Estimation of ANT-DBS Electrodes on Target Positioning Based on a New PerceptTM PC LFP Signal Analysis.

Deep brain stimulation of the Anterior Nucleus of the Thalamus (ANT-DBS) is an effective therapy in epilepsy. Poorer surgical outcomes are related to deviations of the lead from the ANT-target. The target identification relies on the visualization of anatomical structures by medical imaging, which presents some disadvantages. This study aims to research whether ANT-LFPs recorded with the PerceptTM PC neurostimulator can be an asset in the identification of the DBS-target. For this purpose, 17 features were extracted from LFPs recorded from a single patient, who stayed at an Epilepsy Monitoring Unit for a 5-day period. Features were then integrated into two machine learning (ML)-based methodologies, according to different LFP bipolar montages: Pass1 (nonadjacent channels) and Pass2 (adjacent channels). We obtained an accuracy of 76.6% for the Pass1-classifier and 83.33% for the Pass2-classifier in distinguishing locations completely inserted in the target and completely outside. Then, both classifiers were used to predict the target percentage of all combinations, and we found that contacts 3 (left hemisphere) and 2 and 3 (right hemisphere) presented higher signatures of the ANT-target, which agreed with the medical images. This result opens a new window of opportunity for the use of LFPs in the guidance of DBS target identification.

Thalamic Deep Brain Stimulation for Neuropathic Pain: Efficacy at Three Years' Follow-Up.

OBJECT: Chronic neuropathic pain is estimated to affect 3-4.5% of the worldwide population, posing a serious burden to society. Deep Brain Stimulation (DBS) is already established for movement disorders and also used to treat some "off-label" conditions. However, DBS for the treatment of chronic, drug refractory, neuropathic pain, has shown variable outcomes with few studies performed in the last decade. Thus, this procedure has consensus approval in parts of Europe but not the USA. This study prospectively evaluated the efficacy at three years of DBS for neuropathic pain. METHODS: Sixteen consecutive patients received 36 months post-surgical follow-up in a single-center. Six had phantom limb pain after amputation and ten deafferentation pain after brachial plexus injury, all due to traumas. To evaluate the efficacy of DBS, patient-reported outcome measures were collated before and after surgery, using a visual analog scale (VAS) score, University of Washington Neuropathic Pain Score (UWNPS), Brief Pain Inventory (BPI), and 36-Item Short-Form Health Survey (SF-36). RESULTS: Contralateral, ventroposterolateral sensory thalamic DBS was performed in sixteen patients with chronic neuropathic pain over 29 months. A postoperative trial of externalized DBS failed in one patient with brachial plexus injury. Fifteen patients proceeded to implantation but one patient with phantom limb pain after amputation was lost for follow-up after 12 months. No surgical complications or stimulation side effects were noted. After 36 months, mean pain relief was sustained, and the median (and interquartile range) of the improvement of VAS score was 52.8% (45.4%) (p = 0.00021), UWNPS was 30.7% (49.2%) (p = 0.0590), BPI was 55.0% (32.0%) (p = 0.00737), and SF-36 was 16.3% (30.3%) (p = 0.4754). CONCLUSIONS: DBS demonstrated efficacy at three years for chronic neuropathic pain after traumatic amputation and brachial plexus injury, with benefits sustained across all pain outcomes measures and slightly greater improvement in phantom limb pain.

Decompressive craniectomy for massive internal carotid artery infarction after pediatric penetrating neck trauma.

Pediatric penetrating carotid arterial trauma is a rare unreported cause of malignant cerebral infarction. Despite increasing evidence of benefit of decompressive hemicraniectomy (DCH) in pediatric malignant stroke, indications and predictors of outcome remain controversial. We report a 4-year-old boy with penetrating zone II neck trauma with laceration of the right internal carotid artery who developed malignant cerebral infarction requiring DCH. Impressive neurological recovery and excellent functional outcome was observed with good psychomotor development and quality of life. To our knowledge, this is the first reported case of pediatric malignant ICA infarction due to penetrating arterial trauma with good neurologic outcome after DCH.

Epithelioid sarcoma of the spine: case report and literature review.

Epithelioid sarcomas are rare mesenchymal neoplasms mainly arising in the limbs of young adults. We report the case of a 24-year-old male presenting low back pain radiating to both lower limbs, constipation and urinary retention. The MRI scan showed an intraspinal lesion extending from L4 to S2. Surgery resulted in gross total removal of the extradural lesion and partial removal of the intradural component. The immunohistological study of the lesion was consistent with an epithelioid sarcoma. The patient was submitted to radiotherapy and chemotherapy, but a local recurrence of the lesion and dissemination along the neuraxis were observed 3 months after surgery. Despite treatment, the patient died 4 months after the surgical procedure due to multiorgan failure. Despite there being isolated reports of epithelioid sarcomas appearing in the spine, this is, to our knowledge, the first case with intradural extension.

Intracerebral hemorrhage after deep brain stimulation surgery guided with microelectrode recording: analysis of 297 procedures.

OBJECTIVES: Report the incidence of symptomatic and asymptomatic intracerebral hemorrhage (ICH) in patients submitted to deep brain stimulation (DBS) guided with microelectrode recording (MER) with further analysis of potential risk factors, both inherent to the patient and related to the pathology and surgical technique. METHODS: We performed a retrospective observational study. 297 DBS procedures were concluded in 277 patients in a single hospital centre between January 2010 and December 2020. All surgeries were guided with MER. We analysed the incidence of symptomatic and asymptomatic ICH and its correlation to age, sex, diagnosis, hypertension and perioperative hypertension, diabetes, dyslipidaemia, antiplatelet drugs, anatomic target, and number of MER trajectories. RESULTS: There were a total of 585 electrodes implanted in 277 patients. 16 ICH were observed, of which 6 were symptomatic and 10 asymptomatic, none of which incurred in permanent neurological deficit. The location of the hemorrhage varied between cortical and subcortical plans, always in relation with the trajectory or the final position of the electrode. The incidence of symptomatic ICH per lead-implantation was 1%, and the CT-scan demonstrated asymptomatic ICH in 1.7% more patients. Male patients or with hypertension are 2.7 and 2.2 times more likely to develop ICH, respectively. However, none of these characteristics has been shown to have a statistically significant association with the occurrence of ICH, as well as age, diagnosis, diabetes, dyslipidaemia, antiplatelet drugs, anatomic target, number of MER trajectories and perioperative hypertension. CONCLUSIONS: MER-guided DBS is a safe technique, with low incidence of ICH and no permanent deficits in our study. Hypertension and male sex seem to be risk factors for the development of ICH in this surgery. Nevertheless, no statistically significant factors were found for the occurrence of this complication.

Thalamic deep brain stimulation for neuropathic pain after amputation or brachial plexus avulsion.

OBJECT: Fifteen hundred patients have received deep brain stimulation (DBS) to treat neuropathic pain refractory to pharmacotherapy over the last half-century, but few during the last decade. Deep brain stimulation for neuropathic pain has shown variable outcomes and gained consensus approval in Europe but not the US. This study prospectively evaluated the efficacy at 1 year of DBS for phantom limb pain after amputation, and deafferentation pain after brachial plexus avulsion (BPA), in a single-center case series. METHODS: Patient-reported outcome measures were collated before and after surgery, using a visual analog scale (VAS) score, 36-Item Short-Form Health Survey (SF-36), Brief Pain Inventory (BPI), and University of Washington Neuropathic Pain Score (UWNPS). RESULTS: Twelve patients were treated over 29 months, receiving contralateral, ventroposterolateral sensory thalamic DBS. Five patients were amputees and 7 had BPAs, all from traumas. A postoperative trial of externalized DBS failed in 1 patient with BPA. Eleven patients proceeded to implantation and gained improvement in pain scores at 12 months. No surgical complications or stimulation side effects were noted. In the amputation group, after 12 months the mean VAS score improved by 90.0% ± 10.0% (p = 0.001), SF-36 by 57.5% ± 97.9% (p = 0.127), UWNPS by 80.4% ± 12.7% (p < 0.001), and BPI by 79.9% ± 14.7% (p < 0.001). In the BPA group, after 12 months the mean VAS score improved by 52.7% ± 30.2% (p < 0.001), SF-36 by 15.6% ± 30.5% (p = 1.000), UWNPS by 26.2% ± 40.8% (p = 0.399), and BPI by 38.4% ± 41.7% (p = 0.018). Mean DBS parameters were 2.5 V, 213 microseconds, and 25 Hz. CONCLUSIONS: Deep brain stimulation demonstrated efficacy at 1 year for chronic neuropathic pain after traumatic amputation and BPA. Clinical trials that retain patients in long-term follow-up are desirable to confirm findings from prospectively assessed case series.

Bilateral deep brain stimulation of the subthalamic nucleus: Targeting differences between the first and second side.

INTRODUCTION AND OBJECTIVES: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a recognized treatment for drug-refractory Parkinson's disease (PD). However, the therapeutic success depends on the accuracy of targeting. This study aimed to evaluate potential accuracy differences in the placement of the first and second electrodes implanted, by comparing chosen electrode trajectories, STN activity detected during microelectrode recording (MER), and the mismatch between the initially planned and final electrode positions on each side. MATERIALS AND METHODS: In this retrospective cohort study, we analyzed data from 30 patients who underwent one-stage bilateral DBS. For most patients, three arrays of microelectrodes were used to determine the physiological location of the STN. Final target location depended also on the results of intraoperative stimulation. The choice of central versus non-central channels was compared. The Euclidean vector deviation was calculated using the initially planned coordinates and the final position of the tip of the electrode according to a CT scan taken at least a month after the surgery. RESULTS: The central channel was chosen in 70% of cases on the first side and 40% of cases on the second side. The mean length of high-quality STN activity recorded in the central channel was longer on the first side than the second (3.07±1.85mm vs. 2.75±1.94mm), while in the anterior channel there were better MER recordings on the second side (1.59±2.07mm on the first side vs. 2.78±2.14mm on the second). Regarding the mismatch between planned versus final electrode position, electrodes on the first side were placed on average 0.178±0.917mm lateral, 0.126±1.10mm posterior and 1.48±1.64mm inferior to the planned target, while the electrodes placed on the second side were 0.251±1.08mm medial, 0.355±1.29mm anterior and 2.26±1.47mm inferior to the planned target. CONCLUSION: There was a tendency for the anterior trajectory to be chosen more frequently than the central on the second side. There was also a statistically significant deviation of the second electrodes in the anterior and inferior directions, when compared to the electrodes on the first side, suggesting that another cause other than brain shift may be responsible. We should therefore factor this during planning for the second implanted side. It might be useful to plan the second side more anteriorly, possibly reducing the number of MER trajectories tested and the duration of surgery.

Deep Brain Stimulation of the Anterior Nucleus of the Thalamus in Drug-Resistant Epilepsy in the MORE Multicenter Patient Registry.

BACKGROUND AND OBJECTIVES: The efficacy of deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) in patients with drug-resistant epilepsy (DRE) was demonstrated in the double-blind Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy randomized controlled trial. The Medtronic Registry for Epilepsy (MORE) aims to understand the safety and longer-term effectiveness of ANT DBS therapy in routine clinical practice. METHODS: MORE is an observational registry collecting prospective and retrospective clinical data. Participants were at least 18 years old, with focal DRE recruited across 25 centers from 13 countries. They were followed for at least 2 years in terms of seizure frequency (SF), responder rate (RR), health-related quality of life (Quality of Life in Epilepsy Inventory 31), depression, and safety outcomes. RESULTS: Of the 191 patients recruited, 170 (mean [SD] age of 35.6 [10.7] years, 43% female) were implanted with DBS therapy and met all eligibility criteria. At baseline, 38% of patients reported cognitive impairment. The median monthly SF decreased by 33.1% from 15.8 at baseline to 8.8 at 2 years (p < 0.0001) with 32.3% RR. In the subgroup of 47 patients who completed 5 years of follow-up, the median monthly SF decreased by 55.1% from 16 at baseline to 7.9 at 5 years (p < 0.0001) with 53.2% RR. High-volume centers (>10 implantations) had 42.8% reduction in median monthly SF by 2 years in comparison with 25.8% in low-volume center. In patients with cognitive impairment, the reduction in median monthly SF was 26.0% by 2 years compared with 36.1% in patients without cognitive impairment. The most frequently reported adverse events were changes (e.g., increased frequency/severity) in seizure (16%), memory impairment (patient-reported complaint, 15%), depressive mood (patient-reported complaint, 13%), and epilepsy (12%). One definite sudden unexpected death in epilepsy case was reported. DISCUSSION: The MORE registry supports the effectiveness and safety of ANT DBS therapy in a real-world setting in the 2 years following implantation. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that ANT DBS reduces the frequency of seizures in patients with drug-resistant focal epilepsy. TRIAL REGISTRATION INFORMATION: MORE ClinicalTrials.gov Identifier: NCT01521754, first posted on January 31, 2012.

Towards a Closed-loop Neuro-Robotic Approach to DBS Electrode Implantation based on Real-Time Wrist Rigidity Evaluation.

The iHandU system is a wearable device that quantitatively evaluates changes in wrist rigidity during Deep Brain Stimulation (DBS) surgery, allowing clinicians to find optimal stimulation settings that reduce patient symptoms. Robotic accuracy is also especially relevant in DBS surgery, as accurate electrode placement is required to increase effectiveness and reduce side effects. The main goal of this work is to integrate the advantages of each system in a closed-loop system between an industrial robot and the iHandU system. For this purpose, a comparative analysis of a Leksell stereotactic frame and neuro-robotic system accuracies was performed using a lab-made phantom. The neuro-robotic system reached 90% of trajectories, while the stereotactic frame reached all trajectories. There are significant differences in accuracy errors between these trajectories (p < 0.0001), which can be explained by the high correlation between the neuro-robotic system errors and the distance from the trajectory to the origin of the Leksell coordinate system (ρ = 0.72). Overall accuracy is comparable to existing neuro-robotic systems, achieving a deviation of (1.0 ± 0.5) mm at the target point. The accuracy of DBS electrode positioning and stimulation parameters choice leads to better long-term clinical outcomes in Parkinson's disease patients. Our neuro-robotic system combines real-time feedback assessment of the patient's symptomatic response and automatic positioning of the DBS electrode in a specific brain area.

Lung cancer: atypical brain metastases mimicking neurocysticercosis.

The authors describe a case of a 47-year-old male smoker with a 3-month history of hearing loss, tinnitus and dizziness. Physical examination revealed neurosensory hearing loss. Small rounded hypodensities without mass effect were evident in a computed tomography scan of the head, confirmed by brain magnetic resonance imaging as multiple cystic lesions in both cerebral and cerebellar hemispheres, without perilesional edema or gadolinium enhancement, suggestive of neurocysticercosis. Extraparenchymal involvement was also noted. Albendazole and dexamethasone were started. As a chest radiograph showed a bilateral reticulonodular pattern, a bronchoscopy was performed showing normal results. However, transbronchial biopsy revealed lung adenocarcinoma. Thoracoabdominopelvic computed tomography scan showed secondary lung and bone lesions. Since brain lesions were not suggestive of secondary tumor lesions, a brain biopsy was performed confirming metastatic disease. This case illustrates some peculiar imagiological features of brain metastases in lung cancer, indicating that sometimes invasive procedures are required to establish a definitive diagnosis.

Multiple brain abscesses - a rare complication of bronchiectasis.

BACKGROUND: Brain abscess can arise as a complication of a variety of infections, trauma or surgery. Bacteria can invade the brain by direct spread or through haematogenous seeding. Brain abscesses are described as a rare complication of bronchiectasis. CASE DESCRIPTION: A 44 -year -old woman with pulmonary tuberculosis in childhood and with the diagnosis of bilateral extensive bronchiectasis who presented behaviour alterations and later, paresis of the sixth cranial nerve, was diagnosed multiple brain abscesses. The microbiological exams were negative. The study of the primary focus of infection could only identify infected bronchiectasis. Empiric antibiotics and anti- -oedematous treatment were prescribed with progressive clinical improvement. Because of inadequate response she was submitted to surgery. She was discharged with diplopia, without any other neurological alterations. CONCLUSION: In the present clinical case, the infected bronchiectasis were the only focal infection detected, so in patients with this disease and with new neurological manifestations, infected lesions in the central nervous system should be excluded.

Early deep brain stimulation in patients with myoclonus-dystonia syndrome.

Myoclonus-dystonia (MD) is a rare movement disorder which is disabling and frequently refractory to medical treatment. Deep brain stimulation (DBS) of the globus pallidus interna (GPi) has been used to treat some patients. Although there is significant motor improvement with DBS, the impact on disability and on quality of life has been infrequently reported. Also, the benefit of the procedure is not established in patients without ε-sarcoglycan gene (SGCE) mutations. We present two patients with severe MD treated with GPi-DBS, one of the patients without a SGCE mutation. Motor improvements (rest/action/total subscores of the Unified Myoclonus Rating Scale and movement subscore of the Burke-Fahn-Marsden Dystonia Rating Scale [BFMRS]) and disability (BFMRS disability subscore) were carefully evaluated preoperatively and at 6 and 12months after surgery. Quality of life (addressed using the Portuguese version of the Medical Outcomes Study 36-item Short-Form General Health Survey, version 2.0 [SF-36v2]) was tested preoperatively and 12months after DBS. At 12-month follow-up, myoclonus improved 78.6% in Patient 1 and 80.7% in Patient 2, while dystonia improved 37% and 86.7%, respectively. Improvements in disability ranged from 71.4% to 75%. With regard to quality of life, all parameters addressed by the SF-36v2 improved or stabilized in both patients. No major adverse effects were noticed. Improvements in motor symptoms are consistent with reports in the literature and were obtained regardless of the identification of a SGCE gene mutation. There were also significant benefits on disability and quality of life. DBS should be considered for MD.

Twiddler (or Not) Syndrome: Questioning etiology for an uncommon form of hardware malfunction in deep brain stimulation.

BACKGROUND: Hardware failure or malfunction after deep brain stimulation is an infrequent but costly occurrence with currently available systems. CASE DESCRIPTION: The authors present the case of a 65-year-old female patient with predominantly tremoric Parkinson's disease who, 4 months after bilateral subthalamic nucleus stimulation with very good clinical results, began to display signs of recurrent disease and an increasingly smaller response to stimulation. Radiological studies, changes in electrode impedance and surgical findings and results established the diagnosis of Twiddler syndrome. Close patient follow-up, lack of a psychiatric history and physical examination findings were, however, contrary to the previously described causative mechanism. CONCLUSION: The clinical and radiological setup of Twiddler syndrome must be readily recognized. Its causative mechanism should remain under discussion, and intraoperative technical details may help to explain its occurrence.

Long-term mortality analysis in Parkinson's disease treated with deep brain stimulation.

Background. Few data have been published regarding long-term mortality in patients with Parkinson's disease treated with DBS. Methods. This study analyzed long-term mortality rates, causes, and correlates in PD patients treated with DBS. Results. 184 consecutive patients were included; mean follow-up was 50 months. Fifteen deaths occurred (total 8.15%, annual mortality rate 1.94%). Mean age at disease onset and at surgery was 48 ± 2.4 and 63 ± 1.6 years, respectively. Mean disease duration until death was 21 ± 7.8 years. Most deaths related to stroke, myocardial infarction, other vascular/heart disorders, or severe infection; one suicide was recorded. Deceased PD patients were mostly male and had lower motor benefit after DBS, but univariate analysis failed to show significant differences regarding gender and motor benefit. Survival was 99% and 94% at 3 and 5 years. Conclusions. Long-term survival is to be expected in PD patients treated with DBS, possibly higher than previously expected. Death usually supervenes due to vascular events or infection.