The scalp hair collar and tuft signs: A retrospective multicenter study of 78 patients with a systematic review of the literature.

BACKGROUND: Hair collar sign (HCS) and hair tuft of the scalp (HTS) are cutaneous signs of an underlying neuroectodermal defect, but most available data are based on case reports. OBJECTIVE: We sought to define the clinical spectrum of HCS and HTS, clarify the risk for underlying neurovascular anomalies, and provide imaging recommendations. METHODS: A 10-year multicenter retrospective and prospective analysis of clinical, radiologic, and histopathologic features of HCS and HTS in pediatric patients was performed. RESULTS: Of the 78 patients included in the study, 56 underwent cranial and brain imaging. Twenty-three of the 56 patients (41%) had abnormal findings, including the following: (1) cranial/bone defect (30.4%), with direct communication with the central nervous system in 28.6%; (2) venous malformations (25%); or (3) central nervous system abnormalities (12.5%). Meningeal heterotopia in 34.6% (9/26) was the most common neuroectodermal association. Sinus pericranii, paraganglioma, and combined nevus were also identified. LIMITATIONS: The partial retrospective design and predominant recruitment from the dermatology department are limitations of this study. CONCLUSIONS: Infants with HCS or HTS are at high risk for underlying neurovascular anomalies. Magnetic resonance imaging scans should be performed in order to refer the infant to the appropriate specialist for management.

Analgesic efficacy of erector spinae plane blocks for lumbar spine surgery: a randomized double-blind controlled clinical trial.

INTRODUCTION: Erector spinae plane block has been proposed to reduce opioid use and improve pain relief with controversial results. This randomized clinical study aimed to assess the efficacy of erector spinae plane block in major spine surgery including multimodal and 'Enhance Recovery After Surgery' programs. METHOD: After institutional review board approval, adult patients undergoing elective lumbar spine surgery with standardized general anesthesia, rehabilitation and multimodal analgesia protocols were randomly allocated to receive bilateral ultrasound-guided block with saline versus ropivacaine (3.75 mg/mL). Before surgery, a bilateral erector spinae plane block was performed at lumbar level (third vertebrae) with 20 mL of solution for each side. The primary outcome was morphine consumption after 24 hours. Secondary outcomes included pain scores and side effects, from postanesthesia care unit to discharge, and questionnaires at 3 months on pain and quality of life (EQ-5D). RESULTS: From November 2019 to July 2021, 50 patients were enrolled with similar characteristics and surgery for each group. After the first 24 hours, there was no statistical difference regarding cumulative intravenous morphine consumption between ropivacaine and saline groups: 7.3 mg (3.7-19) vs 12.5 mg (3.5-26) (p=0.51). Over the five postoperative days, opioid sparing, pain scores and side effects were similar between groups. At 3 months, pain relief, incidence of chronic pain and EQ-5D were similar between groups. DISCUSSION: Erector spinae plane block used in conjunction with 'Enhance Recovery After Surgery' and multimodal analgesia protocols provides limited reduction in opioid consumption and no long-term benefits. TRIAL REGISTRATION NUMBER: EudraCT 2019-001678-26.

Parasagittal transinsular electrodes for stereo-EEG in temporal and insular lobe epilepsies.

OBJECTIVE: Direct invasive EEG recordings of the insula - due to its particular anatomical position, deeply seated between both opercula - can only be performed with intracerebral electrodes. To date, the technique most commonly used for insular stereoelectroencephalography (SEEG) is the orthogonal-transopercular electrode approach with the Talairach methodology. We propose another technique utilizing MRI with transinsular parasagittal electrodes and a posterior entry point. This avoids passing through the opercula and sylvian vessels running over the insular surface. METHODS: Nine patients, whose seizures implicated the insula, underwent brain surgery. Under general anesthesia with a Leksell frame, 3D-T(1) SPGR MRI with gadolinium enhancement was achieved. Surgical planning was performed using the StealthStation with an entry point in the parieto-occipital junction setting the target for the first contact of the lead at the most anterior part of the insula. The trajectory was manipulated in order to have at least 4 contacts per electrode track within the insular cortex. All patients had a postoperative MRI to verify the exact position of each contact. RESULTS: Insular seizures were recorded in all patients. There was neither intracranial bleeding nor infection. In all of the cases, except 1, the seizures recorded were found to be propagations of the primary epileptic zone located in the temporal lobe, either in the mesial structures or the superior temporal gyrus. Eight patients were operated, 7 with an antero-mesial temporal lobectomy and 1 with dysplasia of the superior temporal gyrus. No insular resections were performed. CONCLUSION: We report a novel technique for insular SEEG with parasagittal electrodes, parallel to the insular cortex, with an entry point at the parieto-occipital junction. This technique is based entirely on use of MRI, and avoids passing through the opercula and sylvian vessels.

Stereotactic coregistration of 201Tl SPECT and MRI applied to brain tumor biopsies.

UNLABELLED: The aim of the present study was to determine the clinical feasibility of integration of stereotactic SPECT (sSPECT) with 201Tl in the stereotactic MRI (sMRI)-based planning of brain tumor biopsy. Furthermore, the predictive value of the integrated techniques was analyzed by comparison with the corresponding histologically determined metabolic activity. METHODS: Ten patients underwent combined 201Tl SPECT- and MRI-guided stereotactic biopsy of intracranial lesions according to a previously described technique. An area of abnormal 201Tl uptake was used to guide the stereotactic biopsy trajectory. Several samples were taken along the trajectory above and beneath the target. An extensive histologic diagnosis (tumor grade, mitotic index [MI], and Ki67 index) and the 201Tl index were obtained for all samples and compared statistically. RESULTS: Combined 201Tl sSPECT- and sMRI-guided biopsy could be performed on all patients. Ki67 index, MI, and tumor grade correlated significantly. The correlations between MI or Ki67 index and 201Tl index were not significant (0.18 and 0.09, respectively). A trend to significance existed between tumor grade and 201Tl index (R = 0.31; P = 0.06). Mean 201Tl index for grade III tumors (3.27 +/- 1.89 [SD]) was significantly different from that for grade IV tumors (4.34 +/- 1.29). The sample position on the trajectory correlated with the MI (R = 0.39; P = 0.01). In 4 of the 10 patients, a variation in tumor grade could be observed along the trajectory. In all patients, the highest proliferative activity was within 5-10 mm of the target. CONCLUSION: These results support the view that 201Tl SPECT may contribute to the successful management of brain tumor patients requiring stereotactic biopsy, without causing a significant increase in discomfort or morbidity. The development of similar techniques integrating sSPECT data in the planning of stereotactic biopsy should be considered by centers performing stereotactic surgery and having access to SPECT technology. In the long term, this technique could become a support for focused gene therapy and cell transfer.

Deep brain stimulation in movement disorders: stereotactic coregistration of two-dimensional electrical field modeling and magnetic resonance imaging.

OBJECT: Adjusting electrical parameters used in deep brain stimulation (DBS) for dystonia remains time consuming and is currently based on clinical observation alone. The goal of this study was to visualize electrical parameters around the electrode, to correlate these parameters with the anatomy of the globus pallidus internus (GPI), and to study the relationship between the volume of stimulated tissue and the electrical parameter settings. METHODS: The authors developed a computer-assisted methodological model for visualizing electrical parameters (the isopotential and the isoelectric field magnitude), with reference to the stereotactic target, for different stimulation settings (monopolar and bipolar) applied during DBS. Electrical field values were correlated with the anatomy of the GPI, which was determined by performing stereotactic magnetic resonance imaging in one reference patient. By using this method it is possible to compare potential and electrical field distributions for different stimulation modes. In monopolar and bipolar stimulation, the shape and distribution of the potential and electrical field are different and depend on the stimulation voltage. Distributions visualized for patient-specific parameters can be subsequently correlated with anatomical information. The application of this method to one patient demonstrated that the 0.2-V/ mm isofield line fits best with the lateral GPI borders at the level of the stimulated contacts. CONCLUSIONS: The electrical field is a crucial parameter because it is assumed to be responsible for triggering action potentials. Electrical field visualization allows the calculation of the stimulated volume for a given isoline. Its application to an entire series of patients may help determine a threshold for obtaining a therapeutic effect, which is currently unknown, and consequently may aid in optimizing parameter settings in individual patients.

Comparison of atlas- and magnetic resonance imaging-based stereotactic targeting of the globus pallidus internus in the performance of deep brain stimulation for treatment of dystonia.

OBJECT: To assess the validity of relying on atlases during stereotactic neurosurgery, the authors compared target coordinates in the globus pallidus internus (GPi) obtained using magnetic resonance (MR) imaging with those determined using an atlas. The targets were used in deep brain stimulation (DBS) for the treatment of generalized dystonia. METHODS: Thirty-five patients, who were treated using bilateral DBS of the GPi, were included in this study. The target was selected on three-dimensional MR images by direct visual recognition of the GPi. The coordinates were automatically recorded using dedicated software. They were translated into the anterior commissure-posterior commissure (AC-PC) coordinate system by using a matrix transformation process. The same GPi target was defined, based on the locations of brain structures shown in the atlases of Schaltenbrand and Talairach. Magnetic resonance imaging-based GPi target coordinates were statistically compared with the corresponding atlas-based coordinates by applying the Student t-test. A significant difference (p < 0.001) was demonstrated in x, y, and z directions between MR imaging-based and Schaltenbrand atlas-derived target coordinates. The comparison with normalized Talairach atlas coordinates demonstrated a significant difference (p < 0.01) in the y and z directions, although not in the x direction (p = 0.12). No significant correlation existed between MR imaging-based target coordinates and patient age (p > 0.1). No significant correlation was observed between MR imaging-based target coordinates and patient sex in the y and z directions (p > 0.9), although it was significant in the x direction (p < 0.05). A significant variation in coordinates and the length of the AC-PC line was revealed only in the y direction (p < 0.005). CONCLUSIONS: A significant difference was found between target coordinates obtained by direct visual targeting on MR images (validated by postoperative clinical results) and those obtained by indirect targeting based on atlases.

Electrical stimulation of the globus pallidus internus in patients with primary generalized dystonia: long-term results.

OBJECT: Primary generalized dystonia (PGD) is a medically refractory disease of the brain causing twisting or spasmodic movements and abnormal postures. In more than 30% of cases it is associated with the autosomal DYT1 mutation. Continuous electrical stimulation of the globus pallidus internus (GPi) has been used successfully in the treatment of PGD. The aim of this study was to examine the long-term efficacy and safety of deep brain stimulation (DBS) in the treatment of PGD in children and adults with and without the DYT1 mutation. METHODS: Thirty-one patients with PGD were selected for surgery. Electrodes were bilaterally implanted under stereotactic guidance and connected to neurostimulators that were inserted subcutaneously. Efficacy was evaluated by comparing scores on the clinical and functional Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) before and after implantation. The efficacy of stimulation improved with time. After 2 years, compared with preoperative values, the mean (+/- standard deviation) clinical and functional BFMDRS scores had improved by 79 +/- 19% and 65 +/- 33%, respectively. At the 2-year follow-up examination the improvement was comparable in patients with and without the DYT1 mutation in both the functional (p = 0.12) and clinical (p = 0.33) scores. Children displayed greater improvements in the clinical score than adult patients (p = 0.04) at 2 years of follow up. In contrast, there was no significant difference in functional scores between children and adults (p = 0.95). CONCLUSIONS: Electrical stimulation of the GPi is an effective, reversible, and adaptable treatment for PGD and should be considered for conditions refractory to pharmaceutical therapies.

Magnetic resonance-based deep brain stimulation technique: a series of 478 consecutive implanted electrodes with no perioperative intracerebral hemorrhage.

OBJECTIVE: The aim of this study was to determine the safety of a deep brain stimulation technique consisting of a combination of routine general anesthesia, magnetic resonance imaging direct targeting, and a single penetration technique in a large population of patients undergoing operation for movement disorders. METHODS: One hundred ninety-four patients treated with deep brain stimulation between 1996 and 2007 were assessed via a computerized database for intra- and perioperative events. Most patients were young; only 62 of them were older than 40 years (mean age, 31.1 years). General anesthesia was induced in all cases before placement of a magnetic resonance imaging-compatible stereotactic frame. Electrode implantation was done under radioscopic control via a rigid immobile cannula using a single cerebral perforation. No perioperative microelectrode recording or neurostimulation testing was used. Systematic postoperative magnetic resonance imaging was performed before frame removal. RESULTS: A total of 478 electrodes were implanted in 220 procedures: 426 for dystonic-dyskinetic syndromes and 52 for Parkinson disease. The mean number of parenchymal penetrations per patient was 2.5 for the dystonic-dyskinetic syndrome group and 2.08 for the Parkinson disease group. Postimplantation magnetic resonance imaging detected no perioperative intraparenchymal hemorrhages. CONCLUSION: We consider that the risk of hemorrhagic complication is multifactorial but closely related to the chosen technique.

Deep brain stimulation for dystonia. Surgical technique.

Stimulation electrodes are implanted under general anesthesia, without intra-operative electrophysiology or clinical testing, based only on stereotactic MRI and direct anatomical localization of the postero-ventro-basal GPi. We retrospectively analyzed the surgical procedure that has been designed and implemented in our center, using the Leksell G frame, for initiating deep brain stimulation in 65 dystonic patients. We report the surgical technique and the hardware and software complications. We recommend immediate postoperative stereotactic MRI under general anesthesia as a prerequisite to check the reliability of MR acquisition (magnet stability) and the exact localization of each electrode. This technique allowed us to reduce the duration of the operation to 4 h, including general anesthesia, frame fixation, MRI acquisition, implantation of two electrodes under radioscopic control, immediate postoperative stereotactic MRI and frame removal. Surgery-related morbidity was very low with a 0% hemorrhage rate and three delayed unilateral infections re-operated 6 months later. Hardware and software complications were rare. The advances in 3D-MR imaging permit the electrode implantation for deep brain stimulation without resorting to intraoperative localization techniques, which is especially helpful in children and for treating dystonia. The maximum follow-up period is 58 months (first case: November 1996). GPi stimulation has proven to be an effective treatment for most dystonic syndromes with particular efficacy in the disease due to the DYT1 mutation.