The external oblique intercostal block: anatomical evaluation and case series

Study Objective We report a modified block technique aimed at obtaining upper midline and lateral abdominal wall analgesia: the external oblique intercostal (EOI) block. Design A cadaveric study and retrospective cohort study assessing the potential analgesic effect of the EOI block. Setting Cadaver lab and operating room. Patients Two unembalmed cadavers and 22 patients. Interventions Bilateral ultrasound-guided EOI blocks on cadavers with 29 ml of bupivacaine 0.25% with 1 ml of India ink; single-injection or continuous EOI blocks in patients. Measurements Dye spread in cadavers and loss of cutaneous sensation in patients. Main Results In the cadaveric specimens, we identified consistent staining of both lateral and anterior branches of intercostal nerves from T7–T10. We also found consistent dermatomal sensory blockade of T6–T10 at the anterior axillary line and T6–T9 at the midline in patients receiving the EOI block. Conclusions We demonstrate the potential mechanism of this technique with a cadaveric study that shows consistent staining of both lateral and anterior branches of intercostal nerves T7–T10. Patients who received this block exhibited consistent dermatomal sensory blockade of T6–T10 at the anterior axillary line and T6–T9 at the midline. This block can be used in multiple clinical settings for upper abdominal wall analgesia.

Emotional Components of Pain Perception in Borderline Personality Disorder and Major Depression—A Repetitive Peripheral Magnetic Stimulation (rPMS) Study

Various studies suggested alterations in pain perception in psychiatric disorders, such as borderline personality disorder (BPD) and major depression (MD). We previously investigated affective components of pain perception in BPD compared to healthy controls (HC) by increasing aversive stimulus intensities using repetitive peripheral magnetic stimulation (rPMS) and observed alterations in emotional rather than somatosensory components in BPD. However, conclusions on disorder specific alterations in these components of pain perception are often limited due to comorbid depression and medication in BPD. Here, we compared 10 patients with BPD and comorbid MD, 12 patients with MD without BPD, and 12 HC. We applied unpleasant somatosensory stimuli with increasing intensities by rPMS and assessed pain threshold (PT), cutaneous sensation, emotional valence, and arousal by a Self-Assessments Manikins scale. PTs in BPD were significantly higher compared to HC. The somatosensory discrimination of stimulus intensities did not differ between groups. Though elevated rPMS intensities led to increased subjective aversion and arousal in MD and HC, these emotional responses among intensity levels remained unchanged in BPD. Our data give further evidence for disorder-specific alterations in emotional components of pain perception in BPD with an absent emotional modulation among varying aversive intensity levels.

Restoration of Trigeminal Cutaneous Sensation with Cross-Face Sural Nerve Grafts: Case Report and Literature Review

Complete anesthesia leaves patients susceptible to occult injury, and facial sensation is an important component of interaction and activities of daily living. Although treating facial palsy is considered debilitating for patients, trigeminal nerve palsy and sensory deficits of the face are overlooked components of disability. The authors reported the first case in Vietnam: 38 year-old man who lost the sensation on his right face follow by V cranial nerve tumor resection one year before. The sensation of the trigeminal cutaneous nerve was restored with cross-face sural nerve graft from contralateral side in 2018. The patient demonstrated improved sensation in the reconstructed dermatomes without donor-site aNBormalities at the time of 18 months post operation. Keywords: Facial palsy, facial sensation, trigeminal nerve tumor, cross-face nerve graft.

Skin stretch suturing with Nice knots in the treatment of small- or medium-sized wounds

Background To investigate the clinical efficacy and outcomes of skin stretch suturing with self-locking sliding Nice knots in the treatment of small- or medium-sized wounds. Methods From June 2015 to May 2018, 26 patients with small- or medium-sized wounds were included in the present study. Skin stretch suturing with self-locking slide Nice knots was performed to gradually close the soft-tissue defects in these patients. The time of wound closure and healing was recorded. The color and blood supply of the skin, cutaneous sensation, the stretch of skin, and the hair growth situation of the skin wound were observed and recorded. Results There were 17 males and 9 females with an average age of 30.65 years (range, 15–48 years). The areas of the soft-tissue defects were between 3.2 × 7.1 cm and 8.0 × 15.2 cm. All patients underwent stretch suturing with self-locking slide Nice knots to close the soft-tissue defects. All wounds were successfully closed and healed. The mean time of wound closure was 10.69 days (range, 5–20 days), and the mean time of wound healing was 16.85 days (range, 10–24 days). The cutaneous sensation of skin wound recovered normally, and the color of the skin wounds was the same as that of normal skin at the last follow-up. The hair growth situation of the skin wounds also returned to normal. Conclusions This study revealed that Nice knots yielded an accepted clinical result as a new method to close small- or medium-sized wounds that was simple and less minimally invasive, resulted in progressive tension, did not return to previous results, and partially replace flaps or free skin grafts.

Comparison of Postural Sway, Plantar Cutaneous Sensation According to Saccadic Eye Movement Frequency in Young Adults

The crossover trial study aimed to identify the saccadic eye movement (SEM) frequency to improve postural sway (PS) and plantar cutaneous sensation (PUS) in young adults. The 17 participants randomly performed 0.5-, 2-, and 3-Hz SEM. The SEM frequency was determined to allow the target to appear once per 2 s (0.5 Hz), twice per second (2 Hz), or thrice per second (3 Hz). SEM performance time was 3 min with a washout period of 5 min. PS and PUS were measured at baseline and during 0.5-Hz, 2-Hz, and 3-Hz SEMs using a Zebris FDM 1.5 force plate. PS was determined by measuring the sway area, path length, and speed of center of pressure (COP) displacement, and PUS was determined via the plantar surface area (PSA). In PS parameters, there was a significant difference among the SEM frequencies in the COPsway area PSAleft foot and PSAright foot. Compared to that at baseline, COPsway area decreased at 0.5 Hz and 2 Hz, while PSAleft foot and PSAright foot increased at 2 Hz. These results suggest that 2 Hz SEM may improve PS and PSA.

The Effect of the Degree of Anxiety of Learners during the Use of VR on the Flow and Learning Effect

Virtual reality (VR) learning content that provides negative experiences makes learners anxious. Thus, experimental research was conducted to determine how anxiety felt by learners using VR impacts learning. To measure the learning effects, flow, a leading element of learning effects, was measured. Flow has a positive effect on learning as a scale of how immersed an individual is in the work he or she is currently performing. The evaluation method used the empirical recognition scale by Kwon (2020) and the six-item short-form State-Trait Anxiety Inventory (STAI) from Marteau and Becker (1992), which were used in the preceding study. The difference in flow between high- and low-anxiety groups was explored by measuring the degree the study participants felt using an Fire Safety Education Game based on VR that allows learners to feel the heat and wind of the fire site with their skin. As a result of the experiment, no difference in flow was found between the high- and low-anxiety groups that played the same VR game with cutaneous sensation. However, the high-anxiety group who played the VR game with cutaneous sensation showed a higher flow than the group that played the basic fire safety education VR game. Based on these results, the following conclusions were drawn: the closer to reality the VR learning and training system for negative situations is reproduced, the more realistically the learner feels the anxiety. In other words, the closer to reality the virtual environment is reproduced, the more realistically the learner feels the feelings in the virtual space. In turn, through this realistic experience, the learner becomes immersed in the flow more deeply. In addition, considering that flow is a prerequisite for the learning effect, the anxiety that learners feel in the virtual environment will also have a positive effect on the learning effect. As a result, it can be assumed that the more realistically VR is reproduced, the more effective experiential learning using VR can be.

Henry Head’s lifelong studies of cutaneous sensation

In 1900 research on cutaneous sensation was defined by histological techniques defining sensory receptors in skin, leading to undetermined conceptual problems when considered in relation to Brown-Séquard’s startling finding that there were two qualitatively different afferent pathways in the spinal cord. Four modalities were considered to function as the determinants of sensory input. In 1903 Rivers and Head carried out the first interventional study of human cutaneous sensation, and analysed the return of sensation following section and immediate suture of the dorsal cutaneous branch of Head’s left radial nerve. This resulted in the revolutionary idea summarised in his description of protopathic and epicritic sensory systems in peripheral sensory nerve. Although this concept was at best seen as controversial and even ridiculed by some of his many contemporaneous critics, more recently this concept has proven a fundamentally important stimulus to understanding the physiology of cutaneous sensation. His writings show him to have been capable of deeply instructive thought, based on his clinical experience and his admiration of Hughlings Jackson’s teaching concerning the hierarchical organisation of brain function. First and foremost a clinician neuroscientist, his ideas were ahead of their time and not understood.

Lateral Perturbation-Induced and Voluntary Stepping in Fallers and Nonfallers After Stroke

Objective A loss of balance poststroke from externally induced perturbations or during voluntary movements is often recovered by stepping. The purpose of this study was to characterize stepping behavior during lateral induced waist-pull perturbations and voluntary steps in community-dwelling fallers and nonfallers with chronic stroke. Methods This study used a cohort design. Thirty participants >6 months poststroke were exposed to 24 externally triggered lateral waist-pull perturbations and 20 voluntary steps. Balance tolerance limit (BTL) (transition from single to multiple steps) and first step type were determined for the waist-pull perturbations. Step parameters of initiation time, velocity, first step length, and clearance were calculated at and above BTL and for the voluntary steps. Hip abductor/adductor torque, foot cutaneous sensation, and self-reported falls that occurred 6 months prior were evaluated. Results Twelve participants were classified retrospectively as fallers and 18 as nonfallers. Fallers had a reduced BTL and took more medial first steps than nonfallers. Above BTL, no between-group differences were found in medial steps. At BTL, the nonparetic step clearance was reduced in fallers. Above BTL, fallers took longer to initiate a paretic and nonparetic step and had a reduced nonparetic step length and clearance compared with nonfallers. There was a between-group difference in step initiation time for voluntary stepping with the paretic leg (P < .05). Fallers had a reduced paretic abductor torque and impaired paretic foot cutaneous sensation. Conclusion A high fall rate poststroke necessitates effective fall prevention strategies. Given that more differences were found during perturbation-induced stepping between fallers and nonfallers, further research assessing perturbation-induced training on reducing falls is needed. Impact Falls assessments should include both externally induced perturbations along with voluntary movements in determining the fall risk.

Intracortical Microstimulation Elicits Human Fingertip Sensations

The restoration of cutaneous sensation to fingers and fingertips is critical to achieving dexterous prosthesis control for individuals with sensorimotor dysfunction. However, localized and reproducible fingertip sensations in humans have not been reported via intracortical microstimulation (ICMS) in humans. Here, we show that ICMS in a human participant was capable of eliciting percepts in 7 fingers spanning both hands, including 6 fingertip regions (i.e., 3 on each hand). Median percept size was estimated to include 1.40 finger or palmar segments (e.g., one segment being a fingertip or the section of upper palm below a finger). This was corroborated with a more sensitive manual marking technique where median percept size corresponded to roughly 120% of a fingertip segment. Percepts showed high intra-day consistency, including high performance (99%) on a blinded finger discrimination task. Across days, there was more variability in percepts, with 75.8% of trials containing the modal finger or palm region for the stimulated electrode. These results suggest that ICMS can enable the delivery of localized fingertip sensations during object manipulation by neuroprostheses.