Search

Introduction: Fractures in ankylosing spine disorders (ASD) are associated with high complication and mortality rates. During the posterior stabilization of these fractures, reduction is often partial, resulting in the persistence of a significant anterior diastasis. Our objective was to evaluate the safety and efficiency of isolated posterior stabilization in elderly ASD patients, without direct reduction of the anterior diastasis, in terms of clinical and radiological outcomes, complications, and mortality. Methods: This retrospective study included 46 patients, mean age 79.3 years, with ASD, who underwent isolated posterior stabilization, open or percutaneous, for thoracolumbar fractures. The average follow-up was 21.7 months, with a minimum follow-up of 6 months. Autonomy (Parker score) and radiological results (lordotic angulation) were analyzed pre-and post-operatively. Results: Autonomy was maintained at the last follow-up, with no significant difference in Parker’s score. The consolidation rate was 94.6%. No implant failure was recorded. Despite the absence of an anterior procedure, lordotic angulation was significantly reduced by 2.6° at 6 months (p = 0.02). The rate of surgical complications following open surgeries was 10.9% (n = 5), of which 6.5% were infections. No surgical complications were reported in percutaneous surgeries. The rate of medical complications was 67.4% (n = 31), with a rate of 88.2% in the open surgery group, compared to 55.2% in the percutaneous surgery group. An open approach was associated with a five-fold higher risk of complications (p = 0.049). Nine patients died during follow-up (19.6%). Conclusions: Isolated posterior stabilization in the treatment of thoracolumbar spine fractures in elderly ASD patients is a safe technique promoting autonomy preservation, and high radiological bony healing with acceptable complication and mortality rates. The persistent anterior gap is partially reduced when the spine is loaded and does not seem to require an anterior procedure, thus decreasing complications. Percutaneous surgery should be the technique of choice to reduce surgical complications.

Background: Pseudoprogression in gliomas has been extensively described after radiotherapy with or without chemotherapy, but not after chemotherapy alone. Here we describe the occurrence of pseudoprogression in patients with anaplastic oligodendrogliomas treated with postoperative procarbazine, lomustine and vincristine (PCV) chemotherapy alone. Methods: We retrospectively reviewed the medical and radiological files of patients with 1p/19q codeleted, IDH‐mutant anaplastic oligodendrogliomas treated with PCV chemotherapy alone who presented magnetic resonance imaging (MRI) modifications suggestive of tumour progression and in whom the final diagnosis was a pseudoprogression. Results: We identified six patients. All patients underwent a surgical resection and were treated with PCV chemotherapy without radiotherapy. After a median of 11 months following the initiation of chemotherapy (range: 3–49 months), the patients developed asymptomatic white matter MRI modifications around the surgical cavity leading to the suspicion of a tumour progression. These modifications appeared as hyperintense on T2‐fluid‐attenuated inversion recovery (FLAIR) sequence, hypointense on T1 sequence, and lacked mass effect (0/6), contrast enhancement (0/6), restriction on diffusion‐weighted imaging (0/4), relative cerebral blood volume (rCBV) increase on perfusion MRI (0/4), and hypermetabolism on 18F‐fluoro‐L‐dopa positron emission tomography (18F‐DOPA PET) scan (0/3). One patient underwent a surgical resection demonstrating no tumour recurrence; the five other patients were considered as having post‐therapeutic modifications based on imaging characteristics. After a median follow‐up of 4 years all patients were progression‐free. Conclusions: Anaplastic oligodendroglioma patients treated with postoperative PCV chemotherapy alone occasionally develop T2/FLAIR hyperintensities around the surgical cavity that can wrongly suggest tumour progression. Multimodal imaging and close follow‐up should be considered in this situation. [ABSTRACT FROM AUTHOR]

Purpose: To depict the specific brain networks that are modulated by deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD), using diffusion tensor imaging-based fibre tractography (DTI-FT). Materials and methods: Nine patients who received bilateral STN-DBS for PD were included. Electrodes were localized by co-registering preoperative magnetic resonance imaging and postoperative computed tomography. The volume of tissue activated (VTA) was estimated as an isotropic, spherical electric field distribution centred at each effective electrode contact's centroid coordinates, taking into account individual stimulation parameters (i.e. voltage, impedance). Brain connectivity analysis was undertaken using a deterministic DTI-FT method, seeded from a single region of interest corresponding to the VTA. The labelling of the reconstructed white matter fibre tracts relied on their path and (sub)cortical termination territories. Results: Six months after surgery, we observed a statistically significant reduction in both the Unified Parkinson Disease Rating Scale part III and L-dopa equivalent daily dose. Areas consistently connected to the VTA included the brainstem (100%), cerebellum (94%), dorsal (i.e. supplementary motor area) and lateral premotor cortex (94%), and primary motor cortex (72%). An involvement of the hyperdirect pathway (HDP) connecting the STN and the (pre)motor cortex was demonstrated. Conclusions: The connectivity patterns observed in this study suggest that the therapeutic effects of STN-DBS are mediated through the modulation of distributed, large-scale motor networks. Specifically, the depiction of projection neurons connecting the stimulated area/STN to the (pre)motor cortex, reinforce the growing evidence that the HDP might be a potential therapeutic target in PD. If further replicated, these findings could raise the possibility that DTI-FT reconstruction of the HDP may critically improve DBS targeting and stimulation parameters selection, through the development of programming tools that incorporate VTA modelling and patient-specific DTI-FT data. [ABSTRACT FROM AUTHOR]