Parietal network underlying movement control: disturbances during subcortical electrostimulation

Our understanding of brain movement control has changed over the last two decades. Recent findings in the monkey and in humans have led to a parallel and interconnected network. Nevertheless, little is known about these networks. Here, we present two cases of patients with a parietal low-grade glioma. They underwent surgery under local anesthesia with cortical and subcortical mapping. For patient 1, subcortical electrostimulation immediately posterior to thalamocortical fibers induced movement disorders, with an inhibition of leg and arm movements medially and, more laterally, an acceleration of arm movement. For patient 2, electrostimulation of white matter immediately posterior to thalamocortical fibers induced an inhibition of both arm movement. It means that the detected fibers in the parietal lobe may be involved in the motor control modulation. They are distributed veil-like immediately posterior to thalamocortical pathways and could correspond to a fronto-parietal movement control subnetwork. These two cases highlight the major role of the subcortical connectivity in movement regulation, involving parietal lobe, thus the necessity to be identified and preserved during brain surgery.     

Oncological patterns of care and outcomes for 265 elderly patients with newly diagnosed glioblastoma in France

The incidence of glioblastoma (GBM) has increased in patients aged 70 years or older, and will continue to grow. Elderly GBM patients have been excluded from most clinical trials; furthermore, optimal care management as well as benefit/risk ratio of GBM treatments are still being debated. This study describes oncological patterns of care, prognostic factors, and survival for patients ≥70 years in France. We identified patients over 70 with newly diagnosed and histologically confirmed GBM on data previously published by the French Brain Tumor DataBase. We included 265 patients. Neurological deficits and mental status disorders were the most frequent symptoms. The surgery consisted of resection (RS _n?=?95) or biopsy (B _n?=?170); 98 patients did not have subsequent oncological treatment. After surgery, first-line treatment consisted of radiotherapy (RT _n?=?76), chemotherapy (CT _n?=?52), and concomitant radiochemotherapy (CRC _n?=?39). The median age at diagnosis was 76, 74, and 73 years, respectively, for the untreated, B?+?RT and/or CT, RS?±?RT and/or CT groups. Median survival (in days, 95 % CI) with these main strategies, when analyzed according to surgical groups, was: B-CT _n?=?41, 199_[155–280]; B-CRC _n?=?21, 318_[166–480]; B-RT _n?=?37, 149_[130–214]; RS-CT _n?=?11, 245_[211–na]; RS-CRC _n?=?18, 372_[349–593]; RS-RT _n?=?39, 269_[218–343]. This population study for elderly GBM patients is one of the most important in Europe, and could be considered as a historical cohort to compare future treatments. Moreover, we can hypothesize that elderly patients (versus patients <70 years) are undertreated. Karnofsky performance status seems to be the most relevant clinical predictive factor, and RS and CRC have a positive impact on survival for elderly GBM patients in the general population, at least when feasible.     

Early neurological recovery course after surgical treatment of cervical spondylotic myelopathy: a prospective study with 2-year follow-up using three different functional assessment tests

Purpose

Though surgical decompression is today a common option for treatment of cervical spondylotic myelopathy (CSM), little is known about the exact postoperative early neurological recovery course. The purpose of this study was to analyze the functional recovery, its dynamics, its intensity and its pattern, in the early postoperative period after surgical decompression for CSM.

Methods

A prospective non-controlled observational study was performed from March 2006 to July 2008, and included consecutive patients with CSM who underwent surgical decompression. Functional assessments were done before the operation, at 1 month, 6, 12, 18 and 24 months after surgery using three tests: the Japanese Orthopaedic Association (JOA) test, the nine-hole peg test (9HPT) and the Crockard walking test.

Results

Sixty-seven patients were included (mean age of 61 years). The global JOA score improved after surgery, reaching statistical significance at 1 month (from 11.5 ± 2.6 to 13.6 ± 2.0 points, p = 0.0078), then settling to a plateau till the end of follow-up at 24 months (12.7 ± 2.6 points). The 9HPT and the Crockard test did not show any significant improvement after surgery.

Conclusions

Neurological recovery after surgical decompression has been proved to be very fast during the first month, but stabilizes afterwards. The JOA score is the best assessment to reveal neurological improvement in the early recovery course.     

Efficacy,Safety and Characteristics of the Amplatzer Vascular Plug II and IV Utilization for Various Percutaneous Occlusions in Children under 10 Years

Objectives: We aim to describe the efficacy, safety, and characteristics of the Amplatzer Vascular Plug (AVP) II and IV “off-label” use for multiple cardiovascular occlusions in children under 10 years. Methods: Observational retrospective multicenter (2007–2020, 6 centers) review of paediatric procedures using AVP II or IV. Results: A total of 125 children (49.6% aged ≤ 1 year, 147 lesions) underwent 136 successive procedures (success rate: 98.5%) using 169 devices (109 AVP IV, 60 AVP II). The mean device diameter was 7.7 ± 3.2 mm (4–20 mm). The median AVP size to vessel diameter ratio was 1.3 (0–2). The median age and weight at implantation were 1.0 year (0.01–9.98) and 8.4 kg (1–69). Procedures were heterogeneous (55 patent ductus arteriosus (PDA), 28 collaterals, 18 sequestrations, 22 arteriovenous/veinovenous/coronary fistulas, 6 vertical veins, 6 conduits, 5 ventricular septal defects, 7 miscellaneous). Day 1 and 6-month occlusion rates were respectively 94.8% and 98.5%. Major adverse events (MAE) occurred in 5.2% of cases (no procedure-related deaths), and more frequently in weight ≤ 5 kg (p = 0.01), younger patients (p = 0.03) during PDA closure (p = 0.02) of tubular types (p = 0.02) using larger devices (p = 0.03) and AVP II (p = 0.003). Independent predictor of MAE risk was a higher AVP diameter to patient weight ratio (Odds-ratio: 2.33, 95% confidence interval 1.31–4.13, p = 0.004, optimal cut off: 1.45). Conclusions: Both AVPs are safe and effective for percutaneous occlusions in children under 10. Such devices represent an alternative “off label” use for well selected paediatric patients.     

Cellular mechanisms and integrative timing of neuroendocrine control of GnRH secretion by kisspeptin

The hypothalamus integrates endogenous and exogenous inputs to control the pituitary–gonadal axis. The ultimate hypothalamic influence on reproductive activity is mediated through timely secretion of GnRH in the portal blood, which modulates the release of gonadotropins from the pituitary. In this context neurons expressing the RF-amide neuropeptide kisspeptin present required features to fulfill the role of the long sought-after hypothalamic integrative centre governing the stimulation of GnRH neurons. Here we focus on the intracellular signaling pathways triggered by kisspeptin through its cognate receptor KISS1R and on the potential role of proteins interacting with this receptor. We then review evidence implicating both kisspeptin and RFRP3 – another RF-amide neuropeptide – in the temporal orchestration of both the pre-ovulatory LH surge in female rodents and the organization of seasonal breeding in photoperiodic species.     

The effect of femoral offset modification on gait after total hip arthroplasty

Background and purpose

A decrease of 15% in femoral offset (FO) has been reported to generate a weakness of the abductor muscle, but this has not been directly linked to an alteration of gait. Our hypothesis was that this 15% decrease in FO may also generate a clinically detectable alteration in the gait.

Patients and methods

We performed a prospective comparative study on 28 patients who underwent total hip arthroplasty (THA) for unilateral primary osteoarthritis. The 3D hip anatomy was analyzed preoperatively and postoperatively. 3 groups were defined according to the alteration in FO following surgery: a minimum decrease of 15% (9 patients), restored (14), and a minimum increase of 15% (5). A gait analysis was performed at 1-year follow-up using an ambulatory device. Each limb was compared to the contralateral healthy limb.

Results

In contrast to the “restored” group and the “increased” group, in the “decreased” group there was a statistically significant asymmetry between sides, with reduced range of motion and a lower maximal swing speed on the operated side.

Interpretation

A decrease in FO of 15% or more after THA leads to an alteration in the gait. We recommend 3-D preoperative planning because the FO may be underestimated by up to 20% on radiographs and it may therefore not be restored, with clinical consequences.The femoral offset (FO) and limb length have to be restored during total hip arthroplasty (THA) in order to improve the functional outcomes and to reduce the risk of limping, dislocation (McGrory et al. 1995, Downing et al. 2001, Bourne and Rorabeck 2002, Asayama et al. 2005, Kiyama et al. 2010), and edge loading (Sariali et al. 2010). The restoration of the FO also appears to be crucial to improve the long-term survival rates of THA. Sakalkale et al. (2001) reported that restoration of the FO reduces the wear in THA.With respect to the functional outcomes of THA, a decrease of 15% in FO has been reported to generate weakness of the abductor muscle (Asayama et al. 2005), but this has not been directly linked to an alteration of gait. Indeed, this threshold was defined under laboratory conditions using a CYBEX machine, which does not correspond to realistic activities of daily living. Our hypothesis was that a 15% decrease in the FO may also generate a clinically detectable alteration of gait.Many devices are available for analysis of gait, but most of them are constraining and cannot be used without laboratory conditions (Lamontagne et al. 2011). Some authors have proposed the use of devices for ambulatory gait analysis that can be used for long distances and under realistic daily living conditions (Aminian et al. 2004). For example, the Physilog device (Aminian et al. 2004) has been validated as an evaluation tool for the clinical assessment of patients before and after THA.We analyzed the consequences of an alteration in FO after THA for gait under realistic walking conditions.     

Limited plastic potential of the left ventral premotor cortex in speech articulation: Evidence From intraoperative awake mapping in glioma patients

Objectives: Despite previous lesional and functional neuroimaging studies, the actual role of the left ventral premotor cortex (vPMC), i.e., the lateral part of the precentral gyrus, is still poorly known. Experimental design:We report a series of eight patients with a glioma involving the left vPMC, who underwent awake surgery with intraoperative cortical and subcortical language mapping. The function of the vPMC, its subcortical connections, and its reorganization potential are investigated in the light of surgical findings and language outcome after resection. Principal observations: Electrostimulation of both the vPMC and subcortical white matter tract underneath the vPMC, that is, the anterior segment of the lateral part of the superior longitudinal fascicle (SLF), induced speech production disturbances with anarthria in all cases. Moreover, although some degrees of redistribution of the vPMC have been found in four patients, allowing its partial resection with no permanent speech disorders, this area was nonetheless still detected more medially in the precentral gyrus in the eight patients, despite its invasion by the glioma. Moreover, a direct connection of the vPMC with the SLF was preserved in all cases. Conclusions: Our original data suggest that the vPMC plays a crucial role in the speech production network and that its plastic potential is limited. We propose that this limitation is due to an anatomical constraint, namely the necessity for the left vPMC to remain connected to the lateral SLF. Beyond fundamental implications, such knowledge may have clinical applications, especially in surgery for tumors involving this cortico‐subcortical circuit. Hum Brain Mapp 35:1587–1596, 2014. © 2013 Wiley Periodicals, Inc.     

The effect of delivering the chemokine SDF-1α in a matrix-bound manner on myogenesis

Several chemokines are important in muscle myogenesis and in the recruitment of muscle precursors during muscle regeneration. Among these, the SDF-1α chemokine (CXCL12) is a potent chemoattractant known to be involved in muscle repair. SDF-1α was loaded in polyelectrolyte multilayer films made of poly(l-lysine) and hyaluronan to be delivered locally to myoblast cells in a matrix-bound manner. The adsorbed amounts of SDF-1α were tuned over a large range from 100 ng/cm² to 5 μg/cm², depending on the initial concentration of SDF-1α in solution, its pH, and on the film crosslinking extent. Matrix-bound SDF-1α induced a striking increase in myoblast spreading, which was revealed when it was delivered from weakly crosslinked films. It also significantly enhanced cell migration in a dose-dependent manner, which again depended on its presentation by the biopolymeric film. The low-crosslinked film was the most efficient in boosting cell migration. Furthermore, matrix-bound SDF-1α also increased the expression of myogenic markers but the fusion index decreased in a dose-dependent manner with the adsorbed amount of SDF-1α. At high adsorbed amounts of SDF-1α, a large number of Troponin T-positive cells had only one nucleus. Overall, this work reveals the importance of the presentation mode of SDF-1α to emphasize its effect on myogenic processes. These films may be further used to provide insight into the role of SDF-1α presented by a biomaterial in physiological or pathological processes.