Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 97
Filter
1.
Heliyon ; 10(4): e26166, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38390037

ABSTRACT

Actual cost fluctuations in construction projects are common in the construction industry, including the Kingdom of Saudi Arabia (KSA). This study's objective is to establish a simulation forecasting model for Saudi projects' cost changes that will be used to anticipate the actual cost spent at the project's end. It also indicates if there are cost overruns or savings by considering ten identified cost-risk impact factors. The study involves a systematic, integrated approach to developing system dynamics (SD) to reflect the ten cost overrun impact factors (COICs) in the KSA construction industry. Thus, the Decision-Making Trial and Evaluation Laboratory (DEMATEL) technique aids in evolving a Causal Loop Diagram (CLD) in the SD modeling stages. After performing the consistency and extreme tests, the model is verified by being applied in two case studies (an academic building and an infrastructure project) in Riyadh City, KSA. The main findings reveal that the model provided cost savings for the first and second case studies of 4.8% and 3.76%, respectively. Different experts have evaluated the developed dynamic system. According to the experts who support the developed model, the model is applicable if the contractor has a reasonable profit margin. In contrast, opponents' experts noted that the system still generates a profit margin despite change orders and project delays. The main conclusion that the experts recognize is that the approach successfully considered the relationships between the influencing factors. The findings can be utilized to create an integrated conceptual framework for construction management, which could result in a rapid and profitable project launch.

2.
J Pharm Bioallied Sci ; 15(Suppl 2): S1023-S1026, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37694099

ABSTRACT

Cancer is a disease triggered by an uncontrolled growth of a group of cells usually from a single cell. Chemotherapy is a common and systematic therapy that involves the use of anticancer drugs also known as chemotherapeutical agents to treat cancer. Tyrosine kinases are a subset of protein kinases that are a family of over 90 enzymes that selectively phosphorylate tyrosine residues in various substrates. Receptors with internal tyrosine kinase activity mediate the actions of several growth factors, differentiation factors, and hormones, resulting in the reproduction and differentiation of the affected cells. In the fight against cancer, the platelet-derived growth factor receptor has emerged as a novel target via inhibition of this receptor resulting in the inhibition of tyrosine kinase cascade. Docking investigations were conducted using the Genetic Optimization for Ligand Docking (GOLD) Suite (v. 5.7.1) from the Cambridge Crystallographic Data Center. A high-definition X-ray crystallography of the platelet-derived growth factor protein [Protein Data Bank (PDB) ID 6JOL] was downloaded from the website PDB with a resolution of 2 A. Compounds II, III, VII, and VIII have greater binding energies than the GOLD standard medication sorafenib, which gives Piecewise Linear Potential (PLP) fitness value (85.3). Other ligands exhibit good inhibitory action and docking scores comparable to that of the reference ligand sorafenib.

3.
Nat Rev Neurol ; 17(2): 75-87, 2021 02.
Article in English | MEDLINE | ID: mdl-33244188

ABSTRACT

Deep brain stimulation (DBS) is a neurosurgical procedure that allows targeted circuit-based neuromodulation. DBS is a standard of care in Parkinson disease, essential tremor and dystonia, and is also under active investigation for other conditions linked to pathological circuitry, including major depressive disorder and Alzheimer disease. Modern DBS systems, borrowed from the cardiac field, consist of an intracranial electrode, an extension wire and a pulse generator, and have evolved slowly over the past two decades. Advances in engineering and imaging along with an improved understanding of brain disorders are poised to reshape how DBS is viewed and delivered to patients. Breakthroughs in electrode and battery designs, stimulation paradigms, closed-loop and on-demand stimulation, and sensing technologies are expected to enhance the efficacy and tolerability of DBS. In this Review, we provide a comprehensive overview of the technical development of DBS, from its origins to its future. Understanding the evolution of DBS technology helps put the currently available systems in perspective and allows us to predict the next major technological advances and hurdles in the field.


Subject(s)
Biomedical Technology/methods , Biomedical Technology/trends , Deep Brain Stimulation/methods , Deep Brain Stimulation/trends , Implantable Neurostimulators/trends , Biomedical Technology/instrumentation , Deep Brain Stimulation/instrumentation , Depressive Disorder, Major/physiopathology , Depressive Disorder, Major/surgery , Dystonic Disorders/physiopathology , Dystonic Disorders/surgery , Essential Tremor/physiopathology , Essential Tremor/surgery , Forecasting , Humans , Parkinson Disease/physiopathology , Parkinson Disease/surgery
4.
Life Sci ; 260: 118317, 2020 Nov 01.
Article in English | MEDLINE | ID: mdl-32841659

ABSTRACT

BACKGROUND: Glucose regulating protein 78 (GRP78) is one member of the Heat Shock Protein family of chaperone proteins (HSPA5) found in eukaryotes. It acts as the master of the Unfolded Protein Response (UPR) process in the lumen of the Endoplasmic Reticulum (ER). SCOPE: Under the stress of unfolded proteins, GRP78 binds to the unfolded proteins to prevent misfolding, while under the load of the unfolded protein, it drives the cell to autophagy or apoptosis. Several attempts reported the overexpression of GRP78 on the cell membrane of cancer cells and cells infected with viruses or fungi. MAJOR CONCLUSIONS: Cell-surface GRP78 is used as a cancer cell target in previous studies. Additionally, GRP78 is used as a drug target to stop the progression of cancer cells by different compounds, including peptides, antibodies, and some natural compounds. Additionally, it can be used as a protein target to reduce the infectivity of different viruses, including the pandemic SARS-CoV-2. Besides, GRP78 targeting is used in diagnosis and imaging modalities using radionuclides. GENERAL SIGNIFICANCE: This review summarizes the various attempts that used GRP78 both in therapy (fighting cancer, viral and fungal infections) and diagnosis (imaging).


Subject(s)
Antineoplastic Agents/therapeutic use , Betacoronavirus/drug effects , Biological Products/therapeutic use , Coronavirus Infections/drug therapy , Heat-Shock Proteins/antagonists & inhibitors , Molecular Targeted Therapy , Neoplasms/drug therapy , Pneumonia, Viral/drug therapy , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Endoplasmic Reticulum Chaperone BiP , Heat-Shock Proteins/metabolism , Humans , Neoplasms/complications , Neoplasms/metabolism , Neoplasms/virology , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , SARS-CoV-2
5.
Cancer Treat Rev ; 69: 84-89, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29936313

ABSTRACT

Statins are widely used to treat hypercholesterolaemia. However, by inhibiting the production of mevalonate, they also reduce the production of several isoprenoids that are necessary for the function of small GTPase oncogenes such as Ras. As such, statins offer an attractive way to inhibit an "undruggable" target, suggesting that they may be usefully repurposed to treat cancer. However, despite numerous studies, there is still no consensus whether statins are useful in the oncology arena. Numerous preclinical studies have provided evidence justifying the evaluation of statins in cancer patients. Some retrospective studies of patients taking statins to control cholesterol have identified a reduced risk of cancer mortality. However, prospective clinical studies have mostly not been successful. We believe that this has occurred because many of the prospective clinical trials have been poorly designed. Many of these trials have failed to take into account some or all of the factors identified in preclinical studies that are likely to be necessary for statins to be efficacious. We suggest an improved trial design which takes these factors into account. Importantly, we suggest that the design of clinical trials of drugs which are being considered for repurposing should not assume it is appropriate to use them in the same way as they are used in their original indication. Rather, such trials deserve to be informed by preclinical studies that are comparable to those for any novel drug.


Subject(s)
Drug Repositioning , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Neoplasms/drug therapy , Research Design , Humans , Treatment Failure
6.
JAMA Neurol ; 75(3): 353-359, 2018 03 01.
Article in English | MEDLINE | ID: mdl-29340590

ABSTRACT

Importance: Collective evidence has strongly suggested that deep brain stimulation (DBS) is a promising therapy for Tourette syndrome. Objective: To assess the efficacy and safety of DBS in a multinational cohort of patients with Tourette syndrome. Design, Setting, and Participants: The prospective International Deep Brain Stimulation Database and Registry included 185 patients with medically refractory Tourette syndrome who underwent DBS implantation from January 1, 2012, to December 31, 2016, at 31 institutions in 10 countries worldwide. Exposures: Patients with medically refractory symptoms received DBS implantation in the centromedian thalamic region (93 of 163 [57.1%]), the anterior globus pallidus internus (41 of 163 [25.2%]), the posterior globus pallidus internus (25 of 163 [15.3%]), and the anterior limb of the internal capsule (4 of 163 [2.5%]). Main Outcomes and Measures: Scores on the Yale Global Tic Severity Scale and adverse events. Results: The International Deep Brain Stimulation Database and Registry enrolled 185 patients (of 171 with available data, 37 females and 134 males; mean [SD] age at surgery, 29.1 [10.8] years [range, 13-58 years]). Symptoms of obsessive-compulsive disorder were present in 97 of 151 patients (64.2%) and 32 of 148 (21.6%) had a history of self-injurious behavior. The mean (SD) total Yale Global Tic Severity Scale score improved from 75.01 (18.36) at baseline to 41.19 (20.00) at 1 year after DBS implantation (P < .001). The mean (SD) motor tic subscore improved from 21.00 (3.72) at baseline to 12.91 (5.78) after 1 year (P < .001), and the mean (SD) phonic tic subscore improved from 16.82 (6.56) at baseline to 9.63 (6.99) at 1 year (P < .001). The overall adverse event rate was 35.4% (56 of 158 patients), with intracranial hemorrhage occurring in 2 patients (1.3%), infection in 4 patients with 5 events (3.2%), and lead explantation in 1 patient (0.6%). The most common stimulation-induced adverse effects were dysarthria (10 [6.3%]) and paresthesia (13 [8.2%]). Conclusions and Relevance: Deep brain stimulation was associated with symptomatic improvement in patients with Tourette syndrome but also with important adverse events. A publicly available website on outcomes of DBS in patients with Tourette syndrome has been provided.


Subject(s)
Deep Brain Stimulation/methods , Registries , Tourette Syndrome/therapy , Treatment Outcome , Adolescent , Adult , Cohort Studies , Databases, Factual/statistics & numerical data , Female , Globus Pallidus/physiology , Humans , International Cooperation , Male , Middle Aged , Severity of Illness Index , Single-Blind Method , Thalamus/physiology , Young Adult
8.
Clin Neurophysiol ; 127(4): 2010-9, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26971483

ABSTRACT

OBJECTIVE: High-amplitude beta band oscillations within the subthalamic nucleus are frequently associated with Parkinson's disease but it is unclear how they might lead to motor impairments. Here we investigate a likely pathological coupling between the phase of beta band oscillations and the amplitude of high-frequency oscillations around 300 Hz. METHODS: We analysed an extensive data set comprising resting-state recordings obtained from deep brain stimulation electrodes in 33 patients before and/or after taking dopaminergic medication. We correlated mean values of spectral power and phase-amplitude coupling with severity of hemibody bradykinesia/rigidity. In addition, we used simultaneously recorded magnetoencephalography to look at functional interactions between the subthalamic nucleus and ipsilateral motor cortex. RESULTS: Beta band power and phase-amplitude coupling within the subthalamic nucleus correlated positively with severity of motor impairment. This effect was more pronounced within the low-beta range, whilst coherence between subthalamic nucleus and motor cortex was dominant in the high-beta range. CONCLUSIONS: We speculate that the beta band might impede pro-kinetic high-frequency activity patterns when phase-amplitude coupling is prominent. Furthermore, results provide evidence for a functional subdivision of the beta band into low and high frequencies. SIGNIFICANCE: Our findings contribute to the interpretation of oscillatory activity within the cortico-basal ganglia circuit.


Subject(s)
Beta Rhythm , Motor Cortex/physiopathology , Parkinson Disease/diagnosis , Parkinson Disease/physiopathology , Subthalamic Nucleus/physiopathology , Beta Rhythm/physiology , Cohort Studies , Deep Brain Stimulation/methods , Female , Humans , Magnetoencephalography/methods , Male
9.
Stereotact Funct Neurosurg ; 93(4): 227-30, 2015.
Article in English | MEDLINE | ID: mdl-25998245

ABSTRACT

BACKGROUND: Bowstringing may occur when excessive fibrosis develops around extension cables in the neck after deep brain stimulation (DBS) surgery. Though the occurrence of this phenomenon is rare, we have noted that it tends to cause maximal discomfort when the cables cross superficially over the convexity of the clavicle. We hypothesise that bowstringing may be avoided by directing the extension cables towards the suprasternal notch. METHODS: When connecting DBS leads to an infraclavicular pectoral implantable pulse generator (IPG), tunnelling is directed towards the suprasternal notch, before being directed laterally towards the IPG pocket. In previously operated patients with established fibrosis, the fibrous tunnel is opened and excised as far cranially as possible, allowing medial rerouting of cables. Using this approach, we reviewed our series of patients who underwent DBS surgery over 10 years. RESULTS: In 429 patients, 7 patients (2%) with cables tunnelled over the convexity of the clavicle complaining of bowstringing underwent cable exploration and rerouting. This eliminated bowstringing and provided better cosmetic results. When the cable trajectory was initially directed towards the suprasternal notch, no bowstringing was observed. CONCLUSION: The tunnelling trajectory appears to influence postoperative incidence of fibrosis associated with DBS cables. Modifying the surgical technique may reduce the incidence of this troublesome adverse event.


Subject(s)
Chest Pain/prevention & control , Deep Brain Stimulation/methods , Neck Pain/prevention & control , Adult , Aged , Chest Pain/etiology , Chest Pain/pathology , Deep Brain Stimulation/adverse effects , Dystonic Disorders/physiopathology , Dystonic Disorders/therapy , Electrodes, Implanted , Female , Fibrosis , Headache/physiopathology , Headache/therapy , Humans , Male , Middle Aged , Neck Pain/etiology , Neck Pain/pathology , Parkinson Disease/physiopathology , Parkinson Disease/therapy , Retrospective Studies
10.
J Neurosurg ; 122(4): 948-54, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25614943

ABSTRACT

OBJECT: Bibliometrics are the methods used to quantitatively analyze scientific literature. In this study, bibliometrics were used to quantify the scientific output of neurosurgical departments throughout Great Britain and Ireland. METHODS: A list of neurosurgical departments was obtained from the Society of British Neurological Surgeons website. Individual departments were contacted for an up-to-date list of consultant (attending) neurosurgeons practicing in these departments. Scopus was used to determine the h-index and m-quotient for each neurosurgeon. Indices were measured by surgeon and by departmental mean and total. Additional information was collected about the surgeon's sex, title, listed superspecialties, higher research degrees, and year of medical qualification. RESULTS: Data were analyzed for 315 neurosurgeons (25 female). The median h-index and m-quotient were 6.00 and 0.41, respectively. These were significantly higher for professors (h-index 21.50; m-quotient 0.71) and for those with an additional MD or PhD (11.0; 0.57). There was no significant difference in h-index, m-quotient, or higher research degrees between the sexes. However, none of the 16 British neurosurgery professors were female. Neurosurgeons who specialized in functional/epilepsy surgery ranked highest in terms of publication productivity. The 5 top-scoring departments were those in Addenbrooke's Hospital, Cambridge; St. George's Hospital, London; Great Ormond Street Hospital, London; National Hospital for Neurology and Neurosurgery, Queen Square, London; and John Radcliffe Hospital, Oxford. CONCLUSIONS: The h-index is a useful bibliometric marker, particularly when comparing between studies and individuals. The m-quotient reduces bias toward established researchers. British academic neurosurgeons face considerable challenges, and women remain underrepresented in both clinical and academic neurosurgery in Britain and Ireland.


Subject(s)
Neurosurgery/statistics & numerical data , Periodicals as Topic/statistics & numerical data , Surgeons/statistics & numerical data , Adult , Aged , Bibliometrics , Biomedical Research/statistics & numerical data , Efficiency , Female , Humans , Ireland , Male , Middle Aged , Publications , Sex Factors , Specialization , United Kingdom
11.
J Neurol Neurosurg Psychiatry ; 86(12): 1307-13, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25362089

ABSTRACT

OBJECTIVE: 61 procedures with selective peripheral denervation for cervical dystonia were retrospectively analysed concerning surgical results, pain, quality of life (QoL) and recurrences. METHODS: The patients were assessed with the Tsui torticollis scale, Visual Analogue Scale (VAS) for pain and Fugl-Meyer scale for QoL. Evaluations were performed preoperatively, early postoperatively, at 6 months, then at a mean of 42 (13-165) months. All patients underwent electromyogram at baseline, which was repeated in cases who presented with recurrence of symptoms after surgery. RESULTS: Six months of follow-up was available for 55 (90%) of the procedures and late follow-up for 34 (56%). The mean score of the Tsui scale was 10 preoperatively. It improved to 4.5 (p<0.001) at 6 months, and 5.3 (p<0.001) at late follow-up. VAS for pain improved from 6.5 preoperatively to 4.2 (p<0.001) at 6 months and 4 (p<0.01) at late follow-up. The Fugl-Meyer score for QoL improved from 43.3 to 46.6 (p<0.05) at 6 months, and to 51.1 (p<0.05) at late follow-up. Major reinnervation and/or change in the dystonic pattern occurred following 29% of the procedures, and led in 26% of patients to reoperation with either additional denervation or pallidal stimulation. CONCLUSIONS: Selective peripheral denervation remains a surgical option in the treatment of cervical dystonia when conservative measures fail. Although the majority of patients experience a significant relief of symptoms, there is a substantial risk of reinnervation and/or change in the pattern of the cervical dystonia.


Subject(s)
Muscle Denervation/methods , Neurosurgical Procedures/methods , Peripheral Nerves/surgery , Torticollis/surgery , Adult , Aged , Electric Stimulation Therapy , Electromyography , Female , Follow-Up Studies , Globus Pallidus , Humans , Male , Middle Aged , Neurosurgical Procedures/adverse effects , Pain/diagnosis , Pain/etiology , Pain Measurement , Quality of Life , Recurrence , Retrospective Studies , Treatment Outcome
12.
Mov Disord ; 29(4): 532-8, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24532491

ABSTRACT

Speech changes after bilateral subthalamic nucleus deep brain stimulation (STN-DBS) can be variable, with the majority of patients experiencing speech deterioration over time. The aim of this study was to describe the perceptual characteristics of speech following chronic STN-DBS and to analyze clinical and surgical factors that could predict speech change. Fifty-four consecutive patients (34 men; mean age ± standard deviation (SD), 58.8 ± 6.3 years; mean ± SD disease duration, 12.5 ± 4.7 years; mean ± SD levodopa equivalent, 1556 ± 671 mg/day; mean ± SD Unified Parkinson's Disease Rating Scale motor part (UPDRS-III) off-medication score, 48.1 ± 17.9 [range, 20-89]; and mean ± SD UPDRS-III on-medication score, 12.4 ± 7.8 [range, 2-31]) participated in this study. They were assessed before and at 1 year after surgery using the Assessment of Intelligibility for the Dysarthric Speech, the perceptual scale from Darley et al., and the UPDRS-III. Speech intelligibility deteriorated on average by 14.4% (P = 0.0006) after 1 year of STN-DBS when off-medication and by 12.3% (P = 0.001) when on-medication. The effect on speech was not linked to age at surgery, unlike the effect on motor outcome. The most significant predictive factors for deterioration of speech intelligibility when patients were off-medication/on-stimulation were lower preoperative speech intelligibility on-medication, longer disease duration, and medially placed left hemisphere active electrode contact. Speech change after STN-DBS is variable and multifactorial. Consistent preoperative speech evaluation would help inform patients about the possible effects of surgery. Appropriate consideration of speech deficits might assist surgical targeting, particularly of the left electrode.


Subject(s)
Deep Brain Stimulation , Parkinson Disease/therapy , Speech Intelligibility/physiology , Subthalamic Nucleus/physiopathology , Aged , Female , Humans , Male , Middle Aged , Parkinson Disease/physiopathology , Treatment Outcome
13.
Dev Psychobiol ; 56(2): 249-61, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24285109

ABSTRACT

Exposure to faces is known to shape and change the face processing system; however, no study has yet documented infants' natural daily first-hand exposure to faces. One- and three-month-old infants' visual experience was recorded through head-mounted cameras. The video recordings were coded for faces to determine: (1) How often are infants exposed to faces? (2) To what type of faces are they exposed? and (3) Do frequently encountered face types reflect infants' typical pattern of perceptual narrowing? As hypothesized, infants spent a large proportion of their time (25%) exposed to faces; these faces were primarily female (70%), own-race (96%), and adult-age (81%). Infants were exposed to more individual exemplars of female, own-race, and adult-age faces than to male, other-race, and child- or older-adult-age faces. Each exposure to own-race faces was longer than to other-race faces. There were no differences in exposure duration related to the gender or age of the face. Previous research has found that the face types frequently experienced by our participants are preferred over and more successfully recognized than other face types. The patterns of face exposure revealed in the current study coincide with the known trajectory of perceptual narrowing seen later in infancy.


Subject(s)
Discrimination, Psychological/physiology , Face , Pattern Recognition, Visual/physiology , Recognition, Psychology/physiology , Visual Perception/physiology , Female , Humans , Infant , Male , Photic Stimulation
14.
Handb Clin Neurol ; 116: 63-71, 2013.
Article in English | MEDLINE | ID: mdl-24112885

ABSTRACT

The renaissance of functional stereotactic neurosurgery was pioneered in the mid 1980s by Laitinen's introduction of Leksell's posteroventral pallidotomy for Parkinson´s disease (PD). This ablative procedure experienced a worldwide spread in the 1990s, owing to its excellent effect on dyskinesias and other symptoms of post-l-dopa PD. Modern deep brain stimulation (DBS), pioneered by Benabid and Pollak in 1987 for the treatment of tremor, first became popular when it was applied to the subthalamic nucleus (STN) in the mid 1990s, where it demonstrated a striking effect on all cardinal symptoms of advanced PD, and permitted reduced dosages of medication. DBS, as a nondestructive, adaptable, and reversible procedure that is proving safe in bilateral surgery on basal ganglia, has great appeal to clinicians and patients alike, despite the fact that it is expensive, laborious, and relies on very strict patient selection criteria, especially for STN DBS. Psychiatric surgery has experienced the same phenomenon, with DBS supplanting completely stereotactic ablative procedures. This chapter discusses the pros and cons of ablation versus stimulation and investigates the reasons why DBS has overshadowed proven efficient ablative procedures such as pallidotomy for PD, and capsulotomy and cingulotomy for obsessive-compulsive disorder and depression.


Subject(s)
Ablation Techniques , Brain/physiology , Brain/surgery , Deep Brain Stimulation , Animals , Humans , Mental Disorders/therapy , Nervous System Diseases/therapy , Pain/surgery
16.
World Neurosurg ; 80(6): e245-53, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23044000

ABSTRACT

BACKGROUND: Deep brain stimulation (DBS) has emerged as a treatment for severe cases of therapy-refractory obsessive-compulsive disorder (OCD), and promising results have been reported. The literature might, however, be somewhat unclear, considering the different targets used, and due to repeated inclusion of individual patients in multiple publications. The aim of this report was to review the literature on DBS for OCD. METHODS: The modern literature concerning studies conducted on DBS in the treatment of OCD was reviewed. RESULTS: The results of DBS in OCD have been presented in 25 reports with 130 patients, of which, however, only 90 contained individual patients. Five of these reports included at least 5 individual patients not presented elsewhere. Sixty-eight of these patients underwent implantation in the region of the internal capsule/ventral striatum, including the nucleus accumbens. The target in this region has varied between groups and over time, but the latest results from bilateral procedures in this area have shown a 50% reduction of OCD scores, depression, and anxiety. The subthalamic nucleus has been suggested as an alternative target. Although beneficial effects have been demonstrated, the efficacy of this procedure cannot be decided, because only results after 3 months of active stimulation have been presented so far. CONCLUSIONS: DBS is a promising treatment for therapy-refractory OCD, but the published experience is limited and the method is at present an experimental therapy.


Subject(s)
Deep Brain Stimulation/methods , Obsessive-Compulsive Disorder/therapy , Adolescent , Adult , Age of Onset , Cross-Over Studies , Deep Brain Stimulation/adverse effects , Drug Resistance , Electrodes, Implanted , Female , Humans , Internal Capsule/physiology , Male , Middle Aged , Neurosurgical Procedures/methods , Obsessive-Compulsive Disorder/physiopathology , Obsessive-Compulsive Disorder/psychology , Psychiatric Status Rating Scales , Randomized Controlled Trials as Topic , Stereotaxic Techniques , Treatment Outcome , Young Adult
17.
Brain Stimul ; 6(4): 500-5, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23088851

ABSTRACT

BACKGROUND: Deep brain stimulation (DBS) of the internal globus pallidus (GPi) is an established therapy for primary generalized dystonia. However, the evolution of dystonia symptoms after DBS discontinuation after years of therapy has only rarely been reported. We therefore longitudinally studied the main physiological measurements known to be impaired in dystonia, with DBS ON and then again after termination of DBS, after at least five years of continuous DBS. OBJECTIVE: We studied whether dystonia evolution after DBS discontinuation in patients benefiting from long-term GPi DBS is different from that observed in earlier stages of the therapy. METHODS: In eleven DYT1 patients treated with bilateral GPi DBS for at least 5 years, dystonia was assessed ON-DBS, immediately after switch-off (OFF-DBS1) and 48 h after DBS termination (OFF-DBS2). We studied the influence of DBS intensity on dystonia when DBS was discontinued. RESULTS: On average a significant difference in symptoms was measured only between ON-DBS and OFF-DBS1 conditions. Importantly, none of the patients returned to their preoperative dystonia severity, even 48 h after discontinuation. The amount of clinical deterioration in the OFF conditions positively correlated with higher stimulation current in the chronic ON-DBS condition. CONCLUSIONS: The duration of DBS application influences symptom evolution after DBS termination. DBS intensity seems to have a prominent role on evolution of dystonic symptoms when DBS is discontinued. In conclusion, DBS induces changing modulation of the motor network with less worsening of symptoms after long term stimulation, when DBS is stopped.


Subject(s)
Deep Brain Stimulation/methods , Dystonia/therapy , Dystonic Disorders/therapy , Globus Pallidus/physiopathology , Adolescent , Adult , Aged , Dystonia/physiopathology , Dystonia/surgery , Dystonic Disorders/physiopathology , Dystonic Disorders/surgery , Female , Globus Pallidus/surgery , Humans , Longitudinal Studies , Male , Middle Aged , Severity of Illness Index , Treatment Outcome
18.
Stereotact Funct Neurosurg ; 91(1): 1-11, 2013.
Article in English | MEDLINE | ID: mdl-23154755

ABSTRACT

BACKGROUND: Deep brain stimulation (DBS) surgery is standard of care for the treatment of certain movement disorders. OBJECTIVE: We sought to characterize the spectrum of steps performed in DBS surgery, at centers around the world where this surgery is performed. METHODS: We identified the main steps in DBS surgery workflow and grouped these 19 steps into 3 phases (preoperative, operative, and postoperative). A survey tool, informed by a pilot survey, was administered internationally by trained study personnel at high- and low-volume DBS centers. Procedural components, duration, and surgeon motivational factors were assessed. Cluster analysis was used to identify procedural and behavioral clusters. RESULTS: One hundred eighty-five procedure workflow surveys (143 DBS centers) and 65 online surveys of surgeon motivational drivers were completed (45% response rate). Significant heterogeneity in technique, operative time, and surgeon motivational drivers was reported across centers. CONCLUSIONS: We provide a description of the procedural steps involved in DBS surgery and the duration of these steps, based on an international survey. These data will enable individual surgeons and centers to examine their own experience relative to colleagues at other centers and in other countries. Such information could also be useful in comparing efficiencies and identifying workflow obstacles between different hospital environments.


Subject(s)
Deep Brain Stimulation/methods , Health Care Surveys , Africa, Northern , Australia , Deep Brain Stimulation/instrumentation , Deep Brain Stimulation/statistics & numerical data , Dystonic Disorders/therapy , Essential Tremor/therapy , Europe , Humans , Japan , Motivation , Neurosurgery/statistics & numerical data , Parkinson Disease/therapy , Physicians/psychology , Pilot Projects , Practice Patterns, Physicians'/statistics & numerical data , South Africa , Surveys and Questionnaires , United States
20.
J Neurosci ; 32(31): 10541-53, 2012 Aug 01.
Article in English | MEDLINE | ID: mdl-22855804

ABSTRACT

Functional neurosurgery has afforded the opportunity to assess interactions between populations of neurons in the human cerebral cortex and basal ganglia in patients with Parkinson's disease (PD). Interactions occur over a wide range of frequencies, and the functional significance of those >30 Hz is particularly unclear. Do they improve movement, and, if so, in what way? We acquired simultaneously magnetoencephalography and direct recordings from the subthalamic nucleus (STN) in 17 PD patients. We examined the effect of synchronous and sequential finger movements and of the dopamine prodrug levodopa on induced power in the contralateral primary motor cortex (M1) and STN and on the coherence between the two structures. We observed discrete peaks in M1 and STN power at 60-90 Hz and at 300-400 Hz. All these power peaks increased with movement and levodopa treatment. Only STN activity at 60-90 Hz was coherent with activity in M1. Directionality analysis showed that STN gamma activity at 60-90 Hz tended to drive gamma activity in M1. The effects of levodopa on both local and distant synchronization at 60-90 Hz correlated with the degree of improvement in bradykinesia-rigidity as did local STN activity at 300-400 Hz. Despite this, there were no effects of movement type, nor interactions between movement type and levodopa in the STN, nor in the coherence between STN and M1. We conclude that synchronization at 60-90 Hz in the basal ganglia cortical network is prokinetic but likely through a modulatory effect rather than any involvement in explicit motor processing.


Subject(s)
Cortical Synchronization/physiology , Movement/physiology , Neurons/physiology , Parkinson Disease/pathology , Parkinson Disease/physiopathology , Subthalamic Nucleus/pathology , Adult , Analysis of Variance , Antiparkinson Agents/pharmacology , Antiparkinson Agents/therapeutic use , Cortical Synchronization/drug effects , Deep Brain Stimulation , Electroencephalography , Female , Fingers/physiopathology , Functional Laterality , Humans , Levodopa/pharmacology , Levodopa/therapeutic use , Magnetoencephalography , Male , Middle Aged , Motor Cortex/drug effects , Motor Cortex/physiopathology , Neurons/drug effects , Parkinson Disease/drug therapy , Psychomotor Performance , Spectrum Analysis , Statistics as Topic , Subthalamic Nucleus/drug effects , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...