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BackgroundDeep brain stimulation (DBS) can be an effective therapy for tics and comorbidities in select cases of severe, treatment-refractory Tourette syndrome (TS). Clinical responses remain variable across patients, which may be attributed to differences in the location of the neuroanatomical regions being stimulated. We evaluated active contact locations and regions of stimulation across a large cohort of patients with TS in an effort to guide future targeting.MethodsWe collected retrospective clinical data and imaging from 13 international sites on 123 patients. We assessed the effects of DBS over time in 110 patients who were implanted in the centromedial (CM) thalamus (n=51), globus pallidus internus (GPi) (n=47), nucleus accumbens/anterior limb of the internal capsule (n=4) or a combination of targets (n=8). Contact locations (n=70 patients) and volumes of tissue activated (n=63 patients) were coregistered to create probabilistic stimulation atlases.ResultsTics and obsessive-compulsive behaviour (OCB) significantly improved over time (p0.05). The median time was 13 months to reach a 40% improvement in tics, and there were no significant differences across targets (p=0.84), presence of OCB (p=0.09) or age at implantation (p=0.08). Active contacts were generally clustered near the target nuclei, with some variability that may reflect differences in targeting protocols, lead models and contact configurations. There were regions within and surrounding GPi and CM thalamus that improved tics for some patients but were ineffective for others. Regions within, superior or medial to GPi were associated with a greater improvement in OCB than regions inferior to GPi.ConclusionThe results collectively indicate that DBS may improve tics and OCB, the effects may develop over several months, and stimulation locations relative to structural anatomy alone may not predict response. This study was the first to visualise and evaluate the regions of stimulation across a large cohort of patients with TS to generate new hypotheses about potential targets for improving tics and comorbidities.

Glioma is one of the most refractory types of brain tumor. Accurate tumor boundary identification and complete resection of the tumor are essential for glioma removal during brain surgery. We present a method based on visible resonance Raman (VRR) spectroscopy to identify glioma margins and grades. A set of diagnostic spectral biomarkers features are presented based on tissue composition changes revealed by VRR. The Raman spectra include molecular vibrational fingerprints of carotenoids, tryptophan, amide I/II/III, proteins, and lipids. These basic in situ spectral biomarkers are used to identify the tissue from the interface between brain cancer and normal tissue and to evaluate glioma grades. The VRR spectra are also analyzed using principal component analysis for dimension reduction and feature detection and support vector machine for classification. The cross-validated sensitivity, specificity, and accuracy are found to be 100%, 96.3%, and 99.6% to distinguish glioma tissues from normal brain tissues, respectively. The area under the receiver operating characteristic curve for the classification is about 1.0. The accuracies to distinguish normal, low grade (grades I and II), and high grade (grades III and IV) gliomas are found to be 96.3%, 53.7%, and 84.1% for the three groups, respectively, along with a total accuracy of 75.1%. A set of criteria for differentiating normal human brain tissues from normal control tissues is proposed and used to identify brain cancer margins, yielding a diagnostic sensitivity of 100% and specificity of 71%. Our study demonstrates the potential of VRR as a label-free optical molecular histopathology method used for in situ boundary line judgment for brain surgery in the margins.

Objective To investigate the indications of optic canal decompression in the patients with front-orbital fibrous dysplasia and the methods of intraoperative optic canal localization and decompression. Methods We collected 30 cases of fibrous dysplasia. All patients had sufficient images assessment. Patients with symptoms underwent surgery, including front-orbital cranioplasty and optic canal decompression. The frontotemporal epidural approaches were used. If there was a proptosis, the approach was extended with the removal of superior orbital ridge. Six patients undertook intraoperative CT and MRI fusion navigation, assisting in confirming the trunk, orbital and cranial orifice of optic nerve. During the operation, the optic canals were decompressed by three-bits method, to confirm the position of optic nerve. Results There were 30 cases of optic canal decompression and one case of vision loss. The visual acuity and vision field of the remaining patients improved to varying degrees. The proptosis disappeared or alleviated after the operation. Thirteen cases were reconstructed with normal internal plate, five cases with titanium plate, nine cases without reconstruction, and two cases were paved with proliferative broken bone on the orbital top; one case recurred with exophthalmos again after five years, but the visual acuity did not decline. Conclusion For the patients with front-orbital fibrous dysplasia, active surgical treatment should be taken, optic canal decompression should be chosen for diminution of vision, craniofacial anaplasty and orbital decompression should be performed in patients with facial deformity. The epidural approach is a good option to locate the optic nerve from the orbital orifice or cranial orifice. Combined with the three-bits method, we can achieve safe and meticulous optic nerve decompression.