A case-based review on the neuroendoscopic management of intraventricular and subarachnoid basal neurocysticercosis

OBJECTIVE

Extraparenchymal localization of neurocysticercosis (NCC) is rare in non-endemic areas. A case of mixed (intraventricular, IV, and subarachnoid basal, SAB) NCC was surgically treated using the neuroendoscope and a systematic review of the literature was performed with the aim to analyze the use of this instrument in the management of the extraparenchymal forms of the parasitic disease.

MATERIALS AND METHODS

Medline and Embase databases were searched for studies where the neuroendoscope was used for the management of IV/SAB NCC cysts, either for the cerebrospinal fluid diversion or cyst removal. Cyst location, complete removal, cyst breakage during removal, intraoperative and postoperative complications, administration of antihelmintic therapy, outcome and follow-up period were extracted from the articles.

RESULTS

281 patients were treated by means of the neuroendoscope. 254 patients who were described in retrospective cohort studies, came all from endemic areas, with no significant difference between sexes. Mean age at surgery was 30.7 years. Of all cysts reported in retrospective studies, 37.9% were located in the fourth ventricle. An attempt of cyst removal was described in the 84.6% of cases and an endoscopic third ventriculostomy was performed in another 76.4%. A small number of complications were reported intraoperatively (9.1%) obtaining, but a good recovery was achieved at follow-up. Only 17 ventriculoperitoneal shunts were placed after the first procedure, defining a low risk of postoperative hydrocephalus even in case of partial cyst removal.

CONCLUSION

Neuroendoscopic removal of an extraparenchymal NCC cyst is a safe procedure that should be preferred for lateral and third ventricle localization and, in a specialized centre, even for a localization in the fourth ventricle if feasible. It is also efficient because of the possibility of performing an internal CSF diversion concomitantly to cyst removal, avoiding the complication registered with VPS. The need for cysticidal treatment after surgery should be addressed in a prospective study.

Surgical limits, pitfalls, and potential solutions in kyphectomy in myelomeningocele: three cases and systematic review of the literature

OBJECTIVES

To describe surgical treatment of 3 cases of severe and progressive thoracolumbar kyphosis in myelomeningocele and provide a systematic review of the available literature on the topic.

METHODS

Medical records and pre- and post-operative imaging of 3 patients with thoracolumbar kyphosis and myelomeningocele were reviewed. A database search was performed for all manuscripts published on kyphectomy and/or surgical treatment of kyphosis in myelomeningocele. Patients' information, preoperative kyphosis angle, type of surgery, levels of surgery degrees of correction after surgery and at follow-up, and complications were reviewed for the included studies.

RESULTS

Three cases underwent posterior vertebral column resection (pVCR) of 2-4 segments at the apex of the kyphosis (kyphectomy). Long instrumentation was performed with all pedicle screws constructed from the thoracic spine to the pelvis using iliac screws. According to literature review, a total of 586 children were treated for vertebral kyphosis related to myelomeningocele. At least one vertebra was excised to gain some degree of correction of the deformity. Different types of instrumentation were used over time and none of them demonstrated to be superior over the other.

CONCLUSION

Surgical treatment of progressive kyphosis in myelomeningocele has evolved over the years incorporating all major advances in spinal instrumentation techniques. Certainly, the best results in terms of preservation of correction after surgery and less revision rates were obtained with long construct and screws. However, complication rate remains high with skin problems being the most common complication. The use of low-profile instrumentation remains critical for treatment of these patients.

The Impact of Lateral Ventricular Opening in the Resection of Newly Diagnosed High-Grade Gliomas: A Single Center Experience

Given the importance of maximizing resection for prognosis in patients with HGG and the potential risks associated with ventricle opening, this study aimed to assess the actual increase in post-surgical complications related to lateral ventricle opening and its influence on OS and PFS. A retrospective study was conducted on newly diagnosed HGG, dividing the patients into two groups according to whether the lateral ventricle was opened (69 patients) or not opened (311 patients). PFS, OS, subependymal dissemination, distant parenchymal recurrences, the development of hydrocephalus and CSF leak were considered outcome measures. A cohort of 380 patients (154 females (40.5%) and 226 males (59.5%)) was involved in the study (median age 61 years). The PFS averaged 10.9 months (±13.3 SD), and OS averaged 16.6 months (± 16.3 SD). Among complications, subependymal dissemination was registered in 15 cases (3.9%), multifocal and multicentric progression in 56 cases (14.7%), leptomeningeal dissemination in 12 (3.2%) and hydrocephalus in 8 (2.1%). These occurrences could not be clearly justified by ventricular opening. The act of opening the lateral ventricles itself does not carry an elevated risk of dissemination, hydrocephalus or cerebrospinal fluid (CSF) leak. Therefore, if necessary, it should be pursued to achieve radical removal of the disease.

Lesson learned in endoscopic endonasal dens resection for C1-C2 spinal cord decompression

PURPOSE

Endoscopic endonasal approach (EEA) is the safest and most effective technique for odontoidectomy. Nevertheless, this kind of approach is yet not largely widespread. The aim of this study is to share with the scientific community some tips and tricks with our ten-year-old learned experience in endoscopic endonasal odontoidectomy (EEO), which remains a challenging surgical approach.

MATERIAL AND METHODS

Our case series consists of twenty-one (10 males, 11 females; age range of 34-84 years) retrospectively analyzed patients with ventral spinal cord compression for non-reducible CVJ malformation, treated with EEA from July 2011 to March 2019.

RESULTS

The results have recently been reported in a previous paper. The only intraoperative complication observed was intraoperative cerebrospinal fluid (CSF) leak (9.5%), without any sign of post-operative CSF leak.

CONCLUSIONS

Considering our experience, EEO represents a valid and safe technique to decompress neural cervical structures. Despite its technical complexity, mainly due to the use of endoscope and the challenging surgical area, with this study we encourage the use of EEO displaying our experience-based surgical tips and tricks.

Introducing endoscopic assistance on routinary basis for vestibular schwannomas resection: A single centre acceptance analysis

OBJECTIVE

The use of endoscopic assistance in retrosigmoid approach for tumors of the cerebellopontine angle brought undoubted technological advantages in skull base surgery. Nonetheless, the use of the endoscope is not as widespread as it could be. The aim of the study is to analyze the impressions of neurosurgeons and otologists with different experience in vestibular schwannoma surgery, experiencing the introduction of the endoscope in surgical daily practice.

METHODS

All patients undergoing vestibular schwannoma surgery were recruited in the period from January 2019 to December 2020. The endoscope-assistance and a minimum follow-up of 12 months were considered inclusion criteria. An eight items questionnaire was administered to the surgeons who used endoscope-assistance during surgery.

RESULTS

A total number of 20 patients were recruited. Five surgeons experienced the use of 0° and 45° optics in the "pre-resection" and "intra-meatal" phases of the procedures. The survey gave positive feedbacks on the introduction of the endoscope in vestibular schwannoma resection. The main drawback was the difficulty to manage the use of angled optics.

CONCLUSIONS

Despite the known limitations of the study, the idea of investigating surgeons' impressions on the use of the endoscope could be another motif to explain why this instrument and its diffusion is limited despite its advantages in vestibular schwannoma surgery.

Deep learning-based algorithm for postoperative glioblastoma MRI segmentation: a promising new tool for tumor burden assessment

OBJECTIVE

Clinical and surgical decisions for glioblastoma patients depend on a tumor imaging-based evaluation. Artificial Intelligence (AI) can be applied to magnetic resonance imaging (MRI) assessment to support clinical practice, surgery planning and prognostic predictions. In a real-world context, the current obstacles for AI are low-quality imaging and postoperative reliability. The aim of this study is to train an automatic algorithm for glioblastoma segmentation on a clinical MRI dataset and to obtain reliable results both pre- and post-operatively.

METHODS

The dataset used for this study comprises 237 (71 preoperative and 166 postoperative) MRIs from 71 patients affected by a histologically confirmed Grade IV Glioma. The implemented U-Net architecture was trained by transfer learning to perform the segmentation task on postoperative MRIs. The training was carried out first on BraTS2021 dataset for preoperative segmentation. Performance is evaluated using DICE score (DS) and Hausdorff 95% (H95).

RESULTS

In preoperative scenario, overall DS is 91.09 (± 0.60) and H95 is 8.35 (± 1.12), considering tumor core, enhancing tumor and whole tumor (ET and edema). In postoperative context, overall DS is 72.31 (± 2.88) and H95 is 23.43 (± 7.24), considering resection cavity (RC), gross tumor volume (GTV) and whole tumor (WT). Remarkably, the RC segmentation obtained a mean DS of 63.52 (± 8.90) in postoperative MRIs.

CONCLUSIONS

The performances achieved by the algorithm are consistent with previous literature for both pre-operative and post-operative glioblastoma's MRI evaluation. Through the proposed algorithm, it is possible to reduce the impact of low-quality images and missing sequences.

Facial nerve outcome score: a new score to predict long-term facial nerve function after vestibular schwannoma surgery

Introduction

Patients' quality of life (QoL), facial nerve (FN), and cochlear nerve (CN) (if conserved) functions should be pursued as final outcomes of vestibular schwannoma (VS) surgery. In regard to FN function, different morphologic and neurophysiological factors have been related to postoperative outcomes. The aim of the current retrospective study was to investigate the impact of these factors on the short- and long-term FN function after VS resection. The combination of preoperative and intraoperative factors resulted in designing and validating a multiparametric score to predict short- and long-term FN function.

Methods

A single-center retrospective analysis was performed for patients harboring non-syndromic VS who underwent surgical resection in the period 2015-2020. A minimum follow-up period of 12 months was considered among the inclusion criteria. Morphological tumor characteristics, intraoperative neurophysiological parameters, and postoperative clinical factors, namely, House-Brackmann (HB) scale, were retrieved in the study. A statistical analysis was conducted to investigate any relationships with FN outcome and to assess the reliability of the score.

Results

Seventy-two patients with solitary primary VS were treated in the period of the study. A total of 59.8% of patients showed an HB value < 3 in the immediate postoperative period (T1), reaching to 76.4% at the last follow-up evaluation. A multiparametric score, Facial Nerve Outcome Score (FNOS), was built. The totality of patients with FNOS grade A showed an HB value < 3 at 12 months, decreasing to 70% for those with FNOS grade B, whereas 100% of patients with FNOS grade C showed an HB value ≥ 3. The ordinal logistic regression showed three times increasing probability to see an HB value ≥ 3 at 3-month follow-up for each worsening point in FNOS score [Exp(B), 2,999; p < 0.001] that was even more probable [Exp(B), 5.486; p < 0.001] at 12 months.

Conclusion

The FNOS score resulted to be a reliable score, showing high associations with FN function both at short- and long-term follow-up. Although multicenter studies would be able to increase its reproducibility, it could be used to predict the FN damage after surgery and the potential of restoring its function on the long-term period.

Traumatic peripheral nerve injuries: a classification proposal

BACKGROUND

Peripheral nerve injuries (PNIs) include several conditions in which one or more peripheral nerves are damaged. Trauma is one of the most common causes of PNIs and young people are particularly affected. They have a significant impact on patients' quality of life and on the healthcare system, while timing and type of surgical treatment are of the utmost importance to guarantee the most favorable functional recovery. To date, several different classifications of PNIs have been proposed, most of them focusing on just one or few aspects of these complex conditions, such as type of injury, anatomic situation, or prognostic factors. Current classifications do not enable us to have a complete view of this pathology, which includes diagnosis, treatment choice, and possible outcomes. This fragmentation sometimes leads to an ambiguous definition of PNIs and the impossibility of exchanging crucial information between different physicians and healthcare structures, which can create confusion in the choice of therapeutic strategies and timing of surgery.

MATERIALS

The authors retrospectively analyzed a group of 24 patients treated in their center and applied a new classification for PNI injuries. They chose (a) five injury-related factors, namely nerve involved, lesion site, nerve type (whether motor, sensory or mixed), surrounding tissues (whether soft tissues were involved or not), and lesion type-whether partial/in continuity or complete. An alphanumeric code was applied to each of these classes, and (b) four prognostic codes, related to age, timing, techniques, and comorbidities.

RESULTS

An alphanumeric code was produced, similar to that used in the AO classification of fractures.

CONCLUSIONS

The authors propose this novel classification for PNIs, with the main advantage to allow physicians to easily understand the characteristics of nerve lesions, severity, possibility of spontaneous recovery, onset of early complications, need for surgical treatment, and the best surgical approach.

LEVEL OF EVIDENCE

according to the Oxford 2011 level of evidence, level 2.

Three-Dimensional Patient-Matched Template Guides Are Able to Increase Mean Diameter and Length and to Improve Accuracy of Cortical Bone Trajectory Screws: A 5-Year International Experience

OBJECTIVE

To analyze whether significant differences exist between free-hand three-dimensional (3D) planning-guided cortical bone trajectory (CBT) screw placement and 3D-printed template-guided CBT screw positioning in terms of accuracy, size of screws, and potential complications.

METHODS

In this retrospective study, data of adult patients in whom CBT screws were placed for lumbar degenerative pathologies were extracted from a prospectively collected database and analyzed. Patients in whom screws were placed using free-hand 3D planning-guided technique were compared with patients in whom screws were positioned using customized 3D-printed templates. Size of the screws, accuracy, clinical outcomes, and complications were analyzed.

RESULTS

The study evaluated 251 patients (1004 screws). The free-hand 3D planning-guided group included 158 patients (632 screws), and the 3D-printed template-guided group included 93 patients (372 screws). The 3D-printed template-guided group involved screws of larger size from L3 to S1. Differences between the 2 groups in terms of accuracy parameters reached statistical significance (P ≤ 0.05).

CONCLUSIONS

With the use of 3D patient-matched template guides, mean diameter and length of CBT screws could be safely increased due to improved accuracy of screw placement. Based on previous evidence regarding CBT biomechanical properties, these advantages could allow increased fixation strength over traditional convergent pedicle screw trajectories. Further biomechanics studies are needed.

Stepwise approach for vertebral hemangioma in children: case-reports and treatment algorithm proposal

PURPOSE

To discuss a treatment algorithm for vertebral hemangioma in children.

METHODS

Vertebral hemangioma (VH) is a rare cause of low back pain in children. In most cases, VHs present as incidental findings and do not require invasive diagnostic procedure. In case of symptomatic presentation, different approaches can be used. Over the years, we have developed a treatment algorithm for VH in children based on our clinical experience. In this manuscript, we propose a stepwise approach to treatment of VHs based on tumor extension and the degree of spinal cord/nerves compression with or without neurological deficit.

RESULTS

According to the proposed protocol, we discuss two cases of aggressive VH treated at our institution by a multidisciplinary team. The first case is about a young girl treated with percutaneous one-level posterior instrumentation followed by medical adjuvant therapy for an L4 "Stage 3" VH. The second case is about an 8-year-old boy with rapidly progressive myelopathy due to T11 "Stage 4" VH treated with a combined anterior and posterior surgery (i.e., posterior decompression and fusion followed by vertebrectomy and expandable cage placement) after preoperative arterial embolization.

CONCLUSION

Given the lack of international guidelines and consensus with regard to treatment of VHs in children, we believe our proposal for a stepwise approach combining clinical and radiological characteristics of the lesion may help guide treatment of this condition in children.

3D-printed guides for cervical pedicle screw placement in primary spine tumor: Case report and technical description

Introduction

For spine surgeons, dealing with unstable cervical spine has been usually challenging, and this becomes more difficult when facing a primary craniovertebral junction tumor. Primary spine tumor surgery should always include column reconstruction in order to guarantee biomechanical stability of the spine, but surgeons should always be aware that instrumentations could create interferences with postoperative radiations. However, although carbon fiber instrumentations have started to be used in thoracolumbar oncology for few years, these options are still not available for cervical spine. In the reported case, the adopted strategy to obtain adequate column reconstruction was based on the idea of reducing the amount of titanium needed for posterior fixation and maximizing the distance between the radiation target and titanium rods.

Case report and aim

We present the case of a 53-year-old woman harboring a craniovertebral junction chordoma. A short occipito-C3 construct was selected. Specifically, titanium cervical pedicle screws were placed by using a new technology consisting in patient-tailored and customized 3D-printed guides. The aim of this case report is to determine the feasibility and safety of 3D-printed guides for cervical pedicle screw (CPS) positioning, even in the case of cervical spine tumor.

Conclusion

CPS could represent a good solution by providing strong biomechanical purchase and tailored 3D-printed guides could increase the safety and the accuracy of this challenging screw placement, even in oncological patients.

Endoscopic endonasal odontoidectomy: a long-term follow-up results for a cohort of 21 patients

BACKGROUND

Endoscopic endonasal odontoidectomy (EEO) has been described as a potential approach for craniovertebral junction (CVJ) disease which could cause anterior bulbomedullary compression and encroaching. Due to the atlantoaxial junction's uniqueness and complex biomechanics, treating CVJ pathologies uncovers the challenge of preventing C1-C2 instability. A large series of patients treated with endonasal odontoidectomy is reported, analyzing the feasibility and necessity of whether or not to perform posterior stabilization. Furthermore, the focus is on the long-term follow-up, especially those whom only underwent partial C1 arch preservation without posterior fixation.

METHODS

This study is a retrospective analysis of patients with ventral spinal cord compression for non-reducible CVJ malformation, consecutively treated with EEO from July 2011 to March 2019. Postoperative dynamic X-ray and CT scans were obtained in each case in order to document CVJ decompression as well as to exclude instability. The anterior atlas-dens interval, posterior atlas-dens interval and C1-C2 total lateral overhang were measured as a morphological criteria to determine upper cervical spine stability.

RESULTS

Twenty-one patients (11:10 F:M) with a mean age of 60.6 years old at the time of surgery (range 34-84 years) encountered the inclusion criteria. For all 21 patients, a successful decompression was achieved at the first surgery. In 11 patients, the partial C1 arch integrity did not require a posterior cervical instrumentation on the bases of postoperative and constant follow-up radiological examination. In 13 cases, an improvement of motor function was recorded at the time of discharge. Only one patient had further motor function improvement at follow-up. Among the patients that did not show any significant motor change at discharge, 4 patients showed an improvement at the last follow-up.

CONCLUSIONS

The outcomes, even in C1 arch preservation without posterior fixation, are promising, and it could be said that the endonasal route potentially represents a valid option to treat lesions above the nasopalatine line.

Fluorescence-Guided Surgery in Glioblastoma: 5-ALA, SF or Both? Differences between Fluorescent Dyes in 99 Consecutive Cases

Background: Glioblastoma (GBM) is the most common primary brain tumor. The extent of resection (EOR) has been claimed as one of the most important prognostic factors. Fluorescent dyes aid surgeons in detecting a tumor’s borders. 5-aminolevulinic acid (5-ALA) and sodium fluorescein (SF) are the most used. Only a few studies have directly compared these two fluorophores. Methods: A single center retrospective analysis of patients treated for GBM in the period between January 2018 and January 2021 was built to find any differences in terms of EOR, Karnofsky Performance Status (KPS), and overall survival (OS) on the use of 5-ALA, SF, or both. Results: Overall, 99 patients affected by isocitrate dehydrogenase (IDH) wild-type Glioblastoma were included. 5-ALA was administered to 40 patients, SF to 44, and both to 15. No statistically significant associations were identified between the fluorophore and EOR (p = 0.783) or postoperative KPS (p = 0.270). Survival analyses did not show a selective advantage for the use of a given fluorophore (p = 0.184), although there appears to be an advantageous trend associated with the concomitant use of both dyes, particularly after stratification by MGMT (p = 0.071). Conclusions: 5-Ala and SF are equally useful in achieving gross total resection of the enhancing tumor volume. The combination of both fluorophores could lead to an OS advantage.

The Relevant Role of Navigated Tractography in Speech Eloquent Area Glioma Surgery: Single Center Experience

Background: Gliomas are among the most challenging pathologies for neurosurgeons due to their infiltrative and recurrent nature in functionally relevant regions. Current knowledge confirms that gross total resection highly influence survival in patient with glioma. However, surgery performed in eloquent brain area, could seriously compromise the quality of life in patient with reduced life expectancy even more if it concerns the language function. Methods: 18 right-handed patients with perisylvian gliomas on the left hemisphere were prospectively analyzed over a period of 12 months. Standardized preoperative Diffusion-Tensor-Imaging based tractography of the five main language Tracts (Arcuate Fasciculus, Frontal Aslant Tract, Inferior Fronto-Occipital Fasciculus, Inferior Longitudinal Fasciculus, Uncinate Fasciculus) was navigated during the surgical procedure. Using a validated method, correlations were made between the pre-operative fascicles and their possible infiltration and surgical damage. The language status was assessed using the Aachen Aphasia Test. Results: In all nine patients who developed a permanent disorder there was pre-operative involvement of at least one fascicle and resection of at least one of these. In this way, areas of high risk of permanent language damage have emerged as a result of surgical injury: the temporoparietal junction, the middle portion of the FAT and the temporal stem. Conclusions: Navigated tractography has proven to be a user-friendly tool that can assess perioperative risk, guide surgical resection, and help the neurosurgeon to find that balance between tumor resection and function preservation.

Craniovertebral junction chordomas: Case series and strategies to overcome the surgical challenge

Introduction:

Chordomas are rare and malignant primary bone tumors. Different strategies have been proposed for chordomas involving the craniovertebral junction (CVJ) compared to other locations. The impossibility to achieve en bloc excision, the impact on stability and the need for proper reconstruction make their surgical management challenging.

Objective:

The objective is to discuss surgical strategies in CVJ chordomas operated in a single-center during a 7 years' experience (2013-2019).

Methods:

Adult patients with CVJ chordoma were retrospectively analyzed. The clinical, radiological, pathological, and surgical data were discussed.

Results:

A total number of 8 patients was included (among a total number of 32 patients suffering from skull base chordoma). Seven patients underwent endoscopic endonasal approach (EEA), and posterior instrumentation was needed in three cases. Three explicative cases were reported: EEA for midline tumor involving lower clivus and upper cervical spine (case 1), EEA and complemental posterior approach for occurred occipitocervical instability (case 2), C2 chordoma which required aggressive bone removal and consequent implant positioning, focusing on surgical planning (timing and type of surgical stages, materials and customization of fixation system) (case 3).

Conclusion:

EEA could represent a safe route to avoid injuries to neurovascular structure in clival locations, while a combined approach could be considered when tumor spreads laterally. Tumor involvement or surgical procedures could give raise to CVJ instability with the need of complementary posterior instrumentation. Thus, a tailored preoperative planning should play a key role, especially when aggressive bone removal and implant positioning are needed.

Skull base reconstruction: A question of flow? A critical analysis of 521 endoscopic endonasal surgeries

Introduction

Post-operative CSF leak still represents the main drawback of Endoscopic Endonasal Approach (EEA), and different reconstructive strategies have been proposed in order to decrease its rate.

Objective

To critically analyze the effectiveness of different adopted reconstruction strategies in patients that underwent EEA.

Materials and methods

Adult patients with skull base tumor surgically treated with EEA were retrospectively analyzed. Data recorded for each case concerned patient demographics, type of surgical approach, histotype, anatomical site of surgical approach, intra-operative CSF leak grade (no leak (INL), low flow (ILFL), high flow (IHFL)), reconstructive adopted strategy, Lumbar Drain positioning, post-operative CSF leak rate and intra/post-operative complications.

Results

A total number of 521 patients (January 2012-December 2019) was included. Intra-operative CSF leak grade showed to be associated with post-operative CSF leak rate. In particular, the risk to observe a post-operative CSF leak was higher when IHFL was encountered (25,5%; Exp(B) 16.25). In particular, vascularized multilayered reconstruction and fat use showed to be effective in lowering post-operative CSF leaks in IHFL (p 0.02). No differences were found considering INL and ILFL groups. Yearly post-operative CSF leak rate analysis showed a significative decreasing trend.

Conclusion

Intra-operative CSF leak grade strongly affected post-operative CSF leak rate. Multilayer reconstruction with fat and naso-septal flap could reduce the rate of CSF leak in high risk patients. Reconstructive strategies should be tailored according also to the type and the anatomical site of the approach.

Lenz microphthalmia syndrome in neurosurgical practice: a case report and review of the literature

Lenz microphthalmia syndrome (LMS) is an allelic X-linked syndrome correlated to a null mutation of B cell lymphoma (BCL-6) corepressor (BCOR) gene, which is essential in the early embryonic development. Phenotypically, this rare hereditary syndrome is characterized by microphthalmia/anophthalmia and other eye disorders; mental disability; dental, ear, and digital abnormalities; and variable malformations affecting the heart, skeleton (limbs and/or spine), and genitourinary tract. In this paper, a case of a young adult with LMS affected additionally by immuno-hematological disturbances was treated with decompressive craniectomy after domestic accidental fall. Case description and a brief review of the current literature about this rare condition are presented here.

Could ZI have a role in DBS for Parkinson's Disease? An observational study to optimize DBS target localization

Deep Brain Stimulation (DBS) of the subthalamic nucleus (STN) is a well-recognized intervention for Parkinson's Disease (PD). We used LEAD-DBS, a toolbox facilitating DBS electrode reconstructions and computer simulations based on postoperative MRI and CT imaging, to investigate the interaction and followed benefits of electrical field generated by STN-DBS and surrounding areas, such as caudal Zona Incerta (cZI). Thirty-two PD patients, treated with directional STN-DBS in the period 2016-2018 at the Walton Center NHS Foundation Trust, were retrospectively recruited. Their MRI and CT imaging were analyzed with LEAD-DBS to measure the volume of tissue activated (VTA). Considering the clinical outcome based on the UPDRS III score improvement of 62.65% at 6 months follow up, we found a VTA intersection of 21.5% with motor STN and 61.7% with cZI. These observations may support the contribution of cZI deep stimulation to improve clinical outcome of PD patients treated with DBS, promoting the intriguing path of dual targeting.