Hirayama disease. Clinical cases

Hirayama disease, or monomelic amyotrophy, is a rare neurological pathology manifested by unilateral or bilateral asymmetric paresis with atrophy of the distal upper extremities. The development of this disease is associated with the forward displacement of the posterior dural sac during neck flexion, which leads to compression of the spinal cord and venous stasis. The diagnosis of monomelic amyotrophy is based on the clinical picture and the results of magnetic resonance imaging of the cervical spine with flexion, showing segmental atrophy of the anterior horns of the spinal cord at C7 — Th1, detachment of the posterior dura mater and venous stasis. Most of the cases described in the literature are from India and Japan, with isolated cases diagnosed in North America and Europe. This article presents two clinical cases of progressive hand weakness in young men. The clinical picture of the disease and the results of additional examination methods are presented, which is necessary to establish a diagnosis of Hirayama’s disease.

DISHphagia – A Riddle Unwrapped a Clinical Case with Literature Review

Diffuse idiopathic skeletal hyperostosis (DISH) is a common but underdiagnosed systemic skeletal disease. It is characterized by calcifications affecting mainly the spinal anterior longitudinal ligament. In the majority of cases, the patients are asymptomatic, but cervical osteophytes can sometimes cause hoarseness, dysphagia (DISHphagia) and even dyspnea. Case description: A 61-year-old man was admitted to our department with complaints of difficulty in swallowing and weight loss. Dysphagia had been increasing gradually for nine months. Barium swallow esophagram revealed asymmetric swallowing with expansion above the upper esophageal sphincter without other abnormalities. The extension was confirmed by esophago-gastro-duodenoscopy (EGD). Furthermore, CT scan of the thorax clearly demonstrated degenerative changes of the cervical and thoracic region, extensive ossification of the anterior longitudinal ligament, and osteophytes from C2-C7 with a forward displacement of the esophagus by 14 mm. The so-called “wax dripping down the candle” phenomenon was as well observed. Conclusion: DISH is a systematic, musculo-skeletal disease of older adults with unknown etiology. Dysphagia is the most common symptom of the disease and might be caused by osteophytes of the cervical region. We presented a case of DISH with a rare localization of the osteophytes in the cervical region C2-C7. Due to the increasing incidence of the Forestier’s syndrome and its associated “DISHphagia”, the gastroenterologist should increase the awareness of this underestimated disease and improve the diagnostic approach.

Free throw technical analysis and its relationship with success in Under-12 basketball players (Análisis técnico de los tiros libres y su relación con el éxito en jugadores de baloncesto menores de 12 años)

The aim of this study was to determine the free throw technique and successful free throw technique both prior to ball release and at ball release moments in under-12 basketball, using a court-applied test. The participants were 102 players from eight male under-12 officially federated basketball teams. We used a point/ideographic/multidimensional observational design to analyse the recordings of 612 free throws. The test consisted of performing one, two or three free throws. One participant performed the free throws and the other passed the ball to him. The roles were exchanged until the two participants performed all the free throw options. As a result, the participants did not execute the free throw using the technique proposed by the literature. This difference was because jumping free throws shoots, with low style, feet at the same distance, and moderate forward displacement of the centre of mass predominated. The free throw technique was in general more regular than that of the successful free throws. Players used an unregulated technique, without meeting the criteria that activate success in the free throw. This technique resulted attempting successful free throws at 4 m from the basket, which is 2.60 m high, with a 485-g ball. Taking into account the characteristics of the participants of the present work in terms of age, strength, maturity, height, weight, and body mass index, coaches and the competition managers should assess what should be improved in under-12 basketball to allow players to increase free throw success. Resumen: El objetivo de este estudio fue determinar la técnica de tiro libre y la técnica de tiro libre con éxito, tanto antes de la salida del balón como en el momento de salida del balón en baloncesto U-12, a través de un test de tiro. Los participantes fueron 102 jugadores de ocho equipos masculinos de baloncesto U-12 federados. Se utilizó un diseño observacional puntual/ideográfico/multidimensional para analizar las grabaciones de 612 tiros libres. La prueba consistía en realizar uno, dos o tres tiros libres. Un participante realizaba los tiros libres y el otro le pasaba el balón. Los participantes intercambiaban los roles hasta que los dos realizaron todas las opciones de tiro libre. Los resultados mostraron que los participantes no ejecutaron el tiro libre utilizando la técnica propuesta por la literatura. Esta diferencia se debió a que predominaron los tiros libres con salto, con estilo bajo, pies a la misma distancia y desplazamiento moderado del centro de masas hacia adelante. La técnica de los tiros libres en general fue más regular que la de los tiros libres con éxito. En conclusión, los jugadores utilizaron una técnica alejada de las recomendaciones teóricas, poco regular, y sin cumplir los criterios que posibilitan éxito en el tiro libre. Esto ocurrió como consecuencia de intentar obtener éxito en una situación de tiro libre a 4 m de la canasta, situada a 2.60 m de altura, y con un balón de 485 g. Teniendo en cuenta las características de los participantes del presente trabajo en cuanto a edad, fuerza, madurez, altura, peso e índice de masa corporal, los entrenadores y los responsables de las competiciones deberían valorar qué debe mejorarse en el baloncesto U-12 para que los jugadores puedan aumentar el éxito en los tiros libres.

Drones’ side effect: facial and ocular trauma caused by an aerial drone

An adult man was struck in the face by his own aerial drone. The propellers hit the upper face region leading to forehead and eyelid lacerations, a partial scleral laceration, conjunctival laceration, hyphaema, traumatic iritis and forward displacement of one haptic of the intraocular lens from a previous cataract surgery. In the last decade, drone use has significantly increased and drone-related injuries have become an emerging cause of trauma. Our case raises awareness of the risks and highlights the need for improvement in regulation of drone use.

A Novel Geometric Modeling and Calculation Method for Forward Displacement Analysis of 6-3 Stewart Platforms

A novel geometric modeling and calculation method for forward displacement analysis of the 6-3 Stewart platforms is proposed by using the conformal geometric algebra (CGA) framework. Firstly, two formulas between 2-blade and 1-blade are formulated. Secondly, the expressions for two spherical joints of the moving platform are given via CGA operation. Thirdly, a coordinate-invariant geometric constraint equation is deduced. Fourthly, a 16-degree univariate polynomial equation without algebraic elimination by using the Euler angle substitution is presented. Fifthly, the coordinates of three spherical joints on the moving platform are calculated without judging the radical symbols. Finally, two numerical examples are used to verify the method. The highlight of this paper is that a new geometric modeling and calculation method without algebraic elimination is obtained by using the determinant form of the CGA inner product algorithm, which provides a new idea to solve a more complex spatial parallel mechanism in the future.

Impact of ablation ratio on 5-year postoperative posterior corneal stability after refractive surgery: SMILE and FS-LASIK

Background To investigate the impact of the ablation ratio on 5-year postoperative posterior corneal stability in myopic eyes after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery. Methods A prospective, nonrandomized, cohort study: 80 eyes of 43 patients underwent SMILE surgery and 63 eyes of 32 patients underwent FS-LASIK surgery at the EYE & ENT Hospital, Fudan University. Ablation ratio was defined as lenticule thickness (SMILE cases) or ablation depth (FS-LASIK cases) divided by central corneal thickness (CCT). Posterior corneal elevation changes were recorded as posterior central elevation (PCE), posterior corneal surface at thinnest point (PTE) and posterior corneal mean elevation (PME). Patients were followed up at 6-month and 5-year interval to investigate the impact of the ablation ratio on posterior corneal elevation after SMILE and FS-LASIK surgery. Results PCE dropped at the 6-month follow-up for both SMILE (decreased by −1.11 ± 2.93 μm, P < 0.05) and FS-LASIK groups (decreased by −0.46 ± 3.72 μm, P < 0.05). PTE also dropped in SMILE (reduced by −2.04 ± 3.02 μm, P < 0.05) and FS-LASIK group (reduced by −1.28 ± 4.21 μm, P < 0.05) at the 6-month follow-up. Stable PCE (elevation change: SMILE −0.28 ± 4.03 μm; FS-LASIK 0.79 ± 4.13 μm, P > 0.05) and PTE (elevation change: SMILE −0.08 ± 4.28 μm; FS-LASIK 1.42 ± 3.85 μm, P > 0.05) for both groups were recorded at the 5-year follow-up compared to the 6-month visit. Ablation ratio was strongly correlated with 5-year postoperative PCE (β = 2.68 ± 1.05, P < 0.01) and PTE (β = 2.35 ± 1.17, P < 0.05). Cut-off value for 5-year postoperative raised PCE and PTE was 27.3 and 27.1%, respectively. Conclusions Ablation ratio was strongly correlated with postoperative posterior corneal elevation in a 5-year follow-up in both SMILE and FS-LASIK groups. PCE and PTE underwent slight backward displacement 6-month postoperatively and remain stable at the 5-year follow-up. Threshold of the ablation ratio for resisting forward displacement of posterior corneal surface was 27.3 and 27.1% for SMILE and FS-LASIK groups, respectively.

Surgical treatment of forward displacement of the uterus.

Based on statistics from Nonat, meadovs, Scanzoni, Mund, and others, we must assume, says the author, that of all uterine displacements, forward displacements are the most frequent, and yet it is precisely in the treatment of these displacements that gynecology is powerless.

Treatment of mesial occlusion with forward displacement of the lower jaw in preschool children. Description of the clinical case

The scientific research is dedicated to studying of treatment problems of mesial malocclusion with the anterior mandible shift among preschool aged children (in the period of temporary dentition). The point of the study is to demonstrate the effect of treating mesial malocclusion associated with the mandible anterior shift and reverse overjet in a clinical case description. During the research of a clinical case long term results were analyzed. The method of treating mesial malocclusion associated with the mandible anterior shift and reverse overjet included usage of the original appliance. The appliance was also supposed to lead to harmonic development of a child’s oro-facial area. The analysis showed advantages of the suggested original orthodontic appliance. The malocclusion was corrected in a short time (3 months), that let us develop physiological jaws and teeth arches relationships and to resolve mandible side shifting before the central incisors erupted. During the eruption permanent incisors take their place and establish the proper overjet, that creates physiological conditions for harmonic oro-facial development. The result is stable over time. The appliance is easy to use and to adapt by children and has a good fixation in oral cavity. Thus, the suggested orthodontic appliance could be recommended for treatment of mesial malocclusion associated with the mandible anterior shifting among preschool aged children.

Differences in Simulated Refractive Outcomes of Photorefractive Keratectomy (PRK) and Laser In-Situ Keratomileusis (LASIK) for Myopia in Same-Eye Virtual Trials

The use of computational mechanics for assessing the structural and optical consequences of corneal refractive procedures is increasing. In practice, surgeons who elect to perform PRK rather than LASIK must often reduce the programmed refractive treatment magnitude to avoid overcorrection of myopia. Building on a recent clinical validation study of finite element analysis (FEA)-based predictions of LASIK outcomes, this study compares predicted responses in the validated LASIK cases to theoretical PRK treatments for the same refractive error. Simulations in 20 eyes demonstrated that PRK resulted in a mean overcorrection of 0.17 ± 0.10 D relative to LASIK and that the magnitude of overcorrection increased as a function of attempted correction. This difference in correction closely matched (within 0.06 ± 0.03 D) observed differences in PRK and LASIK from a historical nomogram incorporating thousands of cases. The surgically induced corneal strain was higher in LASIK than PRK and resulted in more forward displacement of the central stroma and, consequently, less relative flattening in LASIK. This FE model provides structural confirmation of a mechanism of action for the difference in refractive outcomes of these two keratorefractive techniques, and the results were in agreement with empirical clinical data.