These articles are generated by an RSS Feed from Pubmed. WCNeurotech are not responsible for the content of any external links which may be included in the feed.
Effect of Methysergide on Pudendal Inhibition of Micturition Reflex in Cats.
Exp Neurol. 2013 May 17;
Authors: Matsuta Y, Schwen Z, Mally AD, Shen B, Wang J, Roppolo JR, de Groat WC, Tai C
The role of 5-HT2 and opioid receptors in pudendal inhibition of bladder activity induced by intravesical infusion of saline or 0.25% acetic acid (AA) was investigated in anesthetized cats using methysergide (a 5-HT2 receptor antagonist) and naloxone (an opioid receptor antagonist). AA irritated the bladder and significantly (P<0.0001) reduced bladder capacity to 27.0±7.4% of saline control capacity. Pudendal nerve stimulation (PNS) at multiples of the threshold (T) intensity for inducing anal sphincter twitching restored bladder capacity to 60.1± 8.0% at 1-2T (P<0.0001) and 92.2±14.1% at 3-4T (P=0.001) of the saline control capacity. Methysergide (0.03-1 mg/kg, i.v.) suppressed low intensity (1-2T) PNS inhibition but not high intensity (3-4T) inhibition, and also significantly (P<0.05) increased control bladder capacity at the dosage of 0.3-1 mg/kg. During saline infusion without AA irritation, PNS significantly increased bladder capacity to 150.8±9.9% at 1-2T (P<0.01) and 180.4±16.6% at 3-4T (P<0.01) of the saline control capacity. Methysergide (0.1-1 mg/kg) significantly (P<0.05) increased saline control bladder capacity and suppressed PNS inhibition at the dosage of 0.03-1 mg/kg. After methysergide treatment (1 mg/kg), naloxone significantly (P<0.05) reduced control bladder capacity during AA infusion but had no effect during saline infusion. Naloxone also had no influence on PNS inhibition. These results suggest that 5-HT2 receptors play a role in PNS inhibition of reflex bladder activity and interact with opioid receptors in micturition reflex pathway. Understanding neurotransmitter mechanisms underlying pudendal neuromodulation is important for the development of new treatments for bladder disorders.
PMID: 23688680 [PubMed - as supplied by publisher]
Repetitive transcranial magnetic stimulation (rTMS) for treating major depression and schizophrenia: a systematic review of recent meta-analyses.
Ann Med. 2013 May 20;
Authors: Hovington CL, McGirr A, Lepage M, Berlim MT
Background. In recent years, repetitive transcranial magnetic stimulation (rTMS) has been developed for the treatment of major depression (MD) and schizophrenia. Although rTMS has shown some promising findings, the lack of standardization in the methodology employed has resulted in discordant findings. Objectives. The objective of this systematic review was to summarize several meta-analytical studies exploring the efficacy of rTMS in either MD or schizophrenia in order to examine the methodologies that increase the efficacy of rTMS and to provide some recommendations for future studies. Methods. We searched the MEDLINE database for potentially relevant meta-analytic studies on the use of rTMS for treating major depression and schizophrenia published from January 2000 to October 2011. Results. Fifteen rTMS meta-analytical studies were reviewed (11 on MD and 5 on schizophrenia). Several variables were reviewed including outcome measures, side-effects of rTMS, site of stimulation, frequency and intensity of stimulation, and number of treatment sessions. Conclusions. Overall, rTMS appears to be an effective and promising therapeutic for both MD and schizophrenia.
PMID: 23687987 [PubMed - as supplied by publisher]
Implication of dopaminergic modulation in operant reward learning and the induction of compulsive-like feeding behavior in Aplysia.
Learn Mem. 2013;20(6):318-327
Authors: Bédécarrats A, Cornet C, Simmers J, Nargeot R
Feeding in Aplysia provides an amenable model system for analyzing the neuronal substrates of motivated behavior and its adaptability by associative reward learning and neuromodulation. Among such learning processes, appetitive operant conditioning that leads to a compulsive-like expression of feeding actions is known to be associated with changes in the membrane properties and electrical coupling of essential action-initiating B63 neurons in the buccal central pattern generator (CPG). Moreover, the food-reward signal for this learning is conveyed in the esophageal nerve (En), an input nerve rich in dopamine-containing fibers. Here, to investigate whether dopamine (DA) is involved in this learning-induced plasticity, we used an in vitro analog of operant conditioning in which electrical stimulation of En substituted the contingent reinforcement of biting movements in vivo. Our data indicate that contingent En stimulation does, indeed, replicate the operant learning-induced changes in CPG output and the underlying membrane and synaptic properties of B63. Significantly, moreover, this network and cellular plasticity was blocked when the input nerve was stimulated in the presence of the DA receptor antagonist cis-flupenthixol. These results therefore suggest that En-derived dopaminergic modulation of CPG circuitry contributes to the operant reward-dependent emergence of a compulsive-like expression of Aplysia's feeding behavior.
PMID: 23685764 [PubMed - as supplied by publisher]
Non-invasive brain stimulation and the autonomic nervous system.
Clin Neurophysiol. 2013 May 16;
Authors: Schestatsky P, Simis M, Freeman R, Pascual-Leone A, Fregni F
Repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) are non-invasive methods of brain stimulation (NIBS) that can induce significant effects on cortical and subcortical neural networks. Both methods are relatively safe if appropriate guidelines are followed, and both can exert neuromodulatory effects that may be applied to the investigation of the autonomic nervous system (ANS). In addition, ANS measures can shed important light onto the neurobiologic mechanisms of NIBS. Here we present a systematic review on studies testing NIBS and ANS simultaneously. We structure our findings into four broad (not mutually exclusive) categories: (i) studies in which ANS function was modified by NIBS versus those in which it was not; (ii) studies in which NIBS was used to understand ANS function, (iii) studies in which ANS was used to understand NIBS mechanisms and (iv) NIBS/ANS studies conducted in healthy subjects versus those in patients with neuropsychiatric diseases. Forty-four articles were identified and no conclusive evidence of the effects of NIBS on ANS was observed, mainly because of the heterogeneity of included studies. Based on a comprehensive summary of this literature we propose how NIBS might be further developed to enhance our understanding of the cortical mechanisms of autonomic regulation and perhaps to modulate autonomic activity for therapeutic purposes.
PMID: 23684898 [PubMed - as supplied by publisher]
Bilateral Pallidal Stimulation for "Sticking-Out Tongue" Feature in Patients With Primary Focal Tongue Protrusion Dystonia.
Neuromodulation. 2013 May 17;
Authors: Chung JC, Kim JP, Chang WS, Kim HY, Chang JW
INTRODUCTION: Tongue protrusion dystonia can cause difficulty with speech, mastication, breathing, and swallowing. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is a widespread therapeutic alternative for treating medically refractory dystonia. To our knowledge, detailed reports regarding DBS for tongue protrusion dystonia are rare. In this report, we describe two patients with "sticking out" tongue protrusion who had undergone bilateral GPi DBS. METHODS: Operations were performed with surface electromyographic (EMG) monitoring, microelectrode recording, and macrostimulation to identify the point at which tongue kinetic cells respond most effectively. The most effective location for active contacts was identified according to burst EMG response in the posteroventral GPi. RESULTS: Two years after DBS, total Burke, Fahn, and Marsden Dystonia Rating Scale scores of two patients were improved from 12.5 to 1 (92.0%) and from 13 to 1 (92.3%), respectively. One 58-year-old woman who lost 7?kg weight from not eating well improved enough to eat solid food and became free from choking. Another 54-year-old woman who had dysarthria and mumbled could speak more fluently and would not have complained difficulty in reading any more. CONCLUSION: Stimulation on posteroventral GPi for patients with idiopathic "sticking-out" tongue movement changes EMG pattern in orofacial muscles. This fact supports a reason for modulation of unknown circuit connecting tongue-specific area in motor cortex, and basal ganglia.
PMID: 23682929 [PubMed - as supplied by publisher]
Thoracic Radiculopathy Following Spinal Cord Stimulator Placement: Case Series.
Neuromodulation. 2013 May 17;
Authors: Mammis A, Bonsignore C, Mogilner AY
OBJECTIVE: The clinical entity of thoracic radiculopathy following spinal cord stimulator (SCS) placement has not been previously described. MATERIALS AND METHODS: A retrospective review of prospectively acquired data on 172 patients, having undergone thoracic SCS placement at our institution, was performed. In addition, four patients were implanted at outside institutions, and were referred for revision. We examine our early experience with placement of thoracic SCS in surgically treated patients with chronic pain and 15 associated specific postoperative radicular pain complications along respective thoracic dermatomes. We postulate that preexisting thoracic spinal pathology affords less compliance in the placement of larger paddles, and subsequent radicular pain in a band-like abdominal fashion. RESULTS: A syndrome of thoracic radiculopathy, presenting as intractable lower thoracic or abdominal wall pain occurring in the immediate postoperative period, was identified in 15 patients. These patients subsequently underwent revision surgery, with either a more extensive laminectomy to further decompress the dorsal nerve roots or lead removal, both of which resulted in near immediate relief of symptoms. CONCLUSIONS: Thoracic radiculopathy may occur following SCS paddle lead placement. This clinical syndrome is characterized by its immediate postoperative development, band-like thoracic or abdominal pain pattern, severe pain that both overwhelms the incisional pain and is refractory to medications, and absence of motor deficit. The lateral placement of paddle leads increases the risk of radicular symptoms. Preoperative thoracic spine magnetic resonance imaging may be helpful in identifying patients who may be susceptible to this syndrome.
PMID: 23682904 [PubMed - as supplied by publisher]
Multi-target neurostimulation for adequate long-term relief of neuropathic and nociceptive chronic pain components.
Surg Neurol Int. 2013;4(Suppl 3):S170-5
Authors: Chodakiewitz YG, Bicalho GV, Chodakiewitz JW
Successful treatment of chronic pain for patients with failed back surgery syndrome can be extremely complicated. These patients require careful and individualized clinical assessment, as they often present with mixed pain syndromes that involve both neuropathic and nociceptive components. The distinct types of pain involved in such cases may require combined treatments from individual interventions that are analgesically independent and specific for each type of pain involved. Neuromodulation by electric stimulation at appropriately chosen targets and combinations may be an important option to consider for such patients. We present a case of combined debilitating axial nociceptive spinal pain and bilateral neuropathic leg pain in a patient after 14 failed back operations. A combination of spinal cord stimulation (SCS) and deep brain stimulation in the periventricular gray (PVG) have successfully provided the patient with complete relief of both components of his chronic pain condition, after all other pain management options had been exhausted. By alternating activation of each implanted stimulator separately and in conjunction, we were able to demonstrate a clinically independent analgesic character for each stimulation system, each specific to a particular type of pain. The SCS provided complete relief of the neuropathic pain component, without affecting the nociceptive component at all. The PVG stimulation provided complete relief of the nociceptive component, without affecting the neuropathic component at all. In combination, there was complete relief of the total chronic pain condition. There appeared to be no overlapping or synergistic effect between the two neuromodulation systems in the patient. The patient has had prolonged complete relief from his chronic pain condition with the combined neuromodulation intervention over 22 years of follow-up.
PMID: 23682344 [PubMed - in process]
Neuromodulation for cephalgias.
Surg Neurol Int. 2013;4(Suppl 3):S136-50
Authors: Rasskazoff SY, Slavin KV
Headaches (cephalgias) are a common reason for patients to seek medical care. There are groups of patients with recurrent headache and craniofacial pain presenting with malignant course of their disease that becomes refractory to pharmacotherapy and other medical management options. Neuromodulation can be a viable treatment modality for at least some of these patients. We review the available evidence related to the use of neuromodulation modalities for the treatment of medically refractory craniofacial pain of different nosology based on the International Classification of Headache Disorders, 2(nd) edition (ICHD-II) classification. This article also reviews the scientific rationale of neuromodulation application in management of cephalgias.
PMID: 23682340 [PubMed - in process]
Evaluation of Drug-Induced Sleep Endoscopy as a Patient Selection Tool for Implanted Upper Airway Stimulation for Obstructive Sleep Apnea.
J Clin Sleep Med. 2013;9(5):433-438
Authors: Vanderveken OM, Maurer JT, Hohenhorst W, Hamans E, Lin HS, Vroegop AV, Anders C, de Vries N, Van de Heyning PH
STUDY OBJECTIVES: To study the possible predictive value of drug-induced sleep endoscopy (DISE) in assessing therapeutic response to implanted upper airway stimulation (UAS) for obstructive sleep apnea (OSA).
METHODS: During DISE, artificial sleep is induced by midazolam and/or propofol, and the pharyngeal collapse patterns are visualized using a flexible fiberoptic nasopharyngoscope. The level (palate, oropharynx, tongue base, hypopharynx/epiglottis), the direction (anteroposterior, concentric, lateral), and the degree of collapse (none, partial, or complete) were scored in a standard fashion.
RESULTS: We report on the correlation between DISE results and therapy response in 21 OSA patients (apnea-hypopnea index [AHI] 38.5 ± 11.8/h; body mass index [BMI] 28 ± 2 kg/m(2), age 55 ± 11 y, 20 male/1 female) who underwent DISE before implantation of a UAS system. Statistical analysis revealed a significantly better outcome with UAS in patients (n = 16) without palatal complete concentric collapse (CCC), reducing AHI from 37.6 ± 11.4/h at baseline to 11.1 ± 12.0/h with UAS (p < 0.001). No statistical difference was noted in AHI or BMI at baseline between the patients with and without palatal CCC. In addition, no predictive value was found for the other DISE collapse patterns documented.
CONCLUSIONS: The absence of palatal CCC during DISE may predict therapeutic success with implanted UAS therapy. DISE can be recommended as a patient selection tool for implanted UAS to treat OSA.
CITATION: Vanderveken OM; Maurer JT; Hohenhorst W; Ha-mans E; Lin HS; Vroegop AV; Anders C; de Vries N; Van de Heyning PH. Evaluation of drug-induced sleep endoscopy as a patient selection tool for implanted upper airway stimulation for obstructive sleep apnea. J Clin Sleep Med 2013;9(5):433-438.
PMID: 23674933 [PubMed - as supplied by publisher]
Chronic tinnitus: an interdisciplinary challenge.
Dtsch Arztebl Int. 2013 Apr;110(16):278-84
Authors: Kreuzer PM, Vielsmeier V, Langguth B
BACKGROUND: Tinnitus is defined as the perception of sound in the absence of a corresponding external acoustic stimulus. It is a common problem that markedly impairs the quality of life of about 1% of the general population.
METHODS: We selectively reviewed the pertinent literature to provide an overview of the current treatment options for chronic tinnitus.
RESULTS: Cognitive behavioral therapy is effective and is the best studied of all currently available treatments. All patients should have a therapeutic interview for counseling. Auditory stimulation can also lessen tinnitus: It is used in tinnitus maskers and hearing aids, as well as in tinnitus retraining therapy. An improved understanding of the neural mechanisms of tinnitus has led to the development of innovative techniques of neuromodulation and neurostimulation, but these are still experimental. Drugs are indicated only for the treatment of tinnitus-associated symptoms such as depression, sleep disturbances, and anxiety.
CONCLUSION: There are many ways to treat chronic tinnitus, and new treatments are now being developed. As tinnitus has many causes and can be associated with many different comorbid disturbances, multidisciplinary diagnostic evaluation and treatment are important. For many tinnitus patients, long-term therapeutic success depends on the maintenance of a therapeutic relationship with the treating physician, so that the physician and the patient can work together to give careful consideration to each newly proposed diagnostic test or treatment step.
PMID: 23671468 [PubMed - in process]
Pearls and pitfalls: Neurostimulation in headache.
Cephalalgia. 2013 Jun;33(8):512-25
Authors: Jürgens TP, Leone M
CONTEXT: A variety of neuromodulatory approaches available today has broadened our therapeutic options significantly especially in drug refractory patients with chronic cluster headache and chronic migraine.
OVERVIEW: It is a dynamic field with a current trend to non-invasive transcutaneous stimulation approaches. However, sound studies providing evidence for the widespread use of these novel approaches are sparse. For invasive approaches, occipital nerve stimulation is now widely considered the treatment of first choice in chronic trigeminal autonomic cephalgias and - with limitations - chronic migraine. Although equally effective, deep brain stimulation is considered second-line treatment in cluster headache because of its potentially life-threatening side effects. Most recently, stimulation of the sphenopalatine ganglion has also been shown to effectively abort acute cluster headache attacks. Interesting other upcoming approaches include transcutaneous supraorbital nerve stimulation and transcutaneous vagal nerve stimulation.
CONCLUSION: Pearls and pitfalls of common invasive and non-invasive neuromodulatory approaches and open questions are summarised in this review along with recommendations for future studies.
PMID: 23671249 [PubMed - in process]
Therapeutic time window of noninvasive brain stimulation for pain treatment: inhibition of maladaptive plasticity with early intervention.
Expert Rev Med Devices. 2013 May;10(3):339-52
Authors: Andrade DC, Borges I, Bravo GL, Bolognini N, Fregni F
Neuromodulatory effects of noninvasive brain stimulation (NIBS) have been extensively studied in chronic disorders such as major depression, chronic pain and stroke. However, few studies have explored the use of these techniques in acute conditions. A possible use of NIBS in acute disorders is to prevent or reverse ongoing maladaptive plastic alterations, seemingly responsible for treatment refractoriness and detrimental behavioral changes. In this review, the authors discuss the potential role of NIBS in blocking maladaptive plasticity using the transition of acute to chronic pain in conditions such as postsurgical pain, central poststroke pain, pain after spinal cord injury and pain after traumatic brain injury as a model. The authors also present suggestions for clinical trial design using NIBS in the acute stage of illnesses.
PMID: 23668706 [PubMed - in process]
Clinical management of urinary incontinence in women.
Am Fam Physician. 2013 May 1;87(9):634-40
Authors: Hersh L, Salzman B
Most cases of urinary incontinence in women fall under one of three major subtypes: urge, stress, or mixed. A stepped-care approach that advances from least invasive (behavioral modification) to more invasive (surgery) interventions is recommended. Bladder retraining and pelvic floor muscle exercises are first-line treatments for persons without cognitive impairment who present with urge incontinence. Neuromodulation devices, such as posterior tibial nerve stimulators, are an option for urge incontinence that does not respond to behavioral therapy. Pharmacologic therapy with anticholinergic medications is another option for treating urge incontinence if behavioral therapy is unsuccessful; however, because of adverse effects, these agents are not recommended in older adults. Other medication options for urge incontinence include mirabegron and onabotulinumtoxinA. Sacral nerve stimulators, which are surgically implanted, have also been shown to improve symptoms of urge incontinence. Pelvic floor muscle exercises are considered first-line treatment for stress incontinence. Noninvasive electrical and magnetic stimulation devices are also available. Alternatives for treating stress incontinence include vaginal inserts, such as pessaries, and urethral plugs. Limited or conflicting evidence exists for the use of medications for stress incontinence; no medications are approved by the U.S. Food and Drug Administration for this condition. Minimally invasive procedures, including radiofrequency denaturation of the urethra and injection of periurethral bulking agents, can be used if stress incontinence does not respond to less invasive treatments. Surgical interventions, such as sling and urethropexy procedures, should be reserved for stress incontinence that has not responded to other treatments.
PMID: 23668526 [PubMed - in process]
A Multicenter, Prospective Trial to Assess the Safety and Performance of the Spinal Modulation Dorsal Root Ganglion Neurostimulator System in the Treatment of Chronic Pain.
Neuromodulation. 2013 May 13;
Authors: Liem L, Russo M, Huygen FJ, Van Buyten JP, Smet I, Verrills P, Cousins M, Brooker C, Levy R, Deer T, Kramer J
OBJECTIVES: This multicenter prospective trial was conducted to evaluate the clinical performance of a new neurostimulation system designed to treat chronic pain through the electrical neuromodulation of the dorsal root ganglia (DRG) neurophysiologically associated with painful regions of the limbs and/or trunk. MATERIALS AND METHODS: Thirty-two subjects were implanted with a novel neuromodulation device. Pain ratings during stimulation were followed up to six months and compared with baseline ratings. Subjects also completed two separate reversal periods in which stimulation was briefly stopped in order to establish the effects of the intervention. RESULTS: At all assessments, more than half of subjects reported pain relief of 50% or better. At six months postimplant, average overall pain ratings were 58% lower than baseline (p?<?0.001), and the proportions of subjects experiencing 50% or more reduction in pain specific to back, leg, and foot regions were 57%, 70%, and 89%, respectively. When stimulation was discontinued for a short time, pain returned to baseline levels. Discrete coverage of hard-to-treat areas was obtained across a variety of anatomical pain distributions. Paresthesia intensity remained stable over time and there was no significant difference in the paresthesia intensity perceived during different body postures/positions (standing up vs. lying down). CONCLUSIONS: Results of this clinical trial demonstrate that neurostimulation of the DRG is a viable neuromodulatory technique for the treatment of chronic pain. Additionally, the capture of discrete painful areas such as the feet combined with stable paresthesia intensities across body positions suggest that this stimulation modality may allow more selective targeting of painful areas and reduce unwanted side-effects observed in traditional spinal cord stimulation (SCS).
PMID: 23668228 [PubMed - as supplied by publisher]
Pallidal Stimulation in Children: Comparison Between Cerebral Palsy and DYT1 Dystonia.
J Child Neurol. 2013 May 10;
Authors: Marks W, Bailey L, Reed M, Pomykal A, Mercer M, Macomber D, Acosta F, Honeycutt J
The authors compared the outcomes of 17 children aged 7 to 15 years with DYT1 dystonia or cerebral palsy following deep brain stimulation. While patients with cerebral palsy presented with significantly greater motor disability than the DYT1 cohort at baseline, both groups demonstrated improvement at 1 year (cerebral palsy = 24%; DYT1 = 6%). The group as a whole demonstrated significant improvement on the Barry-Albright Dystonia Scale across time. Gains in motor function were apparent in both axial and appendicular distributions involving both upper and lower extremities. Gains achieved by 6 months were sustained in the cerebral palsy group, whereas the DYT1 group demonstrated continued improvement with ongoing pallidal stimulation beyond 18 months. Young patients with dystonia due to cerebral palsy responded comparably to patients with DYT1 dystonia. The severity of motor impairment in patients with cerebral palsy at baseline and follow-up raises the issue of even earlier intervention with neuromodulation in this population to limit long-term motor impairments due to dystonia.
PMID: 23666041 [PubMed - as supplied by publisher]
Quality and Cost-Effectiveness of Interventional Pain Procedures: Minimally Invasive Lumbar Decompression (MILD) as a Paradigm?
Pain Med. 2013 May 10;
Authors: Mogilner AY
PMID: 23663290 [PubMed - as supplied by publisher]
Low-Intensity Focused Ultrasound Pulsation Device Used During Magnetic Resonance Imaging: Evaluation of Magnetic Resonance Imaging-Related Heating at 3?Tesla/128?MHz.
Neuromodulation. 2013 May 10;
Authors: Korb AS, Shellock FG, Cohen MS, Bystritsky A
OBJECTIVE: The objective of this study was to determine magnetic resonance imaging (MRI)-related heating for a low-intensity focused ultrasound pulsation (LIFUP) device used during MRI performed at 3?T/128?MHz. MATERIALS AND METHODS: A special phantom was constructed to mimic the thermal properties of the human brain, and a piece of human temporal bone (skull) was embedded on top. Four fluoroptic thermometry probes, placed above and below the skull, were used to measure temperature changes during MRI (3?T/128?MHz; scanner-reported head average specific absorption rate 1.1-2?W/kg) with and without concurrent LIFUP sonication. LIFUP sonication was applied using a focused ultrasound device (BXPulsar 1001, Brainsonix, Inc., Los Angeles, CA, USA) at a derated spatial-peak temporal-average intensity of 3870?mW/cm(2) . RESULTS: MRI performed at relatively high specific absorption rate (SAR) caused a slight elevation in temperature (?0.6°C). Concurrent use of MRI at a medium-strength SAR and LIFUP sonication resulted in maximum temperature rise of 3.1°C after 8?min of continuous use. CONCLUSIONS: Under the specific conditions utilized for this investigation, LIFUP sonication does not appear to present significant heating risks when used concurrently with MRI. This information has important implications for the use of the LIFUP sonication in human subjects undergoing MRI at 3?T/128?MHz.
PMID: 23663228 [PubMed - as supplied by publisher]
Deep Brain Stimulation of the Subthalamic Nucleus for Peripherally Induced Parkinsonism.
Neuromodulation. 2013 May 10;
Authors: Baizabal-Carvallo JF, Jankovic J
PMID: 23663196 [PubMed - as supplied by publisher]
Successful Treatment of the Pain Associated With Melorheostosis With Spinal Cord Stimulation: A Case Study.
Neuromodulation. 2013 May 10;
Authors: Zaveri M, Goodman Keiser MD
PMID: 23663163 [PubMed - as supplied by publisher]
Visual field defects after radiosurgery for mesial temporal lobe epilepsy.
Epilepsia. 2013 May 10;
Authors: Hensley-Judge H, Quigg M, Barbaro NM, Newman SA, Ward MM, Chang EF, Broshek DK, Lamborn KR, Laxer KD, Garcia P, Heck CN, Kondziolka D, Beach R, Salanova V, Goodman R
PURPOSE: Gamma knife radiosurgery (RS) may be an alternative to open surgery for mesial temporal lobe epilepsy (MTLE), but morbidities and the anticonvulsant mechanisms of RS are unclear. Examination of visual field defects (VFDs) after RS may provide evidence of the extent of a postoperative fixed lesion. VFDs occur in 52-100% of patients following open surgery for MTLE. METHODS: This multicenter prospective trial of RS enrolled patients with unilateral hippocampal sclerosis and concordant video-electroencephalography (EEG) findings. Patients were randomized to low (20 Gy) or high (24 Gy) doses delivered to the amygdala, hippocampal head, and parahippocampal gyrus. Postoperative perimetry were obtained at 24 months after RS. Visual field defect ratios (VFDRs) were calculated to quantify the degree of VFDs. Results were contrasted with age, RS dose and 50% isodose volume, peak volume of radiation-induced change at the surgical target, quality of life measurements, and seizure remission. KEY FINDINGS: No patients reported visual changes and no patients had abnormal bedside visual field examinations. Fifteen (62.5%) of 24 patients had postoperative VFDs, all homonymous superior quadrantanopsias. None of the VFDs were consistent with injury to the optic nerve or chiasm. Clinical diagnosis of VFDs correlated significantly with VFDRs (p = 0.0005). Patients with seizure remission had smaller (more severe) VFDRs (p = 0.04). No other variables had significant correlations. SIGNIFICANCE: VFDs appeared after RS in proportions similar to historical comparisons from open surgery for MTLE. The nature of VFDs was consistent with lesions of the optic radiations. The findings support the hypothesis that the mechanism of RS involves some degree of tissue damage and is not confined entirely to functional changes in neuromodulation.
PMID: 23663063 [PubMed - as supplied by publisher]
Deep brain stimulation for neurological disorders.
IEEE Rev Biomed Eng. 2012;5:88-99
Authors: Oluigbo CO, Salma A, Rezai AR
Deep brain stimulation (DBS) involves the delivery of precise electrical signals to specific deep anatomical structures of the central nervous system, with the objective of altering or modulating neural functioning and achieving a reversible, adjustable and therapeutic or clinically beneficial effect. The exact mechanism of action of DBS is still the subject of ongoing investigations. However, based on extensive clinical investigations, it has become an established modality for the surgical treatment of advanced and medication intractable movement disorders such as Parkinson's disease, essential tremor and dystonia. DBS is also being investigated for conditions such as intractable epilepsy, neurobehavioral and psychiatric disorders such as treatment resistant depression, obsessive compulsive disorders, addiction, obesity, Alzheimer's disease and traumatic brain injury. The advantage of DBS over older deep brain lesioning procedures is its reversibility and adjustability. The design of the DBS systems allows for dynamic adjustment of the effects of electrical stimulation by altering the contacts at which electrical pulses are delivered to the brain and changing the stimulation parameters of those pulses. The clinical results from studies on DBS show that it has great potential making it one of most promising fields which could be used to address challenging neurological problems.
PMID: 23231991 [PubMed - indexed for MEDLINE]
The Cross-Talk Between Spinal Cord Stimulators and the Confirm? Cardiac Monitor.
Neuromodulation. 2013 May 9;
Authors: Chaiban GM, Davidov M, Cummings JE, Lehrian LE, Yee EM, Dugan A, Almualim MS, Atallah JN
INTRODUCTION: Spinal cord stimulators (SCS) function by transmission of electrical impulses to electrode contacts placed within the epidural space depending on the painful area to be treated. Because of the electrical nature of the SCS, there has been concern about the interaction between these devices and devices that monitor or augment the cardiac system. Implantable loop recorders help to identify the causes of syncope or palpitation by continuously evaluating and recording portions of an electrocardiograph in patients being evaluated for cardiac conduction arrhythmias. The purpose of the study is to simulate the possible effects of spinal cord stimulation on a Confirm cardiac monitor (St. Jude Medical, St. Paul, MN, USA). METHODS: Twenty patients without preexisting cardiac disease, who were successfully being treated with SCS, were enrolled. Confirm loop recorders (St. Jude Medical) were placed on their chest wall in a noninvasive manner, with all programmed at identical settings. Multiple stimulation settings were adjusted on the stimulators and the recordings from the Confirm loop recorder were analyzed for evidence of interference. RESULTS: Fifteen of the patients had no electrical noise detected at any of the tested combinations of stimulation. Five patients had some electrical "noise" detected by the loop recorder, but it did not inhibit the cardiologist evaluating the recording from analyzing the electrocardiograph for diagnostic purposes. At no point with any of the patients at any tested setting was there an appearance of a life-threatening arrhythmia. CONCLUSION: Our study demonstrates that spinal cord stimulation is unlikely to interfere with the data collected by the Confirm loop recorder, and the presence of an SCS should not interfere with the ability to use a loop recorder for diagnostic purposes.
PMID: 23659379 [PubMed - as supplied by publisher]
Free Energy, Precision and Learning: The Role of Cholinergic Neuromodulation.
J Neurosci. 2013 May 8;33(19):8227-8236
Authors: Moran RJ, Campo P, Symmonds M, Stephan KE, Dolan RJ, Friston KJ
Acetylcholine (ACh) is a neuromodulatory transmitter implicated in perception and learning under uncertainty. This study combined computational simulations and pharmaco-electroencephalography in humans, to test a formulation of perceptual inference based upon the free energy principle. This formulation suggests that ACh enhances the precision of bottom-up synaptic transmission in cortical hierarchies by optimizing the gain of supragranular pyramidal cells. Simulations of a mismatch negativity paradigm predicted a rapid trial-by-trial suppression of evoked sensory prediction error (PE) responses that is attenuated by cholinergic neuromodulation. We confirmed this prediction empirically with a placebo-controlled study of cholinesterase inhibition. Furthermore, using dynamic causal modeling, we found that drug-induced differences in PE responses could be explained by gain modulation in supragranular pyramidal cells in primary sensory cortex. This suggests that ACh adaptively enhances sensory precision by boosting bottom-up signaling when stimuli are predictable, enabling the brain to respond optimally under different levels of environmental uncertainty.
PMID: 23658161 [PubMed - as supplied by publisher]
Neuromodulation techniques and eating disorders.
Int J Eat Disord. 2013 Jul;46(5):447-50
Authors: Van den Eynde F, Guillaume S
PMID: 23658089 [PubMed - in process]
Neuromodulation Device Therapy for Treatment of Hypertensive Heart Disease.
Circ J. 2013 May 9;
Authors: Todoran TM, Zile MR
Hypertensive heart disease (HHD) is the leading cause of mortality and morbidity in the United States. Despite the availability of medical therapy it remains a challenge to treat. Autonomic nervous system imbalance resulting in overactivity of the sympathetic nervous system and under activity of the parasympathetic nervous system is integral in the development of hypertension and ultimately the development of HHD. Emerging data suggest that neuromodulation device therapy for treatment of HHD is promising.
PMID: 23657125 [PubMed - as supplied by publisher]
How to Avoid Twiddler's Syndrome in Deep Brain Stimulation for Dystonia?
Neuromodulation. 2013 May 3;
Authors: Menghetti C, Zekaj E, Saleh C, Porta M, Servello D
PMID: 23647838 [PubMed - as supplied by publisher]
Catastrophic Failure of a Boston Scientific Artisan Spinal Cord Stimulator.
Neuromodulation. 2013 May 3;
Authors: Amrani J
PMID: 23647813 [PubMed - as supplied by publisher]
Outcomes of Percutaneous and Paddle Lead Implantation for Spinal Cord Stimulation: A Comparative Analysis of Complications, Reoperation Rates, and Health-Care Costs.
Neuromodulation. 2013 May 3;
Authors: Babu R, Hazzard MA, Huang KT, Ugiliweneza B, Patil CG, Boakye M, Lad SP
OBJECTIVES: Spinal cord stimulation (SCS) is a well-established modality for the treatment of chronic pain, and can utilize percutaneous or paddle leads. While percutaneous leads are less invasive, they have been shown to have higher lead migration rates. In this study, we compared the long-term outcomes and health-care costs associated with paddle and percutaneous lead implantation. MATERIALS AND METHODS: We utilized the MarketScan data base to examine patients who underwent percutaneous or paddle lead SCS system implantation from 2000 to 2009. Outcomes including complications, reoperation rates, and health-care costs were evaluated in propensity score matched cohorts using univariate and multivariate analyses. RESULTS: The study cohort was comprised of 13,774 patients. At 90 days following the initial procedure, patients in the SCS paddle group were more likely to develop a postoperative complication than patients receiving percutaneous systems (3.4% vs. 2.2%, p = 0.0005). Two-year (6.3% vs. 3.5%, p = 0.0056) and long-term (five+ years) (22.9% vs. 8.5%, p < 0.0008) reoperation rates were significantly higher in those with percutaneous lead systems. However, long-term health-care costs were similar for those receiving paddle and percutaneous leads ($169,768 vs. $186,139, p = 0.30). CONCLUSIONS: While the implantation of paddle leads is associated with slightly higher initial postoperative complications, these leads are associated with significantly lower long-term reoperation rates. Nonetheless, long-term health-care costs are similar between paddle and percutaneous leads. Additional improvements in SCS technologies that address the shortcomings of current systems are needed to reduce the risk of reoperation due to hardware failure. Further study is required to evaluate the efficacy of newer percutaneous and paddle SCS systems and examine their comparative outcomes.
PMID: 23647789 [PubMed - as supplied by publisher]
The Effect of Sacral Neuromodulation on Anticholinergic Use and Expenditures in a Privately Insured Population.
Neuromodulation. 2013 May 3;
Authors: Anger JT, Cameron AP, Madison R, Saigal CS, Clemens JQ, The Urologic Diseases in America Project
OBJECTIVES: Sacral neuromodulation is Food and Drug Administration approved for many types of voiding dysfunction. Goals of treatment often include cessation of anticholinergic therapy. With the goal of understanding the impact of sacral neuromodulation on anticholinergic use, we analyzed patterns of care using a national claims-based dataset. MATERIALS AND METHODS: The Ingenix (i3) data base contains insurance claims, including utilization and cost data, for 75 large employers. De-identified patients who underwent sacral neuromodulation between 2002 and 2007 were identified by the unique current procedural terminology-4 procedure code for pulse generator implantation, code 64590. The number and costs of anticholinergic prescriptions were compared before and after treatment. RESULTS: There were 266 percutaneous and 794 two-staged procedures performed from 2002 to 2007 in the i3 dataset. A total of 484 pulse generator implantations were performed, representing 46% of the test procedures. During the year prior to pulse generator placement, each patient purchased an average of 2.1 prescriptions for an anticholinergic agent (SD 3.5). During the year after neuromodulation, each patient purchased an average of 1.0 prescription (SD 2.3, p < 0.0001 by t-test). Prescription charges were $241.31 per patient before and $103.52 after neuromodulation, a statistically significant cost difference (p < 0.0001 by t-test). During the year before the procedure, 50% of patients filled anticholinergic prescriptions. This decreased to 23% after the procedure (p < 0.0001 by chi-square test). CONCLUSIONS: Sacral neuromodulation was associated with a significant decrease in the use of anticholinergic medication. Cost-effectiveness analyses that take into account patient quality-adjusted life years are needed to determine the true cost-benefit ratio of sacral neuromodulation.
PMID: 23647745 [PubMed - as supplied by publisher]
Neurologist Consistency in Interpreting Information Provided by an Interactive Visualization Software for Deep Brain Stimulation Postoperative Programming Assistance.
Neuromodulation. 2013 May 3;
Authors: Pallavaram S, Phibbs FT, Tolleson C, Davis TL, Fang J, Hedera P, Li R, Koyama T, Dawant BM, D'Haese PF
INTRODUCTION: Postoperative programming in deep brain stimulation (DBS) therapy for movement disorders can be challenging and time consuming. Providing the neurologist with tools to visualize the electrode location relative to the patient's anatomy along with models of tissue activation and statistical data can therefore be very helpful. In this study, we evaluate the consistency between neurologists in interpreting and using such information provided by our DBS programming assistance software. METHODS: Five neurologists experienced in DBS programming were each given a dataset of 29 leads implanted in 17 patients. For each patient, probabilistic maps of stimulation response, anatomical images, models of tissue activation volumes, and electrode positions were presented inside a software framework called CRAnialVault Explorer (CRAVE) developed in house. Consistency between neurologists in optimal contact selection using the software was measured. RESULTS: With only the efficacy map, the average consistency among the five neurologists with respect to the mode and mean of their selections was 97% and 95%, respectively, while these numbers were 93% and 89%, respectively, when both efficacy and an adverse effect map were used simultaneously. Fleiss' kappa statistic also showed very strong agreement among the neurologists (0.87 when using one map and 0.72 when using two maps). CONCLUSION: Our five neurologists demonstrated high consistency in interpreting information provided by the CRAVE interactive visualization software for DBS postoperative programming assistance. Three of our five neurologists had no prior experience with the software, which suggests that the software has a short learning curve and contact selection is not dependent on familiarity with the program tools.
PMID: 23647701 [PubMed - as supplied by publisher]