Eileen Chusid

Symmetric corticospinal excitability and representation of vastus lateralis muscle in right-handed healthy subjects

The purpose of this study was to determine the size and location of the representations of the anterior thigh muscles on the human motor cortex in the dominant and non‐dominant hemispheres. Motor‐evoked potentials (MEPs) induced by transcranial magnetic stimulation were recorded from the right and left vastus lateralis (rVL, lVL) muscles. A total of ten right‐handed healthy volunteers participated in the study. In a single session experiment, we investigated VL muscle corticospinal excitability (motor threshold, MEP size, short interval intracortical inhibition, intracortical facilitation) and cortical representation (map area, volume, and location) in the dominant and non‐dominant hemispheres. The motor threshold, MEPs, and intracortical excitability did not differ significantly between the hemispheres (P > 0.05). Furthermore, no difference between sides was found in the location of VL motor representation (mediolateral and anteroposterior axis) or in map area and volume (P > 0.05). Vastus lateralis muscle corticospinal excitability and cortical map were symmetrical in right‐handed subjects. Future studies on patients with unilateral lower extremity injuries could examine side‐to‐side plastic reorganization in corticomotor output and map location in both hemispheres. Clin. Anat. 27:1053–1057, 2014.

Neural circuits underlying motor facilitation during observation of implied motion

Abstract In the present study we used single and paired-pulse Transcranial Magnetic Stimulation (TMS) to evaluate the effect of implied motion on primary motor cortex microcircuits. We found that observation of the implied motion of a static image increases MEP amplitude and reduces short-interval intracortical inhibition (SICI), without significant modulation of intracortical facilitation and sensory-motor integration. Our results add to the existing literature on the activation of the observation-execution matching system and describe a selective modulation of GABAergic cortical microcircuits during observation of implied motion.

Severe Chronic Heel Pain in a Diabetic Patient with Plantar Fasciitis Successfully Treated Through Transcranial Direct Current Stimulation

BACKGROUND Recently, transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique, was proposed as a suitable method for the treatment of several chronic pain syndromes. We describe a case of severe heel pain in a diabetic patient with plantar fasciitis successfully treated with tDCS. METHODS The present study investigated whether tDCS treatment could reduce pain and pain-related anxiety in a 65-year-old diabetic man affected by treatment-resistant right heel pain due to plantar fasciitis. The patient underwent five tDCS treatment sessions on 5 consecutive days. Each session consisted of 20-min anodal tDCS over the left primary motor cortex leg area. RESULTS The neurostimulation protocol induced a decrease in pain intensity and pain-related anxiety that outlasted the stimulation (1 week). Furthermore, the patient stopped the intake of opioid medication. CONCLUSIONS Therapeutic neuromodulation with tDCS may represent an alternative option for treating severe lower-extremity pain.

Modulation of prefrontal cortex with anodal tDCS prevents post-exercise facilitation interference during dual task

Abstract In this study we aimed to investigate whether transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) reduces interference effects of a dual task (DT) on post-exercise facilitation (PEF) of the motor evoked potentials. Anodal tDCS reversed the DT interference on PEF after a non-fatiguing isometric contraction. We conclude that anodal DLPFC tDCS improves the ability to allocate attentional resources and modulates plastic adaptations across brain systems.

Anodal cerebellar tDCS modulates lower extremity pain perception

BACKGROUND Previous studies have investigated the use of transcranial direct current stimulation (tDCS) for pain management. The studies investigating therapeutic neuromodulation with tDCS for lower extremity pain are scarce and inconclusive. OBJECTIVE The aim of the present study was to analyze the effects of cerebellar tDCS on lower extremity sensory and pain thresholds in healthy volunteers. METHODS This was a single-blind crossover repeated-measure study. Utilizing randomized conditions, we examined the effects of anodal, cathodal and sham stimulation of the right cerebellum in 14 healthy volunteers on sensory and pain thresholds which were induced in the right leg using electrical stimulation. tDCS intensity was 2 mA and the duration of the stimulation was 10 minutes. RESULTS After anodal cerebellar stimulation the pain threshold of the ipsilateral leg was increased (p < 0.01). We could not detect any significant pain modulation with cathodal or sham stimulation (p > 0.05). Furthermore, no significant modulation of the sensory threshold was detected after anodal, cathodal or sham cerebellar tDCS (p > 0.05). CONCLUSIONS Our results indicate that anodal cerebellar tDCS with a reference electrode positioned over the buccinator area modulates pain processing in the ipsilateral leg. Further investigation is required to evaluate possible application in chronic pain patients.

Observation of implied motion in a work of art modulates cortical connectivity and plasticity

Following the discovery of mirror neurons, much attention has been de-voted to understanding the neural responses evoked by observation of implied motion in works of art. Neuroimaging studies have demonstrated that dorsal premotor cortex (PMd) is commonly involved during observation of movements but the role of the inhibitory and excitatory connections between PMd and primary motor cortex (M1) during observation of implied motion remains uncertain. In this study, using high and low frequency repetitive transcranial magnetic stimulation (rTMS), we examined PMd–M1 connectivity and plasticity during observation of Michelangelo’s frescos with and without implied motion (Sistine Chapel, 1508–1512). We found that observation of implied motion in a painting specifically reduces the activity of inhibitory PMd–M1 connections. On the contrary PMd–M1 facilitatory connections, as examined by means of 5-Hz rTMS, were not modulated during observation of the painting. Our data suggest that observation of implied motion in a painting modulates PMd–M1 connectivity and plasticity. These results are consistent with the hypothesis that art with implied motion might be used as a plasticity-based intervention in rehabilitation.

Modulation of sensorimotor circuits during retrieval of negative Autobiographical Memories: Exploring the impact of personality dimensions

ABSTRACT Autobiographical Memory (AM) retrieval refers to recollection of experienced past events. Previous Transcranial Magnetic Stimulation (TMS) studies have shown that presentation of emotional negative stimuli affects human motor cortex excitability resulting in larger motor evoked potentials (MEPs). Up to date no TMS studies have been carried out in order to investigate the effect of personal memories with negative emotional value on corticospinal excitability. In this study we hypothesized that negative AM retrieval will modulate corticomotor excitability and sensorimotor integration as determined by TMS neurophysiological parameters. Furthermore, we investigated whether TMS responses during retrieval of negative AM are associated with specific personality traits. Twelve healthy subjects were asked to recall either a negative or a neutral AM across two different days in a randomized order. During this memory retrieval, the following TMS parameters were recorded: MEPs; Short‐ interval intracortical inhibition (SICI) and Intracortical facilitation (ICF); Short‐latency afferent inhibition (SAI) and Long‐ latency afferent inhibition (LAI). Personality traits were assessed by using the Big Five scale. Statistical analysis was performed using factorial ANOVAs and multiple linear regression models. When compared to retrieval of neutral AM, recollection of negative AM induced a larger increase in MEP amplitude, an increase in ICF, and a decrease in SAI. The neuroticism personality trait was a significant predictor of the MEP amplitude increase during retrieval of negative AM. Altogether these results indicate that cortical excitability and sensorimotor integration are selectively modulated by the valence of AM. These results provide the first TMS evidence that the modulatory effect of the AM retrieval is associated with specific personality traits. HighlightsRetrieval of negative memories modulates MEP amplitude.Retrieval of negative memories modulates sensorimotor integration.Retrieval of negative memories increases intracortical facilitation.Neuroticism personality trait predicts MEP size during retrieval of negative memories.

An Investigation of Diabetes Knowledge Levels Between Newly Diagnosed Type 2 Diabetes Patients in Galway, Ireland and New York, USA: A Cross-Sectional Study.

Management of diabetes mellitus (DM) involves podiatrists as the primary practitioners engaged in prevention and treatment of lower limb pathology. Patients must first possess adequate knowledge to engage in effective self-management. A knowledge assessment of a DM cohort has never before been conducted in Ireland. The primary research objective was to determine the existence of gaps in specific areas of DM-related knowledge between type 2 DM (T2DM) patients in Galway (GW) and New York (NY). A cross-sectional study compared DM-related knowledge levels between 2 cohorts over a 10-week period. Participants were recently (<3 years) diagnosed with T2DM, were based in general podiatry clinics in GW or NY and had no current or previous diabetic foot ulceration (DFU) or other DM-related foot pathology. Participants were recruited by convenience sampling. A purpose-designed 28-item closed questionnaire was completed by both cohorts to assess knowledge differences. Fifty-two subjects were recruited (GW, n = 32; NY, n = 20). The mean age was 61 ± 10 years; 56% were male. Significant differences were found between cohorts relating to individual questions; specifically regarding knowledge of glycemic control (P = .002) and frequency of self-monitoring of blood glucose (P = .003). Inappropriate foot care practices across both cohorts were highlighted. No significant intercohort differences in particular survey sections were identified. The scores in the systemic and podiatric sections of the questionnaire highlight patterns of common health misconceptions and some highly inappropriate foot care practices respectively across the entire sample. In particular, the dearth of patient awareness regarding uncontrolled blood glucose and its relationship to DFU development, amputation, and associated morbidity is shown to be an area of concern; this must be addressed a priori.

Influence of dual-task on postexercise facilitation: a transcranial magnetic stimulation study.

In this study we investigated the effect of a dual task (DT) comprised of a nonfatiguing leg and foot extension coupled with a calculation task on postexercise facilitation (PEF) of motor evoked potentials (MEPs) tested by using transcranial magnetic stimulation (TMS). Twelve right-handed healthy subjects participated in the study. They were required to perform a motor task, a cognitive task and a DT. The motor task consisted of extending the right leg and foot for 30 sec at 20% of the maximal voluntary contraction. The cognitive task consisted of a 30-sec backward calculation. In the DT condition, motor and cognitive tasks were performed concurrently. Resting motor threshold and 10 MEPs were collected before and immediately after each task. TMS was delivered to the motor hot spot of the right vastus lateralis and tibialis anterior (TA) muscles. Results showed that exercise induced a significant PEF in both VL and TA muscles while calculation was not associated with significant PEF. Furthermore, DT was associated with lack of significant PEF in both muscles (VL, 116.1%±9.6%; TA, 115.7%±9%). Our data indicates DT interference on corticospinal excitability after a nonfatiguing exercise. Our experimental paradigm may be used to address postexercise motor cortex plastic adaptations induced by motor and cognitive tasks of different complexity in sport, aging and neuropsychiatric diseases.

Psychometric properties and podiatric medical student perceptions of USMLE-style items in a general anatomy course.

BACKGROUND In 2010, the New York College of Podiatric Medicine general anatomy course was redesigned to emphasize clinical anatomy. Over a 2-year period, United States Medical Licensing Examination (USMLE)-style items were used in lecture assessments with two cohorts of students (N =200). Items were single-best-answer and extended-matching formats. Psychometric properties of items and assessments were evaluated, and anonymous student post-course surveys were administered. METHODS Mean grades for each assessment were recorded over time and compared between cohorts using analysis of variance. Correlational analyses were used to investigate the relationship between final course grades and lecture examinations. Post-course survey response rates for the cohorts were 71 of 97 (73%) and 81 of 103 (79%). RESULTS The USMLE-style items had strong psychometric properties. Point biserial correlations were 0.20 and greater, and the range of students answering the items correctly was 25% to 75%. Examinations were highly reliable, with Kuder-Richardson 20 coefficients of 0.71 to 0.76. Students (>80%) reported that single-best-answer items were easier than extended-matching items. Students (>76%) believed that the items on the quizzes/examinations were similar to those found on USMLE Step 1. Most students (>84%) believed that they would do well on the anatomy section of their boards (American Podiatric Medical Licensing Examination [APMLE] Part I). CONCLUSIONS Students valued USMLE-style items. These data, coupled with the psychometric data, suggest that USMLE-style items can be successfully incorporated into a basic science course in podiatric medical education. Outcomes from students who recently took the APMLE Part I suggest that incorporation of USMLE-style items into the general anatomy course was a successful measure and prepared them well.