Stereotactic Thalamotomy Research Articles

Unilateral Stereotactic Radiofrequency Thalamotomy for Tremors in Parkinson’s Patients

Unilateral Stereotactic Radiofrequency Thalamotomy for Tremors in Parkinson’s Patients

192 Stereotactic radiofrequency ventral posterolateral thalamotomy – an effective treatment for complex pain in lung cancer?

192 Stereotactic radiofrequency ventral posterolateral thalamotomy – an effective treatment for complex pain in lung cancer?

Impact of biologically effective dose on tremor decrease after stereotactic radiosurgical thalamotomy for essential tremor: a retrospective longitudinal analysis

Stereotactic radiosurgery (SRS) is one of the surgical alternatives for drug-resistant essential tremor (ET). Here, we aimed at evaluating whether biologically effective dose (BEDGy2.47) is relevant for tremor improvement after stereotactic radiosurgical thalamotomy in a population of patients treated with one (unplugged) isocenter and a uniform dose of 130 Gy. This is a retrospective longitudinal single center study. Seventy-eight consecutive patients were clinically analyzed. Mean age was 69.1 years (median 71, range 36–88). Mean follow-up period was 14 months (median 12, 3–36). Tremor improvement was assessed at 12 months after SRS using the ET rating assessment scale (TETRAS, continuous outcome) and binary (binary outcome). BED was defined for an alpha/beta of 2.47, based upon previous studies considering such a value for the normal brain. Mean BED was 4573.1 Gy2.47 (median 4612, 4022.1–4944.7). Mean beam-on time was 64.7 min (median 61.4; 46.8–98.5). There was a statically significant correlation between delta (follow-up minus baseline) in TETRAS (total) with BED (p = 0.04; beta coefficient − 0.029) and beam-on time (p = 0.03; beta coefficient 0.57) but also between TETRAS (ADL) with BED (p = 0.02; beta coefficient 0.038) and beam-on time (p = 0.01; beta coefficient 0.71). Fractional polynomial multivariate regression suggested that a BED > 4600 Gy2.47 and a beam-on time > 70 min did not further increase clinical efficacy (binary outcome). Adverse radiation events (ARE) were defined as larger MR signature on 1-year follow-up MRI and were present in 7 out of 78 (8.9%) cases, receiving a mean BED of 4650 Gy2.47 (median 4650, range 4466–4894). They were clinically relevant with transient hemiparesis in 5 (6.4%) patients, all with BED values higher than 4500 Gy2.47. Tremor improvement was correlated with BED Gy2.47 after SRS for drug-resistant ET. An optimal BED value for tremor improvement was 4300–4500 Gy2.47. ARE appeared for a BED of more than 4500 Gy2.47. Such finding should be validated in larger cohorts.

Dynamic functional changes upon thalamotomy in essential tremor depend on baseline brain morphometry

Patients with drug-resistant essential tremor (ET) may undergo Gamma Knife stereotactic radiosurgical thalamotomy (SRS-T), where the ventro-intermediate nucleus of the thalamus (Vim) is lesioned by focused beams of gamma radiations to induce clinical improvement. Here, we studied SRS-T impacts on left Vim dynamic functional connectivity (dFC, n = 23 ET patients scanned before and 1 year after intervention), and on surface-based morphometric brain features (n = 34 patients, including those from dFC analysis). In matched healthy controls (HCs), three dFC states were extracted from resting-state functional MRI data. In ET patients, state 1 spatial stability increased upon SRS-T (F1,22 = 19.13, p = 0.004). More frequent expression of state 3 over state 1 before SRS-T correlated with greater clinical recovery in a way that depended on the MR signature volume (t6 = 4.6, p = 0.004). Lower pre-intervention spatial variability in state 3 expression also did (t6 = − 4.24, p = 0.005) and interacted with the presence of familial ET so that these patients improved less (t6 = 4.14, p = 0.006). ET morphometric profiles showed significantly lower similarity to HCs in 13 regions upon SRS-T (z ≤ − 3.66, p ≤ 0.022), and a joint analysis revealed that before thalamotomy, morphometric similarity and states 2/3 mean spatial similarity to HCs were anticorrelated, a relationship that disappeared upon SRS-T (z ≥ 4.39, p < 0.001). Our results show that left Vim functional dynamics directly relates to upper limb tremor lowering upon intervention, while morphometry instead has a supporting role in reshaping such dynamics.

Unilateral combined stereotactic radiofrequency pallidotomy and thalamotomy for Idiopathic Parkinson’s disease.

Unilateral combined stereotactic radiofrequency pallidotomy and thalamotomy for Idiopathic Parkinson’s disease.

Radiosurgical Thalamotomy for Essential Tremor: A Prospective Study with Blinded Assessment by a Movement Disorder Neurologist

To prospectively evaluate the effectiveness and safety of radiosurgical thalamotomy in patients with Essential Tremor (ET). Patients underwent stereotactic radiation VIM thalamotomy by a dedicated Cobalt 60 intracranial radiosurgery platform in a fixed headframe. 130 Gy was prescribed to the 100% isodose point with single 4mm collimator. Effectiveness was evaluated using validated tremor rating scale: upper limb CRST Part B ratings (CRST) in comparison to baseline. To be eligible minimal CRST score of 2 in writing or drawing was required. Writing and drawing score assessments were conducted by a single movement disorder neurologist in a blinded fashion. Mean writing and drawing scores were statistically compared with paired t-test. A total of 213 cases (203 patients) were enrolled in the study, 7 cases (and individual patients) withdrew prior to treatment. The total number of thalamotomies performed was 206. Ten patients had right and left thalamotomies on study. Eleven patients underwent a contralateral thalamotomy but their initial thalamotomy was not a case in this study. 30 patients withdrew or were lost to follow-up, 2 patients were withdrawn due to not meeting medication criteria after treatment, 12 patients were withdrawn not meeting CRST rating criteria. Two patients were lost to follow-up immediately following the procedure (one of whom was a patient who underwent right and left staged procedures - no follow-up was obtained after the second procedure). 177 cases completed 6-month follow-up; 169 cases completed 1 year follow-up; 113 cases completed 2-year follow-up. For 189 total evaluable cases pre-treatment, drawing score mean was 2.86 +/- 0.84, pre-treatment writing score mean was 2.96 +/- 0.86. WRITING At one year: 143 cases (writing side targeted) mean writing score 1.28 +/-1.11 P<.01. 77% of cases improved by 1 point or greater. At two years: 102 cases 1.48+/-1.11, P<.01. 78% of cases improved by 1 point or greater. DRAWING At one year: 169 cases mean drawing score 1.42 +/-0.97, P<.01. 71% of cases improved by 1 point or greater. At two years: 113 cases mean drawing score 1.49+/-0.98, P<.01. 71% of cases improved by 1 point or greater. Cumulative side effects at 6 months and 1 year were seen in 17 of 175 of patients. 12 mild, 3 moderate and 2 severe. Mild side effects included numbness of the fingers, lip or hand and mild dysarthria. Severe side effects were 1 thalamic hemorrhage resulting in contralateral weakness. 1 patient developed foot drop and slurring of speech. Cumulative 2-year side effects were 15 mild, 3 moderate and 3 severe (1 additional thalamic hemorrhage). Stereotactic radiosurgical thalamotomy provided a significant reduction in tremor at 1 and 2 years. The treatment is an effective noninvasive treatment option worthy of consideration in many patients. The treatment has a low but non-zero risk of significant SEs.

Connectomic Basis for Tremor Control in Stereotactic Radiosurgical Thalamotomy.

Given the increased use of stereotactic radiosurgical thalamotomy and other ablative therapies for tremor, new biomarkers are needed to improve outcomes. Using resting-state fMRI and MR tractography, we hypothesized that a "connectome fingerprint" can predict tremor outcomes and potentially serve as a targeting biomarker for stereotactic radiosurgical thalamotomy. We evaluated 27 patients who underwent unilateral stereotactic radiosurgical thalamotomy for essential tremor or tremor-predominant Parkinson disease. Percentage postoperative improvement in the contralateral limb Fahn-Tolosa-Marin Clinical Tremor Rating Scale (TRS) was the primary end point. Connectome-style resting-state fMRI and MR tractography were performed before stereotactic radiosurgery. Using the final lesion volume as a seed, "connectivity fingerprints" representing ideal connectivity maps were generated as whole-brain R-maps using a voxelwise nonparametric Spearman correlation. A leave-one-out cross-validation was performed using the generated R-maps. The mean improvement in the contralateral tremor score was 55.1% (SD, 38.9%) at a mean follow-up of 10.0 (SD, 5.0) months. Structural connectivity correlated with contralateral TRS improvement (r = 0.52; P = .006) and explained 27.0% of the variance in outcome. Functional connectivity correlated with contralateral TRS improvement (r = 0.50; P = .008) and explained 25.0% of the variance in outcome. Nodes most correlated with tremor improvement corresponded to areas of known network dysfunction in tremor, including the cerebello-thalamo-cortical pathway and the primary and extrastriate visual cortices. Stereotactic radiosurgical targets with a distinct connectivity profile predict improvement in tremor after treatment. Such connectomic fingerprints show promise for developing patient-specific biomarkers to guide therapy with stereotactic radiosurgical thalamotomy.

Deep Brain Stimulation for Holmes Tremors and Literature Review.

Deep Brain Stimulation for Holmes Tremors and Literature Review.

Morphometric features of drug-resistant essential tremor and recovery after stereotactic radiosurgical thalamotomy.

Essential tremor (ET) is the most common movement disorder. Its neural underpinnings remain unclear. Here, we quantified structural covariance between cortical thickness (CT), surface area (SA), and mean curvature (MC) estimates in patients with ET before and 1 year after ventro-intermediate nucleus stereotactic radiosurgical thalamotomy, and contrasted the observed patterns with those from matched healthy controls. For SA, complex rearrangements within a network of motion-related brain areas characterized patients with ET. This was complemented by MC alterations revolving around the left middle temporal cortex and the disappearance of positive-valued covariance across both modalities in the right fusiform gyrus. Recovery following thalamotomy involved MC readjustments in frontal brain centers, the amygdala, and the insula, capturing nonmotor characteristics of the disease. The appearance of negative-valued CT covariance between the left parahippocampal gyrus and hippocampus was another recovery mechanism involving high-level visual areas. This was complemented by the appearance of negative-valued CT/MC covariance, and positive-valued SA/MC covariance, in the right inferior temporal cortex and bilateral fusiform gyrus. Our results demonstrate that different morphometric properties provide complementary information to understand ET, and that their statistical cross-dependences are also valuable. They pinpoint several anatomical features of the disease and highlight routes of recovery following thalamotomy.

Graph Theoretical Analysis of Structural Covariance Reveals the Relevance of Visuospatial and Attentional Areas in Essential Tremor Recovery After Stereotactic Radiosurgical Thalamotomy.

Essential tremor (ET) is the most common movement disorder. Its pathophysiology is only partially understood. Here, we leveraged graph theoretical analysis on structural covariance patterns quantified from morphometric estimates for cortical thickness, surface area, and mean curvature in patients with ET before and one year after (to account for delayed clinical effect) ventro-intermediate nucleus (Vim) stereotactic radiosurgical thalamotomy. We further contrasted the observed patterns with those from matched healthy controls (HCs). Significant group differences at the level of individual morphometric properties were specific to mean curvature and the post-/pre-thalamotomy contrast, evidencing brain plasticity at the level of the targeted left thalamus, and of low-level visual, high-level visuospatial and attentional areas implicated in the dorsal visual stream. The introduction of cross-correlational analysis across pairs of morphometric properties strengthened the presence of dorsal visual stream readjustments following thalamotomy, as cortical thickness in the right lingual gyrus, bilateral rostral middle frontal gyrus, and left pre-central gyrus was interrelated with mean curvature in the rest of the brain. Overall, our results position mean curvature as the most relevant morphometric feature to understand brain plasticity in drug-resistant ET patients following Vim thalamotomy. They also highlight the importance of examining not only individual features, but also their interactions, to gain insight into the routes of recovery following intervention.

Targeting for stereotactic radiosurgical thalamotomy based on tremor treatment response.

Stereotactic radiosurgery (SRS) treats severe, medically refractory essential tremor and tremor-dominant Parkinson disease. However, the optimal target for SRS treatment within the thalamic ventral intermediate nucleus (VIM) is not clearly defined. This work evaluates the precision of the physician-selected VIM target, and determines the optimal SRS target within the VIM by correlation between early responders and nonresponders. Early responders and nonresponders were assessed retrospectively by Elements Basal Ganglia Atlas autocontouring of the VIM on the pre-SRS-treatment 1-mm slice thickness T1-weighted MRI and correlating the center of the post-SRS-treatment lesion. Using pre- and posttreatment diffusion tensor imaging, the fiber tracking package in the Elements software generated tremor-related tracts from autosegmented motor cortex, thalamus, red nucleus, and dentate nucleus. Autocontouring of the VIM was successful for all patients. Among 23 patients, physician-directed SRS targets had a medial-lateral target range from +2.5 mm to -2.0 mm from the VIM center. Relative to the VIM center, the SRS isocenter target was 0.7-0.9 mm lateral for 6 early responders and 0.9-1.1 mm medial for 4 nonresponders (p = 0.019), and without differences in the other dimensions: 0.2 mm posterior and 0.6 mm superior. Dose-volume histogram analyses for the VIM had no significant differences between responders and nonresponders between 20 Gy and 140 Gy, mean or maximum dose, and dose to small volumes. Tractography data was obtained for 4 patients. For tremor control in early responders, the Elements Basal Ganglia Atlas autocontour for the VIM provides the optimal SRS target location that is 0.7-0.9 mm lateral to the VIM center.

Combined Unilateral Radiofrequency Lesioning of the Motor Thalamus, Field of Forel, and Zona Incerta: A Series of Cases With Dystonia.

Dystonia is a group of disorders characterized by involuntary slow repetitive twisting movements and/or abnormal posture. Surgical options such as neuromodulation through deep brain stimulation and neuroablative procedures are available for patients who do not respond to conservative treatment. To present our series of patients with dystonia who were treated with stereotactic combined unilateral radiofrequency lesioning of the motor thalamus, field of Forel, and zona incerta. Medical records of 50 patients with dystonia who were treated with unilateral combined lesions were reviewed. Outcomes of the surgical procedure were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (with movement and disability subscales) and Unified Parkinson's Disease Rating Scale-tremor items. Based on the symptoms, patients were categorized as having generalized dystonia (34%), hemidystonia (30%), and dystonic tremor (DT) (36%). Primary/idiopathic dystonia, primary genetic/hereditary dystonia, and secondary dystonia accounted for 16%, 4%, and 80% of patients, respectively. The mean follow-up duration was 156.2 ± 88.9 mo. The overall improvement in the Burke-Fahn-Marsden Dystonia Rating Scale scores (movement and disability, respectively) was 57.8% and 36.4% in generalized dystonia, 60.0% and 45.8% in hemidystonia, and 65.6% and 56.8% in DT. Patients with DT showed an 83.3% improvement in mean Unified Parkinson's Disease Rating Scale tremor score. Patients with cerebral palsy showed mean improvements of 66.7% in movement scores and 50.8% in disability scores. No mortality or major morbidity was observed postoperatively. Stereotactic radiofrequency unilateral combined thalamotomy, campotomy, and zona incerta lesions may be an effective surgical alternative for patients with dystonia, especially those with secondary dystonia resistant to deep brain stimulation.

Stereotactic Thalamotomy – A Conventional But A Valuable and Effective Surgical Strategy for Parkinsonian Tremors

Objective: To determine the frequency of improvement in tremors in Parkinsonian patients after stereotactic thalamotomy.&#x0D; Material &amp; Methods: A descriptive case series was conducted in the department of Neurosurgery Unit II, Lahore General Hospital from January 2016 to March 2020. The study included65 patients of Parkinson’s disease with tremors refractory to medicines for 6 months who fulfilled the inclusion criteria. Outcome and possible complications were explained before taking informed consent. An outcome like reduction in tremors was used as a research instrument. It was determined by a modified unified Parkinson's disease rating score (UPDRS). Patients were diagnosed based on history, clinical examination, and MRI brain by a team comprising of neurologists and neurosurgeons. Thalamotomy was done by one surgical team. Patients were examined and scored post-operatively at 3 weeks and 3 months. Improvement was labeled as a reduction in tremors upto grade 1 or more from baseline after thalamotomy.&#x0D; Results: Improvement in tremors after thalamotomy was observed in 58.5% of patients whereas there was no improvement in tremors after thalamotomy in 41.5% of patients. There was no significant association between age and improvement in tremors after thalamotomy (p-value = 0.786). No significant association was found between the duration of medical treatment and improvement in tremors after thalamotomy (p-value = 0.681).&#x0D; Conclusion: Improvement in tremors after thalamotomy was observed in 58.5% of parkinsonian patients. Effect modifiers like age and duration of medical treatment were not significantly associated with improvement in tremors after thalamotomy.

Thalamic anterior part of the ventral posterolateral nucleus and central lateral nucleus in the genesis of central post-stroke pain.

The genesis of central post-stroke pain (CPSP) is important but difficult to understand. We evaluated the involvement of the thalamic anterior part of the ventral posterolateral nucleus (VPLa) and central lateral nucleus (CL) in the occurrence of CPSP. Stereotactic thalamotomy was performed on the posterior part of the ventral lateral nucleus (VLp)-VPLa and CL in 9 patients with CPSP caused by deep-seated intracerebral hemorrhage. Computed tomography (CT) did not reveal definite thalamic lesion in 5 patients but did in 4 patients. Electrophysiological studies of these thalamic nuclei were carried out during the surgery. Anatomical studies using CT were performed in another 20 patients with thalamic hemorrhage who had clear consciousness but had sensory disturbance at onset. Neural activities were preserved and hyperactive and unstable discharges (HUDs) were often recognized along the trajectory in the thalamic VLp-VPLa in 5 patients without thalamic lesion. Surgical modification of this area ameliorated pain, particularly movement-related pain. Neural activities were hypoactive in the other 4 patients with thalamic lesion. However, neural activities were preserved and HUDs were sometimes recognized in the CL. Sensory responses were seen, but at low rate, in the sensory thalamus. Anatomical study showed that the thalamic lesion was obviously smaller in the patients with developing pain in the chronic stage. Change in neural activities around the cerebrovascular disease lesion in the thalamic VPLa or CL might affect the perception of sensory impulses or sensory processing in those thalamic nuclei, resulting in the genesis of CPSP.

Stereotactic radiofrequency ventral posterolateral thalamotomy for cancer pain.

Palliative neuroablative procedures are often performed for medication-refractory cancer pain. A 57-year-old female with lung carcinoma and metastases to the brachial plexus and cervical spine with severe neuropathic pain affecting the right upper limb was referred to the authors’ functional neurosurgery service. This video shows her treatment with an awake stereotactic radiofrequency thalamotomy targeting the left ventral posterolateral nucleus. Postoperatively, she experienced immediate and complete resolution of the pain. Palliative radiofrequency thalamotomy can be a viable and effective procedure for somatotopically distributed regional cancer pain.The video can be found here: https://youtu.be/jykYWXTP3c4

Outcome of Essential Tremors with Stereotactic Thalamotomy: Noble Art of Lesioning

Objective: Objective of study is to identify the effects of Stereotactic thalamotomy of the nucleus ventral intermediate (VIM) for treatment of essential tremor.&#x0D; Material and Methods: This is a descriptive study.It was performed at NCCI, Karachi, duration of study was 7 years, from 2-10-2012 to 7-10-2019. Those patients were included who were with tremors refractory to medication, their duration of disease was &gt; 3 years, and with grade 4 tremors. The thalamotomy was performed in all cases, and follow-up was conducted at 3, 6, and 12 months respectively. The success of the surgery was measured in the form of a reduction in medication number and reduction in dose &gt;50% and by calculating the Essential Tremor Rating Assessment Scale (tetras).&#x0D; Results: Total of 26 patients were included. All patients showed remarkable improvement post-procedure at 12 month follow-up. 20 (77%) patient required no medications. In 6 (23%) patients, the dose of medication was reduced to less than half post-treatment. The tetras score showed marked improvement in all a patient; 4 (15%) patients who had grade 4 tremor, showed the symptoms of minimal tremors graded 0.5 on last visit 3rd visit. Side effect post-procedure were mild transient numbness on the contralateral side was observed in 11 (42.3%) patient, 1 (3.8%) patient had dysarthria.&#x0D; Conclusion: We concluded that stereostatic Ventral intermedius nucleus thalamotomy was effective in reducing tremor grades and improved all functionality with few mild side effects.

Comparison of Stereotactic Subthalamotomy and Ventralis Intermedius (VIM) Thalamotomy in Relieving Parkinsonian Tremor

Background/Objectives: Parkinson’s disease is a neurodegenerative disease with cardinal features of tremor, rigidity, postural instability and bradykinesia. Surgery is indicated for the patients not responding to medical management or who develop motor fluctuations and dyskinesia following prolonged levodopa therapy. Stereotactic Subthalamotomy and VIM (Ventralis Intermedius) Thalamotomy is cheap, safe and effective surgical options for the treatment of Parkinsonian tremor. The objective of the study was to compare Stereotactic Subthalamotomy with Ventralis Intermedius (VIM) Thalamotomy, in terms of improvement in Unified Parkinson’s Disease Rating Scale (UPDRS), for the treatment of Parkinsonian tremor.&#x0D; Material and Methods: This is a randomized control trial (RCT) and 38 tremor predominant Parkinsonian patients were enrolled in the study. Half of the patients underwent Stereotactic Subthalamotomy and another half underwent VIM Thalamotomy. Patients were assessed pre-operatively, immediately post-operatively and followed up at three weeks, six weeks and three months by using UPDRS scores.&#x0D; Results: The mean age of patients was 59.58 years and they were predominantly male. Post-operative UPDRS score was improved significantly in both STN and VIM groups. However, the improvement was significantly higher in STN lesioning compared to VIM lesioning.On the other hand, the improvement in tremor component score of UPDRS was comparable in the both groups. Moreover, post-operative complications were higher following Subthalamotomy (21.05%) which included dyskinesia, dysphasia, transient weakness and hematoma formation.&#x0D; Conclusion: Both Stereotactic Subthalamotomy and VIM Thalamotomy are equally effective in relieving Parkinsonian tremor with a lower complication rate following VIM Thalamotomy.

Vim stereotactic radiosurgical thalamotomy for drug-resistant idiopathic Holmes tremor: a case report

We share our experience with stereotactic gamma knife thalamotomy (GKT) for medically refractory Holmes tremor (HT). A 22-year-old patient underwent gamma knife thalamotomy at ventrointermediate nucleus for disabling HT of the right upper limb. A single 4-mm isocenter was used to target the ventral intermediate nucleus with 130Gy radiation. At 4months follow up, we observed 84% improvement in his Fahn-Tolosa-Marin (FTM) rating scale with significant improvement in the right upper limb dystonic tremor. There was only subtle improvement in the ataxic component of the right lower limb. At 1year after stereotactic GKT, there was sustained neurological improvement with no side effect, We present the stereotactic GKT as a treatment modality for drug-resistant HT. Moreover, it may be considered an alternate treatment modality especially in patients reluctant or contraindicated for any invasive surgical technique. CLINICAL TRIAL REGISTRATION NUMBER: Not required.

Gamma Knife central lateral thalamotomy for the treatment of neuropathic pain.

The goal of this study was to assess the safety and efficacy of stereotactic central lateral thalamotomy with Gamma Knife radiosurgery in patients with neuropathic pain. Clinical and radiosurgical data were prospectively collected and analyzed in patients with neuropathic pain who underwent Gamma Knife central lateral thalamotomy. The safety and efficacy of the lesioning procedure were evaluated by neurological examination and standardized scales for pain intensity and health-related quality of life. Visual analog scale (VAS) for pain, McGill Pain Questionnaire (MPQ), EuroQol-5 dimensions (EQ-5D), and the 36-Item Short Form Health Survey, version 2 (SF-36v2) were measured during baseline and postoperative follow-up evaluations at 3, 6, 12, 24, and 36 months. Eight patients with neuropathic pain underwent Gamma Knife central lateral thalamotomy. Four patients suffered from trigeminal deafferentation pain, 2 from brachial plexus injury, 1 from central poststroke facial neuropathic pain, and 1 from postherpetic neuralgia. No lesioning-related adverse effect was recorded during the follow-up periods. All patients had pain reduction following thalamotomy. The mean follow-up time was 24 months. At the last follow-up visits, 5 patients reported ≥ 50% VAS pain reduction. The overall mean VAS pain score was 9.4 (range 8-10) before radiosurgery. After 1 year, the mean VAS pain score decreased significantly, from 9.4 (range 8-10) to 5.5 (mean -41.33%, p = 0.01). MPQ scores significantly decreased (mean -22.18%, p = 0.014). Statistically significant improvements of the SF-36v2 quality of life survey (mean +48.16%, p = 0.012) and EQ-5D (+45.16%, p = 0.012) were observed. At 2 years after radiosurgery, the VAS pain score remained significantly reduced to a mean value of 5.5 (p = 0.027). Statistically significant improvements were also observed for the MPQ (mean -16.05%, p = 0.034); the EQ-5D (mean +35.48%, p = 0.028); and the SF-36v2 (mean +35.84%, p = 0.043). At the last follow-up visits, pain had recurred in 2 patients, who were suffering from central poststroke neuropathic pain and brachial plexus injury, respectively. Safe, nonpharmacological therapies are imperative for the management of refectory chronic pain conditions. The present series demonstrates that Gamma Knife central lateral thalamotomy is safe and potentially effective in the long term for relieving chronic neuropathic pain refractory to pharmacotherapy and for restoring quality of life.

Vim line technique thalamotomy for Parkinson tremor: Case series

IntroductionThe ventral intermediate (Vim) nucleus of the thalamus is difficult to identify even with 3 T magnetic resonance imaging. Stereotactic Vim thalamotomy is a usual procedure to control Parkinson tremor. Successful relieving of the tremor depends on the accuracy of defining the Vim location. Presentation of casesThree patients with Parkinson tremor were subjected to stereotactic thalamotomy using the Vim line technique (VLT) so as to precisely determine the Vim location. All patients showed good results, with improved tremors, as indicated by the UPDRS score, without any complications. DiscussionThe precise targeting of the Vim nucleus is crucial importance for the successful Vim thalamotomy. Various method has been developed to determine Vim location. Atlas based and Guiot’s technique routinely used by neurosurgeon. VLT is a new technique that has been developed to determine the Vim location on MRI. ConclusionVLT is useful for the determination of the Vim location. However, further research is warranted to prove its effectiveness.