Variability in facial-muscle innervation: A comparative study based on electrostimulation and anatomical dissection.

Facial-nerve palsy is the most common complication during facial surgery. However, there are few detailed reports on the distribution of the terminal branches of the facial nerve to the mimetic muscles. This also applies to the communicating branches. The aim of our study was to assess the variability of communicant and terminal branches of the facial nerve in humans. This prospective study involved anatomical dissections and intraoperative electric stimulation of facial nerves. We first performed 30 dissections to define the branching patterns of the extracranial facial nerve, with particular focus on the penetrating points into the mimetic muscles. We then studied and compared these preliminary data with 14 operative facial stimulations conducted during parotidectomies. Each trunk and branch received systematic electrostimulation. The electrostimulation and facial-and-neck movements were analyzed by two independent reviewers. The peripheral branching and intercommunication of the facial branches were highly variable. Combining electrostimulation and dissections, the frontalis muscle, the depressor labii inferioris and the platysma showed little nerve recuperation whereas the sphincter muscles (orbicularis ori and oculi) were anatomically protected. Facial-muscle innervation differed among individuals. We found complex variations in the facial branching mode. Our study highlights the branches and corresponding areas that could be considered anatomically risky. Clin. Anat. 32:169-175, 2019. © 2018 Wiley Periodicals, Inc.

[A further discussion on acupuncture treatment plan of facial neuritis in Evidence-based Guidelines of Clinical Practice in Acupuncture and Moxibustion].

The treatment plan of facial neuritis in Evidence-based Guidelines of Clinical Practice in Acupuncture and Moxibustion (2011 edition) is discussed, and case information of facial neuritis during the recent five years in department of acupuncture and moxibustion, PLA General Hospital, is retrospectively analyzed. In accordance with anatomy of the facial nerve to form the acupuncture prescription, the detailed diagnosis and treatment method for facial neuritis are introduced. The advantages of the diagnosis and treatment method for facial neuritis are summarized, hoping to establish a more comprehensive, standardized and unified treatment plan.

Determination of a facial nerve safety zone for navigated temporal bone surgery.

BACKGROUND: Transtemporal approaches require surgeons to drill the temporal bone to expose target lesions while avoiding the critical structures within it, such as the facial nerve and other neurovascular structures. We envision a novel protective neuronavigation system that continuously calculates the drill tip-to-facial nerve distance intraoperatively and produces audiovisual warnings if the surgeon drills too close to the facial nerve. Two major problems need to be solved before such a system can be realized. OBJECTIVE: To solve the problems of (1) facial nerve segmentation and (2) calculating a safety zone around the facial nerve in relation to drill-tip tracking inaccuracies. METHODS: We developed a new algorithm called NerveClick for semiautomatic segmentation of the intratemporal facial nerve centerline from temporal bone computed tomography images. We evaluated NerveClick's accuracy in an experimental setting of neuro-otologic and neurosurgical patients. Three neurosurgeons used it to segment 126 facial nerves, which were compared with the gold standard: manually segmented facial nerve centerlines. The centerlines are used as a central axis around which a tubular safety zone is built. The zone's thickness incorporates the drill tip tracking errors. The system will warn when the tracked tip crosses the safety zone. RESULTS: Neurosurgeons using NerveClick could segment facial nerve centerlines with a maximum error of 0.44 ± 0.23 mm (mean ± standard deviation) on average compared with manual segmentations. CONCLUSION: Neurosurgeons using our new NerveClick algorithm can robustly segment facial nerve centerlines to construct a facial nerve safety zone, which potentially allows timely audiovisual warnings during navigated temporal bone drilling despite tracking inaccuracies.

Reanimation of the middle and lower face in facial paralysis: review of the literature and personal approach.

Facial paralysis refers to a condition in which all or portions of the facial nerve are paralysed. The facial nerve controls the muscles of facial expression, paralysis which results in a lack of facial expression which is not only an aesthetic issue, but has functional consequences as the patient cannot communicate effectively. The treatment of long-standing facial paralysis has challenged plastic surgeons for centuries, and still the ultimate goal of normality of the paralysed hemi-face with symmetry at rest as well as the generation of a spontaneous symmetrical smile with corneal protection has not yet fully been reached. Until the end of the 19th century, the treatment of this condition involved non-surgical means such as ointments, medicines and electrotherapy. With the advent and refinement of microvascular surgical techniques in the latter half of the 20th century, vascularised free muscle transfers coupled with cross-facial nerve grafts were introduced, allowing the possibility of spontaneous emotion being restored to the paralysed face became reality. The aim of this article is to revisit the surgical evolution and current options available as well as outcomes for patients suffering from facial paralysis concentrating on middle and lower face reanimation.

[Morphological characteristics and clinical significance of Yifeng (TE 17)].

OBJECTIVE: To study on the anatomical layers and depth of Yifeng (TE 17) so as to provide anatomical basis for clinical treatment. METHODS: Fifteen fresh adult corpse samples, 10 males and 5 females, were randomly taken for investigating the anatomical structures and nerve-blood vessel relationship at the acupoint area of Yifeng (TE 17) with layer anatomical method layer by layer. RESULTS: Anterior of Yifeng (TE 17) is posterior border of condylion, the part backward is the aponeurosis of sternocleidomastoid muscle and anterior border of papillary. Structures of this point are skin, subcutaneous fascia, the posterior border of parotid, venous plexus of infratemporal fossa in turn. And the superficial layer of the point are the branches of great auricular nerve and external jugular vein. The structures of the deep layer are occipital artery, branches of upper jaw's artery and vein, pterygoid venous plexus and facial nerve, mandibular nerve. The average dangerous depth is (35.52 +/- 6.31) mm. CONCLUSION: There are important nerves and blood vessels around Yifeng (TE 17), which should be noted in acupuncture.

Localization of the Na+-activated K+ channel Slick in the rat central nervous system.

Na+-activated K+ currents (K(Na)) have been reported in multiple neuronal nuclei and the properties of K(Na) vary in different cell types. We have described previously the distribution of Slack, a Na+-activated K+ channel subunit. Another recently cloned Na+-activated K+ channel is Slick, which differs from Slack in its rapid activation and its sensitivity to intracellular ATP levels. We now report the localization of Slick in the rat central nervous system using in situ and immunohistochemical techniques. As for Slack, we find that Slick is widely distributed in the brain. Specifically, strong hybridization signals and immunoreactivity were found in the brainstem, including auditory neurons such as the medial nucleus of the trapezoid body. As has also been shown for Slack, Slick is expressed in the olfactory bulb, red nucleus, facial nucleus, pontine nucleus, oculomotor nucleus, substantia nigra, deep cerebellar nuclei, vestibular nucleus, and the thalamus. Slick mRNA and protein, however, also are found in certain neurons that do not express Slack. These neurons include those of the hippocampal CA1, CA2, and CA3 regions, the dentate gyrus, supraoptic nucleus, hypothalamus, and cortical layers II, III, and V. These data suggest that Slick may function independently of Slack in these regions. Computer simulations indicate that Slick currents can cause adaptation during prolonged stimuli. Such adaptation allows a neuron to respond to high-frequency stimulation with lower-frequency firing that remains temporally locked to individual stimuli, a property seen in many auditory neurons. Although it is not yet known if Slick and Slack subunits heteromultimerize, the existence of two genes that encode K(Na), that are widely expressed in the nervous system, with both overlapping and nonoverlapping distributions, provides the basis for the reported heterogeneity in the properties of K(Na) from various neurons.

[The identification and functional tracking of the facial nerve during the removal of tumors of the cerebellopontine angle]. / Identifikatsiia i slezhenie za sostoianiem litsevogo nerva vo vremia udaleniia opukholei mostomozzhechkovogo ugla.

Intracranial identification by electrostimulation and monitoring of the status of the facial nerve was intraoperatively used in 21 patients with cerebellopontine angle tumors of varying histological structure. Monopolar and bipolar electrostimulation, as well as electromyography and mechanography for recording the function of the facial nerve were compared. During removal of cerebellopontine angle tumors, identification and monitoring of the function of the facial nerve provide anatomic retention of this nerve when the tumor is radically eliminated. This is of essential significance for acoustic neurinomas. A combination of monopolar and bipolar stimulation for identification of the facial nerve simplifies removal of these tumors. As compared with electromyography, mechanography of facial nerve function during these operations is a more convenient technique due to the simplicity and absence of false operation for electric interferences. The study provided the optimum procedure for intracranial stimulation to identify the facial nerve within the cerebellopontine angle.

Restoration of function in the paralyzed rabbit orbicularis oculi muscle by direct functional electrical stimulation.

Restoration of the ability to blink and protect the eye in the patient with facial paralysis remains a challenge. Although many treatments exist, no one approach corrects all the deficits associated with the loss of orbicularis oculi function. In this study, the author investigated the feasibility of restoring function by direct electrical stimulation of the paralyzed orbicularis oculi muscle in the rabbit model. Using a pacing device developed by the author, functional restoration of a normal-appearing blink was produced throughout 30 days of continuous pacing in six rabbits with transected facial nerves. Histologic evaluations of the paced tissues demonstrated no evidence of detrimental effects attributable to the electrical stimulation. The findings of this study support the feasibility of employing direct electrical stimulation to restore the function of paralyzed orbicularis oculi muscles. Potential applications may also exist in other areas in which peripheral denervation creates functional impairment.

[Intraoprative identification and monitoring of motor structures of the brain stem]. / Intraoperatsionnaia identifikatsiia i monitoring sostoianiia dvigatel'nykh struktur stvola mozga.

The purpose of this work was to evaluate the method of identification of motor structures of the bottom of the IV ventricle in order to find the zone through which it is possible to safely approach the bulky formation and to assess the efficacy of subsequent monitoring of these structures for the prevention of their intraoperative injury. Fourteen patients with bulky tumors of the caudal portions of the brain stem aged 4 to 57 were examined. Motor structures of the brain stem (nerves VII or IX, X, and XII, depending on the site of injury) were identified by direct electrostimulation of the surface of the rhomboid fossa and recording of the motor functions by mechanography of EMG. The results indicate that intraoperative identification of motor structures followed by monitoring thereof is a useful instrument which helps reduce the surgical risk of injuring these structures during surgery on the brain stem.

Immunocytochemical detection of estrogen receptor in the facial nucleus of the newborn rat by three antibodies with distinct epitopes.

With the aid of three different antibodies, which recognize specific parts of the native estrogen receptor (ER) molecule, expression of the ER was confirmed not only in the hypothalamus but also in the ventromedial subdivision of the facial nucleus (n7) in neonatal (7-day-old) rats. In contrast, in 3-week-old prepubertal rats, the ER was detected in the hypothalamus and the amygdala, but not in the n7. Thus, the expression of ER in the n7 was shown to be a transient phenomenon. Transient appearance of ER has also been reported in the cerebral cortex of newborn rats and mice. Physiological significance of transient appearance of ER molecules in this subdivision is speculated as being related to the auditory function.

[Supplementary innervation of lower teeth. Review of the literature]. / Contribuição ao estudo da inervação suplementar dos dentes inferiores - uma revisão bibliográfica.

When pain persists after a successful injection of the inferior alveolar nerve, the professional must think on the possibility of supplementary nerve supply of the region. This review updates the current knowledge of this supplementary innervation. Not every patient will require this kind of anesthesia, however, the dentist must be aware of its existence.

The position and branching pattern of the facial nerve and their effect on transcutaneous electrical stimulation in the orofacial region.

A significant proportion (31%) of southern (Hong Kong) Chinese patients who received therapeutic transcutaneous electrical stimulation with the Myo-Monitor experienced uncomfortable twitching of the muscles of facial expression of the upper and middle portions of the face. This can be attributed, at least in part, to anatomic variation in the position and branching pattern of the upper (temporofacial) division of the facial nerve in the sample population. Our observations of living patients support the contention that muscular contraction resulting from Myo-Monitor stimulation is neurally mediated.

Facial nerve akinesia.

In ophthalmology, increasing attention has been directed to methods of local anesthesia and akinesia that provide complete analgesia and immobilization of the eye conducive to work with the surgical microscope, particularly in operations for cataracts. The volume of anesthetic agent often used to achieve these goals may approach the toxic level of the drug in some patients. A method of producing akinesia of the temporal, zygomatic, and buccal divisions of the facial nerve that requires only a small volume of anesthetic is described. In our experience, this method can, in many cases, provide akinesia of the orbicularis oculi equal in effect to some established methods of infiltrative akinesia that require large doses of anesthetic.

Acupuncture points of the cranial nerves.

An attempt is made to name most of the acupuncture points in the face and forehead region using anatomic nomenclature known to western medicine. All acupuncture points in the face and forehead region are located along terminal or cutaneous branches of the trigeminal nerve and the motor points formed between muscular branches of the facial nerve to the muscles of facial expression. It is believed such nomenclatures will be comprehensible to basic medical scientists and clinical practitioners who have knowledge of anatomical sciences.

Brain traits through phylogeny: evolution of neural characters.

We have previously derived a hypothetical tree of the lines of mammalian descent, based upon a comprehensive numerical taxonomic cross-analysis of primitive and derived states of 15 brain traits in 38 representative species. In this communication we use this tree to describe the probable sequence of changes that have taken place in phylogenetic history. 2 characters proved to be multiply convergent, occurring in parallel in several disparate lines of descent. The remaining 9 characters each appeared in ancestors of one or another of the lineages and characterize related progeny.

Hypothalamic descending afferents to cells of origin of the greater petrosal nerve in the rat, as revealed by a combination of retrograde HRP and anterograde autoradiographic techniques.

Projections from the hypothalamus to cells of origin of the greater petrosal nerve were studied by the HRP and autoradiographic techniques in the rat. After an injection of [3H]amino acids into the hypothalamus and an application of HRP to the greater petrosal nerve, we found that a compact group of HRP-labeled neurons was located within a dense accumulation of silver grains in the nucleus reticularis parvocellularis. The present results show that the hypothalamus projects directly to cells of origin of the greater petrosal nerve.