Takemoto Shin

Arrangement of Motoneurons Innervating the Intrinsic Laryn-Geal Muscles of Cats as Demonstrated by Horseradish Peroxidas

After HRp injection into the posterior cricoarytenoid (PCA), the thyroarytenoid (TA), the lateral cricoarytenoid (LCA) and the interarytenoid (IA) muscles, labeled neurons were identified in the nucleus ambiguus ipsilaterally. The motoneurons for the cricothyroid muscle (CT) were found ipsilaterally in the retrofacial and ambiguus nuclei. The labeled cell columns of PCA, TA, LCA and IA were situated more caudal than that of CT in the order of PCA, TA, LCA and IA. In the nuc. ambiguus, the motoneurons of CT showed compact form and were located in the ventral part, those of PCA were aggregated and occupied the middle part, those of TA were scattered and were seen in the dorsal part, and those of LCA and IA were sparse and were recognized widely in the nucleus.

Localization of efferent neurons innervating the pharyngeal constrictor muscles and the cervical esophagus muscle in the cat by means of the horseradish peroxidase method

Following horseradish peroxidase (HRP) injection into the cephalopharyngeal muscle (CeP), the hyopharyngeal muscle (HP), the thyropharyngeal muscle (TP), the cricopharyngeal muscle (CP) and the cervical esophagus muscle (CE) of the cat, labeled neurons were identified in the nucleus retrofacialis and the rostral part of the nucleus ambiguus ipsilaterally. The rostral end of the labeled cell column was located more rostrally for CeP and HP than for TP, CP and CE. No difference was noted within the former two or within the latter three. The level of the caudal end of the labeled cell column became more caudal in the order of CeP, HP, TP and CP. The caudal end was located more rostral for CE than for TP. The neurons for CE were located more ventro-laterally than those for the other muscles.

LXIX Electromyographic Investigation of the Intrinsic Laryngeal Muscles Related to Speech Sounds

Electromyography is one of the most helpful experimental procedures in the field of physiology of the larynx and provides direct information about activity of the laryngeal muscles. Many electromyographic investigations of the intrinsic laryngeal muscles have been made since Weddell et alP first recorded electrical action potentials of these muscles. In almost all of these studies, a needle electrode was inserted into the intrinsic laryngeal muscles through the mouth except in the cricothyroid muscle in which an electrode was always placed through the skin. When the subject has a needle and wire in his mouth and throat, it is extremely difficult or impossible to utter speech sounds normally. In the past, therefore, electromyographic investigations related to phonation, except of the cricothyroid muscle, were limited to only some vowels.

Voice tremor: Dysregulation of voluntary expiratory muscles

We studied three patients; two with voice and hand tremor, and one with voice tremor. Voice tremor was associated with synchronous rhythmic contraction of cricothyroid and rectus abdominis muscles, but not always vocalis muscle. Voice tremor was manifested only in voluntary phonation or expiration, not in involuntary phonation, voluntary inspiration, or involuntary expiration and inspiration (breathing at rest). Impaired regulation of the CNS programs innervating the voluntary expiratory muscles probably causes voice tremor. Clonazepam and propranolol were helpful in blinded studies.

Topographic Arrangement of Motoneurons Innervating the Suprahyoid and Infrahyoid Muscles: A Horseradish Peroxidase Study in Cats

The topographic arrangement of motoneurons innervating the muscles which participate in the rostrocaudal movement of the larynx was studied in cats by means of the horseradish peroxidase (HRP) method. After HRP injection into these muscles, all labeled neurons were found in the nuclei of the brainstem and cervical nerves (C1, C2) ipsilaterally. The mylohyoid and anterior digastric motoneurons were seen in a cluster in the medial part of the rostrocaudal area of the motor trigeminal nucleus. Within the medial part of the nucleus, the mylohyoid motoneurons were located ventrally and the anterior digastric motoneurons dorsally. The posterior digastric neurons were situated in the accessory facial nucleus, the stylohyoid neurons in the ventral aspect of the facial nucleus, the geniohyoid motoneurons in the ventral aspect of the hypoglossal nucleus, and the thyrohyoid motoneurons in the lateral aspect of the hypoglossal nucleus and the dorsomedial part of the ventral horn cells of C1. The HRP-labeled neurons of the sternohyoid and sternothyroid muscles were observed in the central portion of the ventral horn cells of C1 and C2.

Detection of Largyneal Sensory-Evoked Potentials (LSEPs) in the Cat

We previously reported on evoked potentials elicited by electrical stimulation of the superior laryngeal nerve at an appropriate site on the dural surface as a reflection of activities in the brain stem and cortex in anesthetized cats. This evoked potential was called the laryngeal sensory evoked potential (LSEP). In this study we attempted to establish a less invasive procedure for measuring LSEP. The procedures were recording on the scalp using chloride-coated silver disk electrodes and stimulation by insertion of a bipolar platinum hooked wire electrode into the laryngeal mucosa. Evoked potentials could be detected using these less invasive procedures. The response morphologies and relative timing of LSEP components were quite similar for each method in a given cat. However, the amplitudes were slightly lower and the latencies were slightly prolonged with the less invasive techniques. These results suggest that this LSEP method might be applicable to human beings as a noninvasive method for evaluating the function of the laryngeal sensory pathway

Treatment of frontal sinus cyst with a T-shaped bile duct tube.

The major aspect of the surgical treatment of frontal sinus cyst (pyoccle and/or mucocele) is widening of the obstructed naso-frontal duct to allow drainage of the cyst. We usually take an extranasal approach to the frontal sinus (after Oginos method) and put a silicon tube into the naso-frontal duct to drain it and to prevent re-obstruction of the duct.In our department during the past three years and eight months, 16 patients with frontal cyst were treated surgically. The first nine cases were treated by insertion of a simple tube and the next seven cases by insertion of a T-shaped tube.Simple tubes often slip out spontaneously before inner epithelization of the nasofrontal duct has taken place. Our T-shaped tube is adapted from the silicon drainage tube used for bile duct surgery. It is firmly placed in the naso-frontal duct, and is easily removed without complications.

Autonomic function test (Measurement of coefficient of variation of R-R intervals in ECGs) in patients with abnormal sensation in the pharyngolaryngeal region.

In 58 patients with abnormal sensation of the pharyngolaryngeal region autonomic function was tested with AUTONOMIC (NEC Co.).At rest, the coefficient of variation (CV) was normal in 34 patients (59%), below normal in 15 patients (26%) and above normal in nine patients (15%). After five deep respirations the CV increased significantly in 11 patients and decreased significantly in five patients. These results suggest that there are various abnormalities in patients with abnormal sensation in the pharyngolaryngeal region.

Mechanisms of normal and disturbed swallowing.

This paper is a discussion of the mechanisms of normal and disturbed swallowing based on studies undertaken by the author and on a review of the literature. The morphology of the peripheral receptor involved in deglutition was studied by electron microscope, and it was observed that the endings of the sensory nerves distributed in the laryngeal mucosa have no myelin sheath and are composed of nonmedullated nerve fibers. The afferent impulse in the deglutitive reflex is conveyed to multiple synapses via the solitary nucleus, and is then conveyed to the medullary reticular formation. The efferent impulse from the central nervous system activates the internal laryngeal muscles, the infra- and supra- hyoid muscles and the pharyngeal constrictor muscles according to predetermined programming. Case studies are presented of patients suffering from swallowing disturbances associated with the Wallenberg syndrome, the Ramsay-Hunt syndrome, neural sarcoidosis, the Meige syndrome, etc.