCTION

In France, intracranial aneurysm (IA) patients are managed by neurosurgeons and by interventional neuroradiologists. The growth of endovascular treatment led us to reflect on the role of neurosurgeons in the management of patients with IA. The present study aimed to highlight the current organization of IA management in France.

METHOD

A 60-question survey was sent to the neurosurgeons in 34 hospitals managing IA patients. Thirty-three questions dealt with standards of care, follow-up procedures and the involvement of the specific specialist.

RESULTS

Twenty-seven centers (79.4%) responded to the survey. A Vascular Multidisciplinary Discussion Team was organized, including both surgeons and neuroradiologists, in 92% of responding centers. There were department protocols in 66% of centers, a local registry in 33% and clinical trials in IA in 60%. Patients with unruptured IA were first seen by a neurosurgeon or by an interventional neuroradiologist, with different practices. For ruptured IA, the neurosurgeons were contacted first in 93% of cases, and were systematically involved in initial intensive care unit management. The patients were hospitalized in the neurosurgery department in 89% of the centers. The neurosurgeons took care of initial follow-up in 85% of the centers, and of lifetime follow-up in 36%. In most centers, radiological monitoring of IA was based on MRI angiography for patients who were embolized or under surveillance, and on CT angiography after microsurgery.

CONCLUSION

Despite the growth of endovascular treatments, the present survey and the literature highlight a major role of neurosurgeons in treatment, follow-up and care coordination.

Characteristics of IDH-mutant gliomas with non-canonical IDH mutation

BACKGROUND

Approximately 10% of IDH-mutant gliomas harbour non-canonical IDH mutations (non-p.R132H IDH1 and IDH2 mutations).

OBJECTIVE

The aim of this study was to analyse the characteristics of non-canonical IDH-mutant gliomas.

MATERIALS AND METHODS

We retrospectively analysed the characteristics of 166 patients with non-canonical IDH mutant gliomas and compared them to those of 155 consecutive patients with IDH1 p.R132H mutant gliomas.

RESULTS

The median age at diagnosis was 38 years in patients with non-canonical IDH mutant gliomas and 43 years in glioma patients with IDH1 p.R132H-mutant tumours. Family history of cancer was more frequent among glioma patients harbouring non-canonical IDH mutations than in patients with IDH1 p.R132H mutations (22.2% vs 5.1%; P < 0.05). Tumours were predominantly localised in the frontal lobe regardless of the type of IDH mutation. Compared to IDH1 p.R132H-mutant gliomas, tumours with non-canonical IDH mutations were more frequently found in the infratentorial region (5.5% vs 0%; P < 0.05) and were often multicentric (4.8% vs 0.9%; P < 0.05). Compared to IDH1 P.R132H-mutant gliomas, tumours with non-canonical IDH1 mutations were more frequently astrocytomas (65.6% vs 43%, P < 0.05), while those with IDH2 mutations were more frequently oligodendrogliomas (85% vs 48.3%; P < 0.05). The median overall survival was similar in patients with IDH1 p.R132H-mutant gliomas and patients with non-canonical IDH-mutant gliomas.

CONCLUSION

Gliomas with non-canonical IDH mutations have distinct radiological and histological characteristics. The presence of such tumours seems to be associated with genetic predisposition to cancer development.

Patient-reported functional executive challenges and caregiver confirmation in adult brain tumor survivors

PURPOSE

The main objective of this study was to provide further information concerning the validity of patient-reported executive function (EF) in survivors of primary brain tumor (PBT) compared with a report provided by each patient's caregiver.

METHODS

Forty survivors of PBT, 40 non-cancer controls and their proxies completed an assessment of functional executive disorders (e.g., planning, inhibition, shifting, action initiation). Comparisons of self and informant EF reports were examined, for both patients and non-cancer controls. The extent of the concordance between patients' reports and their caregivers' reports was also determined.

RESULTS

PBT survivors and their caregivers reported more problems related to EF in contrast with the non-cancer comparison group (significant differences). There was a high level of agreement between patients' and caregivers' ratings within the patient group.

CONCLUSIONS

This study provides evidence suggesting that at an average of 3.67 (SD = 2.31) years following treatment for a PBT, EF difficulties are reported by patients and their caregivers. This study establishes a consistency between what is reported by survivors and what is reported by those who frequently interact with them. Further research investigating the link between these ratings and quality of life as well as other functions is encouraged.

IMPLICATIONS FOR CANCER SURVIVORS

This study's results demonstrate the importance of listening to PBT survivors' perception of EF difficulties. While not confirmed by neuropsychological evaluations, the functional executive challenges reported by these survivors' close relatives reflect what PBT survivors themselves report. Specialists should pay close attention to these difficulties to guarantee optimal post-cancer care.

Surgical Site Infections after glioblastoma surgery: results of a multicentric retrospective study

BACKGROUND

The effects of surgical site infections (SSI) after glioblastoma surgery on patient outcomes are understudied. The aim of this retrospective multicenter study was to evaluate the impact of SSI on the survival of glioblastoma patients.

METHODS

Data from SSI cases after glioblastoma surgeries between 2009 and 2016 were collected from 14 French neurosurgical centers. Collected data included patient demographics, previous medical history, risk factors, details of the surgical procedure, radiotherapy/chemotherapy, infection characteristics, and infection management. Similar data were collected from gender- and age-paired control individuals.

RESULTS

We used the medical records of 77 SSI patients and 58 control individuals. 13 were excluded. Our analyses included data from 64 SSI cases and 58 non-infected glioblastoma patients. Infections occurred after surgery for primary tumors in 38 cases (group I) and after surgery for a recurrent tumor in 26 cases (group II). Median survival was 381, 633, and 547 days in patients of group I, group II, and the control group, respectively. Patients in group I had significantly shorter survival compared to the other two groups (p < 0.05). The one-year survival rate of patients who developed infections after surgery for primary tumors was 50%. Additionally, we found that SSIs led to postoperative treatment discontinuation in 30% of the patients.

DISCUSSION

Our findings highlighted the severity of SSIs after glioblastoma surgery, as they significantly affect patient survival. The establishment of preventive measures, as well as guidelines for the management of SSIs, is of high clinical importance.

Radiotherapy target volume definition in newly diagnosed high grade glioma using 18F-FET PET imaging and multiparametric perfusion MRI: A prospective study (IMAGG)

PURPOSE

The aim of this study was to prospectively investigate tumor volume delineation by amino acid PET and multiparametric perfusion magnetic resonance imaging (MRI) in patients with newly diagnosed, untreated high grade glioma (HGG).

MATERIALS AND METHODS

Thirty patients with histologically confirmed HGG underwent O-(2-[¹⁸F]-fluoroethyl)-l-tyrosine (¹⁸F-FET) positron emission tomography (PET), conventional Magnetic Resonance Imaging (MRI) as contrast-enhanced (CE) and fluid-attenuated inversion recovery (FLAIR) and multiparametric MRI as relative cerebral blood volume (rCBV) and permeability estimation map (K2). Areas of MRI volumes were semi-automatically segmented. The percentage overlap volumes, Dice and Jaccard spatial similarity coefficients (OV, DSC, JSC) were calculated.

RESULTS

The ¹⁸F-FET tumor volume was significantly larger than the CE volume (median 43.5 mL (2.5-124.9) vs. 23.8 mL (1.4-80.3), p = 0.005). The OV between ¹⁸F-FET uptake and CE volume was low (median OV 0.59 (0.10-1)), as well as spatial similarity (median DSC 0.52 (0.07-0.78); median JSC 0.35 (0.03-0.64)). Twenty-five patients demonstrated both rCBV and CE on MRI: The median rCBV tumor volume was significantly smaller than the median CE volume (p < 0.001). The OV was high (median 0.83 (0.54-1)), but the spatial similarity was low (median DSC 0.45 (0.04-0.83); median JSC 0.29 (0.07-0.71)). Twenty-eight patients demonstrated both K2 and CE on MRI. The median K2 tumor volume was not significantly larger than the median CE volume. The OV was high (median OV 0.90 (0.61-1)), and the spatial similarity was moderate (median DSC 0.75 (0.01-0.83); median JSC 0.60 (0.11-0.89)).

CONCLUSION

We demonstrated that multiparametric perfusion MRI volumes (rCBV, K2) were highly correlated with CE T1 gadolinium volumes whereas ¹⁸F-FET PET provided complementary information, suggesting that the metabolically active tumor volume in patients with newly diagnosed untreated HGG is critically underestimated by contrast enhanced MRI. ¹⁸F-FET PET imaging may help to improve target volume delineation accuracy for radiotherapy planning.

P04.12 Characteristics of IDH-mutant gliomas with non-canonical IDH mutations

BACKGROUND

About 10% of IDH-mutant gliomas harbor non-canonical IDH mutations (non-R132H IDH1 and IDH2 mutations). The aim of the present study was to analyze the characteristics of these gliomas in comparison to those of IDH1 R132H mutant gliomas.

MATERIAL AND METHODS

We retrospectively analyzed the characteristics of a multicentric series of 161 gliomas with non-canonical IDH mutations and compared them to those of consecutive series of 109 IDH1 R132H mutant gliomas. Medical, radiological and pathological were reviewed.

RESULTS

Median age at diagnosis was 35 years in gliomas with a non-canonical IDH1 mutation, 42 years in those with an IDH2 mutation and 44 years in those with an IDH1R132H mutation. A familial history of cancer was more frequent in gliomas with a non-canonical IDH mutation than in those with an IDH1 R132H mutation (22,3% vs 5,5%, p<0.05). In both IDH1 R132H-mutant and non-canonical IDH-mutant gliomas the most frequent location was the frontal lobe. Yet, compared to IDH1R132H-mutant gliomas those with a non-canonical IDH mutation had more frequently an infratentorial location (5,5% vs 0% p<0,05) and were more frequently multicentric (4,9%, versus 0.9%, p<0.05). Compared to IDH1R132H-mutant gliomas, gliomas with a non-canonical IDH1 mutation were more frequently astrocytomas (65.7% vs 45%, p<0.05) while those with an IDH2 mutation were more frequently oligodendrogliomas (82% vs 55%, p<0.05). The median overall survival in IDH1 R132H-mutant and non-canonical IDH-mutant gliomas was similar (122 versus 120 months).

CONCLUSION

Gliomas with non-canonical IDH mutations are associated with distinct clinical, radiological and histological characteristics. Their prognosis, however, is similar to that of gliomas with canonical IDH mutations.

[Meningeal melanoma arising from a preexisting meningeal melanocytoma: A clinical, pathological and cytogenetic study about one case]

Meningeal melanocytic tumors are rare. We report an exceptional case of transformation of a meningeal melanocytoma in a malignant melanoma. The course of the disease extents from 61-years to 85-years and ends with the death of the patient. Besides histopathological and immunohistochemical data, we also report the array CGH study of the melanocytoma and melanoma components suggesting the malignant transformation from whole chromosome gains in the melanocytoma to additional segmental aberrations in the malignant melanoma. Beyond the rarity of this tumor subtype, this case report highlights the potential interest of molecular analyses for diagnostic and prognostic purposes in the field of meningeal melanocytic tumors.

The molecular landscape of glioma in patients with Neurofibromatosis 1

Neurofibromatosis type 1 (NF1) is a common tumor predisposition syndrome in which glioma is one of the prevalent tumors. Gliomagenesis in NF1 results in a heterogeneous spectrum of low- to high-grade neoplasms occurring during the entire lifespan of patients. The pattern of genetic and epigenetic alterations of glioma that develops in NF1 patients and the similarities with sporadic glioma remain unknown. Here, we present the molecular landscape of low- and high-grade gliomas in patients affected by NF1 (NF1-glioma). We found that the predisposing germline mutation of the NF1 gene was frequently converted to homozygosity and the somatic mutational load of NF1-glioma was influenced by age and grade. High-grade tumors harbored genetic alterations of TP53 and CDKN2A, frequent mutations of ATRX associated with Alternative Lengthening of Telomere, and were enriched in genetic alterations of transcription/chromatin regulation and PI3 kinase pathways. Low-grade tumors exhibited fewer mutations that were over-represented in genes of the MAP kinase pathway. Approximately 50% of low-grade NF1-gliomas displayed an immune signature, T lymphocyte infiltrates, and increased neo-antigen load. DNA methylation assigned NF1-glioma to LGm6, a poorly defined Isocitrate Dehydrogenase 1 wild-type subgroup enriched with ATRX mutations. Thus, the profiling of NF1-glioma defined a distinct landscape that recapitulates a subset of sporadic tumors.

Three-Dimensional Endoscopic Magnification for Treatment of Thoracic Spinal Dural Arteriovenous Fistulas: Technical Note

BACKGROUND

Treatment of thoracic spinal dural arteriovenous fistulas (DAVFs) by microsurgery has recently been approached using minimally invasive spine surgery (MISS). The advantages of such an approach are offset by difficult maneuverability within the tubular retractor and by the creation of "tunnel vision" with reduced luminosity to a remote surgical target.

OBJECTIVE

To demonstrate how the pitfalls of MISS can be addressed by applying 3-D endoscopy to the minimally invasive approach of spinal DAVFs.

METHODS

We present 2 cases of symptomatic thoracic DAVFs that were not amenable to endovascular treatment. The DAVFs were excluded solely via a minimally invasive approach using a 3-D endoscope.

RESULTS

Two patients underwent exclusion of a DAVF following laminotomy, one through a midline 5-cm incision and the other through a paramedian 3-cm incision using minimally invasive nonexpandable tubular retractors. The dura opening, intradural exploration, fistula exclusion, and closure were performed solely under endoscopic 3-D magnification. No incidents were recorded and the postoperative course was marked by clinical improvement. Postoperative imaging confirmed the exclusion of the DAVFs. Anatomical details are exposed using intraoperative videos.

CONCLUSION

When approaching DAVFs via MISS, replacing the microscope with the endoscope remedies the limitations related to the "tunnel vision" created by the tubular retractor, but at the expense of losing binocular vision. We show that the 3-D endoscope resolves this latter limitation and provides an interesting option for the exclusion of spinal DAVFs.

Diagnosis Disclosure Process in Patients With Malignant Brain Tumors

BACKGROUND

The way to disclose a cancer diagnosis has evolved, and psycho-oncology has developed a more prominent place in cancer care. The diagnosis disclosure process was established to improve the overall quality of patient care and the communication about a cancer diagnosis.

OBJECTIVES

The aim of this study was to assess the implementation of the disclosure process in a neurosurgical unit.

METHODS

This study was conducted prospectively during a one-year period. All patients were diagnosed with malignant brain tumors and received their diagnosis using the disclosure process. The communication between the provider and the patient during diagnosis disclosure was recorded for analysis, and patients completed a satisfaction survey.

FINDINGS

Ninety-one patients with a brain tumor diagnosis participated in the study. Twenty-six were unable to complete the satisfaction survey because they were either deceased or close to the end of their lives. In total, 65 questionnaires were sent to patients and their families, and 43 responded. Patients were satisfied with the quality of the disclosure process regarding information given, psychological support, and communication with all healthcare providers. This assessment allowed the authors to better characterize the impact of the disclosure process on the overall care of patients and to measure the effect of the components of the disclosure process on patient satisfaction.

Oculomotor Nerve Palsy Complicates Third Ventricle Colloid Cyst Endoscopic Removal: Case Report

BACKGROUND

A colloid cyst is a rare benign tumor. If indicated, surgical treatment can be realized using a microsurgical technique or an endoscopic technique. We report an uncommon complication of a third ventricle colloid cyst endoscopic removal.

CASE DESCRIPTION

The cyst was incidentally discovered on computed tomography scan workup for mild head trauma in a 20-year-old male. Minor headache and minor memory loss were noted on clinical examination. Magnetic resonance imaging workup revealed obstructive hydrocephaly of the lateral ventricles associated with left uncal herniation. Surgery was uneventful. However, left oculomotor palsy was noted postoperatively. Workup revealed oculomotor nerve injury and isolated left mammillary body ischemia, secondary to worsened uncal herniation. This worsening might be caused by acute left ventricle hydrocephaly ascribed to interventricular foramen obstruction during cyst removal.

CONCLUSION

Therefore, in similar presentation, realizing septum fenestration before cyst removal should relieve the pressure in the lateral ventricles thus decreasing the risk of herniation.

[Impact of driving restrictions disclosure on quality of life of patients with a glial tumor: A prospective study]

INTRODUCTION

Disclosure of driving restrictions on patients with glial tumors is a complex and difficult task. The difficulty of such task lies in the moral and ethical conflicts it generates for the patient on one hand and caregivers on the other. These aforementioned conflicts impinge upon the patient's quality of life which is one of the important aspects of neuro-oncologic care.

PATIENTS AND METHOD

In a prospective survey of 31 patients diagnosed with glial tumors, we studied how the patient perceived the disclosure of driving restrictions specifically the amount of retained information, and the level of distress.

RESULTS

It seems that patients fail to assess the juridical implications of driving restrictions. The impact on quality of life as well as psychological and social aspects of these restrictions must not be taken lightly especially in young patients with low-grade glioma who has a long life expectancy.

CONCLUSION

Therefore, we believe that planning a specific psychological and social accompaniment of the patient in relation to driving restrictions is an undeniable necessity.

Interactive anatomical teaching: Integrating radiological anatomy within topographic anatomy

INTRODUCTION

Hours attributed to teaching anatomy have been reduced in medical curricula through out the world. In consequence, changes in anatomical curriculum as well as in teaching methods are becoming necessary. New methods of teaching are being evaluated. We present in the following paper an example of interactive anatomical teaching associating topographic anatomy with ultrasonographic radiological anatomy. The aim was to explicitly show anatomical structures of the knee and the ankle through dissection and ultrasonography.

METHODS

One cadaver was used as an ultrasonographic model and the other was dissected. Anatomy of the knee and ankle articulations was studied through dissection and ultrasonography.

RESULTS

The students were able to simultaneously assimilate both anatomical aspects of radiological and topographic anatomy. They found the teaching very helpful and practical.

CONCLUSION

This body of work provides example of a teaching method combining two important aspects of anatomy to help the students understand both aspects simultaneously.

Anastomosis Between the Ascending Pharyngeal Artery and the Posterior Inferior Cerebellar Artery Through the Jugular Foramen

BACKGROUND

The ascending pharyngeal artery (APA) may, in very rare cases, supply the posterior inferior cerebellar artery (PICA). In reported cases, when such is the case, the ipsilateral vertebral artery (VA) does not supply the PICA, and most of the time it is hypoplastic.

OBJECTIVE

To describe a unique cadaveric observation of a direct anastomosis between the posterior division (neuromeningeal) of the jugular branch of the APA and the PICA, where the PICA is also supplied by a normal-size VA.

METHODS

A direct connection between the APA and the PICA was examined in a cadaveric specimen using a 3-dimensional endoscope and a surgical microscope.

RESULTS

The enlarged jugular branch of the posterior division of the APA entered intracranially via the jugular foramen in its pars vascularis. It then connected directly with the lateral medullary segment of the PICA. The first segment of the PICA originated from a left vertebral artery of normal size and continued its normal course beyond the junction with the jugular branch of the APA.

CONCLUSION

Both the VA and the jugular branch of the APA may simultaneously supply the PICA territory. Recognition of this anatomic variant is relevant when planning surgical or endovascular treatments.

Spreading of multiple Listeria monocytogenes abscesses via central nervous system fiber tracts: case report

Animal studies have shown that Listeria monocytogenes can probably access the brain through a peripheral intraneural route, and it has been suggested that a similar process may occur in humans. However, thus far, its spreading through the central nervous system (CNS) has not been completely elucidated. The authors present a case of multiple L. monocytogenes cerebral abscesses characterized by a pattern of distribution that suggested spread along white matter fiber tracts and reviewed the literature to identify other cases for analysis. They elected to include only those cases with 3 or more cerebral abscesses to make sure that the distribution was not random, but rather followed a pattern. In addition, they included those cases with abscesses in both the brainstem and the cerebral hemispheres, but excluded cases in which abscesses were located solely in the brainstem. Of 77 cases of L. monocytogenes CNS abscesses found in the literature, 17 involved multiple abscesses. Of those, 6 were excluded for lack of imaging and 3 because they involved only the brainstem. Of the 8 remaining cases from the literature, one was a case of bilateral abscesses that did not follow a fiber tract; another was also bilateral, but with lesions appearing to follow fiber tracts on one side; and in the remaining 6, to which the authors added their own case for a total of 7, all the abscesses were located exclusively in the same hemisphere and distributed along white matter fiber tracts. The findings suggest that after entering the CNS, L. monocytogenes travels within the axons, resulting in a characteristic pattern of distribution of multiple abscesses along the white matter fiber tracts in the brain. This report is the first description suggesting intraaxonal CNS spread of L. monocytogenes infection in humans following its entry into the brain. This distinct pattern is clearly seen on imaging and its recognition may be valuable in the diagnosis of listeriosis. This finding may allow for earlier diagnosis, which may improve outcome.

Could ventriculoperitoneal shunt and tracheotomy procedures be realized in the same surgical time?

BACKGROUND

Both tracheotomy and ventriculoperitoneal shunting procedures may be required for the same critically ill patient. However, the risk of surgical site infection (SSI) may be increased if both procedures are performed simultaneously.

METHOD

We performed a retrospective analysis of 41 consecutive patients who underwent both procedures simultaneously in our institution between March 2000 and January 2008.

RESULTS

Analysis revealed no difference in SSI rate between patients undergoing both procedures simultaneously and in staged procedures.

CONCLUSIONS

VP shunting and tracheotomy procedures could be performed simultaneously without increasing the risk of surgical site infection. Such strategy may shorten the length of stay in critical care units.

Venous organization in the transverse foramen: dissection, histology, and magnetic resonance imaging

OBJECT

The anatomical arrangement of the venous system within the transverse foramen is controversial; there is disagreement whether the anatomy consists of a single vertebral vein or a confluence of venous plexus. Precise knowledge of this arrangement is necessary in imaging when vertebral artery dissection is suspected, as well as in surgical approaches for the cervical spine. This study aimed to better explain anatomical organization of the venous system within the transverse foramen according to the Trolard hypothesis of a transverse vertebral sinus.

METHODS

This was an anatomical and radiological study. For the anatomical study, 10 specimens were analyzed after vascular injection. After dissection, histological cuts were prepared. For the radiological study, a high-resolution MRI study with 2D time-of-flight segment MR venography sequences was performed on 10 healthy volunteers.

RESULTS

Vertebral veins are arranged in a plexiform manner within the transverse canal. This arrangement begins at the upper part of the transverse canal before the vertebral vein turns into a single vein along with the vertebral artery running from the transverse foramen of the C-6. This venous system runs somewhat ventrolaterally to the vertebral artery. In most cases, this arrangement is symmetrical and facilitates radiological readings. The anastomoses between vertebral veins and ventral longitudinal veins are uniform and arranged segmentally at each vertebra.

CONCLUSIONS

These findings confirm recent or previous anatomical descriptions and invalidate others. It is hard to come up with a common description of the arrangement of vertebral veins. The authors suggest providing clinicians as well as anatomists with a well-detailed description of components essential to the understanding of this organization.

[The nurse's role in the disclosure of a brain tumor]

The announcement of a brain tumour, in particular glioblastoma, is a psychological shock for the patient and their family. A review has been carried out into this subject by a team of nurses sharing their work time between the neurosurgical department and the disclosure process unit.

Comparison of injection/dissection and injection/corrosion methods: example of vertebral veins in the transverse canal

PURPOSE

In order to contribute some new elements to the discussion on the organization of the vertebral veins inside the transverse canal, we compared two dissection techniques: injection/dissection and injection/corrosion. The aim of this study was to compare these two techniques to study the vertebral veins, and also to emphasize the importance of preserving specimens in anatomical museums.

METHODS

Using the injection/dissection technique, latex was injected into ten specimens, then the transverse canal was opened to expose the vertebral veins and their anastomoses. Using the injection/corrosion technique, altufix was injected into eight specimens that were afterwards plunged in sulfuric acid and washed daily until complete corrosion was obtained.

RESULTS

Both techniques showed concordant results. The vertebral veins were plexuous, located ventro-laterally to the artery and received constant metamerical branches at each level. The injection/dissection technique conserved the anatomical relationships allowing metamerical analysis of the vertebral veins. The injection/corrosion technique, however, failed to conserve these relationships but provided a precise visualization of smaller anastomosis.

CONCLUSIONS

By analyzing different aspects of the vertebral veins anatomy in the transverse canal, the two techniques complete each other. This study emphasizes the importance of preserving the anatomical preparations: in addition to the historical and cultural value of these preparations, they contain precious information that furthers our anatomical knowledge.

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).

[Head injuries in infants and children]

Head injuries in children are frequent reasons for visits to emergency departments. Depending on age, the causes are different: falls for younger infants and accidents for older children. Those treating children, especially in cases of serious injury, must be aware of the specificities of paediatric anatomy and physiology. As with adults, the initial assessment and surveillance help to prevent the condition from worsening.

[Care of the tracheostomy in brain injury patients]

The evolution of a patient suffering from a serious head injury can require the placement of a tracheotomy. This helps with respirator weaning and usually enables the patient to be moved from the neurosurgical intensive care ward to the neurosurgery ward. Patients fitted with a tracheotomy will therefore be cared for by post-intensive care neurological rehabilitation departments.

[Head trauma, anatomy and physiopathology, clinical and paraclinical diagnoses]

The brain, situated in the skull, can suffer a trauma through direct or indirect shocks. Primary and secondary lesions determine the evolution of the trauma. The initial clinical assessment and repeated clinical examinations are the basis of the monitoring. The diagnosis of any head lesion is made by CT-scan. A head injury must always be considered to be associated with other lesions until there is evidence to the contrary.

[Epidemiology of traumatic head injuries]

Head injuries are a major public health problem the incidence of which is difficult to compare across the world. Accidents on the public highway, falls and assaults are the most frequent etiologies. The financial and social cost is significant and underestimated.