Navigated intraoperative ultrasound in neuro-oncology: volumetric accuracy and correlation with high-field MRI.

OBJECTIVE: The use of intraoperative techniques to detect residual tumors has recently become increasingly important. Intraoperative MRI has long been considered the gold standard; however, it is not widely used because of high equipment costs and long acquisition times. Consequently, real-time intraoperative ultrasound (ioUS), which is much less expensive than MRI, has gained popularity. The aim of the present study was to evaluate the capacity of ioUS to accurately determine the primary tumor volume and detect residual tumors. METHODS: A prospective study of adult patients who underwent surgery for intra-axial brain tumors between November 2017 and October 2020 was performed. Navigated intraoperative ultrasound (nioUS) of the brain was used to guide tumor resection and to detect the presence of residual disease. Both convex (5-8 MHz) and linear array (6-13 MHz) probes were used. Tumor volume and residual disease were measured with nioUS and compared with MR images. A linear regression model based on a machine learning pipeline and a Bland-Altman analysis were used to assess the accuracy of nioUS versus MRI. RESULTS: Eighty patients (35 females and 45 males) were included. The mean age was 58 years (range 25-80 years). A total of 88 lesions were evaluated; there were 64 (73%) gliomas, 19 (21.6%) metastases, and 5 (5.7%) other tumors, mostly located in the frontal (41%) and temporal (27%) lobes. Most of the tumors (75%) were perfectly visible on ioUS (grade 3, Mair grading system), except for those located in the insular lobe (grade 2). The regression model showed a nearly perfect correlation (R2 = 0.97, p < 0.001) between preoperative tumor volumes from both MRI and nioUS. Ultrasonographic visibility significantly influenced this correlation, which was stronger for highly visible (grade 3) tumors (p = 0.01). For residual tumors, the correlation between postoperative MRI and nioUS was weaker (R2 = 0.78, p < 0.001) but statistically significant. The Bland-Altman analysis showed minimal bias between the two techniques for pre- and postoperative scenarios, with statistically significant results for the preoperative concordance. CONCLUSIONS: The authors' findings show that most brain tumors are well delineated by nioUS and almost perfectly correlated with MRI-based measurements both pre- and postoperatively. These data support the hypothesis that nioUS is a reliable intraoperative technique that can be used for real-time monitoring of brain tumor resections and to perform volumetric analysis of residual disease.

Long-Term Results of Cortical Motor Stimulation for Neuropathic Peripheral and Central Pain: Real-World Evidence From Two Independent Centers.

BACKGROUND AND OBJECTIVES: Cortical motor stimulation (CMS) is used to modulate neuropathic pain. The literature supports its use; however, short follow-up studies might overestimate its real effect. This study brings real-world evidence from two independent centers about CMS methodology and its long-term outcomes. METHODS: Patients with chronic refractory neuropathic pain were implanted with CMS. The International Classification of Headache Disorders 3rd Edition was used to classify craniofacial pain and the Douleur Neuropathique en 4 Questions Scale score to explore its neuropathic nature. Demographics and clinical and surgical data were collected. Pain intensity at 6, 12, and 24 months and last follow-up was registered. Numeric rating scale reduction of ≥50% was considered a good response. The Clinical Global Impression of Change scale was used to report patient satisfaction. RESULTS: Twelve males (38.7%) and 19 females (61.3%) with a mean age of 55.8 years (±11.9) were analyzed. Nineteen (61.5%) were diagnosed from painful trigeminal neuropathy (PTN), and seven (22.5%) from central poststroke pain. The mean follow-up was 51 months (±23). At 6 months, 42% (13/31) of the patients were responders, all of them being PTN (13/19; 68.4%). At last follow-up, only 35% (11/31) remained responders (11/19 PTN; 58%). At last follow-up, the global Numeric rating scale reduction was 34% ( P = .0001). The Clinical Global Impression of Change scale punctuated 2.39 (±0.94) after 3 months from the surgery and 2.95 (±1.32) at last follow-up ( P = .0079). Signs of suspicious placebo effect were appreciated in around 40% of the nonresponders. CONCLUSION: CMS might show long-term efficacy for neuropathic pain syndromes, with the effect on PTN being more robust in the long term. Multicentric clinical trials are needed to confirm the efficacy of this therapy for this and other conditions.

Response and Safety Outcomes in Treatment-Resistant Depression After Subcallosal Cingulate Gyrus Deep Brain Stimulation: Long-term Follow-up Study.

Objective: To replicate previous findings and to investigate related clinical factors of long-term benefits and safety of subcallosal cingulate gyrus deep brain stimulation (SCG-DBS) for treatment-resistant depression (TRD).Methods: Sixteen patients with TRD (with either major depressive disorder or bipolar disorder, DSM-IV and DSM-5 criteria) receiving chronic SCG-DBS were followed for up to 11 years (January 2008 to June 2019). Demographic, clinical, and functioning data were collected pre-surgery and during the follow-up. Response was defined as a ≥ 50% decrease from baseline in the 17-item Hamilton Depression Rating Scale (HAM-D17) score, and remission was defined as ≤ 7 in the HAM-D17 score. The Illness Density Index (IDI) was used as a longitudinal measure of treatment effects. Survival analyses were performed for response outcomes and relapses.Results: Depressive symptoms were significantly decreased over time (F = 2.37; P = .04). Response and remission rates were 75% and 62.5% at individual endpoint. Based on Kaplan-Meier curve analysis, 55% of patients reached remission in 139 days. IDI curves showed sustained clinical improvements as measured with HAM-D17 and Clinical Global Impression and sustained functioning improvement as measured with Global Assessment of Functioning scores. The procedure was generally safe and well tolerated (122 adverse events across 81 patient-years, of which 25 were related to SCG-DBS). Two patients committed suicide long after surgery.Conclusions: SCG-DBS produced a robust and protracted improvement in most patients, which reinforces the possibility that SCG-DBS could be an alternative for patients with treatment-resistant unipolar or bipolar depression. Identification of clinical and neurobiological response predictors should guide the continuation of DBS for TRD, to obtain its indication soon.

Occipital nerve stimulation and deep brain stimulation for refractory cluster headache: a prospective analysis of efficacy over time.

OBJECTIVE: Occipital nerve stimulation (ONS) and deep brain stimulation (DBS) are widely used surgical treatments for chronic refractory cluster headache (CH). However, there is little literature regarding long-term follow-up of these treatments. METHODS: The authors describe two prospective cohorts of patients with refractory CH treated with ONS and DBS and compare preoperative to postoperative status at 6 and 12 months after the surgery and at final follow-up. Efficacy analysis using objective and subjective variables is reported, as well as medication reduction and complications. RESULTS: The ONS group consisted of 13 men and 4 women, with a median age of 44 years (range 31-61 years). The median number of attacks per week (NAw) before surgery was 28 (range 7-70), and the median follow-up duration was 48 months. The DBS group comprised 5 men and 2 women, with a median age of 50 years (range 29-64 years). The median NAw before surgery was 56 (range 14-140), and the median follow-up was 36 months. The NAw and visual analog scale score were significantly reduced for the ONS and DBS groups after surgery. However, while all the patients from the DBS group were considered responders at final follow-up, with more than 85% being satisfied with the treatment, approximately 29% of initial responders to ONS became resistant by the final follow-up (p = 0.0253). CONCLUSIONS: ONS is initially effective as a treatment for refractory CH, although a trend toward loss of efficacy was observed. No clear predictors of good clinical response were found in the present study. Conversely, DBS appears to be effective and provide a more stable clinical response over time with an acceptable rate of surgical complications.

Long-Term Safety and Performance of a Polymeric Clamplike Cranial Fixation System.

OBJECTIVE: After a craniotomy procedure to access the brain, neurosurgeons have several options to fix the bone flap to the skull. The aim of this study was to assess if a polymeric clamplike fixation system (Cranial LOOP) is a safe and reliable system that maintains over time an appropriate alignment of the bone flap. METHODS: This is an observational, retrospective, case series study of 60 patients who underwent a craniotomy and were subject to cranial bone flap fixation with the Cranial LOOP fixation system. Baseline clinical parameters, surgical variables, medical records, and all postoperative medical images available were reviewed to assess the bone flap alignment and potential adverse events. RESULTS: A total of 182 Cranial LOOPs were implanted in the 60 patients (56.01 ± 20.21 years, 55% women) included in the study. The cranial fixation system maintained a good bone flap alignment in 95% of the patients studied immediately after surgery and in up to 96.7% of them at the end of follow-up. No intraoperative complications were reported. An ulcer potentially related to a device was detected, which was solved without the need for device removal. No artifacts were observed in any of the 219 medical images analyzed. CONCLUSIONS: Cranial LOOP is a safe and reliable postoperative long-term cranial bone flap fixation system. This device can fix the bone flap after a wide range of craniotomy procedures, performed in multiple locations, and provides good bone flap alignment. Cranial LOOP does not interfere in patient follow-up through medical imaging.

[Sclerosing epithelioid fibrosarcoma of the paravertebral column. Case report and literature review]. / Fibrosarcoma epitelioide esclerosante a nivel paraespinal. Caso clínico y revisión de la literatura.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of low-grade fibrosarcoma, with specific histological and immunohistochemical features and a poor prognosis. We report a case of SEF of the paravertebral column in a 49-year old male who presented a paraspinal mass with extension into the L4-L5 neural foramen and invasion of the L5 nerve root. Histology of the tumourectomy specimen and its immunohistochemical study led to the diagnosis of SEF. This case was particularly unusual due to its paravertebral column location and, despite its low grade, illustrates the malignant potential of SEF.