Overall distribution pattern of the intramuscular nerves of the extraocular muscles and its clinical implications / Patrón de distribución general de los nervios intramusculares de los músculos extraoculares y sus implicaciones clínicas

SUMMARY: The purpose of this study was to reveal the overall distribution pattern of the intramuscular nerves of each extraocular muscle and provide morphological guidance for the selection of the neuromuscular compartment during extraocular muscle transplantation and target localization of the botulinum toxin A injection to correct strabismus. We studied 12 Chinese head specimens that were fixed with formalin. The extraocular muscles from both sides of each head were removed, and a modified Sihler's staining technique was used to reveal the overall distribution pattern of the intramuscular nerves. We observed an intramuscular nerve-dense region formed by the intramuscular arborized branches in the semitransparent superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique, inferior oblique, and levator palpebrae superioris muscles with Sihler's staining technique. The seven extraocular muscles can each be divided into two neuromuscular compartments. The intramuscular nerve-dense regions of the superior, inferior, medial, and lateral rectus and the superior oblique, inferior oblique, and levator palpebrae superioris muscles were positioned at 33.50 % -72.72 %, 40.21 % - 66.79%, 37.92 % - 64.51 %, 31.69 % - 56.01 %, 26.35 % - 64.98 %, 40.46 % - 73.20 %, and 27.72 % - 66.07 % of the lengths of the muscle bellies, respectively, and the centers of intramuscular nerve dense regions were located at 59.50 %, 54.18 %, 51.68 %, 50.08 %, 48.38 %, 56.49 %, and 50.77 % of the length of each muscle belly, respectively. The aforementioned values are the means of the actual values. These results suggest that when the strabismus is corrected with muscle transplantation, the extraocular muscle should be transplanted based on the neuromuscular compartment, which would benefit the function of both donor and recipient muscles. The localization of these nerve dense regions is recommended as an optimal target for the injection of botulinum toxin A to treat strabismus.

RESUMEN: El objetivo de este estudio fue revelar el patrón de distribución de los nervios intramusculares de cada músculo extraocular y, proporcionar una guía morfológica para la selección del compartimento neuromuscular durante el trasplante de músculo extraocular, y la localización de la inyección de toxina botulínica A para corregir el estrabismo. Estudiamos 12 muestras de cabezas de individuos chinos fijadas en formalina. Se extrajeron los músculos extraoculares de ambos lados de cada cabeza y, se utilizó una técnica de tinción de Sihler modificada para revelar el patrón de distribución general de los nervios intramusculares. Observamos una región densa en nervios intramusculares formada por los ramos intramusculares en los músculos recto superior semitransparente, recto inferior, recto medial, recto lateral, oblicuo superior, oblicuo inferior y elevador del párpado superior con técnica de tinción de Sihler. Los siete músculos extraoculares se pueden dividir cada uno en dos compartimentos neuromusculares. Las regiones intramusculares densamente nerviosas de los músculos recto superior, inferior, medial y lateral y los músculos oblicuo superior, oblicuo inferior y elevador del párpado superior se colocaron en 33,50 % -72,72 %, 40,21 % -66,79 %, 37,92 % -64,51 % , 31,69 % -56,01 %, 26,35 % -64,98 %, 40,46 % -73,20 % y 27,72 % -66,07 % de las longitudes de los vientres musculares, respectivamente, y los centros de las regiones densamente nerviosas intramusculares se ubicaron en 59,50 %, 54,18 % , 51,68 %, 50,08 %, 48,38 %, 56,49 % y 50,77 % de la longitud de cada vientre muscular, respectivamente. Los valores antes mencionados son medios de los valores reales. Estos resultados sugieren que cuando el estrabismo se corrige con trasplante de músculo, el músculo extraocular debe trasplantarse en función del compartimento neuromuscular, lo que beneficiaría la función tanto de los músculos donantes como receptores. Se recomienda la localización de estas regiones densas en nervios, como un objetivo óptimo para la inyección de toxina botulínica A para tratar el estrabismo.

Síndrome disautonómico de Ross: variaciones de un tema / Disautonomic Ross syndrome: variations about one theme

El síndrome de Ross fue descrito en 1958 como una afección degenerativa del sistema nervioso autónomo definido por la tríada de anhidrosis generalizada, disminución de los reflejos tendinosos y pupila tónica. Desde su descripción inicial se han descrito cerca de cuarenta casos. Comunicamos tres pacientes con variantes de interés que incluyen la presencia de espasmos cíclicos espontáneos del esfínter de iris, el desarrollo conjunto de síndrome de Holmes-Adie en un lado y síndrome Horner posganglionar en el otro, trastornos del desarrollo piloso en el lado de la anhidrosis, alteraciones de la motilidad intestinal, lengua sin papilas gustativas y disfunción sexual.

Ross Syndrome was described in 1958 as a degenerative condition of the autonomic nervous system defined by a triad of generalized anhidrosis, reduction of tendon reflexes and tonic pupil. Since its initial description about 40 cases have been described. We communicate three cases with variants of interest involving the presence of the simultaneous development of syndrome of Holmes-Adie on one side and Horner syndrome in the other, disorders of pilous follicle development on the side of anhidrosis, spontaneous disturbances of intestinal motility, tonque without papillae and sexual dysfunction.

Afferent projections from motoneurons innervating extraocular muscles to the cerebellum demonstrated by the retrograde double-labeling technique.

The objective of this study was to investigate the characteristics and distributions of neuronal origin of cerebellar afferents from motor cranial nerve nuclei innervating extraocular muscles by the method of retrograde transport of two fluorescence tracers in rats. Under deep anesthesia and aseptic conditions, 5 microl of 3% solution of Fluoro-Gold (FG) in phosphate buffer solution (PBS) was injected into the bellies of the six extraocular muscles to study the labeling of motoneurons innervating corresponding extraocular muscles. The cerebellum was exposed by craniotomy, and 0.3 microl of 10% solution of Dextran Tetramethyl Rhodamine Biotin (Micro Ruby: or MR) in PBS was injected into many regions of the anterior vermis (lobule I, II) and the posterior vermis (lobule VI, VII, IX, X), the flocculus, the paraflocculus and the deep cerebellar nuclei. Multiple injections were made to cover the entire cerebellum in order to obtain a near maximum labeling of cerebellar afferent neurons. In other cases, only small single or a few injections were made in specific areas of the cerebellum to study specific distributions and topographic organization. In one group of rats, injections were made both in the extraocular muscles with FG and in the cerebellum with MR to study the double labeling of neurons, which project their axons to both the extraocular muscle and the cerebellum. Another group of rats were injected in both sites with only PBS and served as the control for auto-fluorescence background. After 3 days postoperative survival time, all animals were deeply reanesthetized and perfused with heparinized normal saline solution, followed by 4% paraformaldehyde in 0.1 M phosphate buffer, pH 7.4, and 30% sucrose solution in PBS. The brainstem and the cerebellum were removed immediately, and stored in sucrose solution in PBS at 4 degrees C. Serial transverse sections of the brainstem and sagittal sections of the cerebellum were obtained by a freezing microtome at 40 microm thickness, collected on uncoated glass slides, and immediately dried. All sections were examined under an epifluorescence or confocal microscope equipped with filter systems for FG and MR. The presence of both single and double retrograde labeled neurons in the Oculomotor (CN 3), Trochlear (CN 4) and Abducens (CN 6) nuclei was recorded, photographed, stored as computer images files and printed out as hard copies. The labeling neurons in the vicinity of the CN 3, 4, 6 from all sections were plotted onto diagrams and counted Neurons labeled only with MR retrogradely transported from injection sites in the cerebellum were found bilaterally and scattered throughout in the Oculomotor, Trochlear and Abducens nuclei. These neurons labeled only with MR were small and medium-sized interneurons and represented only a small proportion of the entire population. Neurons labeled only with FG retrogradely transported from injection sites in the extraocular muscles were the most numerous, and distributed almost throughout the entire population of small, medium-sized and large motoneurons, which innervate the extraocular muscles. A smaller proportion of small and medium-sized FG labeled neurons within these nuclei were also double labeled with MR, indicating that they project their axon collaterals to both extraocular muscles and the cerebellum. In conclusion, the present findings provide clear anatomical evidence that a small population of motoneurons in the Oculomotor, Trochlear and Abducens nuclei of the rat project their axon collaterals directly to the cerebellum and the extraocular muscle, in addition to the cerebellar afferents from other interneurons within these nuclei. The findings also indicate that cerebellar neuronal circuits play more direct roles in monitoring and controlling eye movements than previously known.

Avaliação por imagem das lesões isoladas do III par craniano / Imaging assessment of isolated lesions affecting cranial nerve III

Este trabalho tem por objetivo fazer uma revisão da anatomia e das principais doenças do III par craniano, demonstrando-as através de estudos por imagem, com ênfase em ressonância magnética. Os métodos de imagem são peça fundamental na avaliação de pacientes com suspeita de lesão do nervo oculomotor, uma vez que o quadro clínico é freqüentemente inespecífico e a gama de doenças que podem acometê-lo é bastante ampla. Realizamos também breve levantamento da literatura.

Estudo micro-mesoscópico da parede lateral do seio cavernoso humano / Micro-mesoscopic study of the lateral wall of the human cavernous sinus

Os autores estudam as estruturas contidas no seio cavernoso humano, tanto em seu interior como na sua parede lateral, através de cortes frontais seriados espessos. Mostram a importância desta parede que é frequentemente usada como via de acesso cirúrgico às afecçoes presentes nesta estrutura venosa da dura-máter.

Relación anatómica de la arteria cerebelar superior con los nervios oculomotor y troclear considerando el grupo étnico e índice cefálico / Anatomical relation of the superior cerebellar artery with oculomotor and trochlear nerves considering ethnic group and cephalic index

Las características anatómicas de la arteria cerebelar superior (ACS) han sido objeto de numerosos estudios. Sin embargo, aún existe poca información cualitativa y cuantitativa acerca de la relación anatómica entre los nervios craneales y arterias cerebelares, de utilidad práctica para el especialista. La compresión vascular que puede originar la ACS en su relación con el nervio oculomotor (NOM) y con el nervio troclear (NETRO), causaría alteraciones visuales y neurológicas que pueden conducir a tratamiento quirúrgico. Por ello, el objetivo de nuestro estudio es analizar y complementar estas relaciones anatómicas considerando el grupo étnico e índice cefálico-horizontal. La investigación se basó en la observación de 70 encéfalos de individuos brasileños, adultos, de ambos sexos, provenientes del Servicio de verificación de óbitos de la Escola Paulista de Medicina, Sao Paulo, Brasil. SE efectuó un registro antropológico de cada individuo, considerando el grupo étnico (GE)(blancos o caucásicos y no-blancos o mestizos) y mediciones cefálicas según normas. Los encéfalos fueron retirados, inyectados con látex neopreno y fijados, de acuerdo a técnicas específicas. Nuestras observaciones muestran que la ACS contacta con el NOM, en el lado derecho en el 77,8 por ciento en el grupo blanco y en el 16,0 por ciento en los no-blancos; en el 73,7 por ciento en los dólico-mesocefálos (DM) y en el 90,6 por ciento en los braqui-hiperbraquicéfalos (BH). En su relación con el NETRO, la ACS contacta con este nervio, en el lado derecho en el 48,9 por ciento en el grupo blanco, y en el 32,0 por ciento en el no-blancos, en el 44,7 por ciento en los DM y en el 39,7 por ciento en los BH

Núcleo e Sub-Núcleos do Nervo Oculomotor / Necleus and Sub-nuclei of the Oculomotor Nerve

Os autores descrevem a organizaçäo anatômica e funcional dos sub-núcleos do nervo oculomotor e propöem um novo esquema para sua representaçäo, baseado em estudos auto-radiográficos recentes.

Sintopia do nervo oculomotor com os demais nervos crânicos na fissura orbitária superior / Syntopsy of the oculomotor nerve with the other cranial nerves in superior orbital fissure

Estudou-se a sintopia e a bifurcaçäo do nervo oculomotor ao cruzar a fissura orbitária superior, em 30 hemicabeças de indivíduos adultos e masculinos, dissecadas ao estereomicroscópio. A sintopia e as características do nervo ao cruzar a fissura orbitária superior foram analisadas e discutidas frente à literatura. Em 15 casos (50%), o nervo oculomotor apresenta-se como tronco único, e em outros 15 casos (50%), bifurcado a esse nível. Foram estudadas suas relaçöes com os nervos troclear, abducente, nosociliar, frontal e lacrimal, bem como os casos de ausência de sintopia dele em algum dos lados