Unilateral Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy Thalamotomy for Essential Tremor.

BACKGROUND: Essential tremor (ET) affects numerous adults, impacting quality of life (QOL) and often defying pharmacological treatment. Surgical interventions like deep brain stimulation (DBS) and lesional approaches, including radiofrequency, gamma-knife radiosurgery, and magnetic resonance imaging (MRI)-guided focused ultrasound, offer solutions but are not devoid of limitations. OBJECTIVES: This retrospective, single-center, single-blinded pilot study aimed to assess the safety and efficacy of unilateral MRI-guided laser interstitial thermal therapy (MRIg-LITT) thalamotomy for medically intractable ET. METHODS: Nine patients with ET, unresponsive to medications and unsuitable for DBS, underwent unilateral MRIg-LITT thalamotomy. We assessed tremor severity, QOL, cognitive function, and adverse events (AE) over a 12-month period. RESULTS: Tremor severity significantly improved, with a reduction of 83.37% at 12 months post-procedure. QOL scores improved by 74.60% at 12 months. Reported AEs predominantly included transient dysarthria, proprioceptive disturbances, and gait balance issues, which largely resolved within a month. At 3 months, 2 patients (22%) exhibited contralateral hemiparesis requiring physiotherapy, with 1 patient (11%) exhibiting persistent hemiparesis at 12 months. No significant cognitive impairment was detected post-procedure. CONCLUSIONS: Unilateral MRIg-LITT thalamotomy yielded substantial and enduring tremor alleviation and enhanced QOL in patients with ET that is resistant to medication. The AE profile was acceptable. Our findings support the need for additional research with expanded patient cohorts and extended follow-up to corroborate these outcomes and to refine the role of MRIg-LITT as a targeted and minimally invasive approach for ET management. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Stereotactic robot-assisted MRI-guided laser interstitial thermal therapy thalamotomy for medically intractable Parkinson's disease tremor: technical note and preliminary effects on 2 cases.

BACKGROUND: Medically intractable Parkinson's disease (PD) tremor is a common difficult clinical situation with major impact on patient's quality of life (QOL). Deep brain stimulation (DBS) is an effective therapy but is not an option for many patients. Less invasive lesional brain surgery procedures, such as thalamotomy, have proven to be effective in these indications. Here, we describe the technical nuances and advantages of stereotactic robot-assisted MRI-guided laser interstitial thermal therapy (MRIg-LITT) thalamotomy for medically intractable PD tremor. METHOD: We describe 2 patients with medically intractable PD tremor treated with stereotactic robot-assisted MRIg-LITT thalamotomy performed under general anesthesia with intraoperative electrophysiological testing. Pre and postoperative tremor scores were assessed using the Fahn-Tolosa-Marin tremor rating scale (TRS). RESULTS: At 3-month follow-up, both patients demonstrated significant improvement in tremor symptoms subjectively and according to the TRS (75% for both). Patients also had substantial improvements in their QOL (32.54% and 38%) according to the 39-item PD questionnaire. Both patients underwent uncomplicated MRIg-LITT thalamotomy. CONCLUSIONS: In patients with medically intractable PD tremor who are unsuitable candidates for DBS, thalamotomy utilizing a stereotactic robot, intraoperative electrophysiological testing, and laser ablation with real-time MRI guidance may be a viable treatment option. However, further studies with larger sample sizes and longer follow-up periods are necessary to confirm these preliminary results.

Microsurgical anatomy of the inferior intercavernous sinus.

PURPOSE: Intercavernous sinuses (ICSs) are physiological communications between the cavernous sinuses. The ICSs run between the endosteal and meningeal layers of the dura mater of the sella turcica. Whereas the anterior and posterior ICSs have been frequently described, the inferior ICS (iICS) has been less well studied in the literature; however, poor awareness of the ICS's anatomy can lead to serious problems during transsphenoidal, transsellar surgery. The objective of the present anatomical study was to describe the iICS in detail. METHODS: The study was carried out over a 6-month period in a university hospital's anatomy laboratory, using brains extracted from human cadavers. The brains were injected with colored neoprene latex and dissected to study the iICS (presence or absence, shape, diameter, length, distance between inferior and anterior ICSs, distance between inferior and posterior ICSs, relationships, and boundaries). RESULTS: Seventeen cadaveric specimens were studied, and an iICS was found in all cases (100%). The shape was variously plexiform (47.1%), filiform (35.3%), or punctiform (17.6%). The mean ± standard deviation diameter and length of the iICS were 3.75 ± 2.90 mm and 11.92 ± 2.96 mm, respectively. The mean iICS-anterior ICS and iICS-posterior ICS distances were 5.36 ± 1.99 mm and 7.03 ± 2.28 mm, respectively. CONCLUSION: The iICS has been poorly described in the literature. However, damage to the iICS during transsphenoidal, transsellar surgery could lead to serious vascular complications. A precise radiological assessment appears to be essential for a safe surgical approach.

A Novel, Hybrid, Stereotactic Approach (Radiosurgery and Dual Ommaya Reservoirs) for the Treatment of Mixed (Polycystic and Solid) Craniopharyngioma.

BACKGROUND: Craniopharyngioma is a difficult entity to treat, which is particularly true for mixed craniopharyngioma (i.e., a mixture of both solid and cystic components). The present case report illustrates a minimally invasive, two-component, stereotactic treatment approach as an alternative to standard microsurgery. CASE DESCRIPTION: A 38-year-old patient presented with progressive intracranial hypertension followed by pan-hypopituitarism, deterioration of the visual field, and cognitive impairment. Brain MRI revealed hydrocephalus and a suprasellar mixed solid and polycystic lesion that was suggestive of craniopharyngioma. Using a robot-assisted, stereotactic treatment approach, we combined the installation of catheters for 2 Ommaya reservoirs with 5-fraction CyberKnife radiosurgery of the solid tumor. The high intracranial pressure and visual field deterioration resolved completely. A partial improvement in endocrine function was noted, and the patient returned to work 6 weeks after surgery. CONCLUSION: A combined, robot-assisted, stereotactic approach to the treatment of mixed (solid and polycystic) craniopharyngioma is a safe alternative to microsurgery. Further studies including larger numbers of patients will be needed to assess the long-term efficacy and morbidity and mortality rates associated with this approach.

Minimally invasive, robot-assisted iliosacral screw insertion for fusionless fixation in children with neuromuscular scoliosis.

Fusionless surgery coupled with growing rod techniques is increasingly advocated for the treatment of early-onset scoliosis in general and neuromuscular scoliosis in particular. Iliosacral screws have excellent biomechanical characteristics but are hard to place safely. Here, the authors report on robot-assisted iliosacral screw positioning as part of growing rod surgery for the fusionless correction of early-onset scoliosis. The technique is based on a bilateral double sliding rod construct anchored to the pelvis proximally with 6 hooks or sublaminar bands and distally with iliosacral screws placed by the robot. The video can be found here: https://youtu.be/5HGH_DiD-ck .

Correction to: Unilateral duplicated abducens nerve coursing through both the sphenopetroclival venous gulf and cavernous sinus: a case report.

In the Original Publication of the article, one of the references was missed to include. This reference and the text citation are given below.

Unilateral duplicated abducens nerve coursing through both the sphenopetroclival venous gulf and cavernous sinus: a case report.

In this anatomy report, we describe the first case of abducens nerve duplication limited to the sphenopetroclival venous gulf and the cavernous sinus. The objective point of division of the two duplicated roots was localized at the gulfar face of the dural porus, just distal to the unique cisternal trunk of the abducens nerve, as it pierced the petroclival dural mater. In the gulfar segment, both roots traveled through a variant of Dorello's canal called the "petrosphenoidal canal" and remained separated through the posterior half of the cavernous sinus. Both roots finally fused in the anterior half of the cavernous sinus to innervate the lateral rectus muscle as a single trunk. Although many variants of the abducens nerve have been reported over the recent decades, this anatomic variation has never been previously described and enriches the continuum of abducens nerve variations reported in the literature data. Awareness of this variation is crucial for neurosurgeons, especially during clival or petrosal surgical approaches used for resection of skull base chordomas.

Minimally invasive transforaminal lumbar interbody fusion with the ROSA(TM) Spine robot and intraoperative flat-panel CT guidance.

BACKGROUND: Circumferential arthrodesis is commonly used to treat degenerative lumbar diseases. Minimally invasive techniques may enable faster recovery and reduce the incidence of postoperative infections. METHODS: We report on the surgical technique of a transforaminal lumbar interbody fusion (TLIF) procedure performed with the assistance of a new robotic device (ROSA(TM) Spine) and intraoperative flat-panel CT guidance. CONCLUSIONS: The combined use of this new robotic device and intraoperative CT enables accurate and safe arthrodesis in the treatment of degenerative lumbar disc diseases.

Prelemniscal Radiations: A New Reliable Landmark of the Thalamic Nucleus Ventralis Intermedius Location.

BACKGROUND: The thalamic nucleus ventralis intermedius (Vim nucleus) is the main surgical target for the management of intractable tremor. The Vim nucleus cannot be reliably located with routine stereotactic imaging, and so targeting relies on indirect coordinates. OBJECTIVE: We propose to investigate if colored fractional anisotropy (FA) mapping can help to locate the Vim nucleus by identifying its borders, particularly the prelemniscal radiations (Raprl) that lie below and behind the nucleus. METHOD: We retrospectively reviewed the colored FA maps for 18 consecutive patients having undergone gamma knife stereotactic Vim thalamotomy for disabling tremor. RESULTS: The Raprl were easily located on colored FA maps and enabled the identification of the lower and posterior borders of the Vim nucleus in all patients. In the medial plane, the mean distance ± SD between the Raprl and Vim nucleus was 0.77 ± 1.19 mm (range: 0.1-3.3). The Raprl were located 1.35 ± 1.33 mm (range: 0.2-3.9) behind the Vim nucleus and 1.99 ± 1.23 mm (range: 0.7-4.4) below it. The mean vector distance ± SD between the Vim nucleus and the Raprl was 3 ± 1.38 mm (range: 1.25-5.2). CONCLUSION: The Raprl can be easily seen on colored FA maps and constitute a reliable landmark for the borders of the Vim nucleus.

The impact of the reference imaging modality, registration method and intraoperative flat-panel computed tomography on the accuracy of the ROSA® stereotactic robot.

OBJECTIVE: To establish the impact of the imaging modality, registration method and use of intraoperative computed tomography (CT) scan on the accuracy of the ROSA® stereotactic robot. METHODS: Using a dedicated phantom device, we measured the accuracy of the stereotactic robot for 20 targets as a function of the registration method (frameless, FL, or frame-based, FB) and the reference imaging modality (3T magnetic resonance imaging, MRI, CT scanner or flat-panel CT, fpCT). We performed a retrospective study of the accuracy of the first 26 FB and 31 FL robotized stereotactic surgeries performed in our department. RESULTS: In a phantom study, the mean target accuracy was 1.59 mm for 3T MRI-guided FL surgery, 0.3 mm for fpCT-guided FL surgery and 0.3 mm for CT-guided FB surgery. In our retrospective series, the mean accuracy was 0.81 mm for FB stereotactic surgery, 1.22 mm for our 24 stereotactic surgery procedures with FL (surface recognition) registration and 0.7 mm for our 7 stereotactic surgery procedures with FL fiducial marker registration. Intraoperative fpCT fully corrected all the registration errors. CONCLUSIONS: The ROSA stereotactic robot is highly accurate. Robotized FB stereotactic surgery is more accurate than robotized FL stereotactic surgery.

Robotically assisted deployment of flow diverter stents for the treatment of cerebral and cervical aneurysms.

BACKGROUND: Despite the growing sophistication of robot-assisted surgery, it is necessary to demonstrate that robots can reliably perform complex procedures on site and then remotely. Although a flow diverter stent is one of the most effective and widely used devices, its placement is sometimes challenging. OBJECTIVE: To evaluate the feasibility and safety of the CorPath GRX robotic platform for the embolization of cerebral and cervical aneurysms using flow diverter stents. METHODS: We performed a single-center technical study of the first 10 flow diverter stent deployments with the CorPath GRX Robotic System (Corindus Inc, Waltham, Massachusetts, USA) for the treatment of cerebral aneurysms between April and October 2022. RESULTS: Ten patients underwent robot-assisted embolization with flow diverter stents: there were nine intracranial aneurysms (paraclinoid n=6; posterior communicating artery aneurysm n=1; anterior communicating artery n=2) and one cervical aneurysm. Four procedures were performed with coils plus a flow diverter stent, one was performed with woven endobridge plus a flow diverter stent and four were performed with flow diverter stents alone. Of these procedures, two were performed with telescoping flow diverters.All flow diverter stents were deployed with robotic assistance, with only one partial conversion to a manual technique (caused by guidewire torquability limitations). No perioperative complications were observed. CONCLUSION: Robot-assisted flow diverter stent deployment using the CorPath GRX platform is feasible and appears to be safe. Larger, in-depth studies of the technique's safety and benefits are now warranted.

Intracranial Solitary Fibrous Tumour Management: A French Multicentre Retrospective Study.

BACKGROUND: Intracranial solitary fibrous tumour (iSFT) is an exceptional mesenchymal tumour with high recurrence rates. We aimed to analyse the clinical outcomes of newly diagnosed and recurrent iSFTs. METHODS: We carried out a French retrospective multicentre (n = 16) study of histologically proven iSFT cases. Univariate and multivariate Cox models were used to estimate the prognosis value of the age, location, size, WHO grade, and surgical extent on overall survival (OS), progression-free survival (PFS), and local recurrence-free survival (LRFS). RESULTS: Eighty-eight patients were included with a median age of 54.5 years. New iSFT cases were treated with gross tumour resection (GTR) (n = 75) or subtotal resection (STR) (n = 9) and postoperative radiotherapy (PORT) (n = 32, 57%). The median follow-up time was 7 years. The median OS, PFS, and LRFS were 13 years, 7 years, and 7 years, respectively. Forty-two patients experienced recurrence. Extracranial metastasis occurred in 16 patients. Median OS and PFS after the first recurrence were 6 years and 15.4 months, respectively. A higher histological grade was a prognosis factor for PFS (p = 0.04) and LRFS (p = 0.03). GTR influenced LRFS (p = 0.03). CONCLUSION: GTR provided benefits as a first treatment for iSFTs. However, approximately 40% of patients experienced relapse, which remains a challenging state.

Bilateral abducens paralysis revealing bipartite spheno-occipital synchondrosis fracture in a child: case based update.

BACKGROUND: After reviewing the literature about sella turcica and spheno-occipital synchondrosis fracture, we present the case of a 6-year-old girl who suffered complex sphenoid bone fracture produced by an indirect mechanism. METHODS: The girl fell from her height after a blunt head injury due to a falling lamppost. RESULTS: Computer tomography (CT) scan showed occipital, sellar and clival fractures with pneumatocephalus. The probable fracture mechanism is contre-coup injury linked to osseous and brain oscillations after head trauma. CONCLUSION: Two complications, abducens nerve palsy and cerebrospinal fluid fistula, are observed and discussed.

Anatomy and surgical landmarks for the ansa pectoralis: application to pectoralis major nerve selective neurotomy.

BACKGROUND: Ansa pectoralis neurotomy is a surgical approach in the treatment of the pectoralis major muscle spasticity causing an attitude in adduction and internal rotation of the shoulder. OBJECTIVE: To establish the anatomical landmarks allowing an easier localisation of the ansa pectoralis during neurotomy. MATERIAL AND METHODS: Fifteen adult human cadavers (10 embalmed and 5 fresh) were dissected in order to determine anatomical landmarks allowing an easier localization of the ansa pectoralis during neurotomy. RESULTS: In all the cadavers, the lateral pectoral nerve arose from the lateral cord of the brachial plexus, 0.2 cm above to 1.5 cm below the inferior border of the clavicle with a mean distance of 0.76 cm for left and right side, whereas the medial pectoral nerve arose from the medial cord of the brachial plexus, 0.7-2.3 cm below the inferior border of the clavicle with a mean distance of 0.61 cm for the left side and 0.68 cm for the right side. We systematically found both the origin of pectoral nerves and the ansa pectoralis at the level of the middle third of the distance between the sternoclavicular and the acromioclavicular joints. Moreover, ansa pectoralis was constantly localized lateral to the thoracoacromial artery. In four cases, the division of the lateral pectoral nerve was not found. In one case, medial pectoral nerve did not exist. CONCLUSION: Ansa pectoralis can be found by a curved incision made at the mid-third of the distance between the sternoclavicular and the acromioclavicular joints, the medial point being located just below the lower edge of the clavicle and the lateral point 2 cm below the inferior edge of the clavicle.

Are stereotactic sample biopsies still of value in the modern management of pineal region tumours? Lessons from a single-department, retrospective series.

OBJECTIVE: Recent improvements in imaging-based diagnosis, the broader application of neuroendoscopic techniques and advances in open surgery techniques mean that the need for stereotactic biopsies in the management of pineal region tumours must be reevaluated. The primary aim of this retrospective study was to establish whether stereotactic biopsy is still of value in the modern management of pineal region tumours. METHODS: From 1985 to 2009, 88 consecutive patients underwent a stereotactic biopsy in our institution (51 males and 37 females; median age at presentation 30; range 2-74). RESULTS: Accurate tissue diagnoses were obtained in all but one case (i.e. 99%). In one case (1%), three distinct stereotactic procedures were necessary to obtain a tissue diagnosis. There was no mortality or permanent morbidity associated with stereotactic biopsy. One patient (1%) presented an intra-parenchymal hematoma but no related clinical symptoms. Five patients (6%) presented transient morbidity, which lasted for between 2 days and 3 weeks after the biopsy. CONCLUSIONS: To guide subsequent treatment, we believe that histological diagnosis is paramount. Stereotactic biopsies are currently the safest and the most efficient way of obtaining this essential information. Recent improvements in stereotactic technology (particularly robotic techniques) appear to be very valuable, with almost no permanent morbidity or mortality risk and no decrease in the accuracy rate. In our opinion, other available neurosurgical techniques (such as endoscopic neurosurgery, stereotactic neurosurgery and open microsurgery) are complementary and not competitive.

A matched comparison of outcomes between percutaneous endoscopic lumbar discectomy and open lumbar microdiscectomy for the treatment of lumbar disc herniation: a 2-year retrospective cohort study.

BACKGROUND CONTEXT: Although open lumbar microdiscectomy (OLMD) is considered to be the gold standard method for discectomy, recent progress in endoscopic spinal surgery has increased the popularity of percutaneous endoscopic lumbar discectomy (PELD) for this indication. However, one of the main drawbacks of PELD is incomplete decompression, especially at the start of the surgeon's learning curve. The functional outcomes of PELD and OLMD in patients matched for age, hernia level, and hernia location have not previously been compared. PURPOSE: To compare OLMD with PELD in terms of the clinical outcome and the time to recovery. STUDY DESIGN: Retrospective, matched cohort study. PATIENT SAMPLE: Data of all patients who underwent elective spinal surgery between January 2015 and June 2017 were extracted from the local database. OUTCOME MEASURES: Clinical outcomes were assessed using a 0-to-10 visual analogue scale (VAS) for lower back pain (LBP) and leg pain were scored before surgery and at postoperative day 1 and at each follow-up visit (3, 12, and 24 months), the Oswestry Disability Index (ODI: 0%-100%), the length of hospital stay, time to resumption of work, recurrence of Lumbar disc herniation, procedure failures, and complications. METHODS: The participants were matched for age, disc level, and location of the herniated disk (central and paracentral vs. far-lateral). The participants' mean±standard deviation age was 47.09±12.55 (range: 28-70). We compared the various clinical outcomes between the two groups to identify which procedure had better immediate and long-term functional outcomes. The differences in mortality and occurrence of postoperative complications were also compared in patients with PELD versus controls. RESULTS: Fifty-eight patients were enrolled (29 with PELD and 29 with OLMD). Both groups reported significant reductions in LBP and leg pain (p<0.01) postoperatively and an improvement in the ODI at 24 months postsurgery. The intergroup difference in the VAS for LBP at 1 day and 3 months was statistically significant (1.48 vs. 3.5, and 1.62 vs. 2.72, respectively; p=0.01 and 0.026, respectively) but the intergroup difference in the ODI was not. The mean length of hospital stay and the time to resumption of work were significantly shorter in the PELD group than in the OLMD group (2.55 vs. 3.21 days, and 4.45 vs. 6.62 weeks, respectively; p=0.037 and 0.01, respectively. There were no significant intergroup differences in terms of complications, recurrence, or procedure failures. CONCLUSIONS: Both PELD and OLMD can provide equivalent, satisfactory outcomes. However, PELD demonstrated several potential advantages, including more rapid recovery and lower LBP early on. Further large-scale, randomized studies with long-term follow-up are now warranted.

Which features of an outpatient treatment for COVID-19 would be most important for pandemic control? A modelling study.

The global pandemic of coronavirus disease 2019 (COVID-19) has challenged healthcare systems worldwide. Lockdown, social distancing, and screening are thought to be the best means of stopping the virus from spreading and thus of preventing hospital capacity from being overloaded. However, it has also been suggested that effective outpatient treatment can control pandemics. We adapted a mathematical model of the beneficial effect of lockdown on viral transmission and used it to determine which characteristics of outpatient treatment would stop an epidemic. The data on confirmed cases, recovered cases, and deaths were collected from Santé Publique France. After defining components of the epidemic flow, we used a Morris global sensitivity analysis with a 10-level grid and 1000 trajectories to determine which of the treatment parameters had the largest effect. Treatment effectiveness was defined as a reduction in the patients' contagiousness. Early treatment initiation was associated with better disease control-as long as the treatment was highly effective. However, initiation of a treatment with a moderate effectiveness rate (5%) after the peak of the epidemic was still better than poor distancing (i.e. when compliance with social distancing rules was below 60%). Even though most of today's COVID-19 research is focused on inpatient treatment and vaccines, our results emphasize the potentially beneficial impact of even a moderately effective outpatient treatment on the current pandemic.

Cortical hemodynamic mapping of subthalamic nucleus deep brain stimulation in Parkinsonian patients, using high-density functional near-infrared spectroscopy.

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for idiopathic Parkinson's disease. Despite recent progress, the mechanisms responsible for the technique's effectiveness have yet to be fully elucidated. The purpose of the present study was to gain new insights into the interactions between STN-DBS and cortical network activity. We therefore combined high-resolution functional near-infrared spectroscopy with low-resolution electroencephalography in seven Parkinsonian patients on STN-DBS, and measured cortical haemodynamic changes at rest and during hand movement in the presence and absence of stimulation (the ON-stim and OFF-stim conditions, respectively) in the off-drug condition. The relative changes in oxyhaemoglobin [HbO], deoxyhaemoglobin [HbR], and total haemoglobin [HbT] levels were analyzed continuously. At rest, the [HbO], [HbR], and [HbT] over the bilateral sensorimotor (SM), premotor (PM) and dorsolateral prefrontal (DLPF) cortices decreased steadily throughout the duration of stimulation, relative to the OFF-stim condition. During hand movement in the OFF-stim condition, [HbO] increased and [HbR] decreased concomitantly over the contralateral SM cortex (as a result of neurovascular coupling), and [HbO], [HbR], and [HbT] increased concomitantly in the dorsolateral prefrontal cortex (DLPFC)-suggesting an increase in blood volume in this brain area. During hand movement with STN-DBS, the increase in [HbO] was over the contralateral SM and PM cortices was significantly lower than in the OFF-stim condition, as was the decrease in [HbO] and [HbT] in the DLPFC. Our results indicate that STN-DBS is associated with a reduction in blood volume over the SM, PM and DLPF cortices, regardless of whether or not the patient is performing a task. This particular effect on cortical networks might explain not only STN-DBS's clinical effectiveness but also some of the associated adverse effects.