Seiji Kawakita

Effect of sinus surgery on visual disturbance caused by spheno-ethmoid mucoceles

Fifteen patients suffering from visual disturbance of varying degrees caused by a mucocele of the posterior ethmoid and/or sphenoid sinuses underwent marsupialization of a mucocele into the nasal cavity. Five of the eight patients with severe visual loss worse than 20/200 showed recovery of measurable vision. Two of these five were operated on within 24 hours after the onset of visual loss and showed marked recovery to 20/25 and 20/15. The other seven patients who had relatively mild visual disturbance experienced improvement of visual acuity or remission of subjective complaints such as blurred vision postoperatively. During operation partial bony defect was found in the optic canal in 12 patients and in the skull base in 12 patients. A good understanding of this disease by ophthalmologists and otolaryngologists is essential for early diagnosis and prompt surgical treatment to avoid permanent visual dysfunction and operative sequelae.

Histochemical Study of the Canine Inferior Pharyngeal Constrictor Muscle: Implications for its Function

The inferior pharyngeal constrictor muscle (IPC), which consists of the thyropharyngeal (TP) and cricopharyngeal (CP) muscles. plays an important role during deglutition. The histochemical properties of the canine IPC muscle were investigated. The motor endplates of the TP muscle clustered at the midlength of the muscle, while those of the CP muscle were scattered diffusely. The glycogen depletion technique suggested that most of the CP muscle fibers terminated into the belly of the muscle and fiber lengths varied. With ATPase stain, type II fibers were shown to be predominant in the TP muscle, while type I fibers were predominant in the CP muscle. The diameter of the TP muscle fibers was significantly larger than that of the CP muscle. Although the histochemical characteristics of these two muscles were markedly different, they gradually changed, resulting in their coordinated physiological movements.

Scanning Electron Microscopic Study of the Neuromuscular Junctions of the Cricothyroid and Thyroarytenoid Muscles in Rats

Neuromuscular junctions were observed in the cricothyroid (CT) and thyroarytenoid (TA) muscles of adult rats by scanning electron microscopy after removing the intramuscular connective tissue components using the HCI hydrolysis method. Morphologically, the junctions were classified into three types in the CT muscle and two types in the TA muscle, based on the structural characteristics of the subneural apparatuses, including junctional folds. In the CT muscle, type 1 junctions (32%) consisted of more than 15 cup-like depressions with slit-like junctional folds. Type 2 junctions (20%) were characterized by approximately 10 cup-like depressions with a small number of pit- or slit-like junctional folds. Type 3 junctions (48%) had irregular labyrinthine gutters with slit-like junctional folds. In the TA muscle, type 1 (82%) and 2 (18%) junctions had similar structures to type 1 and 2 junctions in the CT muscle, respectively. Histochemical studies using myosin adenosine triphosphatase staining showed that both CT and TA muscles predominantly consisted of type II muscle fibers (78% and 82%, respectively), and that the diameter of type II fibers was larger than that of type I fibers. These findings suggest that the type 2 junction belongs to type I muscle fibers, while both type 1 and type 3 junctions belong to type II fibers, and that the type 3 junction is a structural variation of the type 1 junction. The significance of the structural differences of the subneural apparatuses in the intrinsic laryngeal muscles is discussed briefly.Neuromuscular junctions were observed in the cricothyroid (CT) and thyroarytenoid (TA) muscles of adult rats by scanning electron microscopy after removing the intramuscular connective tissue components using the HCl hydrolysis method. Morphologically, the junctions were classified into three types in the CT muscle and two types in the TA muscle, based on the structural characteristics of the subneural apparatuses, including junctional folds. In the CT muscle, type 1 junctions (32%) consisted of more than 15 cup-like depressions with slit-like junctional folds. Type 2 junctions (20%) were characterized by approximately 10 cup-like depressions with a small number of pit- or slit-like junctional folds. Type 3 junctions (48%) had irregular labyrinthine gutters with slit-like junctional folds. In the TA muscle, type 1 (82%) and 2 (18%) junctions had similar structures to type 1 and 2 junctions in the CT muscle, respectively. Histochemical studies using myosin adenosine triphosphatase staining showed that both CT and TA muscles predominantly consisted of type II muscle fibers (78% and 82%, respectively), and that the diameter of type II fibers was larger than that of type I fibers. These findings suggest that the type 2 junction belongs to type I muscle fibers, while both type 1 and type 3 junctions belong to type II fibers, and that the type 3 junction is a structural variation of the type 1 junction. The significance of the structural differences of the subneural apparatuses in the intrinsic laryngeal muscles is discussed briefly.

Scanning electron microscopic study of the muscle fiber ends at the myotendinous junction in the posterior cricoarytenoid and cricothyroid muscles in rats.

The fine structural organization of muscle fiber ends at the myotendinous junction in the posterior cricoarytenoid (PCA) and cricothyroid (CT) muscles in adult rats was studied by scanning electron microscopy, after removal of tendon connective tissues using the HCI-hydrolysis method. The muscle fiber ends in the PCA muscle had a relatively simple conical appearance and contained a great number of longitudinal slits on the surface. In the CT muscle, the muscle fiber ends were classified into two types. One type had a conical appearance similar to the PCA muscle with many slits on the surface, while the other type was characterized by a complex arrangement of cylindrical cytoplasmic processes and deep clefts, as seen in common skeletal muscles. These findings suggest that the PCA muscle is evolutionarily primitive, and that the CT muscles represent a transitional form between primitive and evolved muscles.The fine structural organization of muscle fiber ends at the myotendinous junction in the posterior cricoarytenoid (PCA) and cricothyroid (CT) muscles in adult rats was studied by scanning electron microscopy, after removal of tendon connective tissues using the HCl-hydrolysis method. The muscle fiber ends in the PCA muscle had a relatively simple conical appearance and contained a great number of longitudinal slits on the surface. In the CT muscle, the muscle fiber ends were classified into two types. One type had a conical appearance similar to the PCA muscle with many slits on the surface, while the other type was characterized by a complex arrangement of cylindrical cytoplasmic processes and deep clefts, as seen in common skeletal muscles. These findings suggest that the PCA muscle is evolutionarily primitive, and that the CT muscles represent a transitional form between primitive and evolved muscles.

Motor Innervation of the Guinea Pig Interarytenoid Muscle: Reinnervation Process Following Unilateral Denervation

The authors investigated the process of denervation and reinnervation of the interarytenoid (IA) muscle in the guinea pig using transmission electron microscopy and glycogen depletion technique after unilateral transection of the recurrent laryngeal nerve (RLN) and superior laryngeal nerve to clarify the innervation pattern of the unpaired IA muscle. Anastomosis between the bilateral arytenoid branches was confirmed in the belly of the IA muscle. Five weeks after transection, all of the IA muscle fibers appeared to have been reinnervated by the contralateral RLN. As the arytenoid branch of the RLN runs together with that of the contralateral RLN in a single intramuscular nerve funiculus, it is possible that collateral sprouting branches grow and extend into the adjacent denervated Schwanns sheaths. The authors conclude that the unpaired IA muscle, as a whole, receives specific motor nerve supply from the bilateral RLNs, although each muscle fiber is innervated unilaterally.

Postnatal changes in the types of muscle fibre in the canine inferior pharyngeal constrictor

Deglutition is considered to be immature in infants and to mature postnatally. We evaluated postnatal changes in muscle fibre type composition in the canine inferior pharyngeal constrictor muscle, which consists of the thyropharyngeal (TP) and cricopharyngeal (CP) muscles, using ATPase staining with respect to the maturation of deglutition. In the TP muscle type IIA and type IIB fibres, the main components in the adult, were already predominant at 1 week postnatally. The percentage of primitive type IIC fibre showed a rapid reduction and reached the adult level within 6 weeks. In the CP muscle, the majority of fibres were type IIC at 2 weeks. At 2 months, more than 20% of the fibres were still type IIC and the proportion of type I fibres as a main component in the adult was smaller than that of the adult. None of the puppies younger than 9 weeks old had a fibre type composition similar to that of the adult. In the extensor digitorum longus and flexor digitorum superficialis, the compositions of muscle fibre types became similar to that of the adult at 6 and 9 weeks of age, respectively. Thus, the TP muscle matured more rapidly than the limb muscles, while the CP muscle matured more slowly. We speculated that the TP and CP muscles have specific individual differentiation patterns associated with their functional roles before and after birth, compared with the limb muscles.

Ganglion cells in the posterior cricoarytenoid muscle of the rat following experimental denervation.

Objective —To investigate morphological changes of the i.m. ganglion cells in the posterior cricoarytenoid (PCA) muscle of the rat following denervation of the recurrent laryngeal nerve. Material and Methods —The recurrent laryngeal nerve on the left side of the rat was resected. Three weeks after transection, the PCA muscle was removed for morphological study using light and electron microscopy. Results —No morphological changes were found in the i.m. ganglion cells in the PCA muscle, even though the myelinated nerve fibers were destroyed and had disappeared in ramified i.m. bundles. Around the cell body, numerous non-myelinated nerve fibers were found; these contained a large number of clear, spherical synaptic vesicles ≈50 nm in diameter and several dense-cored vesicles ≈100 nm in diameter. In contrast, neuromuscular junctions in most muscle fibers with partially disoriented and/or disintegrated myofibrils showed degenerative figures. In some instances, however, multiple nerve terminals were detected in contact with the postsynaptic membrane. Like the varicose swellings of non-myelinated nerve fibers around the ganglion cell body, these nerve terminals contained, in addition to clear synaptic vesicles (50 nm in diameter), several dense-cored vesicles (100 nm in diameter). Conclusion —We suggest that i.m. ganglion cells in the rat PCA muscle may supply postganglionic nerve fibers to the denervated neuromuscular junctions after transection of the nerve.

Motor Innervation of the Arytenoid Muscle Viewed from

Seij i Kawakita ), Ryuichi Aibara 2 ), Masamitsu Hyodo ), Yuji Kawamura 3) and Eiji Yumoto 1) Using 38 guinea pigs with unpaired arytenoid muscle (AR) , the innervation pattern of the AR was studied viewed from reinnervation process following unilateral (left) recurrent laryngeal nerve (RLN) transection. Light and electron microscopic observation, glycogen depletion experiment, and histochemical study using the adenosine triphosphatase (ATPase) stain were carried out. Seven days after transection, both myelinated and unmyelinated fibers were noted in the intramuscular nerve funiculus. Thus, the anastomosis of the arytenoid branches between both RLNs was found in the belly of AR. Three types of the neuromuscular junctions (NMJs) were observed; normal, degenerated, and regenerated NMJs. Five weeks after transection, however, neither degeneration nor regeneration of the NMJ were seen. Until three weeks after transection, half of the AR fibers were stained with PAS staining following electrical stimulation of the contra lateral (right) RLN. Five weeks after transection, all the AR fibers were unstained. Therefore, all the AR fibers were considered to have been reinnervated by the contra lateral RLN. ATP stain of the AR showed that type 2 fibers were predominant regardless of the period following unilateral denervation. The present study indicates that transection of the unilateral RLN facilitates collateral sprouting from the contra lateral RLN, and that these collateral sprouting reinnervated the denervated muscle fibers before degeneration occurs. Therefore the AR, as a whole, receives a specific motor innervation from the bilateral RLNs, although each muscle fiber is innervated by the unilateral RLN.

Motor innervation of the arytenoid muscle in Guinea Pig

tetrasodium salt, nitroblue tetrazolium in phosphate-buffered saline. Before this reaction, some sections were provided for immunohistochemistry with use of anti-VIP or CGRP sera. A small number of NADPH-d nerve fibers could be detected in the epithelium. Most of these fibers with varicosities reached the surface of the epithelium and appeared to be free-ended. The NADPH-d nerve fibers associated with blood vessels were found in the lamina propria, submucosa, and inferior costrictor muscle. The distribution of NADPH-d nerve fibers in the submucosal gland region was different from that in the region of the hypopharynx. The submucosal glands at the level of the thyropharyngeal muscle were richly supplied with NADPH-d nerve fibers. On the contrary, the submucosal glands at the level of the cricopharyngeal muscle (CPM) were poorly supplied with NADPH-d nerve fibers. In the inferior costrictor muscle the quantity of NADPH-d nerve fibers were more abundant in the CPM than in the thyropharyngeal muscle. A cluster of cells, presumably parasympathetic ganglia, were found in the submucosa and muscle layer of the CPM. Most of these cells were NADPH-d positive. VIP and CGRP were co-localized with some of the NADPH-d fibers. VIP was more frequently co-localized with NADPH-d than CGRP. In the ganglia, most of the cells were co-localized with VIP and no cells were co-localized with CGRP. The present findings indicate that NO is involved in the regulation of blood supply and glandular secretion in the canine hypopharynx in coordination with intrinsic VIP or extrinsic CGRP.

Bilateral Gradenigo's Syndrome; A Case Report.

Gradenigos syndrome was diagnosed in a 5-year-old male with bilateral acute otitis media, paralysis of both abducens nerves and bilateral irritation of the trigeminal nerves. After myringotomy and administration of antibiotics, his tympanic membrance became normal, and the bilateral trigeminal nerve irritation disappeared, but residual mastoiditis was revealed by X-ray examination. Right extended mastoidectomy was performed including removal of the bony sinus plate on Mar. 2, 1990. Although bilateral abducens palsy improved immediately, serological findings and double vision deteriorated again 10 days after the operation. Reexploration was done on Mar. 16, 1990. Residual inflammatory changes in the petrous apex were eradicated, especially around the lateral sinus and anterior to the superior semicircular canal through the petrous apex. An extradural abscess was found at the petrous apex. The left trigeminal nerve irritation and the left abducens paralysis was attributed to the right petrositis because bilateral abducens nerve function recovered completely after the second operation on the right temporal bone. Since extradural abscess at the petrous apex is difficult to diagnose preoperatively and has been reported in many patients with Gradenigos syndrome, it must be kept in mind in the diagnosis and the treatment of Gradenigos syndrome. Twelve cases of Gradenigos syndrome reported in Japan from 1960 to 1992 were reviewed. Acute otitis media was the cause in five, all children. In three of them abducens paralysis appeared within one week after onset of the acute otitis media. Mortality of Gradenigos syndrome is still 10%, similar to that of brain abscess associated with otitis media.