Terminal branching of internal laryngeal nerve: a cadaveric study

Background: Innervation of larynx is much more complicated than previously been thought. Laryngopharynx is the common gateway for many specialists like oral surgeons, ENT surgeons, anaesthetists, UGI endoscopists and bronchoscopists. The sub-mucosal neural network can be anaesthetised by topical application or injection of local anaesthetics. In this study destination of the internal laryngeal nerve and its penetration into the intrinsic muscles of larynx are analysed.Methods: A total of 40 en bloc cadaveric specimens were investigated in the department of anatomy, Madras Medical College, Chennai and from Melmaruvathur Adhiparasakthi Institute of Medical Sciences and Research, Kanchipuram. Conventional anatomy dissection method was used in the identification of internal laryngeal branch of superior laryngeal nerve and its branches.Results: Irrespective of the number of divisions at the point of entry into thyrohyoid membrane, 4 branches were constantly traceable. The branches were traced by 2 approaches- (A) those supplying the mucus membrane- (i) to the junction of aryepiglottic fold and lateral border of epiglottis; (ii) to the posterior surface of interarytenoideus; (iii) to the posterior surface of posterior arytenoideus; and (iv) descending to apex of the pyriform fossa behind cricothyroid junction; (B) penetration into intrinsic muscles- (i) a branch terminated after entering interaryteoideus; and (ii) another terminated after entering the posterior cricoarytenoideus muscle.Conclusions: The knowledge of variation into branches and area of supply of internal laryngeal nerve is essential for anatomists and clinicians. It is not a nerve to be neglected as the knowledge of its branches is very much essential for the surgeons operating in this area of air and food passage.

Post traumatic near total amputation of apex of tongue: a rare case report

Post traumatic near total amputation of apex of tongue is a rare scenario but when happens it causes life threatening situation due to active intraoral bleeding and risk of aspiration especially in children. Tongue is a unique organ which has very rich blood supply and resides in intraoral cavity. Due to its rich blood supply profuse bleeding is commonly seen after the tongue injury. It helps in swallowing, speech, taste, mastication and airway protection. It facilitates perception of gustatory stimuli. Here author presents a case of 13 months old female child, who presented to emergency department with history of fell down from the bed and sustained tongue injury with profuse bleeding. On examination patient had near total amputation of apex of tongue. Gentle debridement followed by meticulous complex repair of intrinsic muscles of tongue was done. On post-operative day two patient was discharged uneventfully.

Vascularity Outcomes of Lingual Artery Ligation in Transoral Robotic Base of Tongue Resections

To explore the effect of lingual artery ligation on tongue vascularity, we performed an analysis of 25 patients who underwent transoral robotic surgery for base of tongue cancers (May 2011 to December 2019). Hounsfield units of the intrinsic muscles (IMs) and genioglossus muscles (GGs) were measured in postoperative imaging (mean 4 months) as a surrogate for vascularity. In ligated patients (n = 15), the values from the ligated/resected side of the tongue were compared with the contralateral side and the nonligated side of resection. Individually, IMs and GGs on the ligated side demonstrated no significant difference to the contralateral side ( P = .662 and .618, respectively). Ligation produced a significant decrease in IM measurements but no difference between GG values vs nonligated patients ( P = .050 and .818, respectively). No difference was appreciated in mean values for combined IMs and GGs between cohorts ( P = .212). No gross tongue atrophy or complications were incurred. Future studies are warranted to delineate long-term effects.

The energetic function of the human foot and its muscles during accelerations and decelerations

The human foot is known to aid propulsion by storing and returning elastic energy during steady-state locomotion. While its function during other tasks is less clear, recent evidence suggests the foot and its intrinsic muscles can also generate or dissipate energy based on the energetic requirements of the center of mass during non-steady state locomotion. In order to examine contributions of the foot and its muscles to non-steady state locomotion, we compared the energetics of the foot and ankle joint while jumping and landing before and after the application of a tibial nerve block. Under normal conditions, energetic contributions of the foot rose as work demands increased, while the relative contributions of the foot to center of mass work remained constant with increasing work demands. Under the nerve block, foot contributions to both jumping and landing decreased. Additionally, ankle contributions were also decreased under the influence of the block for both tasks. Our results reinforce findings that foot and ankle function mirror the energetic requirements of the center of mass and provide novel evidence that foot contributions remain relatively constant under increasing energetic demands. Also, while the intrinsic muscles can modulate the energetic capacity of the foot, their removal accounted for only a three-percent decrement in total center of mass work. Therefore, the small size of intrinsic muscles appears to limit their capacity to contribute to center of mass work. However, their role in contributing to ankle work capacity is likely important for the energetics of movement.

Noninvasive Measurement of Tongue Pressure and Its Correlation with Swallowing and Respiration

Tongue pressure plays a critical role in the oral and pharyngeal stages of swallowing, contributing considerably to bolus formation and manipulation as well as to safe transporting of food from the mouth to the stomach. Smooth swallowing relies not only on effective coordination of respiration and pharynx motions but also on sufficient tongue pressure. Conventional methods of measuring tongue pressure involve attaching a pressure sheet to the hard palate to monitor the force exerted by the tongue tip against the hard palate. In this study, an air bulb was inserted in the anterior oral cavity to monitor the pressure exerted by the extrinsic and intrinsic muscles of the tongue. The air bulb was integrated into a noninvasive, multisensor approach to evaluate the correlation of the tongue pressure with other swallowing responses, such as respiratory nasal flow, submental muscle movement, and thyroid cartilage excursion. An autodetection program was implemented for the automatic identification of swallowing patterns and parameters from each sensor. The experimental results indicated that the proposed method is sensitive in measuring the tongue pressure, and the tongue pressure was found to have a strong positive correlation with the submental muscle movement during swallowing.

Anastomosis Patterns between the Median and Ulnar Nerves in the Upper Limbs

There are four types of anastomoses between the median and ulnar nerves in the upper limbs. It consists of crossings of axons that produce changes in the innervation of the upper limbs, mainly in the intrinsic muscles of the hand. The forearm has two anatomical changes – Martin-Gruber: branch originating close to the median nerve joining distally to the ulnar nerve; and Marinacci: branch originating close to the ulnar nerve and distally joining the median nerve. The hand also has two types of anastomoses, which are more common, and sometimes considered a normal anatomical pattern – Berrettini: Connection between the common digital nerves of the ulnar and median nerves; and Riche-Cannieu: anastomosis between the recurrent branch of the median nerve and the deep branch of the ulnar nerve. Due to these connection patterns, musculoskeletal disorders and neuropathies can be misinterpreted, and nerve injuries during surgery may occur, without the knowledge of these anastomoses. Therefore, knowledge of them is essential for the clinical practice. The purpose of the present review is to provide important information about each type of anastomosis of the median and ulnar nerves in the forearm and hand.

Endoscopic Posterior Approach for Cervicothoracic and Upper Thoracic Foraminotomies: 2-Dimensional Operative Video

Lower cervical and cervicothoracic radiculopathies can be challenging to treat through an anterior approach in patients with short-statured necks. With unilateral pathology, a posterior foraminotomy affords preservation of motion and avoids risks to anterior structures; yet, traditional open or even tubular retractor-based open systems are associated with postoperative muscle pain. Endoscopic approaches reduce muscle retraction and resection and are associated with shorter recovery time. This video demonstrates the endoscopic technique for performing cervicothoracic and thoracic foraminotomies. We present the case of a patient with severe left-hand weakness, particularly in grasp and hand intrinsic muscles. The differential diagnosis included a combined median and ulnar neuropathy, lower trunk plexopathy, medial cord plexopathy, thoracic outlet syndrome, and combined C8 and T1 radiculopathies. Imaging did not show brachial plexus pathology; instead, severe foraminal narrowing at the C8 and T1 roots was noted. We performed a fully endoscopic approach to decompress 2 levels of foraminal stenosis on the left side. Because the levels were adjacent, we operated through a single incision. Recovery of motor-evoked potentials to the abductor pollicis brevis was identified intraoperatively. The patient consented to the procedure and publication.

Neuromechanical adaptations of foot function to changes in surface stiffness during hopping

Humans choose work-minimizing movement strategies when interacting with compliant surfaces. Our ankles are credited with stiffening our lower limbs and maintaining the excursion of our body's center of mass on a range of surface stiffnesses. We may also be able to stiffen our feet through an active contribution from our plantar intrinsic muscles (PIMs) on such surfaces. However, traditional modelling of the ankle joint has masked this contribution. We compared foot and ankle mechanics and muscle activation on Low, Medium and High stiffness surfaces during bilateral hopping using a traditional and anatomical ankle model. The traditional ankle model overestimated work and underestimated quasi-stiffness compared to the anatomical model. Hopping on a low stiffness surface resulted in less longitudinal arch compression with respect to the high stiffness surface. However, because midfoot torque was also reduced, midfoot quasi-stiffness remained unchanged. We observed lower activation of the PIMs, soleus and tibialis anterior on the low and medium stiffness conditions, which paralleled the pattern we saw in the work performed by the foot and ankle. Rather than performing unnecessary work, participants altered their landing posture to harness the energy stored by the sprung surface in the low and medium conditions. These findings highlight our preference to minimize mechanical work when transitioning to compliant surfaces and highlight the importance of considering the foot as an active, multi-articular, part of the human leg.

Isolated Complete Tongue Paralysis as a Manifestation of Focal Cortical Infarction

Although isolated contralateral tongue deviation following unilateral cortical infarction was occasionally reported, the unilateral lesion usually produces no significant deficit of tongue motility considering bilateral supranuclear innervation of the hypoglossal nerve. We observed a patient with obvious tongue paralysis, including intrinsic muscles, caused by ischemic stroke involving the motor area of the tongue in the primary motor cortex.