Abstract: BACKGROUND:: Parkinson's patients, on average, gain weight following DBS. OBJECTIVE:: To determine potential differences in weight gain when comparing the STN versus the GPi target. METHODS:: A retrospective analysis was performed on the prospective randomized cohort of NIH COMPARE DBS patients who received unilateral STN or GPi DBS. Baseline weights were recorded prior to DBS surgery and at 6, 12, and 18 months post-operatively. Relationships between weight change and changes in BDI score, UPDRS motor score (part III) (also the dyskinesia duration and disability subscores from UPDRS IV), and HY stage were determined via Spearman's rank order correlation coefficients. Regression analyses were performed to investigate the effects of potential factors on weight change over time. RESULTS:: Patients in the COMPARE DBS cohort gained a significant amount of weight- a mean of 4.86 lbs (SD 8.73) (p-value = 0.0006), but there was no significant difference between STN and GPi targets (weight gain of 4.29± 6.79 and 5.38±10.32 pounds, respectively; p-value = 0.684). Weight gain did not correlate with BDI score change, UPDRS motor score, dyskinesia duration, dyskinesia disability change, or the HY stage (p-values were 0.617, 0.210, and 0.305 respectively). No specific variable was associated with weight gain, and there were no differences in binge eating post-surgery in either target. CONCLUSION:: There were significant changes in weight over time following DBS therapy. However, neither BDI score change nor UPDRS score change or dyskinesia was correlated with weight gain. No significant factor was associated with the weight change.
Abstract: Chronic lumbar pain due to degenerative disc disease affects a large number of people, including those of fully active age. The usual self-repair system observed in nature is a spontaneous attempt at arthrodesis, which in most cases leads to pseudoarthrosis. In recent years, many possible surgical fusion techniques have been introduced; PLIF is one of these. Because of the growing interest in minimally invasive surgery and the unsatisfactory results reported in the literature (mainly due to the high incidence of morbidity and complications), a new titanium lumbar interbody cage (I-FLY) has been developed to achieve solid bone fusion by means of a stand-alone posterior device. The head of the cage is blunt and tapered so that it can be used as a blunt spreader, and the core is small, which facilitates self-positioning. From 2003 to 2007, 119 patients were treated for chronic lumbar discopathy (Modic grade III and Pfirrmann grade V) with I-FLY cages used as stand-alone devices. All patients were clinically evaluated preoperatively and after 1 and 2 years by means of a neurological examination, visual analogue score (VAS) and Prolo Economic and Functional Scale. Radiological results were evaluated by polyaxial computed tomography (CT) scan and flexion-extension radiography. Fusion was defined as the absence of segmental instability on flexion-extension radiography and Bridwell grade I or II on CT scan. Patients were considered clinical "responders" if VAS evaluation showed any improvement over baseline values and a Prolo value >7 was recorded. At the last follow-up examination, clinical success was deemed to have been achieved in 90.5% of patients; the rate of bone fusion was 99.1%, as evaluated by flexion-extension radiography, and 92.2%, as evaluated by CT scan. Morbidity (nerve root injury, dural lesions) and complications (subsidence and pseudoarthrosis) were minimal. PLIF by means of the stand-alone I-FLY cage can be regarded as a possible surgical treatment for chronic low-back pain due to high-degree DDD. This technique is not demanding and can be considered safe and effective, as shown by the excellent clinical and radiological success rates.
Abstract: OBJECT: The purpose of this study was to evaluate the efficacy of intra-operative computerized tomography (CT) scanning in the analysis of bone removal accuracy during anterior cervical corpectomy, in order to allow any necessary immediate correction in the event of inadequate bone removal. METHODS: From September 2009 to December 2010 we performed an intra-operative (CT) scan using the O-Arm(â„¢) Image system to assess the rate of central and lateral decompression in all patients treated for cervical spondylotic myelopathy by anterior cervical corpectomy and fusion. RESULTS: Out of a population of 187 patients admitted to our department, with a diagnosis of myelopathy due to spondylotic degenerative cervical stenosis, 15 patients underwent a surgical treatment with anterior cervical corpectomy and fusion. There were nine males (60%) and six females (40%); the mean age was 52.4Â years, ranging from 41 to 57Â years. The pre-operative radiologic investigations (MRI and CT scans) revealed in the nine patients (60%) the extent of the compression to one vertebral body (C4 one case, C5 four cases, C6 four cases), while in the six cases (40%) the compression regarded two vertebral body (C3 and C4 one case, C4 and C5 two cases, C5 and C6 three cases). During surgery, when the decompression was judged completely, a CT scan was performed: in 11 cases (73.3%) the decompression was considered adequate, while in four cases (26.7%) it was deemed insufficient and the surgical strategy was changed in order to optimize the bone removal. In these cases an additional scan was taken to prove the efficacy of decompression, achieved in all patients. CONCLUSION: Intra-operative CT scan performed during cervical corpectomy is a really useful tool in helping to ensure complete bone removal and the adequacy of surgery. The O-arm(â„¢) Image system grants optimal image quality, allowing correctly assessing the rate of decompression and, in any case of doubt, allows an intra-operative evaluation of the final correct positioning of the graft.
Abstract: In the past years, local field potential (LFP) signals recorded from the subthalamic nucleus (STN) in patients undergoing deep brain stimulation (DBS) for Parkinson's disease (PD) disclosed that DBS has a controversial effect on STN beta oscillations recorded 2-7 days after surgery for macroelectrode implantation. Nothing is known about these DBS-induced oscillatory changes 30 days after surgery. We recorded STN LFPs during ongoing DBS in 7 patients with PD, immediately (hyperacute phase) and 30 days (chronic phase) after surgery. STN LFP recordings showed stationary intranuclear STN beta LFP activity in hyperacute and chronic phases, confirming that beta peaks were also present in chronic recordings. Power spectra of nuclei with significant beta activity (54% of the sample) showed that it decreased significantly during DBS (p=0.021) under both recording conditions. The time course of beta activity showed more evident DBS-induced changes in the chronic than in the hyperacute phase (p=0.014). DBS-induced changes in STN beta LFPs in patients undergoing DBS in chronic phase provide useful information for developing a new neurosignal-controlled adaptive DBS system.
Abstract: STUDY DESIGN: Radiographic study. OBJECTIVE: More detailed anatomical knowledge of the C2 pedicle is required to optimize and minimize the risk of screw placement. The aim of this study was to evaluate the linear and angular dimensions of the true C2 pedicle using axial computed tomography. BACKGROUND DATA: Although earlier studies have analyzed the anatomy of the C2 pars interarticularis, little attention has been focused on the dimensions of the C2 pedicle. METHODS: Ninety-three patients (47 males, 46 females; mean age 48.4 y) who had previous cervical spinal computed tomography imaging were evaluated for this study. Axial images of the C2 pedicle were selected and the following pedicle parameters were determined: pedicle width (the mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis) and pedicle transverse angle (PTA, ie, the angle between the pedicle axis and the midline of the vertebral body). RESULTS: The overall mean pedicle width was 5.8+/-1.2 mm. The mean pedicle width in male patients (6.0+/-1.3 mm) was greater than that in the female patients (5.6+/-1.1 mm). This difference was not found to be statistically significant (P=0.679). The overall mean PTA was 43.9+/-3.9 degrees. The mean PTA in male patients was 43.2+/-3.8 degrees, whereas that in female patients was 44.7+/-3.7 degrees. CONCLUSIONS: Given the significant variability in pedicle widths and the need for precise trajectory planning in pedicle cannulation, preoperative planning is absolutely mandatory. A significant percentage of patients have pedicle widths that may not accommodate screw fixation. In addition, the angle of entry into the C2 pedicle must be carefully measured for safe instrumentation at this level.
Abstract: Deep brain stimulation (DBS) of the ventralis oralis (VO) complex of the thalamus improves tics in patients with Tourette syndrome (TS). To neurophysiologically describe the VO complex we recorded, in seven patients with TS undergoing DBS electrode implantation, single-unit activity during surgery and local field potentials (LFPs) a few days after surgery. Single unit recordings showed that the VO complex is characterized by a localized pattern of bursting neuronal activity. LFP spectra demonstrated that VO of TS patients has a prominent oscillatory activity at low frequencies (2-7 Hz) and in the alpha-band (8-13 Hz), and a virtually absent beta activity. In each patient, the main LFP frequency significantly correlated with single-unit interburst frequency. In conclusion, we observed an oscillatory bursting activity in the VO as target region in patients with severe TS undergoing DBS surgery. (c) 2010 Movement Disorder Society.
Abstract: Tourette's syndrome is a chronic neurobehavioral disorder that can demonstrate refractoriness to conservative treatments, or to invasive nonsurgical treatments such as botulinum toxin infiltration, or to psychobehavioral treatments. In these cases, the surgical option is often proposed, either with lesional interventions, or more recently with deep brain stimulation (DBS). This latter modality is currently preferred because of its reversibility and modularity. Some relevant issues, however, still persist in terms of appropriate indication to treatment, selection of target, and follow-up evaluation.
Abstract: This study presents a simple decision-support system for the detection of tic events during the Tourette Syndrome (TS). The system is based on a triaxial accelerometer placed on the patient's trunk. TS is a neurological disorder that emerges during childhood and that is characterized by a large spectrum of involuntary/compulsive movements and sounds. 12 subjects with chronic TS participated in the study and the tic events were both measured by the proposed device and visually classified through video recording. 3D-acceleration timeseries were combined through a module operator and their noise was eliminated by a median filter. Signal to noise ratio was improved by a nonlinear energy operator. Finally, a time-variant threshold was used to detect tic events. The automatic tic recognition showed a performance around 80 % in terms of sensitivity, specificity and accuracy. In conclusion, this simple, automatic and unobtrusive method offers an alternative approach to quantitatively assess the tic events in clinical and non clinical environments. This overcomes the limitations of the current motor tic evaluation which is done by clinical observation and/or video-inspection in specialized neurological centres.
Abstract: BACKGROUND: Deep brain stimulation (DBS) is a commonly performed surgical technique for the treatment of movement disorders, and recent surgical trials concerning the treatment of a wider range of disorders have recently been published. Despite DBS being non-ablative and minimally invasive, numerous complications and side effects have been recorded. In particular, concerning the growing interest in novel indications for DBS, an enthusiastic approach has put neurosurgeons at risk of underestimating some of the complications that might be associated with specific characters of the treated disease. OBJECTIVE: Our objective was to evaluate hardware failures and rates of infective complications in correlation to the different indications to DBS, in order to ascertain whether DBS in Tourette syndrome (TS) is characterized by specific risks and pitfalls. METHODS: We retrospectively reviewed our experience of 531 procedures on 272 patients treated for various movement disorders, among which 39 patients were treated for conservative treatmentrefractory TS. RESULTS: A statistically significant association of infective complications was found with the TS subgroup. CONCLUSIONS: It is our belief that specific behavioral characters of the TS patients may be put into association with this specific complication and need to be considered carefully when indicating DBS as treatment of choice for these patients.
Abstract: Although lesional, neuroimaging, and brain stimulation studies have provided an insight into the neural mechanisms of judgement and decision-making, all these works focused on the cerebral cortex, without investigating the role of subcortical structures such as the basal ganglia. Besides being an effective therapeutic tool, deep brain stimulation (DBS) allows local field potential (LFP) recordings through the stimulation electrodes thus providing a physiological "window" on human subcortical structures. In this study we assessed whether subthalamic nucleus LFP oscillations are modulated by processing of moral conflictual, moral nonconflictual, and neutral statements. To do so, in 16 patients with Parkinson's disease (8 men) bilaterally implanted with subthalamic nucleus (STN) electrodes for DBS, we recorded STN LFPs 4 days after surgery during a moral decision task. During the task, recordings from the STN showed changes in LFP oscillations. Whereas the 14-30 Hz band (beta) changed during the movement executed to perform the task, the 5-13 Hz band (low-frequency) changed when subjects evaluated the content of statements. Low-frequency band power increased significantly more during conflictual than during nonconflictual or neutral sentences. We conclude that STN responds specifically to conflictual moral stimuli, and could be involved in conflictual decisions of all kinds, not only those for moral judgment. LFP oscillations provide novel direct evidence that the neural processing of conflictual decision-making spreads beyond the cortex to the basal ganglia and encompasses a specific subcortical conflict-dependent component.
Abstract: Technological advances have driven diagnostic and therapeutic improvements in the field of neurosurgery. The basic concepts underlying some of the most significant medical advances originated from specific needs in the management of neurosurgical disorders. The authors look at the historical background of modern neurosurgery and, in view of the evolution of the mechanical and computerised devices now considered the gold standard in the different branches of neurosurgery (trauma, oncological, vascular and functional), consider the possible future scenario in this field.
Abstract: Local field potentials (LFPs) recorded through electrodes implanted in patients with Parkinson's disease (PD) for deep brain stimulation (DBS) provided physiological information about the human basal ganglia. However, LFPs were always recorded 2-7 days after electrode implantation ("acute" condition). Because changes in the tissue surrounding the electrode occur after DBS surgery and could be relevant for LFPs, in this work we assessed whether impedance and LFP pattern are a function of the time interval between the electrode implant and the recordings. LFPs and impedances were recorded from 11 patients with PD immediately after (T-0h), 2 h after (T-2h), 2 d after (T-48h), and 1 month after (T-30d, "chronic" condition) surgery. Impedances at T-0h were significantly higher than at all the other time intervals (T-2h, p=0.0005; T-48h, p=0.0002; T-30d, p=0.003). Correlated with this change (p=0.005), the low-frequency band (2-7 Hz) decreased at all time intervals (p=0.0005). Conversely, the low- (8-20 Hz) and the high-beta (21-35 Hz) increased in time (low-beta, p=0.003; high beta, p=0.022), but did not change between T-48h and T-30d. Our results suggest that DBS electrode impedance and LFP pattern are a function of the time interval between electrode implant and LFP recordings. Impedance decrease could be related to changes in the electrode/tissue interface and in the low-frequency band. Conversely, beta band modulations could raise from the adaptation of the neural circuit. These findings confirm that results from LFP analysis in the acute condition can be extended to the chronic condition and that LFPs can be used in novel closed-loop DBS systems.
Abstract: There is debate over the cognitive and behavioral effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease (PD). To evaluate these effects, we performed a prospective, naturalistic controlled, 3-year follow-up study. A total of 65 PD patients were enrolled, of whom 32 underwent STN-DBS (PD-DBS) and 33, even though eligible for this treatment, declined surgery and chose other therapeutic procedures (PD-control). Motor and neuropsychological functions were assessed in all the subjects at baseline (T0) and 36 months (T36). The PD-DBS patients were also evaluated at 1, 6, 12, and 24 months after surgery (T1, T6, T12, and T24). At T1, compared with T0, the PD-DBS patients recorded worse logical executive function task and verbal fluency (FAS) scores, whereas their performance of memory tasks remained stable. At T12, their cognitive profile had returned within the pre-DBS range, thereafter remaining stable until T36. FAS scores at T36 were significantly worse in the PD-DBS compared with the PD-control patients. This is the first long-term naturalistic controlled study of cognitive functions in PD patients submitted to STN-DBS. Our results confirm previous reports of a worsening of verbal fluency after DBS, but show that STN-DBS seems to be relatively safe from a cognitive standpoint, as the short-term worsening of frontal-executive functions was found to be transient. (c) 2009 Movement Disorder Society.
Abstract: Invasive treatment for Gilles de la Tourette syndrome has shown interesting results in a number of published reports; it seems to be evolving into a promising therapeutic procedure for those patients demonstrating disabling clinical pictures who are refractory to conservative treatments. There are important issues concerning the stimulated brain target, with different nuclei currently under investigation. Our group asked in this pilot study whether Tourette syndrome could be treated by tailoring specific brain targets for specific symptoms. Deep brain stimulation for Tourette syndrome may thus in the future be tailored and patient specific, utilizing specific target regions for individual clinical manifestations. In our early experience we did not adequately address non-motor clinical symptoms as we only used a thalamic target. More recently in an obsessive compulsive disease cohort we have had success in using the anterior limb of the internal capsule and nucleus accumbens region as targets for stimulation. We therefore explored the option of a "rescue" procedure for our Tourette patients with persistent obsessive-compulsive disorder following ventralis oralis/centromedianus-parafascicularis (Vo/CM-Pf) deep brain stimulation. Following two cases where rescue anterior limb of internal capsule/nucleus accumbens leads were employed, we performed two additional procedures (anterior limb of the internal capsule plus ventralis oralis/centromedianus-parafascicularis and anterior limb of the internal capsule alone) with some mild improvement of comorbid obsessive-compulsive disorder, although the number of observations in this case series was low. Overall, the effects observed with using the anterior limb of the internal capsule either alone or as a rescue were less than expected. In this report we detail our experience with this approach.
Abstract: AIM: The aim of this paper was to assess the efficacy of a minimally invasive treatment with percutaneous vertebroplasty and kyphoplasty for traumatic fracture of thoracolumbar junction. Treatment of stable traumatic vertebral fractures of the thoracolumbar junction without neurological deficit is still controversy. Conservative treatment, characterized by discomfort and limitation in patient mobility, was progressively replaced by minimally invasive techniques such as percutaneous vertebroplasty and kyphoplasty. METHODS: Between January 2003 and August 2005, 34 patients suffering from 42 thoracolumbar fractures were treated at Neurosurgical Department of Istituto Galeazzi (Milan). The treatment selected (vertebroplasty versus kyphoplasty), depended on age of patients, timing and type of fracture. Results were clinically assessed by Visual Analogue Score (VAS) and Oswestry Disability Index. RESULTS: Mean preoperative VAS was 8.32 (range 5-10). Percutaneous vertebroplasty was performed in 25 cases (73.5%); while 9 patients were treated by kyphoplasty (27.5%); 27 patients showed a single level and 7 multilevel of the fractures. No complications occurred (infection, neurological deficit, embolic events) after treatment. At the early follow-up 91.7% of the patients achieved a good pain control already after 24 hours. Pain relief and disability, analyzed by VAS and Oswestry Disability Index, showed a good results at late follow-up time. CONCLUSIONS: Percutaneous vertebroplasty and kyphoplasty are two safe and effective techniques for treatment of thoracolumbar traumatic fractures and allow a good pain-control and return to normal working activity and social life.
Abstract: Deep brain stimulation (DBS) has been used in a small number of patients with Tourette's syndrome and results on tics and comorbidities have been promising. The choice of the DBS target appears to influence the effectiveness; preliminary studies and case reports suggest that certain target areas may be more effective than others in patients with specific symptoms and comorbidities. Clinical data on the effect of DBS on tics and behavioral symptoms support its use in patients with severe, refractory Tourette's syndrome, particularly in younger adults who have a greater severity and prevalence of tics and comorbidities, and are more likely to experience social impairment. Although DBS has shown potential as an 'add-on' therapy for Tourette's syndrome patients failing to show adequate improvement with conventional conservative treatments, several issues remain to be resolved, including patient selection, choice of target, and adverse effects. Successful DBS requires an experienced multidisciplinary team for the management of these complex pre-, peri- and postoperative issues. Future studies should include establishment of consistent inclusion criteria and specific practical requirements for clinical trials, evaluation of the impact of DBS on non-tic symptoms and their influence on outcome, social impairment and quality of life, and the identification of optimum neurophysiologically based DBS targets for improved efficacy in specific patient subtypes.
Abstract: BACKGROUND: Eighteen patients with severe and refractory Tourette syndrome (TS) underwent bilateral thalamic deep brain stimulation (DBS). OBJECTIVE: To assess the long-term outcome on tics, behavioral symptoms, and cognitive functions in the largest case series of thalamic DBS for TS to date. METHODS: In this prospective cohort study, 15 of the original 18 patients were evaluated before and after surgery according to a standardized protocol that included both neuropsychiatric and neuropsychological assessments. RESULTS: In addition to marked reduction in tic severity (p = 0.001), 24-month follow-up ratings showed improvement in obsessive-compulsive symptoms (p = 0.009), anxiety symptoms (p = 0.001), depressive symptoms (p = 0.001), and subjective perception of social functioning/quality of life (p = 0.002) in 15 of 18 patients. There were no substantial differences on measures of cognitive functions before and after DBS. CONCLUSIONS: At 24-month follow-up, tic severity was improved in patients with intractable Tourette syndrome (TS) who underwent bilateral thalamic deep brain stimulation. Available data from 15 of 18 patients also showed that neuropsychiatric symptoms were improved and cognitive performances were not disadvantaged. Controlled studies on larger cohorts with blinded protocols are needed to verify that this procedure is effective and safe for selected patients with TS. Level of evidence: This study provides class IV evidence that bilateral thalamic deep brain stimulation reduces global tic severity measured 24 months after implantation in patients with severe intractable Tourette syndrome.
Abstract: BACKGROUND CONTEXT: Successful placement of pedicle screws in the cervical spine requires a sufficient three-dimensional understanding of pedicle morphology to allow accurate identification of the screw axis. PURPOSE: The goal of the present study was to assess morphologic trends from one level to the next with respect to linear and angular parameters associated with the subaxial cervical pedicles. STUDY DESIGN/SETTING: We evaluated the pedicle morphology of cervical spine using axial and sagittal computed tomography (CT) imaging. The C3-C7 vertebrae in 122 patients (610 vertebrae) were evaluated (age range, 14-93; mean, 48 years). METHODS: Thin cut (2.5mm thickness) axial CT images were measured. Sagittal reconstructions were obtained using 1.25-mm thickness slices. The following pedicle parameters were assessed: pedicle width (PW, the mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis), pedicle height (PH, rostro-caudal dimension of the pedicle determined on the sagittal image), maximal screw length (MSL, distance from the posterior cortex of the lateral mass to the anterior wall of the vertebral body along the pedicle axis), and pedicle transverse angle (PTA, angle between the pedicle axis and the midline vertebral body). RESULTS: The overall mean PW and PH ranged from 4.7 to 6.5mm and 6.4 to 7.0mm, respectively. For both these parameters there was a trend toward increasing size proceeding caudally in the cervical spine. The mean PW and PH was greater in males than in females, and this difference was statistically significant at all levels (p<.0001). The overall mean MSL ranged from 29.9 to 32.9 mm. All intersections of the pedicle axis and the posterior cortex of the lateral mass were located at the most lateral portion of the lateral mass for the C3-C6 vertebrae. The overall mean PTA ranged from 37.8 degrees to 45.3 degrees . The overall mean PTA was approximately 44 degrees from C3 to C6 and 37.8 degrees at C7. CONCLUSION: The findings of our radiological anatomical study suggest that the preoperative CT scans of patients undergoing cervical transpedicular fixation should be thoroughly analyzed and close attention paid to the pedicle size and its angulation. The placement of cervical pedicle screws should be individualized for each patient and based on detailed preoperative planning.
Abstract: Despite the availability of both pharmacological and behavioral therapies for Gilles de la Tourette Syndrome (GTS), a subgroup of patients suffer intractable disease and require treatment through non-conservative means. Since 1955, various neurosurgical procedures have been considered as a potential resort for this severely affected sub-group; this article reviews the neurosurgical treatment for GTS, with in-depth discussion on deep brain stimulation (DBS). Internationally, 39 cases of GTS undergoing DBS treatment have been published. Yet, despite the small numbers of patients assessed in centers involved and the inconsistency of postoperative assessment between centres, DBS has been considered the most promising neurosurgical procedure. Patients resorting to surgical measures often carry the additional burden of a diverse range of behavioral disturbances found to significantly impair health-related quality of life; comorbid psychopathologies must be considered when postoperatively evaluating the benefits of DBS. The authors acknowledge that out of the 39 documented cases of GTS treated with DBS, 18 cases originate from Italy; thus, it seems both relevant and pertinent to recount and present the lived Italian experience of that subgroup of GTS treated by DBS, for the first time. Recommendations from such experience are presented.
Abstract: Gilles de la Tourette's syndrome (Tourette's syndrome; TS) is an inherited tic disorder commonly associated with other neurobehavioural conditions such as attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). While the clinical presentation of TS and other features of this disorder have been well characterized, the genetic and neurobiological basis of the disease remains incompletely elucidated. The suggestion of a central role of dopamine in the aetiology of TS has been made on the basis of experimental studies, evidence from neuroimaging studies and the therapeutic response patients with TS have to agents that antagonize or interfere with putative dopaminergic pathways. Tetrabenazine is such an agent; it depletes presynaptic dopamine and serotonin stores and blocks postsynaptic dopamine receptors. In clinical studies, tetrabenazine has been found to be effective in a wide range of hyperkinetic movement disorders, including small numbers (<50) of patients with TS in some studies. Results of a retrospective chart review enrolling only patients with TS (n = 77; mean age approximately 15 years) showed that 2 years' treatment with tetrabenazine resulted in an improvement in functioning and TS-related symptoms in over 80% of patients, findings that suggest that treatment with tetrabenazine may have long-term benefits. The authors' experience with 120 heavily co-medicated patients with TS confirms these findings. Long-term (mean 19 months) tetrabenazine treatment resulted in a Clinical Global Impressions of Change scale rating of 'improved' in 76% of patients. Such findings are promising and suggest that tetrabenazine may be suitable as add-on therapy in patients for whom additional suppression of tics is required.
Abstract: BACKGROUND: There have been several reports of successful deep brain stimulation (DBS) for the treatment of severe Gilles de la Tourette syndrome (GTS). METHOD: 18 cases of GTS who were resistant to at least 6 months of standard and innovative treatments, as well as to psychobehavioural techniques, underwent DBS. DBS was placed bilaterally in the centromedian-parafascicular (CM-Pfc) and ventralis oralis complex of the thalamus. Patients were evaluated after surgery, with immediate and formal assessments at least every 3 months, including "on-off" and "sham off" in the first nine patients. RESULTS: All patients responded well to DBS, although to differing degrees. The duration of follow-up assessments ranged from 3 to 18 months. The comorbid symptoms of obsessive-compulsive behaviour, obsessive-compulsive disorder, self-injurious behaviours, anxiety and premonitory sensations decreased after treatment with DBS. There were no serious permanent adverse effects. CONCLUSIONS: DBS is a useful and safe treatment for severe GTS. The results of ours and previous DBS reports suggest that the CM-Pfc and ventralis oralis complex of the thalamus may be a good DBS target for GTS.
Abstract: Interbody fusions using intervertebral cages have become increasingly common in spinal surgery. Computational simulations were conducted in order to compare different cage designs in terms of their biomechanical interaction with the spinal structures. Differences in cage design and surgical technique may significantly affect the biomechanics of the fused spine segment, but little knowledge is available on this topic. In the present study, four 3D finite element models were developed, reproducing the human L4-L5 spinal unit in intact condition and after implantation of three different cage models. The intact model consisted of two vertebral bodies and relevant laminae, facet joints, main ligaments and disc. The instrumented models reproduced the post-operative conditions resulting after implant of the different cages. The three considered devices were hollow threaded titanium cages, the BAK (Zimmer Centerpulse, Warsaw, IN, USA), the Interfix and the Interfix Fly (both by Medtronic Sofamor Danek, Memphis, TN, USA). Simulations were run imposing various loading conditions, under a constant compressive preload. A great increase in the stiffness induced on the spinal segment by all cages was observed in all the considered loading cases. Stress distributions on the bony surface were evaluated and discussed. The differences observed between the biomechanics of the instrumented models were associated with the geometrical and surgical features of the devices.
Abstract: OBJECT: Surgical decompression is the recommended treatment in patients with moderate to severe degenerative lumbar spinal stenosis (DLSS) in whom symptoms do not respond to conservative therapy. Multilevel disease, poor patient health, and advanced age are generally considered predictors of a poor outcome after surgery, essentially because of a surgical technique that has always been considered invasive and prone to causing postoperative instability. The authors present a minimally invasive surgical technique performed using a unilateral approach for lumbar decompression. METHODS: A retrospective study was conducted of data obtained in a consecutive series of 473 patients treated with unilateral microdecompression for DLSS over a 5-year period (2000-2004). Clinical outcome was measured using the Prolo Economic and Functional Scale and the visual analog scale (VAS). Radiological follow-up included dynamic x-ray films of the lumbar spine and, in some cases, computed tomography scans. RESULTS: Follow-up was completed in 374 (79.1%) of 473 patients--183 men and 191 women. A total of 520 levels were decompressed: 285 patients (76.2%) presented with single-level stenosis, 86 (22.9%) with two-level stenosis, and three (0.9%) with three-level stenosis. Three hundred twenty-nine patients (87.9%) experienced a clinical benefit, which was defined as neurological improvement in VAS and Prolo Scale scores. Only three patients (0.8%) reported suffering segmental instability at a treated level, but none required surgical stabilization, and all were successfully treated conservatively. CONCLUSIONS: Evaluation of the results indicates that unilateral microdecompression of the lumbar spine offers a significant improvement for patients with DLSS, with a lower rate of complications.
Abstract: The study consists of a biomechanical comparison between the intact C5-C6 spinal segment and the same segment implanted with the Bryan artificial disc prosthesis (Medtronic Ltd., Memphis, TN, USA), by the use of the finite element (FE) method. Our target is the prediction of the influence of prosthesis placement on the resulting mechanics of the C5-C6 spine unit. A FE model of the intact C5-C6 segment was built, employing realistic models of the vertebrae, disc and ligaments. Simulations were conducted imposing a compression preload combined to a flexion/extension moment, a pure lateral bending moment and a pure torsion moment, and the calculated results were compared to data from literature. The model was then modified to include the Bryan cervical disc prosthesis, and the simulations were repeated. The location of the instantaneous center of rotation (ICR) of C5 with respect to C6 throughout flexion/extension was calculated in both models. In general, the moment-rotation curves obtained from the disc prosthesis-implanted model were comparable to the curves obtained from the intact model, except for a slightly greater stiffness induced by the artificial disc. The position of the calculated ICRs was rather stable throughout flexion-extension and was generally confined to a small area, qualitatively matching the corresponding physiological region, in both models. These results imply that the Bryan disc prosthesis allows to correctly reproduce a physiological flexion/extension at the implanted level. The results of this study have quantified aspects that may assist in optimizing cervical disc replacement primarily from a biomechanical point of view.
