Motor corticospinal excitability abnormalities differ between distinct chronic low back pain syndromes.

OBJECTIVES: It is not known whether cortical plastic changes reported in low-back pain (LBP) are present in all etiologies of LBP. Here we report on the assessment of patients with three LBP conditions: non-specific-LBP (ns-LBP), failed back surgery syndrome (FBSS), and sciatica (Sc). METHODS: Patients underwent a standardized assessment of clinical pain, conditioned pain modulation (CPM), and measures of motor evoked potential (MEPs)-based motor corticospinal excitability (CE) by transcranial magnetic stimulation, including short interval intracortical inhibition (SICI), and intracortical facilitation (ICF). Comparisons were also made with normative data from sex- and age-matched healthy volunteers. RESULTS: 60 patients (42 women, 55.1±9.1 years old) with LBP were included (20 in each group). Pain intensity was higher in patients with neuropathic pain [FBSS (6.8±1.3), and Sc (6.4±1.4)] than in those with ns-LBP (4.7±1.0, P<0.001). The same was shown for pain interference (5.9±2.0, 5.9±1.8, 3.2±1.9, P<0.001), disability (16.4±3.3, 16.3±4.3, 10.4±4.3, P<0.001), and catastrophism (31.1±12.3, 33.0±10.4, 17.4±10.7, P<0.001) scores for FBSS, Sc, and ns-LBP groups, respectively. Patients with neuropathic pain (FBSS, Sc) had lower CPM (-14.8±1.9, -14.1±16.7, respectively) compared to ns-LBP (-25.4±16.6; P<0.02). 80.0% of the FBSS group had defective ICF compared to the other two groups (52.5% for ns-LBP, P=0.025 and 52.5% for Sc, P=0.046). MEPs (140%-rest motor threshold) were low in 50.0% of patients in the FBSS group compared to 20.0% of ns-LBP (P=0.018) and 15.0% of Sc (P=0.001) groups. Higher MEPs were correlated with mood scores (r=0.489), and with lower neuropathic pain symptom scores(r=-0.415) in FBSS. CONCLUSIONS: Different types of LBP were associated with different clinical, CPM and CE profiles, which were not uniquely related to the presence of neuropathic pain. These results highlight the need to further characterize patients with LBP in psychophysics and cortical neurophysiology studies.

Motor cortex stimulation for chronic neuropathic pain: results of a double-blind randomized study.

Motor cortex stimulation via surgically implanted electrodes has been used as an off-label treatment for chronic neuropathic pain, but its efficacy has not been fully established. We aimed to objectively study the efficacy of motor cortex stimulation and characterize potential predictors of response. In this randomized, double-blind, sham-controlled, single centre trial, we recruited 18 patients with chronic neuropathic pain who did not adequately respond to conventional treatment and had a numerical pain rating scale (NRS) score ≥6. Patients were initially assigned to receive 3 months of active ('on') or sham ('off') stimulation in a double-blind cross-over phase. This was followed by a 3-month single-blind phase, and 6 months of open-label follow-up. A meaningful response in our trial was defined as a ≥30% or 2-point reduction in NRS scores during active stimulation. Using Bayesian statistics, we found a 41.4% probability of response towards on versus off motor cortex stimulation. The probability of improvement during active stimulation (double-blind, single-blind and open-label phases) compared to baseline was 47.2-68.5%. Thirty nine per cent of the patients were considered long-term responders, 71.4% of whom had facial pain, phantom limb pain or complex regional pain syndrome. In contrast, 72.7% of non-responders had either post-stroke pain or pain associated with brachial plexus avulsion. Thirty-nine per cent of patients had a substantial postoperative analgesic effect after electrode insertion in the absence of stimulation. Individuals with diagnoses associated with a good postoperative outcome or those who developed an insertional effect had a near 100% probability of response to motor cortex stimulation. In summary, we found that ∼40% of patients responded to motor cortex stimulation, particularly those who developed an insertional effect or had specific clinical conditions that seemed to predict an appropriate postoperative response.

Sifting the wheat from the chaff? Evidence for the existence of an asymmetric fibromyalgia phenotype.

BACKGROUND: The different phenotypic presentations of fibromyalgia (FM) have been infrequently studied and may have diagnostic and therapeutic implications. The aim of this study was to explore differences between FM patients with classical symmetric (s-FM) presentation and FM patients with marked asymmetric (a-FM) pain. METHODS: We performed two consecutive cross-sectional studies on FM patients and matched healthy volunteers (HV). FM patients were divided into a-FM (and s-FM groups according to their score of pain intensity on each body side; patients with a difference of ≥40 mm in VAS between left and right sides were classified as a-FM, otherwise classified as s-FM. Participants (FM = 32; HV = 31) were assessed for clinical, cortical excitability (CE), quantitative sensory testing (QST; study 1), and intraepidermal nerve fibre density (IENFD) determinations (study 2). RESULTS: While pain intensity did not significantly differ between s-FM and a-FM patients, pain interference in daily activities was significantly higher in the a-FM as compared to the s-FM group (54.7 ± 8.9 and 37.6 ± 13.5; p < .0001). PPT was significantly lower in the more painful side of a-FM as compared to the HV (27.7 ± 7.9 and 49.9 ± 13.0; p < .0001), while PPT in the less painful side of a-FM was significantly higher than PPT values in the s-FM (35.8 ± 8.3 and 27.7 ± 5.5; p = .031). S-FM and a-FM had significantly abnormal intracortical inhibition values on CE measurements compared to HV. There were no significant differences in IENFD between groups. CONCLUSIONS: Within the current FM criteria, there exist different phenotypes with clinical, psychophysics, and neurophysiological findings that are not related to peripheral IENFD abnormalities. SIGNIFICANCE: Current fibromyalgia criteria may contain different phenotypes of fibromyalgia based on the lateralization of pain.

Quality of Life After Motor Cortex Stimulation: Clinical Results and Systematic Review of the Literature.

BACKGROUND: Motor cortex stimulation (MCS) is routinely used for the treatment of chronic neuropathic pain but its effect on quality of life remains uncertain. OBEJCTIVE: To systematically review the published literature on MCS and quality of life and report the effects of this therapy in a series of patients prospectively followed in our center. METHODS: The systematic literature review was conducted using the search words "motor cortex stimulation and pain and neurosurgery" and "motor cortex stimulation and pain and quality of life." Quality of life in our clinical trial was investigated in a series of 10 patients with chronic neuropathic pain prospectively followed for 12 mo after MCS. RESULTS: Two hundred eighteen nonreplicated articles were pooled for analysis. Of these, 6 described measures of quality of life in the pre- and postoperative period. In these studies, 64 patients with different clinical conditions associated with neuropathic pain were followed for 6 to 84 mo after MCS surgery. Improvement in quality of life ranged from 35% to 85%. In our clinical series, visual analog scale (VAS), SF-12 physical (PhysCS), and mental scores (MenCS) recorded 12 mo after MCS were improved by 60 ± 10% (P = .002), 50 ± 13% (P = .002), and 22 ± 6% (P = .01), respectively. No significant correlation was found between postoperative improvement in pain and either PhysCS (r = 0.18; P = .6) or MenCS (r = -0.24; P = .5). CONCLUSION: MCS improves quality of life in patients with chronic refractory neuropathic pain. Additional factors other than a simple analgesic effect may contribute to these results.

Retrocaval Ureter in Children: A Report of Eight Cases.

OBJECTIVE: The aim of this study is to report on our last nine years' experience in the diagnosis and treatment of retrocaval ureter. METHODS: Eight patients with retrocaval ureter were reviewed. Intravenous urography and retrograde pyelography were used for confirming the diagnosis. All of the patients had undergone surgery, one case being done laparoscopically. The mean age of the patients was 9.2 years (range 2 to 13 years). RESULTS: Five patients were boys and three were girls. The clinical manifestations were right flank pain in three (37.5%), gross haematuria in one (12.5%) and urinary tract infection in one (12.5%). Three asymptomatic patients were diagnosed by routine physical examination. All of the patients had Type 2 and right-sided retrocaval ureter. Associated anomalies were seen in none of the patients. Retrocaval ureter is a rare anomaly in the paediatric age group. CONCLUSION: Laparoscopy is a promising method to repair the retrocaval ureter.

Expression of high-mobility group box protein 1 in diabetic foot atherogenesis.

The role of high mobility group box 1 (HMGB1) has been demonstrated in stroke and coronary artery disease but not in peripheral arterial occlusive disease (PAOD). The pathogenesis of HMGB1 in acute and chronic vascular injury is also not well understood. We hypothesized that HMGB1 induces inflammatory markers in diabetic PAOD patients. We studied 36 diabetic patients, including 29 patients with PAOD, who had undergone amputation for diabetic foot and 7 nondiabetic patients who had undergone amputation after traumatic injury. Expression of HMGB1 and inflammatory markers were quantified using immunohistochemical staining. Mitochondrial DNA copy number was quantified using real-time polymerase chain reaction. Compared with that in the traumatic amputation group, HMGB1 expression in vessels was significantly higher in the diabetes and diabetic PAOD groups. In all subjects, arterial stenosis grade was positively correlated with the expression levels of HMGB1, 8-hydroxyguanosine, malondialdehyde, vascular cell adhesion molecule 1, and inflammatory markers CD3, and CD68 in both the intima and the media of vessels. Furthermore, HMGB1 expression level was positively correlated with 8-hydroxyguanosine, vascular cell adhesion molecule 1, nuclear factor-kB, CD3, and CD68 expression. Within the PAOD subgroup, subjects with HMGB1 expression had higher expression of the autophagy marker LC3A/B and higher mitochondrial DNA copy number. HMGB1 may be an inflammatory mediator with roles in oxidative damage and proinflammatory and inflammatory processes in diabetic atherogenesis. Moreover, it may have dual effects by compensating for increased mitochondrial DNA copy number and increased autophagy marker expression.

Neuropathic pain after brachial plexus avulsion--central and peripheral mechanisms.

REVIEW: The pain that commonly occurs after brachial plexus avulsion poses an additional burden on the quality of life of patients already impaired by motor, sensory and autonomic deficits. Evidence-based treatments for the pain associated with brachial plexus avulsion are scarce, thus frequently leaving the condition refractory to treatment with the standard methods used to manage neuropathic pain. Unfortunately, little is known about the pathophysiology of brachial plexus avulsion. Available evidence indicates that besides primary nerve root injury, central lesions related to the abrupt disconnection of nerve roots from the spinal cord may play an important role in the genesis of neuropathic pain in these patients and may explain in part its refractoriness to treatment. CONCLUSIONS: The understanding of both central and peripheral mechanisms that contribute to the development of pain is of major importance in order to propose more effective treatments for brachial plexus avulsion-related pain. This review focuses on the current understanding about the occurrence of neuropathic pain in these patients and the role played by peripheral and central mechanisms that provides insights into its treatment. Pain after brachial plexus avulsion involves both peripheral and central components; thereby it is characterized as a mixed (central and peripheral) neuropathic pain syndrome.

Identification of aac(2')-I type b aminoglycoside-modifying enzyme genes in resistant Acinetobacter baumannii.

The aim of this study was to investigate the mechanism underlying the drug resistance of Acinetobacter baumannii toward aminoglycosides. A total of 32 A. baumannii strains were identified by molecular identification and subsequently isolated. The isolates were then amplified by polymerase chain reaction to analyze the 9 aminoglycoside-modifying enzyme genes and 7 16S rRNA methylase genes. Five types of aminoglycoside-modifying enzyme genes and 1 type of 16S rRNA methylase gene were detected in the 32 drug-resistant A. baumannii strains. Positive genes included 7 detection modes, of which the all-6-gene-positive mode aac(2')-Ib+aac(3)-I+aac(6')-Ib+ant(3'')-I+aph(3')-I+armA exhibited the largest number of strains (12, 37.5%). The resistance of A. baumannii against aminoglycosides resulted from the presence of 5 types of aminoglycoside-modifying enzyme genes and the 16S rRNA methylase gene armA. This study is the first to isolate the aac(2')-Ib aminoglycoside-modifying enzyme gene from A. baumannii in a domestic clinical setting.

Liposomal topical capsaicin in post-herpetic neuralgia: a safety pilot study.

UNLABELLED: Topical treatments have gained popularity for general use as an adjunct to systemic drugs in neuropathic pain, but their use produces variable clinical results and local adverse events. OBJECTIVE: To evaluate the safety and analgesic effect of a formulation of liposomal capsaicin (LC) (0.025%) in patients with post herpetic neuralgia (PHN). METHOD: Patients who remained symptomatic after first-and second-line treatment were randomized to receive LC for six weeks in a placebo-controlled, crossover design study. Clinical assessment was performed at baseline, in the second, fourth and sixth week of treatment. RESULTS: Thirteen patients completed both treatment periods. Visual Analog Scale (VAS) was significantly decreased after the end of the study (p = 0.008), however the effect of treatment was not significant (p = 0.076). There was no difference on global impression of change and other pain characteristics. LC was safe and well tolerated. However, at the concentration used, its analgesic effects were marginal and not significant.

Liposomal topical capsaicin in post-herpetic neuralgia: a safety pilot study / Capsaicina lipossomal tópica na neuralgia pós-herpética: um estudo piloto de segurança

Topical treatments have gained popularity for general use as an adjunct to systemic drugs in neuropathic pain, but their use produces variable clinical results and local adverse events. Objective To evaluate the safety and analgesic effect of a formulation of liposomal capsaicin (LC) (0.025%) in patients with post herpetic neuralgia (PHN). Method Patients who remained symptomatic after first-and second-line treatment were randomized to receive LC for six weeks in a placebo-controlled, crossover design study. Clinical assessment was performed at baseline, in the second, fourth and sixth week of treatment. Results Thirteen patients completed both treatment periods. Visual Analog Scale (VAS) was significantly decreased after the end of the study (p = 0.008), however the effect of treatment was not significant (p = 0.076). There was no difference on global impression of change and other pain characteristics. LC was safe and well tolerated. However, at the concentration used, its analgesic effects were marginal and not significant. .

Os tratamentos tópicos ganharam popularidade para uso geral como um adjuvante de medicamentos sistêmicos na dor neuropática, mas seu uso produz resultados clínicos variáveis e eventos adversos locais. Objetivo Avaliar o efeito de segurança e analgesia de uma formulação de capsaicina lipossomal (LC) (0,025%) em pacientes com neuralgia pós-herpética. Método Os pacientes que permaneceram sintomáticos após tratamento de primeira e de segunda linha foram randomizados para receber LC durante seis semanas em um estudo cruzado controlado por placebo. A avaliação clínica foi realizada no início do estudo, na segunda, quarta e sexta semana de tratamento. Resultados Treze pacientes completaram dois períodos de tratamento. Escala Visual Analógica diminuiu significativamente após o final do estudo (p = 0,008), no entanto, o efeito do tratamento não era significativo (p = 0,076). Não houve diferença na impressão global de mudança e de outras características da dor. LC foi segura e bem tolerada. No entanto, para a concentração utilizada, os seus efeitos analgésicos foram marginais e não significativos. .

Repetitive transcranial magnetic stimulation in chronic pain: a review of the literature.

OBJECTIVE: To review the literature on the analgesic effects of repetitive transcranial magnetic stimulation (rTMS) in chronic pain according to different pain syndromes and stimulation parameters. DATA SOURCES: Publications on rTMS and chronic pain were searched in PubMed and Google Scholar using the following key words: chronic pain, analgesia, transcranial magnetic stimulation, neuropathic pain, fibromyalgia, and complex regional pain syndrome. STUDY SELECTION: This review only included double-blind, controlled studies with >10 participants in each arm that were published from 1996 to 2014 and written in English. Studies with relevant information for the understanding of the effects of rTMS were also cited. DATA EXTRACTION: The following data were retained: type of pain syndrome, type of study, coil type, target, stimulation intensity, frequency, number of pulses, orientation of induced current, number of session, and a brief summary of intervention outcomes. DATA SYNTHESIS: A total of 33 randomized trials were found. Many studies reported significant pain relief by rTMS, especially high-frequency stimulation over the primary motor cortex performed in consecutive treatment sessions. Pain relief was frequently >30% compared with control treatment. Neuropathic pain, fibromyalgia, and complex regional pain syndrome were the pain syndromes more frequently studied. However, among all published studies, only a few performed repetitive sessions of rTMS. CONCLUSIONS: rTMS has potential utility in the management of chronic pain; however, studies using maintenance sessions of rTMS and assessing the effects of rTMS on the different aspects of chronic pain are needed to provide a more solid basis for its clinical application for pain relief.

Methadone in post-herpetic neuralgia: A pilot proof-of-concept study.

OBJECTIVE: This research was designed as a pilot proof-of-concept study to evaluate the use of low-dose methadone in post-herpetic neuralgia patients who remained refractory after first and second line post-herpetic neuralgia treatments and had indications for adding an opioid agent to their current drug regimens. METHODS: This cross-over study was double blind and placebo controlled. Ten opioid naïve post-herpetic neuralgia patients received either methadone (5 mg bid) or placebo for three weeks, followed by a 15-day washout period and a second three-week treatment with either methadone or placebo, accordingly. Clinical evaluations were performed four times (before and after each three-week treatment period). The evaluations included the visual analogue scale, verbal category scale, daily activities scale, McGill pain questionnaire, adverse events profile, and evoked pain assessment. All patients provided written informed consent before being included in the study. ClinicalTrials.gov: NCT01752699 RESULTS: Methadone, when compared to placebo, did not significantly affect the intensity of spontaneous pain, as measured by the visual analogue scale. The intensity of spontaneous pain was significantly decreased after the methadone treatment compared to placebo on the category verbal scale (50% improved after the methadone treatment, none after the placebo, p=0.031). Evoked pain was reduced under methadone compared to placebo (50% improved after the methadone treatment, none after the placebo, p=0.031). Allodynia reduction correlated with sleep improvement (r=0.67, p=0.030) during the methadone treatment. The side effects profile was similar between both treatments. CONCLUSIONS: Methadone seems to be safe and efficacious in post-herpetic neuralgia. It should be tried as an adjunctive treatment for post-herpetic neuralgia in larger prospective studies.

Methadone in post-herpetic neuralgia: A pilot proof-of-concept study

OBJECTIVE: This research was designed as a pilot proof-of-concept study to evaluate the use of low-dose methadone in post-herpetic neuralgia patients who remained refractory after first and second line post-herpetic neuralgia treatments and had indications for adding an opioid agent to their current drug regimens. METHODS: This cross-over study was double blind and placebo controlled. Ten opioid naïve post-herpetic neuralgia patients received either methadone (5 mg bid) or placebo for three weeks, followed by a 15-day washout period and a second three-week treatment with either methadone or placebo, accordingly. Clinical evaluations were performed four times (before and after each three-week treatment period). The evaluations included the visual analogue scale, verbal category scale, daily activities scale, McGill pain questionnaire, adverse events profile, and evoked pain assessment. All patients provided written informed consent before being included in the study. ClinicalTrials.gov: NCT01752699 RESULTS: Methadone, when compared to placebo, did not significantly affect the intensity of spontaneous pain, as measured by the visual analogue scale. The intensity of spontaneous pain was significantly decreased after the methadone treatment compared to placebo on the category verbal scale (50% improved after the methadone treatment, none after the placebo, p = 0.031). Evoked pain was reduced under methadone compared to placebo (50% improved after the methadone treatment, none after the placebo, p = 0.031). Allodynia reduction correlated with sleep improvement (r = 0.67, p = 0.030) during the methadone treatment. The side effects profile was similar between both treatments. Conclusions: Methadone seems to be safe and efficacious in post-herpetic neuralgia. It should be tried as an adjunctive treatment for post-herpetic ...

Role of mitochondrial DNA variants and copy number in diabetic atherogenesis.

Hyperglycemia-induced reactive oxygen species production can cause diabetes and its complications, including atherosclerosis. The role of mitochondrial DNA variants and mitochondrial copy number in the pathogenesis of diabetic atherogenesis is not well understood. We examined 36 diabetic patients who had undergone amputation for diabetic foot and seven non-diabetic patients who had undergone amputation after traumatic injury. Mitochondrial DNA was extracted and used for sequencing. Single nucleotide polymorphisms (SNPs) relative to the Cambridge reference sequence were analyzed. Mitochondrial DNA copy number was quantified by real-time PCR. Twenty-one novel variants were detected in 29 diabetic patients with arterial stenosis; six of the variants were heteroplasmic, and most occurred in highly evolutionarily conserved residues. These variants were more prevalent in patients with arterial stenosis than in those without stenosis. The novel variants included four in complex I (ND1: C3477A/C, A3523A/G; ND5: C13028A/C, C13060A/C), one in complex IV (COX1: T6090A/T), and one in rRNA (12srRNA: G857G/T). Compared with non-diabetic patients, the diabetic patients had significantly less mitochondrial DNA. Furthermore, among diabetic patients with arterial stenosis, there was a significant positive correlation between mitochondrial DNA copy number and the number of total SNPs. In conclusion, we identified six novel heteroplasmic mitochondrial DNA variants among diabetic patients with arterial stenosis, and we found that diabetic atherogenesis is associated with decreased amounts of mitochondrial DNA.

SU-E-T-448: Switch Patients between Collimation Systems for CyberKnife Treatment Feasibility Study.

PURPOSE: There are two collimation systems associated with the CyberKnife system, the fixed cone collimator and the Iris collimator. The Iris collimator is used more frequently because of its superior flexibility. However, sometimes treatments have to be canceled or postponed due to Iris collimator mechanical failures. The purpose of this study is to investigate the feasibility of switching collimation systems without replanning. METHODS: We first performed Monte Carlo simulations on 10 clinical cases using the Iris collimator and the fixed cone collimator. The conformality index (CI), target volume coverage and the maximum, minimum and mean doses to the critical structures from the iris and fixed plans were compared to determine the feasibility of switching between collimator types without replanning. RESULTS: Our results showed that the two types of collimators deliver similar dose distributions. The average target doses for the fixed plans were 1% to 6% higher than those for the Iris plans. The average CI for the fixed plans was 1.36 compared to 1.28 for the Iris plans. Thus, we adjusted the Iris sizes with a scale factor of 1.024 to achieve a better dose match with the fixed collimators. Doses for the 10 cases were then recalculated. Once this correction was made, the difference between the average target doses for the two collimator plans was reduced to less than 2% and the CIs became almost identical. CONCLUSIONS: Small target dose differences were found between plans using different collimation systems, which may be compensated for by adjusting the Iris collimator sizes to ensure similar dose distributions. The differences in the doses to the critical structures between the collimation systems were insignificant. After adjusting the Iris collimator sizes and re-commissioning the planning system, patients can be safely switched from the Iris collimator to the fixed cone collimator without replanning.

SU-E-T-483: Delay Treatment or Switch to Different Machines? Dosimetric Effect and Tumor Control Probability.

PURPOSE: If the Linac is unavailable during the IMRT treatment schedule, the patient can be switched to a different Linac or prostpond treatment until the origonal Linac is available. The resulting dosimetric difference is estimated and the compromise in the TCP is estimated for both scenarios. This work investigates the feasibility and rationale of switching patients between different accelerators for IMRT in contrast to prostponing the treatment. METHODS: We performed Monte Carlo simulations of photon beams from different Linac models and vendors. Prostate and head and neck treatment plans for Siemens Primus, Primart, Artiste and Varian-21Ex/IX accelerators are studied in this work. Dose distributions for given plans are recalculated using different beam data with the same nominal energy from different Linacs. We have compared DVHs, the maximum, the minimum and the mean dose to the target and critical structures due to switching accelerators. In the process of switching a treatment plan to a different accelerator, there are issues, such as optimum penumbra compensation, dose distribution at the boundary of target and critical structures and multileaf collimator (MLC) leaf width effects, needed to be considered and verified with measurements. In making the final decision whether to switch machines, the TCP based on a linear-quadratic model with time factor is considered. RESULTS: Two DVHs of two plans from Varian and Siemens models are delivered on different machines. Slight dose coverage differences have been observed. TCP estimation with both delayed and without delayed treatments is calculated. Undesired drop of TCP is observed with treatment gap. CONCLUSIONS: Based on the analyses done in this work, it is therapeutically more beneficial to switch a patient to a different machine than to postpone a treatment until the original machine is available, especially for fast growing tumors such as head and neck cancers.

SU-E-J-03: Positioning Errors of Metal Localization Devices with Motion Artifacts on KV and MV Cone Beam CT.

PURPOSE: To investigate motion artifacts of kV CBCT and MV CBCT images on metal localization devices for image guided radiation therapy. METHODS: 8 MU pelvis CBCT template for Siemens Artiste MVision and Pelvis template for Varian IX on-board Exact Arms kV were used to acquire CBCT images in this study. Images from both CBCT modalities were compared in CNRs, metal landmark absolute positions, and image volume distortion on three different planes of view. The images were taken on a breathing-simulated thoracic phantom in which several typical metal localization devices were implanted, including clips and wires for breast patients, gold seeds for prostate patients, and BBs as skin marks. To magnify the artifacts, a 4cm diameter metal ball was also implanted in the thoracic phantom to mimic the metal artifacts. The amplitude of the sinusoidal breathing was 1cm, and the period varies from 2sec, 4sec to 8sec. RESULTS: For MV CBCT, the CNR at 4sec breathing cycle with 1cm breathing amplitude was 5.0, 3.4 and 4.6 for clips, gold seeds and BBs, respectively while it was 1.5, 2.0 and 1.6 for kV CBCT. On the images, kV CBCT showed symmetric streaking artifacts both in the transverse and longitudinal directions relative to the motion direction. kV CBCT images predicted 89% of the expected volume, while MV CBCT images predicted 95% of the expected volume. Simulated soft tissue observed in MVCT cannot be detected in kVCT. CONCLUSIONS: MV CBCT images showed better volume prediction, less streaking effects and better CNRs of a moving metal target, i.e. clips, BBs, gold seeds and metal balls than kV CBCT images. MV CBCT was more advantageous compared to kV CBCT with less motion artifacts for metal localization devices.

The assessment and management of pain in the demented and non-demented elderly patient.

Persistent pain is a frequent health problem in the elderly. Its prevalence ranges from 45% to 80%. Chronic diseases, such as depression, cardiovascular disease, cancer and osteoporosis have a higher prevalence in aged individuals and increase the risk of developing chronic pain. The presence of pain is known to be associated with sleep disorders in these patients, as well as functional impairment, decreased sociability and greater use of the health system, with consequent increase in costs. Alzheimer's disease patients seem to have a normal pain discriminative capacity and they may probably have weaker emotional and affective experience of pain when compared to other types of dementia. Many patients have language deficits and thus cannot properly describe its characteristics. In more advanced cases, it becomes even difficult to determine whether pain is present or not. Therefore, the evaluation of these patients should be performed in a systematic way. There are three ways to measure the presence of pain: by direct questioning (self-report), by direct behavioral observation and by interviews with caregivers or informants. In recent years, many pain scales and questionnaires have been published and validated specifically for the elderly population. Some are specific to patients with cognitive decline, allowing pain evaluation to be conducted in a structured and reproducible way. The next step is to determine the type of painful syndrome and discuss the bases of the pharmacological management, the use of multiple medications and the presence of comorbidities demand the use of smaller doses and impose contra-indications against some drug classes. A multiprofessional approach is the rule in the management of these patients.