Localisation of the centre of the highest region of muscle spindle abundance of anterior forearm muscles.

The centre of the highest region of muscle spindle abundance (CHRMSA) in the intramuscular nerve-dense region has been suggested as the optimal target location for injecting botulinum toxin A to block muscle spasms. The anterior forearm muscles have a high incidence of spasticity. However, the CHRMSA in the intramuscular nerve-dense region of the forearm anterior muscle group has not been defined. This study aimed to accurately define the body surface position and the depth of CHRMSA in an intramuscular nerve-dense region of the anterior forearm muscles. Twenty-four adult cadavers (57.7 ± 11.5 years) were included in this study. The curved line close to the skin connecting the medial and lateral epicondyles of the humerus was designated as the horizontal reference line (H line), and the line connecting the medial epicondyle of the humerus and the ulnar styloid was defined as the longitudinal reference line (L line). Modified Sihler's staining, haematoxylin-eosin staining and computed tomography scanning were employed to determine the projection points (P and P') of the CHRMSAs on the anterior and posterior surfaces of the forearm. The positions (PH and PL) of point P projected onto the H and L lines, and the depth of each CHRMSA, were determined using the Syngo system. The PH of the CHRMSA of the ulnar head of pronator teres, humeral head of pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, ulnar part of flexor digitorum superficialis, radial part of flexor digitorum superficialis, flexor pollicis longus, ulnar part of flexor digitorum profundus, radial portion of flexor digitorum profundus and pronator quadratus muscles were located at 42.48%, 45.52%, 41.20%, 19.70%, 7.77%, 25.65%, 47.42%, 53.47%, 12.28%, 38.41% and 51.68% of the H line, respectively; the PL were located at 18.38%, 12.54%, 28.83%, 13.43%, 17.65%, 32.76%, 57.32%, 64.12%, 20.05%, 45.94% and 88.71% of the L line, respectively; the puncture depths were located at 21.92%, 27.25%, 23.76%, 18.04%, 15.49%, 31.36%, 26.59%, 41.28%, 38.72%, 45.14% and 53.58% of the PP' line, respectively. The percentage values are the means of individual values. We recommend that the body surface puncture position and depth of the CHRMSA are the preferred locations for the intramuscular injection of botulinum toxin A to block anterior forearm muscle spasms.

Localization of nerve entry points and the center of intramuscular nerve-dense regions in the adult pectoralis major and pectoralis minor and its significance in blocking muscle spasticity.

The aims of this study were to localize the body surface position and depth of nerve entry points, and the center of the intramuscular nerve-dense regions of the pectoralis major and pectoralis minor in order to provide guidance for blocking muscle spasticity. Formalin-fixed adult cadavers (66.3 ± 5.2 years) were used. The curved line on the skin from the acromion to the most inferior point of the jugular notch was defined as the horizontal reference line (H). The line from the most inferior point of the jugular notch to the xiphisternal joint was defined as the longitudinal reference line (L). The nerve entry points was anatomically exposed. Sihler's staining, barium sulfate labeling, and computed tomography were employed to determine the projection points (P) on the body surface. The intersection of the longitudinal line through the P point and the H line and the horizontal line through the P point and the L line were recorded as PH and PL , respectively. The projection of the nerve entry points or the center of the intramuscular nerve-dense regions were in the opposite direction across the transverse plane and were recorded as P'. The percentage positions of PH and PL on the H and L lines, as well as the nerve entry points and the center of the intramuscular nerve-dense regions depths, were determined using the Syngo system. The pectoralis major had two nerve entry points, while the pectoralis minor had only one. In addition, two intramuscular nerve-dense regions were found in the pectoralis major, while only one region was found in the pectoralis minor. The PH of the nerve entry points were located at 47.83%, 32.31%, and 34.31%, while the PH of the center of the intramuscular nerve-dense regions were at 41.95%, 55.88%, and 32.58% of line H, respectively. The PL of the nerve entry points were at -9.84%, 36.16%, and 2.44%, while the PL for each of three center of the intramuscular nerve-dense regions was at -3.87%, 25.29%, and -7.13% of line L, respectively. The depth for each of the nerve entry points was at 17.76%, 17.53%, and 25.51% of line P-P'', respectively, and the depth of the center of the intramuscular nerve-dense regions was at 5.23%, 6.75%, and 13.73% of line P-P', respectively. These percentage values are all means. The definition of the surface position and depth of these nerve entry points and center of the intramuscular nerve-dense regions can improve the localization efficiency and efficacy of target blocking for pectoralis major and minor spasticity.

Intramuscular innervation of the lateral rectus muscle evaluated using sihler's staining technique: Potential application to strabismus surgery.

The latest research suggests that the abducens nerve may be divided into subbranches that reach functionally distinct zones of the lateral rectus muscle. The goal of the study was to examine this muscle's innervation, including the detailed distribution of the intramuscular subbranches of the abducens nerve. Twenty-five lateral rectus muscle specimens were harvested (with the orbital segment of the abducens nerve), fixed in 10% formalin solution, and stained with Sihler's whole mount nerve staining technique. Subbranches running to the lateral rectus divided into two main groups: superior and inferior. Both groups of subbranches are distributed in a fan-shaped manner, show a characteristic "tree-like" branching pattern and form terminal plexus near the proximal half of the lateral rectus muscle. However, some smaller subbranches run as far as the muscle's insertion, and recurrent subbranches also reach its origin. With respect to their course to the muscle's origin or insertion, the smallest subbranches running within the muscle may be associated with innervation of the tendon. In the majority of cases (88%), superior and inferior subbranches of the abducens nerve overlapped in the central one-third of the lateral rectus muscle's width so that any clearly distinct anatomical segments of the muscle could be observed based on Sihler's technique. In the remaining 12% of specimens, superior and inferior groups of subbranches innervated two distinct compartments of the lateral rectus muscle with no overlapping. Dense, fan-shaped distribution of abducens nerve intramuscular subbranches can be observed within the lateral rectus muscle. Clin. Anat. 33:585-591, 2020. © 2019 Wiley Periodicals, Inc.

Division of neuromuscular compartments and localization of the center of the intramuscular nerve-dense region in pelvic wall muscles based on Sihler's staining.

The innervation of the pelvic wall muscles is not very clear. This study aimed to reveal the division of neuromuscular compartments and localize the surface position and depth of the center of the intramuscular nerve-dense region (CINDR) of the pelvic wall muscles based on Sihler's staining. Twenty-four adult cadavers were used. To localize the CINDR of the pelvic wall muscles, horizontal (H) and longitudinal (L) reference lines were drawn, and Sihler's staining was used to reveal the intramuscular nerve distribution. The CINDR projection points (P and P' points) behind and in front of the body surface, the positions of the P points projected onto the H and L lines (PH and PL points), and the depth of CINDR were determined by spiral computed tomography scanning. The piriformis and obturator internus muscles can be divided into two and three neuromuscular compartments, respectively. The PH of CINDR of the piriformis muscle was located at 22.61 ± 2.66% of the H line, the PL was at 28.53 ± 6.08% of the L line, and the puncture depth of the piriformis muscle was at 24.64 ± 2.16% of the PP' line. The PH of CINDR of the obturator internus muscle was at 16.49 ± 1.20% of the H line, the PL was at 10.94 ± 1.09% of its L line, and the puncture depth was 6.26 ± 0.38 cm. These findings may guide the design of the compartmentalized transplantation of the pelvic wall muscles and improve the target localization efficiency and efficacy for injecting botulinum toxin A to treat pelvic wall muscle spasm.

Multiple nerve cords connect the arms of octopuses, providing alternative paths for inter-arm signaling.

Octopuses are remarkable in their ability to use many arms together during behavior (e.g., see Levy et al., 1 Mather,2 Byrne et al.,3 and Hanlon et al.4). Arm responses and multi-arm coordination can occur without engagement of major brain regions,5 which indicates the importance of local proprioceptive responses and peripheral connections. Here, we examine the intramuscular nerve cords (INCs),6,7,8,9 the key proprioceptive anatomy in the arms. INCs are understood to include proprioceptive neurons, multipolar neurons, and motoneurons (reviewed by Graziadei10) and are thought to contribute to structuring whole-arm movement.11 There are four INCs running the full length of each arm (e.g., see Guérin-Ganivet,6 Martoja and May,8 and Graziadei9); we focused on the pair closest to the suckers, called the oral INCs. In tracking the oral INCs, we found that they extend proximally and continue beyond the arm, through the arm's base. Each oral INC bypasses two adjacent arms and is continuous with the nearer oral INC of the third arm over. As a result, an arm connects through oral INC pathways to arms that are two arms away to the right and left of it. In addition to connecting distant arms, nerve fibers project from the central region of the INCs, suggesting function in local tissues. The other two INCs, paired aboral INCs, also extend proximally beyond the arm's base with trajectories suggestive of the oral INC pattern. These data identify previously unknown regions of the INCs that link distant arms, creating anatomical connections. They suggest potential INC proprioceptive function in extra-arm tissues and contribute to an understanding of embodied organization for octopus behavioral control.12,13,14,15.

Localization of the Center of the Intramuscular Nerve Dense Region of the Suboccipital Muscles: An Anatomical Study.

Purpose: This study aimed to determine the body surface puncture position and depth of the center of the intramuscular nerve dense region in the suboccipital muscle to provide morphological guidance for accurate botulinum toxin A injection to treat headaches caused by increased suboccipital muscle tension. Methods: Twenty-four cadavers aged 66.5 ± 5.3 years were studied. The curve line connecting occipital eminence or mastoid process and spinous process of the 7th cervical vertebrae was considered the longitudinal reference line (L) and horizontal reference line (H), respectively. Sihler's staining, barium sulfate labeling, and CT were employed. The body surface projection point of the center of the intramuscular nerve dense region was designated as P. The projection of the center of the intramuscular nerve dense region was in the opposite direction across the transverse plane and was recorded as P'. The intersections of the vertical line through point P and lines L and H were designated as PL and PH. The percentage position of the PH and PL points on the H and L lines and the depths of the center of intramuscular nerve dense regions were identified. Results: Sihler's staining showed one intramuscular nerve-dense region in each suboccipital muscle. The PH of the center of the intramuscular nerve dense region was located at 51.40, 45.55, 20.55, and 43.50%. The PL was located at 31.38, 30.08, 16.91, and 52.94%. The depth of the center of the intramuscular nerve dense region was at 22.26, 22.54, 13.14, and 27.30%. These percentage values are all the means. Conclusion: Accurately defining the body surface position and depth of the center of intramuscular nerve dense region in suboccipital muscles will help to improve botulinum toxin A to target localization efficiency for treating tension-type headache.

Morphologic classification and innervation patterns of the pectineus muscle.

The purpose of this study was to identify the frequency of pectineal hiatus and of pectineus innervations, including femoral, obturator, and/or accessory obturator nerves. Also, this study sought to detailed intramuscular nervous distributions, with a particular focus on the relationship of nerves in multi-innervated pectineus. One hundred (49 right and 51 left) thighs from 52 cadavers (25 men and 27 women) were dissected. The morphology and innervations of the pectineus were investigated. Modified Sihler's whole-mount nerve-staining method was employed for visualization of the intramuscular nerve-distribution patterns of the pectineus. Variation of the pectineus forming a hiatus was identified in 18% of the specimens. The femoral innervations to the pectineus were identified in all specimens. Additional innervation either by the obturator or the accessory obturator branch to the pectineus was identified in 10% or 2% of specimens, respectively. No case of triple innervation to the pectineus was observed. In cases of dually innervated pectineus, two nerves formed a communication system inside the muscle. Among the three nerves supplying the pectineus, the femoral nerve branched more than the other two nerves and covered the greatest area in the muscle. The pectineal hiatus appears to be a common variation. The femoral nerve branch in a dually innervated pectineus is the dominant nerve component that supplies the muscle when considering frequency, branching pattern, and area, even though cooperation between two nerve components is implied. This study serves to advance the existing anatomical knowledge about the pectineus muscle, which is of clinical value.

Intramuscular Nerve Distribution of the Inferior Oblique Muscle.

Purpose: The intramuscular nerve distribution in the extraocular muscles is important for understanding their function. This study aimed to determine the intramuscular nerve distribution of the oculomotor nerve within the inferior oblique muscle (IO) using Sihler's staining.Method: Seventy-two IOs from 50 formalin-embalmed cadavers were investigated. The IO including its branch of the oculomotor nerve was finely dissected from its origin to its insertion point into the sclera. The total length of the muscle and its width were measured. The intramuscular nerve course was investigated after performing Sihler's staining, which is a whole-mount nerve-staining technique that stains the nerves while rendering other soft tissues either translucent or transparent.Results: The total length of the muscle and muscle width were 30.0 ± 2.8 mm (mean±standard deviation), 8.8 ± 1.2 mm, respectively. The oculomotor nerve enters the IO around the middle of the muscle and then divides into multiple smaller branches without distinct subdivisions. The intramuscular nerve distribution within the IO has a root-like arborization and supplies the entire width of the muscle. The Sihler's stained intramuscular nerve course (covering a length of 7.6 ± 1.2 mm) finishes around the distal one-third of the IO in gross observations.Conclusion: Sihler's staining is a useful technique for visualizing the gross nerve distribution of the IO. This new information about the nerve distribution and morphological features will improve the understanding of the biomechanics of the IO.

Localization of the center of the intramuscular nerve dense region of the medial femoral muscles and the significance for blocking spasticity.

PURPOSE: To identify the body surface position and depth of the center of the intramuscular nerves dense region (CINDR) of the medial femoral muscles. METHODS: Utilizing twelve Chinese adult cadavers (six men and six women), with an age range from 35 to 75 (66.5±5.4) years, the body surface curves between the greater trochanter of the femur and the pubic tubercle and lateral femoral epicondyle were designated as horizontal (H) and longitudinal (L) reference lines, respectively. Sihler's staining was performed on one side of the medial femoral muscles to show the intramuscular nerve dense regions, and the contralateral CINDR was labeled with barium sulfate and scanned by computed tomography, and three-dimensional reconstruction was performed. The body surface projection point of CINDR was designated as P. Projection of P in the opposite direction was identified as P'. The intersection of the longitudinal line from P to line H, and that of the horizontal line from P to line L was designated as PH and PL, respectively. The percentage positions of PH and PL on the H and L lines and the depth of the CINDRs were determined under the Syngo system. RESULTS: The pectineus, gracilis, adductor longus, and adductor brevis muscles each possess one intramuscular nerve dense region; the adductor magnus muscle has two. The PH was located at 80.32%, 95.67%, 85.64%, 94.92%, 84.48%, and 88.83% of line H, respectively. PL was at 12.76%, 40.68%, 33.26%, 23.39%, 25.57%, and 35.29% of line L, respectively. The depth of CINDRs was at 17.58%, 27.89%, 23.05%, 30.45%, 34.09%, and 29.52% of PP' line, respectively. These percentage values are all means. No statistical difference was observed neither between the left and right sides nor between the male and female cadavers (P>0.05). CONCLUSION: These results may help improve the efficiency and efficacy of botulinum toxin A injection in the treatment of medial femoral muscle spasticity.

Intramuscular Nerves of the Inferior Rectus Muscle: Distribution and Characteristics.

PURPOSE: Knowledge of the distribution of intramuscular nerves of the extraocular muscles is crucial for understanding their function. The purpose of this study was to elucidate the intramuscular distribution of the oculomotor nerve within the inferior rectus muscle (IRM) using Sihler's staining. METHOD: Ninety-three IRM from 50 formalin-embalmed cadavers were investigated. The IRM including its branches of the oculomotor nerve was finely dissected from its origin to the point where it inserted into the sclera. The intramuscular nerve course was investigated after performing Sihler's whole-mount nerve staining technique that stains the nerves while rendering other soft tissues either translucent or transparent. RESULTS: The oculomotor nerve enters the IRM around the distal one-fourth of the muscle and then divides into multiple smaller branches. The intramuscular nerve course finishes around the distal three-fifth of the IRM in gross observations. The types of branching patterns of the IRM could be divided into two subcategories based on whether or not topographic segregation was present: (1) no significant compartmental segregation (55.9% of cases) and (2) a several-zone pattern with possible segregation (44.1% of cases). Possible compartmentalization was less clear for the IRM, which contained overlapping mixed branches between different trunks. CONCLUSION: Sihler's staining is a useful technique for visualizing the gross nerve distribution of the IRM. The new information about the nerve distribution and morphological features provided by this study will improve the understanding of the biomechanics of the IRM, and could be useful for strabismus surgery.

Intramuscular Nerve Distribution in the Medial Rectus Muscle and Its Clinical Implications.

PURPOSE: The intramuscular nerve distribution in the extraocular muscles may be crucial for understanding their physiological and pathological responses. This study aimed to determine the oculomotor nerve distribution in the medial rectus muscle (MR) using Sihler's staining. METHOD: Thirty-seven MRs from 23 cadavers were investigated. The MR including the oculomotor nerve was finely dissected from its origin to its insertion point into the sclera. The total length of the muscle-belly, tendon length and maximum width of the muscle were measured. We evaluated the pattern of distribution and the length of the intramuscular nerve distribution by gross observation after performing Sihler's staining, which is a method for visualizing the distribution of nerve fibers without alteration of the nerve. RESULTS: The total length of the muscle-belly, tendon length, and muscle width were 37.6 ± 4.6 mm, 4.4 ± 1.9 mm, and 10 ± 1.8 mm, respectively. The oculomotor nerve enters the MR at a mean of two-fifths along the muscle (24 ± 2.0 mm posterior to the insertion point) and then typically divides into a few branches (mean of 2.1). The intramuscular nerve distribution showed a Y-shaped ramification, forming the terminal nerve plexus, and its course typically finished at around 17 ± 1.5 mm posterior to the muscle insertion point by gross observation. The nerve plexus in the upper part generally coursed more distally than the lower part. CONCLUSION: This new information regarding the nerve distribution pattern of MR will be helpful for understanding MR function and the diverse pathophysiology of strabismus.

Hip Adductor Intramuscular Nerve Distribution Pattern of Children: A Guide for BTX-A Treatment to Muscle Spasticity in Cerebral Palsy.

To investigate the intramuscular nerve distribution pattern in the hip adductors of children and to precisely locate the injection site for botulinum toxin type A (BTX-A) as a treatment for hip adductor spasticity in children with cerebral palsy. Modified Sihler's whole mount nerve staining technique was employed to observe the distribution of intramuscular nerves in hip adductors of children and to further locate zones where terminal nerves are concentrated. The terminal nerves of the adductor longus appeared in a longitudinal distribution band parallel to the line between the upper 1/3 point of the lateral boundary and the center of the medial boundary. In adductor brevis, the terminal nerves showed a sheet-like distribution with a nerve dense area located in the middle of the muscle belly that extends from the upper-inner region to the lower-outer region. Gracilis showed a dense area of terminal nerves in the middle of the muscle belly, closer to the posterior boundary. In adductor magnus, the dense area of terminal nerves showed a sheet-like distribution in the middle and lower region of the muscle belly. The dense area of terminal nerves in the pectineus was located in the middle of the muscle belly. This study is the first to systematically investigate the intramuscular nerve distribution pattern in the hip adductors. The results indicated that the best targets for BTX-A injection, when treating spasticity, are the dense regions of terminal nerves described above.

Intramuscular Distribution of the Abducens Nerve in the Lateral Rectus Muscle for the Management of Strabismus.

AIMS: To elucidate the intramuscular distribution and branching patterns of the abducens nerve in the lateral rectus (LR) muscle so as to provide anatomical confirmation of the presence of compartmentalization, including for use in clinical applications such as botulinum toxin injections. METHODS: Thirty whole-mount human cadaver specimens were dissected and then Sihler's stain was applied. The basic dimensions of the LR and its intramuscular nerve distribution were investigated. The distances from the muscle insertion to the point at which the abducens nerve enters the LR and to the terminal nerve plexus were also measured. RESULTS: The LR was 46.0 mm long. The abducens nerve enters the muscle on the posterior one-third of the LR and then typically divides into a few branches (average of 1.8). This supports a segregated abducens nerve selectively innervating compartments of the LR. The intramuscular nerve distribution showed a Y-shaped ramification with root-like arborization. The intramuscular nerve course finished around the middle of the LR (24.8 mm posterior to the insertion point) to form the terminal nerve plexus. This region should be considered the optimal target site for botulinum toxin injections. We have also identified the presence of an overlapping zone and communicating nerve branches between the neighboring LR compartments. CONCLUSION: Sihler's staining is a useful technique for visualizing the entire nerve network of the LR. Improving the knowledge of the nerve distribution patterns is important not only for researchers but also clinicians to understand the functions of the LR and the diverse pathophysiology of strabismus.

Muscle architecture and intramuscular nerve distribution pattern of adult elbow muscle / 解剖学报

[Abstract] Objective To study the morphology, muscle architecture index and distribution pattern of intramuscular nerve dense area of elbow muscle, so as to provide anatomical location for poster-lateral approach of elbow joint and transplantation of elbow muscle flap. Methods Through gross anatomy, muscle architecture index and modified Sihler’s intramuscular nerve staining, 10 cases with an average age of 64. 2 years were selected. Results The elbow muscle was approximate triangle, the muscle wet weight was (6. 31±0. 85) g, the muscle length was (6. 24±0. 78) cm, the muscle fiber length was (4. 74±0. 88) cm, pennation angle(70. 60±6. 41)°and the muscle physiological cross-sectional area was (0. 41±0. 15) cm

Localization of center of intramuscular nerve dense regions in adult anterior brachial muscles: a guide for botulinum toxin A injection to treat muscle spasticity.

This study aimed to identify the location and depth of the center of intramuscular nerves dense regions (CINDRs) in anterior brachial muscles. Twelve adult cadavers were used. One side anterior brachial muscles were isolated and subjected to Sihler's staining to show intramuscular nerve dense regions. Then the data was used to localize CINDRs in situ on the same muscles of the contralateral side. The localization method involved dissection and exposure of CINDRs, barium sulfate labeling, body surface reference line design, spiral computed tomography scan, three-dimensional image reconstruction, and Syngo system measurements. The number of CINDRs in coracobrachialis, biceps brachii and brachialis muscle were 3, 2 and 2, respectively. The body surface coordinates for the three CINDRs in coracobrachialis muscle were at 24.22%, 18.89% and 8.15% on the horizontal reference line and 21.37%, 31.78% and 30.07% on the longitudinal reference line. For biceps brachii muscle, they were at 49.68% and 40.28% on the horizontal reference line and 56.60% and 67.63% on the longitudinal reference line. For brachialis muscle, they were at 48.34% and 52.45% on the horizontal reference line and 71.30% and 81.62% on the longitudinal reference line. On cross-sectional planes, the depths of these CINDRs were at 22.81%, 26.76% and 27.99% (coracobrachialis); 14.79% and 17.45% (biceps); 34.03% and 30.26% (brachialis) of section diameters through CINDRs. These results may help to guide the injection of botulinum toxin A for the treatment of spasticity in the anterior brachial muscles and improve treatment efficacy and efficiency.

Localization of the centre of the highest region of the triceps brachii muscle spindle abundance and its significance in muscle spasticity block / Localización del centro de la región más alta del huso del músculo tríceps braquial y su importancia en el bloqueo de la espasticidad muscular

SUMMARY: This study aimed to accurately localize the location and depth of the centre of the highest region of muscle spindle abundance (CHRMSA) of the triceps brachii muscle. Twenty-four adult cadavers were placed in the prone position. The curve connecting the acromion and lateral epicondyle of the humerus close to the skin was designed as the longitudinal reference line (L), and the curve connecting the lateral and the medial epicondyle of the humerus was designed as the horizontal reference line (H). Sihler's staining was used to visualize the dense intramuscular nerve region of the triceps brachii muscle. The abundance of muscle spindle was calculated after hematoxylin and eosin stain. CHRMSA was labelled by barium sulphate, and spiral computed tomography scanning and three- dimensional reconstruction were performed. Using the Syngo system, the projection points of CHRMSA on the posterior and anterior arm surface (P and P' points), the position of P points projected to the L and H lines (PL and PH points), and the depth of CHRMSA were determined. The PL of the CHRMSA of the long, medial, and lateral heads of the triceps brachii muscle were located at 34.83 %, 75.63 %, and 63.93 % of the L line, respectively, and the PH was located at 63.46 %, 69.62 %, and 56.07 % of the H line, respectively. In addition, the depth was located at 34.73 %, 35.48 %, and 35.85 % of the PP' line, respectively. These percentage values are all the means. These body surface locations and depths are suggested to be the optimal blocking targets for botulinum toxin A in the treatment of triceps brachii muscle spasticity.

RESUMEN: Este estudio tuvo como objetivo localizar con precisión la ubicación y la profundidad del centro de la región más alta del huso muscular (CHRMSA) del músculo tríceps braquial. Se colocaron veinticuatro cadáveres adultos en posición prona y se designó la curva que conecta el acromion y el epicóndilo lateral del húmero cerca de la piel como la línea de referencia longitudinal (L), y la curva que conecta los epicóndilos lateral y medial del húmero fue designada como la línea de referencia horizontal (H). Se usó la tinción de Sihler para visualizar la región nerviosa intramuscular densa del músculo tríceps braquial. La abundancia de huso muscular se calculó después de la tinción con hematoxilina y eosina. CHRMSA se marcó con sulfato de bario y se realizó una tomografía computarizada espiral y una reconstrucción tridimensional. Usando el sistema Syngo, fueron determinados los puntos de proyección de CHRMSA en la superficie posterior y anterior del brazo (puntos P y P'), la posición de los puntos P pro- yectados en las líneas L y H (puntos PL y PH) y la profundidad de CHRMSA. Los PL de la CHRMSA de las cabezas larga, medial y lateral del músculo tríceps braquial se ubicaron en el 34,83 %, 75,63 % y 63,93 % de la línea L, respectivamente, y el PH se ubicó en el 63,46 %, 69,62 %, y 56,07 % de la línea H, respectivamente. La profundidad se ubicó en el 34,73 %, 35,48 % y 35,85 % de la línea PP', respectivamente. Estos valores porcentuales son todas las medias. Se sugiere que estas ubicaciones y profundidades de la superficie corporal son los objetivos de bloqueo óptimos para la toxina botulínica A en el tratamiento de la espasticidad del músculo tríceps braquial.

Polyglucosan bodies in intramuscular nerves: Association with muscle fiber denervation atrophy.

Polyglucosan bodies (PB) in the intramuscular nerves have been rarely studied, and their presence particularly in subjects without neurologic disorders has been thought to be age-related. We examined, by using light and electron microscopy, 204 consecutive muscle biopsies. PB was found in 5 quadriceps intramuscular nerves (2.45% of all biopsies). All 5 quadriceps containing PB exhibited varying degrees of muscle fiber denervation atrophy with or without fiber type grouping. These quadriceps with PB, compared with the other 119 quadriceps without PB, showed a significantly greater association with muscle fiber denervation atrophy (5/5 versus 55/119; p=0.02, by two-tailed Fisher's exact test), for which aging is not confounding. Electron microscopy identified PB in intramuscular nerve myelinated fibers along with ongoing degenerative changes. Our observation suggests that PB in intramuscular nerves may be pathologic and associated with muscle fiber denervation atrophy.

Intramuscular nerve distribution patterns of anterior forearm muscles in children: a guide for botulinum toxin injection.

Botulinum toxin (BoNT) can relieve muscle spasticity by blocking axon terminals acetylcholine release at the motor endplate (MEP) and is the safest and most effective agent for the treatment of muscle spasticity in children with cerebral palsy. In order to achieve maximum effect with minimum effective dose of BoNT, one needs to choose an injection site as near to the MEP zone as possible. This requires a detailed understanding about the nerve terminal distributions within the muscles targeted for BoNT injection. This study focuses on BoNT treatment in children with muscle spasms caused by cerebral palsy. Considering the differences between children and adults in anatomy, we used child cadavers and measured both the nerve entry points and nerve terminal sense zones in three deep muscles of the anterior forearm: flexor digitorum profundus (FDP), flexor pollicis longus (FPL), and pronator quadratus (PQ). We measured the nerve entry points by using the forearm midline as a reference and demonstrated intramuscular nerve terminal dense zones by using a modified Sihler's nerve staining technique. The locations of the nerve entry points and that of the nerve terminal dense zones in the muscles were compared. We found that all nerve entry points are away from the corresponding intramuscular nerve terminal dense zones. Simply selecting nerve entry points as the sites for BoNT injection may not be an optimal choice for best effects in blocking muscle spasm. We propose that the location of the nerve terminal dense zones in each individual muscle should be used as the optimal target sites for BoNT injection when treating muscle spasms in children with cerebral palsy.

Whole-mount intramuscular nerve distribution pattern of medial and lateral plantar muscles and its clinical significance / 解剖学报

Objective To reveal the whole-mount distribution pattern of intramuscular nerves in the medial and lateral plantar muscles and to explore its clinical significance. Methods Twenty-four adult cadavers were dissected to remove the medial and lateral groups of the plantar muscles. The distribution pattern of the intramuscular nerves was demonstrated by modified Sihler' s staining. Results The nerve branch for adductor hallucis muscle entered the muscle from the deep surface of the insertion of the muscle, while those nerve branches for abductor hallucis, flexor hallucis brevis, abductor digiti minimi and flexor digiti minimi brevis muscles entered the muscle from the deep side of the origin of the muscle. There were one lunate and one rectangular intramuscular nerve dense regions (INDRs) in the abductor hallucis muscle; two reniform INDRs in the transverse head of the adductor hallucis muscle, one reniform and one rectangular INDRs in the oblique head of the adductor hallucis muscle; there were two rectangle INDRs in the flexor hallucis brevis, abductor digiti minimi and flexor digiti minimi brevis muscles. These five muscles were divided into two neuromuscular compartment, but the percentage position of INDR and the center of INDR on muscle length in each muscle were different. Conclusion These result may provide morphological guidance for surgical operation to avoid nerve injury, the selection and matching of muscle transplantation and the injection of botulinum toxin A to block the spasticity of these muscles.

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.