Leg Pain
Benjamin Apichai in Chinese Medicine for Lower Body Pain, 2021
The corticospinal tract is the largest descending tract present in humans2 and is comprised of a lateral (85%) and an anterior (ventral) tract (15%) (Rea 2015). The lateral corticospinal tract sends fibers predominantly to the muscles of the extremities to control the voluntary movement of the limbs, and the cortical innervation is contralateral; in other words, the left motor cortex controls the right extremities. When a stimulus is engaged, the cell body of the lateral corticospinal tract will send an impulse through the tract that travels to the anterior horn of the spinal cord, proceeds through the spinal nerve root, plexus, and peripheral nerve, and is then transmitted via the lower motor neurons into the muscle fibers, resulting in contraction of the limb muscles. The anterior corticospinal tract sends fibers mainly to the trunk or axial muscles. The control is both ipsilateral and contralateral. Therefore, the trunk muscles are generally bilaterally cortically innervated.3
Thermography by Specialty
James Stewart Campbell, M. Nathaniel Mead in Human Medical Thermography, 2023
Static thermographic methods to detect PD have not yielded significant results. Dynamic thermography, however, shows distinct differences compared to control groups (Figure 11.34). To observe the thermal effects of PD, baseline (BL) images are taken after equilibration in a thermographic environment at 23°C (73.4°F) (Figure 11.34a&d). The subjects immerse one hand in 3°C (37.4°F) water up to the wrist for 2 minutes, creating a large thermal contrast for analysis (Figure 11.34b&e). The immersion technique is “dry” – the hand is encased in a plastic bag during immersion. The contralateral hand serves as control. Subsequent images are taken at 0, 2, 4, 6, 8, and 10 minutes after immersion.
Control of Movement and Posture
Nassir H. Sabah in Neuromuscular Fundamentals, 2020
An interesting instance of motor control and coordination is handedness, that is, the preference to use one hand or arm for faster or more precise motor activity. It is estimated that about 90% of humans are right-handed, about 10% are left-handed, and about 1% change hand preference between tasks. That is not to say that the dominant hand achieved some “superiority” over the non-dominant hand. There is evidence of some degree of specialization between the two hands. The dominant hand, controlled by the contralateral hemisphere, is more adept in tasks that require quick, coordinated multi-joint movements, whereas the non-dominant hand performs better in tasks that involve stabilization of position and load compensation. This is a common experience when hammering a nail, for example, or cutting a loaf of bread. The dominant hand is part of the trajectory of the desired movement, while the non-dominant hand stabilizes the object in position, against the load imposed by the movement. It is believed that having both hands perform equally well in all types of motor tasks is redundant and wasteful of neural tissue, whereas a division of labor preserves function with a smaller totality of nervous tissue. The same argument has been applied to the specializations of the two cerebral hemispheres. Redundancy has of course the advantage of added reliability in case of impairment of function of one of the executing entities, but the nervous system allows, to a large extent, for this contingency through learning of new tasks by the unimpaired entity. Even after losing the dominant hand, a person can learn to write with the other hand.
Development of a diagnostic algorithm identifying cases of dislocation after primary total hip arthroplasty—based on 31,762 patients from the Danish Hip Arthroplasty Register
Published in Acta Orthopaedica, 2021
Lars L Hermansen, Bjarke Viberg, Søren Overgaard
We designed the algorithm using a stepwise approach and calculated the sensitivity, specificity, and the positive and negative predictive values for various combinations of the most frequently used codes. The steps were not pre-specified but, instead, were chosen based on the codes that had been applied nationwide from 2010 to 2016 for verified dislocations. The plan was to add codes in steps and continuously increase the sensitivity (i.e., the proportion of true positives of all dislocations), while at the same time keeping the specificity (i.e., the proportion of true negatives of all not having a dislocation) and the positive predictive value (PPV) (i.e., probability that patients based on the algorithm truly have the dislocation) high. The algorithm will identify patients with at least 1 episode of dislocation for a given period of time (i.e., the risk of dislocation) but it will not necessarily identify all dislocations for each patient. It is also important to note that there is a clear distinction between hospital contacts with or without denoted laterality in the DNPR. This is an important aspect in order to distinguish between contralateral THAs. Statistics was performed with STATA software version 15.0 (StataCorp, College Station, TX, USA).
The Effects of Ischemia and Hyperoxygenation on Hair Growth and Cycle
Published in Organogenesis, 2020
Harunosuke Kato, Kahori Kinoshita, Natsumi Saito, Koji Kanayama, Masanori Mori, Natsumi Asahi, Ataru Sunaga, Katsutoshi Yoshizato, Satoshi Itami, Kotaro Yoshimura
Nine-week-old C57BL/6JJcl mice (male) were anesthetized by intraperitoneal injection of somnopentyl (Kyoritsu Seiyaku, Tokyo, Japan). A minimal amount of anesthesia was administered to avoid deep anesthesia and thereby ensure that the O2 partial pressure in the tissue did not decrease. The groin area was depilated using depilating tape (Veet, Reckitt Benckiser, United Kingdom), and a 1.5 × 1.5 cm skin flap was raised. To create an ischemic environment for the skin around the hair follicles in the skin flaps, the femoral artery was ligated and dissected proximal to the inferior epigastric artery so that blood supply to the skin flaps came only from the reverse flow of the femoral artery. The contralateral side served as the control. Both groin areas were monitored, and after 2 weeks, the body hair on the skin flaps was pulled out. The length of the hair was measured, and the skin flaps were evaluated histologically. In addition to hair and skin flap sample collection, a probe (200 µm in diameter) was inserted directly into the fat in the groin to measure O2 partial pressure over time using an O2 partial pressure monitor (Eiko Kagaku, Tokyo, Japan).
Loss of Kir6.1 facilitates peri-infarct depolarizations in focal cerebral ischemia
Published in Neurological Research, 2022
Zelong Zheng, Zhenyu Li, Jianping Lv
There were four patterns of PID propagation including rostro-caudal, latero-medial, caudo-rostral, and contralateral (Figure 1c). In one mouse, there could be one pattern or more. The rostro-caudal pattern, originating from the frontal area and spread caudally to parietal and occipital areas, only accounted for 1.9% (IQR, 0–6.3%) of the total observed PIDs (Figure 1c(a)). The latero-medial pattern, starting from lateral fronto-parietal regions and propagated to the midline, accounted for 11.3% (IQR, 1.5–57.7%) of PIDs in WT mice, 13% (IQR, 6–27.8%) in Kir6.1−/− mice, and 16.6% (IQR, 0–63.3%) in Kir6.2−/− mice (Figure 1c(b)). This pattern appeared to be dominant (88.2–100%) in some mice. The caudo-rostral pattern, originating from parieto-occipital regions and propagated to frontal areas, accounted for 76.8% (IQR, 40.2–85.8%) of PIDs in WT mice, 85% (IQR, 72.2–89%) in Kir6.1−/− mice, and 68.7% (IQR, 31.7–92.7%) in Kir6.2−/− mice, respectively (Figure 1c(c)). This pattern was the most common. The contralateral pattern initiated in the contralateral medial frontal pole and propagated laterally and caudally to contralateral parietal and occipital areas (Figure 1c(d)). Only seven PIDs with this pattern were observed. No significant difference in the distribution of different patterns of PIDs was observed among WT, Kir6.1−/− and Kir6.2−/− mice (Fisher's exact test, P > 0.05).
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