Ventral targeted anterior capsulotomy for treatment-resistant depression and obsessive-compulsive disorder: A treatment method with cases.

BACKGROUND: Ablative surgery using bilateral anterior capsulotomy (BAC) is an option for treatment resistant depression (TRD) and obsessive-compulsive disorder (TROCD). The location and extent of the lesion within anterior limb of the internal capsule (ALIC) remains uncertain. Accumulating evidence has suggested that the lesion should be located ventrally while limiting the dorsal extent. Our center is now targeting specific fiber tracts within the lower half of the ALIC. METHOD: Presurgical diffusion tensor Magnetic Resonance Imaging (MRI) was used to identify individual fibre tracts within the ventral aspect of the ALIC in the last two patients who underwent BAC at our center. One patient had TRD and the other had both TROCD and TRD. Radiofrequency-induced thermal lesions were created in the identified targets with lesion volumes between 20 and 229 mm3 (average 95 mm3). FINDINGS: Both patients were responders with neither experiencing significant side effects including compromised executive functions. LIMITATIONS: The generalizability of our findings is limited because the outcome is based on two subjects. CONCLUSION: This work suggests that BAC can be individually tailored and more limited to the ventral aspect of the ALIC and is effective and safe for TRD and TROCD. Accumulating data also suggests that to be clinically effective the length of the capsulotomy should be about 10mm. BAC's use may increase with the growing utilization and mastery of magnetic resonance guided focused ultrasound.

Protocatechudehyde improves mitochondrial energy metabolism through the HIF1α/PDK1 signaling pathway to mitigate ischemic stroke-elicited internal capsule injury.

ETHNOPHARMACOLOGICAL RELEVANCE: The internal capsule is vulnerable to ischemia, and mild ischemic stroke often results in lesion of the internal capsule, manifested as contralateral hemiplegia. Protocatechudehyde (PCA), a potential neuroprotective agent, has shown therapeutic effects in the study of a variety of nervous system diseases, including ischemic stroke. AIM OF THE STUDY: The aim of this study was to evaluate the effects of PCA on cerebral ischemia reperfusion (CI/R)-elicited internal capsule injury and to elucidate the role of mitochondrial energy metabolism in the underlying mechanism of neuroprotective effects on ischemic stroke. MATERIALS AND METHODS: A rat tMCAO model was established to investigate the therapeutic effects of intravenous PCA (20, 40, and 80 mg/kg, once per day, continued for 7 days) on CI/R-induced internal capsule injury and the regulation of PCA on molecules related to mitochondrial energy metabolism. In vitro, an OGD/R model of PC12 cells was established to further verify the therapeutic mechanism of PCA. RESULTS: Results showed that PCA dose-dependently attenuated neurological deficit, reduced cerebral infarction, alleviated histopathological damage, and improved mitochondrial ultrastructure of the internal capsule after CI/R. Moreover, PCA reversed the upregulation of HIF1α, PDK1 and pPDHA1 expression induced by CI/R and significantly increased the content of acetyl-CoA, ATP, and the activity of ATP synthase. In vitro, PCA treatment promoted cell survival, inhibited apoptosis, attenuated the dissipation of mitochondrial membrane potential in OGD/R-treated PC12 cells, and these therapeutic effects were reversed by the combination of cobalt chloride (CoCl2), a specific pharmacological inducer of HIF1a expression. CONCLUSIONS: These results indicate that PCA exerts a protective effect against CI/R-induced internal capsule injury and improves mitochondrial energy metabolism in the internal capsule, and the mechanism is associated with the inhibition of HIF1α/PDK1 signaling pathway.

Acute motor deficit and subsequent remyelination-associated recovery following internal capsule demyelination in mice.

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system (CNS), characterized by accumulated motor disability. However, whether remyelination promotes motor recovery following demyelinating injury remains unclear. Damage to the internal capsule (IC) is known to result in motor impairment in multiple sclerosis and stroke. Here, we induced focal IC demyelination in mice by lysophosphatidylcholine (LPC) injection, and examined its effect on motor behavior. We also compared the effect of LPC-induced IC damage to that produced by endothelin-1 (ET1), a potent vasoconstrictor used in experimental stroke lesions. We found that LPC or ET1 injections induced asymmetric motor deficit at 7 days post-lesion (dpl), and that both lesion types displayed increased microglia/macrophage density, myelin loss, and axonal dystrophy. The motor deficit and lesion pathology remained in ET1-injected mice at 28 dpl. In contrast, LPC-injected mice regained motor function by 28 dpl, with corresponding reduction in activated microglia/macrophage density, and recovery of myelin staining and axonal integrity in lesions. These results suggest that LPC-induced IC demyelination results in acute motor deficit and subsequent recovery through remyelination, and may be used to complement future drug screens to identify drugs for promoting remyelination.

Tractographic description of major subcortical projection pathways passing the anterior limb of the internal capsule. Corticopetal organization of networks relevant for psychiatric disorders.

BACKGROUND: Major depression (MD) and obsessive-compulsive disorder (OCD) are psychiatric diseases with a huge impact on individual well-being. Despite optimal treatment regiments a subgroup of patients remains treatment resistant and stereotactic surgery (stereotactic lesion surgery, SLS or Deep Brain Stimulation, DBS) might be an option. Recent research has described four networks related to MD and OCD (affect, reward, cognitive control, default network) but only on a cortical and the adjacent sub-cortical level. Despite the enormous impact of comparative neuroanatomy, animal science and stereotactic approaches a holistic theory of subcortical and cortical network interactions is elusive. Because of the dominant hierarchical rank of the neocortex, corticofugal approaches have been used to identify connections in subcortical anatomy without anatomical priors and in part confusing results. We here propose a different corticopetal approach by identifying subcortical networks and search for neocortical convergences thereby following the principle of phylogenetic and ontogenetic network development. MATERIAL AND METHODS: This work used a diffusion tensor imaging data from a normative cohort (Human Connectome Project, HCP; n = 200) to describe eight subcortical fiber projection pathways (PPs) from subthalamic nucleus (STN), substantia nigra (SNR), red nucleus (RN), ventral tegmental area (VTA), ventrolateral thalamus (VLT) and mediodorsal thalamus (MDT) in a normative space (MNI). Subcortical and cortical convergences were described including an assignment of the specific pathways to MD/OCD-related networks. Volumes of activated tissue for different stereotactic stimulation sites and procedures were simulated to understand the role of the distinct networks, with respect to symptoms and treatment of OCD and MD. RESULTS: The detailed course of eight subcortical PPs (stnPP, snrPP, rnPP, vlATR, vlATRc, mdATR, mdATRc, vtaPP/slMFB) were described together with their subcortical and cortical convergences. The anterior limb of the internal capsule can be subdivided with respect to network occurrences in ventral-dorsal and medio-lateral gradients. Simulation of stereotactic procedures for OCD and MD showed dominant involvement of mdATR/mdATRc (affect network) and vtaPP/slMFB (reward network). DISCUSSION: Corticofugal search strategies for the evaluation of stereotactic approaches without anatomical priors often lead to confusing results which do not allow for a clear assignment of a procedure to an involved network. According to our simulation of stereotactic procedures in the treatment of OCD and MD, most of the target regions directly involve the reward (and affect) networks, while side-effects can in part be explained with a co-modulation of the control network. CONCLUSION: The here proposed corticopetal approach of a hierarchical description of 8 subcortical PPs with subcortical and cortical convergences represents a new systematics of networks found in all different evolutionary and distinct parts of the human brain.

Comparison of probabilistic tractography and tract-based spatial statistics for assessing optic radiation damage in patients with autoimmune inflammatory disorders of the central nervous system.

Background: Diffusion Tensor Imaging (DTI) can evaluate microstructural tissue damage in the optic radiation (OR) of patients with clinically isolated syndrome (CIS), early relapsing-remitting multiple sclerosis and neuromyelitis optica spectrum disorders (NMOSD). Different post-processing techniques, e.g. tract-based spatial statistics (TBSS) and probabilistic tractography, exist to quantify this damage. Objective: To evaluate the capacity of TBSS-based atlas region-of-interest (ROI) combination with 1) posterior thalamic radiation ROIs from the Johns Hopkins University atlas (JHU-TBSS), 2) Juelich Probabilistic ROIs (JUEL-TBSS) and tractography methods using 3) ConTrack (CON-PROB) and 4) constrained spherical deconvolution tractography (CSD-PROB) to detect OR damage in patients with a) NMOSD with prior ON (NMOSD-ON), b) CIS and early RRMS patients with ON (CIS/RRMS-ON) and c) CIS and early RRMS patients without prior ON (CIS/RRMS-NON) against healthy controls (HCs). Methods: Twenty-three NMOSD-ON, 18 CIS/RRMS-ON, 21 CIS/RRMS-NON, and 26 HCs underwent 3 T MRI. DTI data analysis was carried out using JUEL-TBSS, JHU-TBSS, CON-PROB and CSD-PROB. Optical coherence tomography (OCT) and visual acuity testing was performed in the majority of patients and HCs. Results: Absolute OR fractional anisotropy (FA) values differed between all methods but showed good correlation and agreement in Bland-Altman analysis. OR FA values between NMOSD and HC differed throughout the methodologies (p-values ranging from p < 0.0001 to 0.0043). ROC-analysis and effect size estimation revealed higher AUCs and R2 for CSD-PROB (AUC = 0.812; R2 = 0.282) and JHU-TBSS (AUC = 0.756; R2 = 0.262), compared to CON-PROB (AUC = 0.742; R2 = 0.179) and JUEL-TBSS (AUC = 0.719; R2 = 0.161). Differences between CIS/RRMS-NON and HC were only observable in CSD-PROB (AUC = 0.796; R2 = 0.094). No significant differences between CIS/RRMS-ON and HC were detected by any of the methods. Conclusions: All DTI post-processing techniques facilitated the detection of OR damage in patient groups with severe microstructural OR degradation. The comparison of distinct disease groups by use of different methods may lead to different - either false-positive or false-negative - results. Since different DTI post-processing approaches seem to provide complementary information on OR damage, application of distinct methods may depend on the relevant research question.

Perioperative neonatal brain injury is associated with worse school-age neurodevelopment in children with critical congenital heart disease.

AIM: To assess the impact of perioperative neonatal brain injury and brain volumes on neurodevelopment throughout school-age children with critical congenital heart disease (CHD). METHOD: Thirty-four survivors of neonatal cardiac surgery (seven females, 27 males) were included. Neonatal preoperative and postoperative cerebral magnetic resonance imaging was performed and neurodevelopment was assessed at 24 months (SD 0.7, n=32, using Bayley Score of Infant and Toddler Development, Child Behavior Checklist) and 6 years (mean age 5y 11mo; SD 0.3, n=30, using Movement Assessment Battery for Children, Wechsler Preschool and Primary Scale of Intelligence, Child Behavior Checklist, Teacher Report Form). Brain injury, brain volumes, and cortical measures were related to outcome with adjustment for maternal educational level. RESULTS: Two-year cognitive score and 6-year Full-scale IQ were poorer in children with neonatal white matter injury (n=21, all p<0.05), with higher teacher-reported attention problems (p=0.03). Five of six children with involvement of the posterior limb of the internal capsule showed motor problems (p=0.03). Children with a below-average Fulll-scale IQ (<85, n=9) showed smaller volumes of basal ganglia thalami (-8%, p=0.03) and brain stem (-7%, p=0.03). INTERPRETATION: Our findings provide evidence of unfavourable outcome in school-age children with critical CHD who acquire perioperative neonatal brain injury. WHAT THIS PAPER ADDS: This paper extends knowledge about neonatal brain injury and long-term outcome in congenital heart disease. Children with white matter injury show lower IQ and more attention problems at school age. Injury of the posterior limb of the internal capsule increases the risk of motor problems. This study provides evidence for worse outcomes in neonates acquiring brain injury around cardiac surgery.

Gamma Ventral Capsulotomy in Intractable Obsessive-Compulsive Disorder.

BACKGROUND: Despite the development of effective pharmacologic and cognitive behavioral treatments for obsessive-compulsive disorder (OCD), some patients continue to be treatment-refractory and severely impaired. Fiber tracts connecting orbitofrontal and dorsal anterior cingulate cortex with subcortical nuclei have been the target of neurosurgical lesions as well as deep brain stimulation in these patients. We report on the safety and efficacy of ventral gamma capsulotomy for patients with intractable OCD. METHODS: Fifty-five patients with severely disabling, treatment-refractory OCD received bilateral lesions in the ventral portion of the anterior limb of the internal capsule over a 20-year period using the Leksell Gamma Knife. The patients were prospectively followed over 3 years with psychiatric, neurologic, and neuropsychological assessments of safety and efficacy, as well as structural neuroimaging. RESULTS: Thirty-one of 55 patients (56%) had an improvement in the primary efficacy measure, the Yale-Brown Obsessive Compulsive Scale, of ≥35% over the 3-year follow-up period. Patients had significant improvements in depression, anxiety, quality of life, and global functioning. Patients tolerated the procedure well without significant acute adverse events. Five patients (9%) developed transient edema that required short courses of dexamethasone. Three patients (5%) developed cysts at long-term follow-up, 1 of whom developed radionecrosis resulting in an ongoing minimally conscious state. CONCLUSIONS: Gamma Knife ventral capsulotomy is an effective radiosurgical procedure for many treatment-refractory OCD patients. A minority of patients developed cysts at long-term follow-up, 1 of whom had permanent neurological sequelae.

[Symmetrical lesions of the cerebral peduncles and internal capsules on MRI in a patient with extranodal NK/T cell lymphoma].

A 72-year-old man was admitted to our hospital because of subacute progressive consciousness disturbance. FLAIR images showed diffuse high intensity areas in the bilateral thalamus, basal ganglia, and white matter. Chest CT revealed a mass in the right lung. The patient was diagnosed with extranodal natural killer/T cell lymphoma (ENKL) according to the results of a biopsy of the right pulmonary mass. The FLAIR images showed diffuse white matter lesions, without a mass such as lymphomatosis cerebri. On diffusion-weighted images, symmetrical high-intensity lesions of the cerebral peduncle and the internal capsule suggested high-density lymphoma cells around neurons. ENKL of the central nervous system and lung is a very rare neoplasm, and this case showed characteristic images.

Capsular stroke modeling based on somatotopic mapping of motor fibers.

Recently, several capsular stroke models have been reported with different targets of destruction. This study was performed to establish an accurate internal capsule (IC) target for capsular stroke modeling in rats. We injected adeno-associated virus serotype 5 (AAV)-CaMKII-EYFP into forelimb motor cortex and AAV-CaMKII-mCherry into hindlimb motor cortex (n = 9) to anterogradely trace the pyramidal fibers and map their somatotopic distribution in the IC. On the basis of the neural tracing results, we created photothrombotic infarct lesions in rat forelimb and hindlimb motor fiber (FMF and HMF) areas of the IC (n = 29) and assessed motor behavior using a forelimb-use asymmetry test, a foot-fault test, and a single-pellet reaching test. We found that the FMFs and HMFs were primarily distributed in the inferior portion of the posterior limb of the IC, with the FMFs located largely ventral to the HMFs but with an area of partial overlap. Photothrombotic lesions in the FMF area resulted in persistent motor deficits. In contrast, lesions in the HMF area did not result in persistent motor deficits. These results indicate that identification of the somatotopic distribution of pyramidal fibers is critical for accurate targeting in animal capsular stroke models: only infarcts in the FMF area resulted in long-lasting motor deficits.

Inflammatory cytokines influence measures of white matter integrity in Bipolar Disorder.

BACKGROUND: Bipolar Disorder (BD) is associated with elevated biomarkers of cell-mediated immune activation and inflammation and with signs of widespread disruption of white matter (WM) integrity in adult life. Consistent findings in animal models link WM damage in inflammatory diseases of the brain and serum levels of cytokines. METHODS: With an exploratory approach, we tested the effects of 22 serum analytes, including pro- and anti-inflammatory cytokines and neurotrophic/hematopoietic factors, on DTI measures of WM microstructure in a sample of 31 patients with a major depressive episode in course of BD. We used whole brain tract-based spatial statistics in the WM skeleton with threshold-free cluster enhancement of DTI measures of WM microstructure: axial (AD), radial (RD), and mean diffusivity (MD), and fractional anisotropy (FA). RESULTS: The inflammation-related cytokines TNF-α, IL-8, IFN-γ and IL-10, and the growth factors IGFBP2 and PDGF-BB, shared the same significant associations with lower FA, and higher MD and RD, in large overlapping networks of WM fibers mostly located in the anterior part of the brain and including corpus callosum, cingulum, superior and inferior longitudinal fasciculi, inferior fronto-occipital fasciculi, uncinate, forceps, corona radiata, thalamic radiation, internal capsule. CONCLUSIONS: Higher RD is thought to signify increased space between fibers, suggesting demyelination or dysmyelination. The pattern of higher RD and MD with lower FA suggests that inflammation-related cytokine and growth factor levels inversely associate with integrity of myelin sheaths. The activated inflammatory response system might contribute to BD pathophysiology by hampering structural connectivity in critical cortico-limbic networks.

An olfactory groove schwannoma with a pseudocyst compressing the basal ganglia, internal capsule and optic tracts.

INTRODUCTION: Olfactory groove schwannomas (OGSs) are extremely rare tumours, particularly in the paediatric population. CASE REPORT: A 13-year-old girl presented with two epileptic seizures, papilloedema and incomplete binasal quadrantanopia. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a large heterogeneously enhancing tumour of the anterior skull base with a prominent dorsal pseudocyst. Interestingly, the pseudocyst embraced the right ICA bifurcation and displaced the optic tracts, optic chiasm and optic nerves and the ipsilateral basal ganglia. The patient underwent surgery via the frontolateral approach, and the tumour was completely removed. The pseudocyst was opened, and its wall was partially resected. It subsequently resolved completely. Histopathological examination yielded the rare diagnosis of schwannoma of the anterior skull base. CONCLUSION: Although extremely rare, olfactory groove schwannomas can be seen in paediatric patients. Our patient is the youngest ever reported with this histopathological diagnosis along with the formation of a large pseudocyst.

Surgical Treatment of Cavernous Malformations Involving the Posterior Limb of the Internal Capsule: Utility and Predictive Value of Preoperative Diffusion Tensor Imaging.

OBJECTIVE: The surgical treatment of cavernous malformations involving the posterior limb of the internal capsule (PLIC-CMs) is challenging. The aim of this study was to determine the utility and predictive value of preoperative diffusion tensor imaging (DTI) in the surgical treatment of PLIC-CMs. METHODS: Patients with PLIC-CMs who were surgically treated between September 2012 and June 2015 were reviewed. All patients underwent preoperative DTI. Three major fiber tracts were selected for evaluation: 1) corticospinal tract (CST); 2) arcuate fasciculus (AF); and 3) optic radiation (OR). The utility of preoperative DTI for surgical approach selection and intraoperative navigation was documented. An involvement grading system of the major fibers was applied to determine the predictive value of preoperative DTI. A last modified Rankin Scale (mRS) score of 0-2 was considered a good outcome, and a last mRS >2 was considered a poor outcome. RESULTS: Thirteen patients with 13 PLIC-CMs were reviewed in this study. All the lesions were radically resected via the corridor formed by CST, AF, and OR. None of the patents suffered from mRS >3, and 7 patients (53.8%) got good outcomes at the last clinic visit. The difference between the preoperative mRS scores and last mRS scores was not significant (P = 0.673). The involvement grade of the fiber tracts was significantly associated with the surgical outcome (P = 0.011). CONCLUSIONS: Preoperative DTI may be a promising tool to determine the surgical approach and predict the surgical outcomes in patients with PLIC-CMs.

Affective Symptoms and White Matter Changes in Brain Tumor Patients.

BACKGROUND: Affective symptoms are frequent in patients with brain tumors. The origin of such symptoms is unknown; either focal brain injury or reactive emotional distress may be responsible. This cross-sectional pilot study linked depressive symptoms and anxiety to white matter integrity. The objective was to test the hypothesis of a relationship between tissue damage and brain function in patients with brain tumors and to provide a basis for further studies in this field. METHODS: Diffusion tensor imaging was performed in 39 patients with newly diagnosed supratentorial primary brain tumor. Patients completed the Beck Depression Inventory, and examiners rated them on the Hamilton Depression Rating Scale (HDRS). State and trait anxiety were measured using the State-Trait Anxiety Inventory. Correlations between fractional anisotropy (FA) and psychological measures were assessed on the basis of regions of interest; the defined regions of interest corresponded to clearly specified white matter tracts. RESULTS: Statistical analysis revealed correlations between FA in the left internal capsule and scores on the HDRS, Beck Depression Inventory, and State-Trait Anxiety Inventory (P < 0.05). HDRS scores were also correlated with FA in the right medial uncinate fasciculus, and state anxiety scores were significantly correlated with FA in the left lateral and medial uncinate fasciculus (P < 0.05). CONCLUSIONS: Our results suggest that neurobiologic mechanisms related to the integrity of tissue in specific white matter tracts may influence affective symptoms in patients with brain tumors, and these mechanisms can be investigated with diffusion tensor imaging. However, prospective observational studies are needed to investigate further the links between brain structures and the severity of affective symptoms in this patient population.

Improved nTMS- and DTI-derived CST tractography through anatomical ROI seeding on anterior pontine level compared to internal capsule.

Imaging of the course of the corticospinal tract (CST) by diffusion tensor imaging (DTI) is useful for function-preserving tumour surgery. The integration of functional localizer data into tracking algorithms offers to establish a direct structure-function relationship in DTI data. However, alterations of MRI signals in and adjacent to brain tumours often lead to spurious tracking results. We here compared the impact of subcortical seed regions placed at different positions and the influences of the somatotopic location of the cortical seed and clinical co-factors on fibre tracking plausibility in brain tumour patients. The CST of 32 patients with intracranial tumours was investigated by means of deterministic DTI and neuronavigated transcranial magnetic stimulation (nTMS). The cortical seeds were defined by the nTMS hot spots of the primary motor area (M1) of the hand, the foot and the tongue representation. The CST originating from the contralesional M1 hand area was mapped as intra-individual reference. As subcortical region of interests (ROI), we used the posterior limb of the internal capsule (PLIC) and/or the anterior inferior pontine region (aiP). The plausibility of the fibre trajectories was assessed by a-priori defined anatomical criteria. The following potential co-factors were analysed: Karnofsky Performance Scale (KPS), resting motor threshold (RMT), T1-CE tumour volume, T2 oedema volume, presence of oedema within the PLIC, the fractional anisotropy threshold (FAT) to elicit a minimum amount of fibres and the minimal fibre length. The results showed a higher proportion of plausible fibre tracts for the aiP-ROI compared to the PLIC-ROI. Low FAT values and the presence of peritumoural oedema within the PLIC led to less plausible fibre tracking results. Most plausible results were obtained when the FAT ranged above a cut-off of 0.105. In addition, there was a strong effect of somatotopic location of the seed ROI; best plausibility was obtained for the contralateral hand CST (100%), followed by the ipsilesional hand CST (>95%), the ipsilesional foot (>85%) and tongue (>75%) CST. In summary, we found that the aiP-ROI yielded better tracking results compared to the IC-ROI when using deterministic CST tractography in brain tumour patients, especially when the M1 hand area was tracked. In case of FAT values lower than 0.10, the result of the respective CST tractography should be interpreted with caution with respect to spurious tracking results. Moreover, the presence of oedema within the internal capsule should be considered a negative predictor for plausible CST tracking.

Comparison of seeding methods for visualization of the corticospinal tracts using single tensor tractography.

OBJECTIVES: To compare five different seeding methods to delineate hand, foot, and lip components of the corticospinal tract (CST) using single tensor tractography. METHODS: We studied five healthy subjects and 10 brain tumor patients. For each subject, we used five different seeding methods, from (1) cerebral peduncle (CP), (2) posterior limb of the internal capsule (PLIC), (3) white matter subjacent to functional MRI activations (fMRI), (4) whole brain and then selecting the fibers that pass through both fMRI and CP (WBF-CP), and (5) whole brain and then selecting the fibers that pass through both fMRI and PLIC (WBF-PLIC). Two blinded neuroradiologists rated delineations as anatomically successful or unsuccessful tractography. The proportions of successful trials from different methods were compared by Fisher's exact test. RESULTS: To delineate hand motor tract, seeding through fMRI activation areas was more effective than through CP (p<0.01), but not significantly different from PLIC (p>0.1). WBF-CP delineated hand motor tracts in a larger proportion of trials than CP alone (p<0.05). Similarly, WBF-PLIC depicted hand motor tracts in a larger proportion of trials than PLIC alone (p<0.01). Foot motor tracts were delineated in all trials by either PLIC or whole brain seeding (WBF-CP and WBF-PLIC). Seeding from CP or fMRI activation resulted in foot motor tract visualization in 87% of the trials (95% confidence interval: 60-98%). The lip motor tracts were delineated only by WBF-PLIC and in 36% of trials (95% confidence interval: 11-69%). CONCLUSIONS: Whole brain seeding and then selecting the tracts that pass through two anatomically relevant ROIs can delineate more plausible hand and lip motor tracts than seeding from a single ROI. Foot motor tracts can be successfully delineated regardless of the seeding method used.

Different magnetic resonance imaging patterns after transcranial magnetic resonance-guided focused ultrasound of the ventral intermediate nucleus of the thalamus and anterior limb of the internal capsule in patients with essential tremor or obsessive-compulsive disorder.

OBJECT: The authors report different MRI patterns in patients with essential tremor (ET) or obsessive-compulsive disorder (OCD) after transcranial MR-guided focused ultrasound (MRgFUS) and discuss possible causes of occasional MRgFUS failure. METHODS: Between March 2012 and August 2013, MRgFUS was used to perform unilateral thalamotomy in 11 ET patients and bilateral anterior limb capsulotomy in 6 OCD patients; in all patients symptoms were refractory to drug therapy. Sequential MR images were obtained in patients across a 6-month follow-up period. RESULTS: For OCD patients, lesion size slowly increased and peaked 1 week after treatment, after which lesion size gradually decreased. For ET patients, lesions were visible immediately after treatment and markedly reduced in size as time passed. In 3 ET patients and 1 OCD patient, there was no or little temperature rise (i.e., < 52°C) during MRgFUS. Successful and failed patient groups showed differences in their ratio of cortical-to-bone marrow thickness (i.e., skull density). CONCLUSIONS: The authors found different MRI pattern evolution after MRgFUS for white matter and gray matter. Their results suggest that skull characteristics, such as low skull density, should be evaluated prior to MRgFUS to successfully achieve thermal rise.

Tractography-guided stimulation of somatosensory fibers for thalamic pain relief.

BACKGROUND: The spinothalamocortical tract (STC) is seen as a neural tract responsible for or involved in the generation or transmission of thalamic pain. Either the thalamus itself or the posterior limb of the internal capsule (PLIC) are targets for deep brain stimulation (DBS) in patients with thalamic pain, but due to its low contrast, conventional MRI cannot visualize the STC directly. OBJECTIVES: To show the feasibility of integrating diffusion tensor imaging-based tractography into the stereotactic treatment planning for identification of an object-oriented lead trajectory that allows STC-DBS with multiple electrode contacts. METHODS: Diffusion tensor imaging was performed in 4 patients with thalamic pain. The STC was modeled and integrated into the stereotactic treatment planning for DBS. DBS-lead implantation was done according to trajectory planning along the modeled STC at the level of the PLIC. RESULTS: After implantation, electrode stimulation was possible over a length of more than 20 mm with a tractography-based trajectory along the PLIC part of the STC. After a follow-up of 12 months, pain relief of more than 40% was achieved in 3 of 4 patients with rating on a visual analogue scale. In 1 patient, stimulation failed to reach any long-lasting positive effects. CONCLUSIONS: Integrating tractography data into stereotactic planning of DBS in thalamic pain is technically feasible. It can be used to identify a lead trajectory that allows for multiple contact stimulation along the STC at the level of the PLIC. Due to long-lasting positive stimulation effect, tractography-guided stimulation of sensory fibers seems to be beneficial for thalamic pain relief.

Bilateral stereotactic anterior capsulotomy for obsessive-compulsive disorder: long-term follow-up.

BACKGROUND AND PURPOSE: Psychosurgery, such as anterior capsulotomy, is a therapeutic option for treatment-resistant obsessive-compulsive disorder (OCD). In this paper, we present a prospective, long-term follow-up study aimed at evaluating both the efficacy and the safety of anterior capsulotomy for the treatment of severe, refractory OCD. METHODS: Twenty-four patients were surgically treated in our centre between 1997 and 2009, 19 of whom were included in this study. Patients were assessed at 3, 6, 12, and 24 months and last follow-up (mean of 7 years) was carried out by phone. OCD symptom severity was evaluated using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). A patient with an improvement rate of over 35% in the Y-BOCS score was considered a responder, while a patient with a 25% improvement was considered a partial responder. RESULTS: With a mean improvement of 31% in the Y-BOCS score at long-term follow-up, 36.8% of the patients responded fully to the procedure and 10.5% were considered partial responders, for an overall response rate of 47.3% of patients. At the end of the study, 3/19 patients had recovered (Y-BOCS score <8) and 3/19 were in remission (Y-BOCS score <16). No cases of mortality were reported and the overall adverse event rate was 57.9%. Only 2 patients had permanent surgical complications. CONCLUSIONS: Anterior capsulotomy is an effective and safe technique for the treatment of severe refractory OCD in patients who have no other alternative to improve their symptoms.

Surgical management of thalamic gliomas: case selection, technical considerations, and review of literature.

This study aimed to identify (1) the thalamic gliomas suitable for surgical resection and (2) the appropriate surgical approach based on their location and the displacement of the posterior limb of the internal capsule (PLIC). A retrospective study over a 5-year period (from 2006 to 2010) was performed in 41 patients with thalamic gliomas. The mean age of these patients was 20.4 years (range, 2-65 years). Twenty (49 %) tumors were thalamic, 19 (46 %) were thalamopeduncular, and 2 (5 %) were bilateral. The PLIC, based on T2-weighted magnetic resonance axial sections, was displaced anterolaterally in 23 (56 %) cases and laterally in 6 (14 %) cases. It was involved by lesion in eight (20 %) cases and could not be identified in four (10 %) cases. Resection, favored in patients with well-defined, contrast-enhancing lesions, was performed in 34 (83 %) cases, while a biopsy was resorted to in 7 (17 %) cases. A gross total resection or near total resection (>90 %) could be achieved in 26 (63 %) cases. The middle temporal gyrus approach, used when the PLIC was displaced anterolaterally, was the commonly used approach (63.5 %). Common pathologies were pilocytic astrocytoma (58 %) in children and grade III/IV astrocytomas (86 %) in adults. Preoperative motor deficits improved in 64 % of the patients with pilocytic lesions as compared to 0 % in patients with grade III/IV lesions (P value, 0.001). Postoperatively, two patients (5 %) had marginal worsening of motor power, two patients developed visual field defects, and one patient developed a third nerve paresis. Radical resection of thalamic gliomas is a useful treatment modality in a select subset of patients and is the treatment of choice for pilocytic astrocytomas. Tailoring the surgical approach, depending on the relative position of the PLIC, has an important bearing on outcome.