Dorsum Of Left Hand Research Articles

Bullous Drug Eruption.

A 63-year-old woman presented at our emergency department with a disseminated dermatosis that developed after undergoing a cardiac catheterization procedure. Her past medical history included an end-stage renal disease undergoing hemodialysis. Clinical examination revealed erosions and hemorrhagic crusts located on her lips and along the arteriovenous fistula. Additionally, we observed five hyperpigmented macules on her left hand's dorsum and palm and multiple hypopigmented macules in the genital area. Upon medical record review, we discovered the occurrence of prior bullous eruptions following contrast administration. A fixed drug eruption (FDE) due to radiocontrast was diagnosed based on clinical history, clinical examination, eruption timeframe, and positive drug provocation test. Intravenous contrast media reactions can be immediate or delayed, with delayed hypersensitivity reactions (DHR) occurring one hour to seven days post-administration. DHRs often present as maculopapular rashes. FDEs are rare. Skin tests are used to identify culprit agents. Ideally, intradermal tests, with delayed readings, and patch tests are combined for optimal sensitivity. Despite lacking standardized protocols, premedication with corticosteroids may mitigate reaction severity.

Effect of Amount of Daily Water Intake and Use of Moisturizer on Skin Barrier Function in Healthy Female Participants.

It is well known that adequate water intake and moisturizer application improves skin barrier function. This study was conducted to analyze the effects of daily water intake and moisturizer application on skin barrier function and the degree of response to barrier recovery. Participants with daily water intake more than 1 L were classified as high daily water intake group (H) and those with less than 1 L as low daily water intake group (L). Each group was subcategorized into four groups according to intervention method: additional water intake (H1, L1), moisturizer (H2, L2), both (H3, L3), and control (H4, L4). Transepidermal water loss (TEWL) and stratum corneum hydration (SCH) were measured at baseline during the 2nd and 4th week. A total of 43 participants completed the study (H: 22, L: 21). At baseline, there was no significant difference in SCH and TEWL in any on the anatomical sites between the high daily water intake and low daily water intake groups. However, SCHs of left forearm (group H2, p=0.004; group H3, p=0.004), left hand dorsum (group H2, p=0.010; group H3, p=0.026), and left shin (group H2, p=0.016; group H3, p=0.001) in group H2 and H3 were significantly increased in the 4th week as compared to the baseline values. The results suggest that the degree of water intake may be related to improved skin barrier function. However, application of additional moisturizers had more favorable impact on skin hydration as compared to additional water intake.

An electronical stimulator for quantitative sensory testing and evoked potential analysis of tactile Aβ nerve fibers

ObjectiveWe aimed to determine the ability of an innovative device, the Cutaneous Mechanical Stimulator (CMS), to evaluate touch sensory pathways in Human. MethodsTwo experiments were conducted in 23 healthy volunteers aged 20–30 years. In the first, mechanical detection thresholds (MDTs) were assessed using Semmes-Weinstein monofilaments and the CMS. In the second experiment, touch-evoked potentials (TEPs) elicited by tactile stimulation of the CMS on the left hand dorsum and left foot dorsum were recorded. Electroencephalographic (EEG) data were recorded at each cutaneous stimulation site in blocks of 20 tactile stimulations delivered by the CMS. The data were segmented into 1000-ms epochs. ResultsMDTs measured by monofilaments and by the CMS were equivalent. Analyses of TEPs showed N2 and P2 components. The latencies of the N2 components on the hand dorsum and foot dorsum resulted in an estimated average conduction velocity of about 40 m.s−1, within the range of Aβ fibers. ConclusionsThese findings showed that the CMS could assess touch sensory pathways in young adults. SignificanceThe CMS can offer new research perspectives, as this device allows easy assessment of the MDT and enables estimation of fiber conduction velocities after tactile stimulation by the device synchronized with EEG recordings.

Simultaneous EEG/MEG yields complementary information of nociceptive evoked responses

ObjectiveNociceptive stimuli have been studied either by dipolar modelling using electroencephalography (EEG) or magnetoencephalography (MEG), but rarely using both techniques simultaneously. This study aims to investigate the spatiotemporal representation of cortical activity in response to non-nociceptive (tactile) and nociceptive (laser) stimuli using parallel EEG-MEG recordings. MethodsWe performed simultaneous EEG and MEG recordings in 12 healthy subjects by applying pneumatic tactile and nociceptive laser stimuli on the right- and left-hand dorsum. We analyzed brain responses for both modalities and methods by means of global field power (GFP), and dipole source locations, strengths and orientations calculated in the depth to identify similarities and differences. ResultsProminent GFP peaks were similar in EEG and MEG for tactile responses but different for nociceptive responses. ConclusionsMethodically, MEG was superior to EEG in detecting the earliest nociceptive laser-evoked components with earlier latency in primary- and secondary somatosensory cortices, whereas EEG was superior to MEG in detecting late nociceptive components due to radially oriented deeper cortical activity. SignificanceEEG and MEG revealed in part differential nociceptive waveform patterns, peak latencies, and source orientations, making combined recordings favorable to examine pain-related activity as a whole in high temporal-spatial resolution.

Ultrasonographic Assessment of the Cutaneous Changes Induced by Topical Use of Novel Peptides Comprising Laminin 5.

Background Laminin 5, which is found in the basement membrane of dermal-epidermal junction (DEJ), is a major adhesive component and associated with proliferating and migrating keratinocytes. In this study, we hypothesized that the topical application of the skin care products containing the novel peptides might restore the DEJ structure by deriving deposition of laminin 5 and promoting the keratinocyte migration. Here, we evaluated the restoration of DEJ by measuring the skin thickness. Methods Single-center retrospective analysis was performed on a total of 13 patients who underwent skin care using Baume L.C.E. (France, Laboratories d' Anjou) between January and March 2021. All patients applied the skin care agent for 2 weeks only on their left hand dorsum. Before the initiation of the application and after 2 weeks, both their hands were evaluated on photography and ultrasound. And the patients were asked to rate their satisfaction with the questionnaire after 2 weeks. Results There was no obvious improvement in photographic assessment and questionnaire. The post–pre difference of skin thickness in ultrasound images was, in left hand, 0.1 ± 0.37 in distal point and 0.1 ± 0.35 in proximal point; and, in right hand, 0 ± 0.17 in distal point and 0 ± 0.15 in proximal point, respectively. The pre–post difference was statistically significant in proximal point ( p = 0.035). Conclusion Topical application of novel peptide derivative comprising laminin 5 demonstrated cutaneous changes including skin thickness, as assessed by ultrasound. Further studies using other modalities including dermal density measurement, three-dimensional photography, optical coherence tomography, or skin biopsy would be helpful to determine the skin-improving effects.

Rhythmic Change of Cortical Hemodynamic Signals Associated with Ongoing Nociception in Awake and Anesthetized Individuals: An Exploratory Functional Near Infrared Spectroscopy Study.

Patients undergoing surgical procedures are vulnerable to repetitive evoked or ongoing nociceptive barrage. Using functional near infrared spectroscopy, the authors aimed to evaluate the cortical hemodynamic signal power changes during ongoing nociception in healthy awake volunteers and in surgical patients under general anesthesia. The authors hypothesized that ongoing nociception to heat or surgical trauma would induce reductions in the power of cortical low-frequency hemodynamic oscillations in a similar manner as previously reported using functional magnetic resonance imaging for ongoing pain. Cortical hemodynamic signals during noxious stimuli from the fontopolar cortex were evaluated in two groups: group 1, a healthy/conscious group (n = 15, all males) where ongoing noxious and innocuous heat stimulus was induced by a contact thermode to the dorsum of left hand; and group 2, a patient/unconscious group (n = 13, 3 males) receiving general anesthesia undergoing knee surgery. The fractional power of low-frequency hemodynamic signals was compared across stimulation conditions in the healthy awake group, and between patients who received standard anesthesia and those who received standard anesthesia with additional regional nerve block. A reduction of the total fractional power in both groups-specifically, a decrease in the slow-5 frequency band (0.01 to 0.027 Hz) of oxygenated hemoglobin concentration changes over the frontopolar cortex-was observed during ongoing noxious stimuli in the healthy awake group (paired t test, P = 0.017; effect size, 0.70), and during invasive procedures in the surgery group (paired t test, P = 0.003; effect size, 2.16). The reduction was partially reversed in patients who received a regional nerve block that likely diminished afferent nociceptive activity (two-sample t test, P = 0.002; effect size, 2.34). These results suggest common power changes in slow-wave cortical hemodynamic oscillations during ongoing nociceptive processing in conscious and unconscious states. The observed signal may potentially promote future development of a surrogate signal to assess ongoing nociception under general anesthesia.

Test\u2013retest reliability of laser evoked pain perception and fMRI BOLD responses

Pain perception is a subjective experience and highly variable across time. Brain responses evoked by nociceptive stimuli are highly associated with pain perception and also showed considerable variability. To date, the test–retest reliability of laser-evoked pain perception and its associated brain responses across sessions remain unclear. Here, an experiment with a within-subject repeated-measures design was performed in 22 healthy volunteers. Radiant-heat laser stimuli were delivered on subjects’ left-hand dorsum in two sessions separated by 1–5 days. We observed that laser-evoked pain perception was significantly declined across sessions, coupled with decreased brain responses in the bilateral primary somatosensory cortex (S1), right primary motor cortex, supplementary motor area, and middle cingulate cortex. Intraclass correlation coefficients between the two sessions showed “fair” to “moderate” test–retest reliability for pain perception and brain responses. Additionally, we observed lower resting-state brain activity in the right S1 and lower resting-state functional connectivity between right S1 and dorsolateral prefrontal cortex in the second session than the first session. Altogether, being possibly influenced by changes of baseline mental state, laser-evoked pain perception and brain responses showed considerable across-session variability. This phenomenon should be considered when designing experiments for laboratory studies and evaluating pain abnormalities in clinical practice.

Quantitative sensory testing of periauricular skin in healthy adults

The aim of this study was to investigate the test-retest reliability of quantitative sensory testing (QST) and mechanical sensitivity mapping of the periauricular skin. Twenty volunteers (10 men, 10 women) participated in two sessions at intervals of one week. Cold and warm detection threshold (CDT&WDT), cold and heat pain threshold (CPT&HPT), mechanical detection and pain threshold (MDT&MPT), pressure pain threshold (PPT) and two-point discrimination (2PD) were measured at five sites: bilateral subauricular and postauricular sites (LA, RA, LB, RB) and the dorsum of left hand (control). Pressure stimulation was applied at each of the four periauricular test sites. The test-retest reliability of the QST data implied fair to excellent agreement as evaluated by the intra-class correlation coefficients (ICC; all >0.4) for different days. There was no difference between each side in the QST parameters and mechanical sensitivity mapping (P ≥ 0.057). Significant differences between subauricular and postauricular sites were shown for WDT and PPT (P ≤ 0.028). NRS scores of mechanical sensitivity mapping showed significant effects of gender, site and point (P ≤ 0.040). QST and mechanical sensitivity mapping can be considered to be a reliable technique to assess somatosensory function of the periauricular skin.

Common Disease with Uncommon Presentation: Spina Ventosa

Introduction: Tuberculosis of short tubular bones of hand and foot is called tuberculousdactilitis or “spinaventosa”. This is uncommon type of osteoarticular tuberculosis more often seen in children than adults. This report describes tuberculosis affecting third metacarpal bone in a 25-year-old male patient presenting with a firm, painless, progressively increasing swelling over the dorsum of left hand. Diagnosis was made by cytological examination of aspirate from the affected area.

Performance analysis on feature extraction using dorsal hand vein image

Personal verification has become a severe and necessary perspective of security access systems. Compared to the traditional authentication codes, the personal identification using biometric feature has attracted more attention these years because the biometric feature is hard to forget and filch and easy to use. Biometrics refers to the identification of the humans by their characteristics or traits. This paper work considers vessels at the back side of the hand called dorsal vein. The features like local binary pattern (LBP), histogram of oriented gradients (HOG) and Weber local descriptor (WLD) are extracted, and performance analysis is done in terms of K-NN classification accuracy. The 10 image of right dorsal hand vein and 10 image of left dorsal hand vein were used from 102 persons, including both male and female. There were 50 males and 52 females. The total number of images is 2040. The WLD method has recognition accuracy up to 98%, the LBP method has 96% of recognition accuracy, and compared with both, the HOG method proclaims the highest recognition accuracy up to 99%.

852 Racial differences in adolescent perceptions of skin color and tone: A questionnaire and colorimetric-based cross-sectional study

Adolescents receive pressure from peers and social media to conform to perceived acceptable standards regarding skin tone. These pressures put them at an increased risk of engaging in unhealthy behaviors to achieve these standards. Thus, we aimed to better understand adolescent attitudes on skin tone in comparison to objective colorimetric data. Fifty patients were recruited from the Johns Hopkins Pediatric Dermatology clinic between the ages of 12-19. Adolescents were asked to fill out a survey on their sunscreen, tanning bed, and skin lightening cream use. They were then given the Pantone Skin Color Guide, consisting of 110 skin color palettes and reported their perceived and desired skin tones. The surveyor then used the standardized Pantone Capsure device, which includes all 110 skin colors for image capture to record the subject’s objective skin tone from the left dorsal hand and also included an internal control. Descriptive statistics, Fisher’s Exact Tests, and ANOVA subgroup analysis were performed. A total of 28.3% of individuals self-reported as black, 17.4% east asian, 39.1% white, and 15.2% of other races with a median Fitzpatrick skin phototype IV. Overall, 20% of adolescents felt pressure to have tan skin, and reported this pressure began at an average age of 12. The overwhelming majority of adolescents (nearly 96%) did not report wearing sunscreen on a daily basis. Only one adolescent reported using skin lightening creams but three patients reported use by family members. Black and asian participants were significantly more likely to desire a lighter skin tone than their perceived tone, while white participants were more likely to desire a darker skin tone (p<0.011). These findings suggest both sun exposure and skin bleaching safety initiatives should target pre-pubertal patients before they engage in risky behaviors aimed at achieving their desired skin tone.

Thermal Manikin of Infant

Compared to an adult, an infant requires more consideration regarding the thermal environment so it is necessary to evaluate the thermal environment as it affects infants. However, experiments on infant subjects regarding their thermal environment based on the different heat balance of their body cannot ethically be conducted. We could instead consider using a thermal model for the human body, but thermal manikins based on heat transfer per unit area are rare. Therefore, this study aims to develop a thermal manikin to model the heat transfer per unit area and the body form of an infant in order to evaluate the infant’s thermal environment. When evaluating the thermal environment or heat balance of the body in the outside environment, it is essential to consider the asymmetry and unevenness of the temperature of the skin, as an element of the human body, and not just the unevenness and asymmetry of physical factors in the environment. Moreover, when receiving short wavelength direct solar radiation, light and shaded areas have significant differences in skin temperature. The following 20 body parts were investigated in the study: anterior head, posterior head, ventral trunk, dorsal trunk (including buttocks), right medial arm, right lateral arm, left medial arm, left lateral arm, right dorsal hand, right palmar hand, left dorsal hand, left palmar hand, right anterior leg, right posterior leg, left anterior leg, left posterior leg, right dorsal foot, right plantar foot, left dorsal foot, and left plantar foot. This paper measured the body surface area for each part of an infant’s body in order to establish the form of an infant model from the view of the heat transfer area, and verified the validity of the model.

Low-Frequency rTMS of the Primary Motor Area Does Not Modify the Response of the Cerebral Cortex to Phasic Nociceptive Stimuli.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive technique of cortical stimulation. Although the exact mechanism of action is not clearly understood, it has been postulated that rTMS action on pain depends most on stimulation sites and stimulation parameters. Most studies concern high-frequency rTMS of the primary motor cortex (M1). High-frequency rTMS over motor cortex seems to induce an analgesic effect while contrasting results were reported after low-frequency rTMS. The aim of the current study was to investigate the effects of 1 Hz rTMS stimulation over the left primary motor cortex on subjective laser pain rating and laser evoked potential (LEP) amplitudes in healthy subjects. Subjects underwent two different sessions (real and sham rTMS) according to a cross-sectional design. In each session, LEPs and laser-pain rating to stimulation of both right and left hand dorsum were collected before 1 Hz rTMS over the left M1 area (baseline), which lasted 20 min. Then, LEPs and laser-pain rating were measured immediately after rTMS (T0), after 20 min from T0 (T0+20), and after 40 min from T0 (T0+40). We could not find any modification of both laser-pain rating and LEP parameters (latencies and amplitudes) following 1 Hz rTMS. Therefore, our results show that the low-frequency rTMS of the M1 area does not change the response of the cerebral cortex to pain.

Mind the Gap: The Effects of Temporal and Spatial Separation in Localization of Dual Touches on the Hand.

In this study, we aimed to relate the findings from two predominantly separate streams of literature, one reporting on the localization of single touches on the skin, and the other on the distance perception of dual touches. Participants were touched with two points, delivered either simultaneously or separated by a short delay to various locations on their left hand dorsum. They then indicated on a size-matched hand silhouette the perceived locations of tactile stimuli. We quantified the deviations between the actual stimulus grid and the corresponding perceptual map which was constructed from the perceived tactile locations, and we calculated the precision of tactile localization (i.e., the variability across localization attempts). The evidence showed that the dual touches, akin to single touch stimulations, were mislocalized distally and that their variable localization error was reduced near joints, particularly near knuckles. However, contrary to single-touch localization literature, we observed for the dual touches to be mislocalized towards the ulnar side of the hand, particularly when they were presented sequentially. Further, the touches presented in a sequential order were slightly “repelled” from each other and their perceived distance increased, while the simultaneous tactile pairs were localized closer to each other and their distance was compressed. Whereas the sequential touches may have been localized with reference to the body, the compression of tactile perceptual space for simultaneous touches was related in the previous literature to signal summation and inhibition and the low-level factors, including the innervation density and properties of receptive fields (RFs) of somatosensory neurons.

Ulcerative Tinea Corporis in an Immunosuppressed patient

Worldwide, Trichophyton rubrum is the most common cause of dermatophytosis. Infection is classically superficial, limited to the cornified layers of the skin, and may be accompanied by varying degrees of inflammation. Dermatophyte invasion is limited by multiple host factors, including sebum production, an intact skin barrier, and immunocompetence. We describe a 65 year old gentleman with a history of diabetes mellitus, hypertension, nephrogenic systemic fibrosis, and immunosuppressed status due to renal transplant who presented with a non-healing ulcer of the left dorsal hand. Further examination revealed palmar erythema and scale as well as annular erythematous plaques with peripheral scale on his bilateral knees. Laboratory testing yielded the diagnosis of tinea corporis, with bacterial superinfection of the left dorsal hand. The patient was started on systemic antimicrobials with complete healing of the ulcer along with total clearance of the rash. This case highlights an unusual presentation of invasive Trichophyton rubrum in the setting of immunosuppression and nephrogenic systemic fibrosis.

P247 Painful laser evoked potential inhibition during high-frequency non-noxious somatosensory stimulation

Objectives The inhibition of single nociceptive inputs by single non-painful stimuli was shown to occur at supraspinal level (Testani et al., 2015). However, the neurophysiological mechanism subserving the analgesia induced by rubbing the painful part of the body or during TENS is still unknown. Our aim was to investigate the site of this inhibition. Methods We studied 10 healthy volunteers. LEPs were recorded after stimulation of the radial and ulnar territories of both the right and left hand dorsum in 2 conditions: (1) no conditioning stimulation (baseline condition), and (2) high-frequency (5 Hz) non-painful electrical stimulation of the right radial nerve (gating condition). Results As compared to the baseline, in the gating condition the N2/P2 amplitude was reduced in amplitude after stimulation of the radial territory of both hands ( p 0.001 and p 0.001 for right and left hand, respectively) and of the right ulnar region (p = 0.008), while no inhibition was found to left ulnar region stimulation (p = 0.06). Discussion Our results show that high-frequency non-painful stimulation of the right radial nerve inhibits the nociceptive input coming from both the ispilateral and contralateral homotopic regions, and from a close ispilateral heterotopic territory. On the contrary, it does not have any effect on the nociceptive input due to stimulation of a contralateral heterotopic area. Conclusion Spinal segmental mechanisms are mainly involved in the nociceptive input inhibition by high-frequency non-noxious somatosensory stimulation. Significance Pain inhibition induced by high-frequency somatosensory stimulation, such as TENS, is likely to occur at the spinal cord level.

O208 Evidence by direct current stimulation (tDCS) of cerebellum involvement in pain perception and modulation in humans

Objective cerebellum is involved in a wide number of integrative functions; its role in pain processing has been scarcely investigated. We tried to clarify this aspect using transcranial cerebellar direct current stimulation (tcDCS) and studying changes in perceptive threshold (PT), pain intensity (VAS) and laser evoked potentials (LEPs) responses (N1 and N2/P2). Materials and methods Fifteen subjects were studied before and after anodal, cathodal and sham tcDCS. LEPs were obtained using a Nd:YAP laser; signals were amplified, band pass filtered. The left hand dorsum was stimulated by laser pulses with short duration (5 ms) and small diameter spots (5 mm). VAS was evaluated by delivering laser pulses at two different intensities, respectively two and three times the pain threshold (PT). Results Cathodal polarization dampened the PT and increased the VAS score, while the anodal one had opposite effects ( p p Discussion tcDCS modulates pain perception and its cortical correlates. As it is effective on N1 and N2/P2 components and these responses are generated by parallel and partially segregated spinal pathways reaching different cortical targets, we speculate that the cerebellum modulates the activity of both somatosensory and cingulate cortices, interfering with the sensory-discriminative as well as emotional dimensions of pain. Conclusions Present findings prove Cerebellum involvement in pain processing and prompt further investigations on tcDCS employments as novel therapeutic tool in chronic pain patients.

You’ve Got to Be “Kidney”, Don’t Be Rash About the Infiltrates

SESSION TITLE: Student/Resident Case Report Poster - Pulmonary Manifestations of Systemic Disease I SESSION TYPE: Student/Resident Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: The differential diagnosis of hypoxia and diffuse pulmonary infiltrates, in a seemingly healthy young man is broad. Infection (due to typical, opportunistic, viral, and fungal sources) or pulmonary edema (cardiogenic and non-cardiogenic) are common etiologies, but when clinical evidence for these conditions fails to accumulate, unusual causes should be entertained. This is a case of a patient whose pulmonary diagnosis was revealed through his kidneys. CASE PRESENTATION: A 21-year-old African American male with a history of Hashimoto’s thyroiditis presented with a one-week history of malaise, non-productive cough, shortness of breath, chest pain; on review of systems he admitted to months of polyarthralgia, rash, and endorsed foamy urine for weeks. His mother had a nonspecific rheumatologic disorder. His exam was significant for fever, hypoxic respiratory distress, sinus tachycardia, rales worse in the lung bases, and a purpuric rash of the left hand dorsum. CT chest revealed multilobar consolidations and bilateral ground-glass opacities (Fig. 1). Lab results revealed anemia, nephrotic range proteinuria, RBC’s and WBC’s in the urine, but no casts; ESR was 106; C3 and C4 were low. ANA, anti-DS DNA, ENA RNP, ENA Smith, Anti-chromatin IgG were all elevated. An infectious work-up was negative. With these findings, the patient was started on high dose methylprednisolone. A renal biopsy revealed interstitial fibrosis (Fig. 2a), segmental endocapillary proliferation, closure of capillary loops and thickened arterioles (Fig. 2b), most consistent with lupus nephritis. Steroids were tapered and he was started on mycophenolate and hydroxychloroquine. The patient improved with this treatment. DISCUSSION: Systemic lupus erythematosus (SLE), an autoimmune disease with a predilection for females of non-European descent, affects 20 to 150 patients per 100,000. It frequently presents with arthritis, serositis, skin, renal, and hematologic involvement1. Pulmonary manifestations may be the presenting symptom in 4-5% of patients2. The clinical presentation of acute lupus pneumonitis is nonspecific, usually with cough, dyspnea, pleuritic pain, hypoxia, patchy alveolar infiltrates on radiography, and absence of clinical and laboratory evidence of infection2. CONCLUSIONS: Pulmonary disease is not uncommon in SLE, but is infrequently the initial manifestation of disease. Indeed, the patient’s months of polyarthralgia, rash, and proteinuria suggest his respiratory woes were not the first indication of SLE. This condition should be considered in the differentia diagnosis of young patients presenting with hypoxemic respiratory failure and imaging features suggestive of pneumonia. Reference #1: Keane, M. P., and Joseph P. Lynch, III. “Rare Diseases Bullet 7: Pleuropulmonary Manifestations of Systemic Lupus Erythematosus.” Thorax 55.2 (2000): 159-66. Reference #2: Torre, Olga, and Sergio Harari. “Pleural and Pulmonary Involvement in Systemic Lupus Erythematosus.” La Presse Médicale 40.1 (2011): E41-51. DISCLOSURE: The following authors have nothing to disclose: Amanda Liggett, Enrique Calvo-Ayala, Dean Troyer No Product/Research Disclosure Information

69. Prolonged inhibitory effect of 1 Hz rTMS of the motor cortex on the nociceptive evoked potentials to contralateral hand stimulation

High frequency motor cortex rTMS produces an inhibitory effect on pain, however there are only few data about the effect of low frequency motor cortex rTMS on clinical and experimental pain. Since low frequency rTMS should have an inhibitory effect on motor cortex, whose activation reduces experimental pain, one could expect that 1 Hz motor cortex rTMS increases objective pain measures, such as laser evoked potentials (LEPs). In 8 healthy subjects, we investigated the effect of 1 Hz rTMS of left motor cortex on LEPs to stimulation of both right and left hand dorsum. LEPs were recorded at 4 different times: baseline, Time 0 (immediately after 20 min of 1 Hz rTMS), Time +20 (20 min after 1 Hz rTMS), Time +40 (40 min after 1 Hz rTMS). rTMS modified the amplitude of N2/P2 LEP component only to right hand stimulation ( F = 12.06, p F = 0.7, p = 0.56). Post-hoc analysis showed that the N2/P2 amplitude was reduced at Time 0, Time +20, and Time +40, as compared to baseline ( p

ID 156 – Prolonged inhibitory effect of 1 Hz rTMS of the motor cortex on the nociceptive evoked potentials to contralateral hand stimulation

High frequency motor cortex rTMS produces an inhibitory effect on pain, however there are only few data about the effect of low frequency motor cortex rTMS on clinical and experimental pain. Since low frequency rTMS should have an inhibitory effect on motor cortex, whose activation reduces experimental pain, one could expect that 1 Hz motor cortex rTMS increases objective pain measures, such as laser evoked potentials (LEPs). In 8 healthy subjects, we investigated the effect of 1 Hz rTMS of left motor cortex on LEPs to stimulation of both right and left hand dorsum. LEPs were recorded at 4 different times: baseline, Time 0 (immediately after 20 min of 1 Hz rTMS), Time +20 (20 min after 1 Hz rTMS), Time +40 (40 min after 1 Hz rTMS). rTMS modified the amplitude of N2/P2 LEP component only to right hand stimulation (F = 12.06, p < 0.001), while there was no effect on left hand LEPs (F = 0.7, p = 0.56). Post-hoc analysis showed that the N2/P2 amplitude was reduced at Time 0, Time +20, and Time +40, as compared to baseline (p < 0.01). Conversely of what expected, 1 Hz rTMS of the motor cortex inhibits contralateral pain; this effects last up to 40 min after the cortical stimulation.