Triplication of the lesser occipital nerve

Triplication of the lesser occipital nerve (LON) was observed bilaterally in an adult male cadaver during routine prosection of the posterior triangle. The three LONs were studied to determine the clinical importance of this variation. The origin of one LON was from a nerve to the trapezius that had a common origin with the trunk of the supraclavicular nerve (C3,4) from the cervical plexus. Such a common origin of a LON may explain the pain referred to the shoulder and arm that is experienced by some patients with cervicogenic headache. Another LON ran across the roof of the posterior triangle, passed through the trapezius and was closely related to the point of exit of the greater occipital nerve (GON) from the trapezius. This LON supplied the nape of the neck, back of the scalp and the auricle. The anomalous course taken by this LON through the trapezius may be an explanation for cervicogenic headache precipitated by neck movement. The close relationship of this variant LON to the exit of the GON from the trapezius seems to be relevant to the management of cervicogenic headache. The authors suggest that the reason for the complete pain relief experienced by some patients with cervicogenic headache by anesthetic blockade of the GON may be because both the GON and LON are blocked simultaneously due to their proximity in these patients.     

肋间臂神经的解剖及其临床意义

目的：为乳癌腋清扫术中保留肋间臂神经(ICBN)提供解剖学基础。方法：对25具成人尸体的50侧腋区进行了解剖，对肋间臂神经及上下相邻皮神经的走行、分支、支配、粗细等情况进行解剖观察。结果：ICBN可分为缺如型、单干型、单干分支型、双干型及3干型；84％的臂内侧皮神经与ICBN上支、上干相交通；34％的第3肋间神经外侧皮支可发支支配腋窝底；3侧第1肋间神经外侧皮支主干进入上臂内侧。结论：肋间臂神经为第2肋间神经外侧皮支的分支，通常为上支或上干，与臂内侧皮神经联合构成，可有第3或第1肋间神经的外侧皮支参与。其损伤可造成乳房切除术后疼痛综合征，乳癌腋清扫术中经胸小肌后方或经腋静脉下方能顺利找到该神经并加以保护。     

The course of the greater occipital nerve in the suboccipital region: a proposal for setting landmarks for local anesthesia in patients with occipital neuralgia

The anatomical relationships of the greater occipital nerve (GON) to the semispinalis capitis muscle (SCM) and the trapezius muscle aponeurosis (TMA) were examined to identify topographic landmarks for use in anesthetic blockade of the GON in occipital neuralgia. The course and the diameter of the GON were studied in 40 cadavers (29 females, 11 males), and the points where it pierced the SCM and the TMA were identified. The course of the GON did not differ between males and females. A left-right difference was detected in the site of the GON in the TMA region but not in the SCM region. The nerve became wider towards the periphery. This may be relevant to entrapment of the nerve in the development of occipital neuralgia. In three cases, the GON split into two branches before piercing the TMA and reunited after having passed the TMA, and it pierced the obliquus capitis inferior muscle in another three cases. The GON and the lesser occipital nerve reunited at the level of the occiput in 80% of the specimens. The occiput and the nuchal midline are useful topographic landmarks to guide anesthetic blockade of the GON for diagnosis and therapy of occipital neuralgia. The infiltration is probably best aimed at the site where the SCM is pierced by the GON.     

Anatomic study of the superficial sural artery and its implication in the neurocutaneous vascularized sural nerve free flap

Combined extended nerve and soft tissue defects of the upper extremity require nerve reconstruction and adequate soft tissue coverage. This study focuses on the reliability of the free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap within this indication. An anatomical study was performed on 26 cadaveric lower extremities that had been Thiel fixated and color silicone injected. Dissection of the fasciocutaneous posterior calf flap involved the medial sural nerve and superficial sural artery (SSA) with its septocutaneous perforators, extended laterally to include the lateral cutaneous branch of the sural nerve and continued to the popliteal origin of the vascular pedicle and the nerves. The vessel and nerves diameter were measured with an eyepiece reticle at 4.5× magnification. Length and diameter of the nerves and vessels were carefully assessed and reported in the dissection book. A total of 26 flaps were dissected. The SSA originated from the medial sural artery (13 cases), the popliteal artery (12 cases), or the lateral sural artery (one case). The average size of the SSA was 1.4 ± 0.4 mm. The mean pedicle length before the artery joined the sural nerve was 4.5 ± 1.9 cm. A comitant vein was present in 21 cases with an average diameter of 2.0 ± 0.8 mm, in 5 cases a separate vein needed to be dissected with an average diameter of 3.5 ± 0.4 mm. The mean medial vascularized sural nerve length was 21.2 ± 8.9 cm. Because of inclusion of the vascularized part of the lateral branch of the sural nerve (mean length of 16.7 ± 4.8 cm), a total of 35.0 ± 9.6 cm mean length of vascularized nerve could be gained from each extremity. The free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap pedicled on the SSA offers a reliable solution for complex tissue and nerve defect. Clin. Anat. 26:903–910, 2013. © 2012 Wiley Periodicals, Inc.     

Anatomical landmarks for localizing the buccal branch of the trigeminal nerve on the face

The current literature is lacking in anatomical landmarks for identifying the buccal branch of the trigeminal nerve on the face. The current study was performed to elucidate this anatomy. Forty cadaveric sides underwent dissection to measure the distances from landmarks of the superficial face to the buccal nerve in this region. On average, the buccal nerve was found to lie 3 cm lateral to the angle of the mouth and at this same level, the nerve was located a mean of 5 mm medial to the medial aspect of the masseter muscle. The buccal nerve was found to be on average 7 mm from the point of entrance of the parotid duct into the buccinator muscle and had an average distance of 5.5 mm from the facial artery. We believe that additional landmarks for identifying the buccal nerve on the face may be of use to the surgeon and dentist.     

Two rare anomalies of the brachial plexus

Morphological variations of the brachial plexus and variants in the distribution of the anterior division of the middle trunk are relatively frequent. Two of the rarest anomalies occurred in the left brachial plexus of a 62-y-old Japanese male, 1 of 104 plexuses dissected between 1996 and 1997 at Kanazawa University Faculty of Medicine. The superior trunk of the brachial plexus was formed by the anterior primary division of C5 and C6 and a thin branch (0.5 mm in diameter) from C4, the middle trunk by the C7, and the inferior trunk by C8 and T1 (Fig.). We could not determine whether there was a branch derived from T2 to T1, since the subject had died of lung carcinoma. The entire anterior division of the middle trunk crossed the axillary artery and joined the medial root of the median nerve which was the continuation of the medial cord after the cord branched off the ulnar nerve. The lateral cord pierced coracobrachialis and divided into the musculocutaneous nerve and the lateral root of the median nerve just after emerging from the muscle, finally joining the medial root of the median nerve superficial to the brachial artery ∼115 mm distal to the lower border of latissimus dorsi to form the median nerve. The musculocutaneous nerve gave rise to the nerves to biceps brachii, brachialis, and the long head of biceps brachii and finally continued as the lateral cutaneous nerve of the forearm. The branch to coracobrachialis had already been cut and its course could not be traced.     

The bilateral anatomical variation of the sural nerve and a review of relevant literature

The sural nerve is a sensory nerve, usually formed in the distal part of the leg by the union of the lateral sural cutaneous nerve or the communicating fibular branch with the medial sural cutaneous nerve. The aim of this paper is to present a case of a variant formation of the sural nerve and a review of the literature related to this case. During the dissection of an adult male cadaver, the medial sural cutaneous nerve and communicating fibular branch, after respectively deriving from the tibial and common fibular nerve, were noticed to continue their course without any formation of a unique nerve trunk on the posterior side of both lower limbs. A transverse communicating branch, connecting these two nerves, was present in both legs. As the sural nerve is of significant diagnostic and therapeutic importance, detailed knowledge of the sural nerve’s anatomy and its contributing nerves is also of great importance.     

Topographical anatomy of the transverse facial artery

The transverse facial artery (TFA) is found in the lateral face and supplies the parotid gland and duct, facial nerve, facial muscles, and skin. To better understand the cutaneous vascularization of the lateral face and to better characterize the topography and other anatomical features of the TFA, microsurgical dissection was performed in 44 cadavers. The number of TFAs present ranged from one to three, and a single TFA was most common (70.5%). The TFA originated from the superficial temporal artery at or above the level of crossing by the temporofacial trunk of the facial nerve in the parotid gland (57.6%). The TFA divided into superior and inferior trunks in the gland, and continued as emerging branch. The superior emerging branch emerged from the gland superior to the parotid duct and divided into many branches. It supplied the malar area, crossed the parotid duct, terminated as perforator, vasa nervorum, or artery to the parotid duct or muscle. The inferior trunk in 72.5% continued as emerging branch instead of terminating in the gland. TFAs were classified into four types; the most common type was Type A in which the superior and inferior emerging branches and the duct‐crossing branch were present. The mean number of perforators to the superficial cutaneous layer was 1.9. Most perforators extended from the superior emerging branches (77.9%). The most common perforating site was below the duct on the anterior third of the masseter muscle. In two cases, the TFA formed an anastomosis with the facial artery. Clin. Anat. 23:168–178, 2010. © 2009 Wiley‐Liss, Inc.     

用股后皮神经桥接下位胸神经与阴部神经治疗截瘫后大小便失禁

本研究设计了用股后皮神经、桥接下位胸神经与阴部神经治疗截瘫后大、小便失禁的新术式,并在34侧成人尸体标本上,对下位胸神经、股后皮神经和阴部神经进行了观测,提供手术时有关的数据。第十、十一肋间神经和肋下神经从骶棘肌外缘至分出外侧皮支间的长度分别为10.4cm、8.8cm 和6.6cm;至梨状肌下缘阴部神经出盆处的距离为31.2cm、27.3cm 和22.0cm。股后皮神经和阴部神经的横径4.5mm 和4.2mm。     

以皮神经及营养血管为蒂臂内侧皮瓣的应用解剖

目的：为带臂内侧以神经及其营养血管筋膜皮瓣提供形态学基础。方法：在３２侧成人上肢标本上,观测臂内侧皮神经营养血管及其周围皮肤的供血情况。结果：臂内侧皮神经的血供来自尺侧上副动脉肌间隔皮支、肱动脉肌间隔皮支和尺侧下副动脉肌间隔皮支,起始处外径分别为１．０ｍｍ、０．６ｍｍ和０．７ｍｍ,穿出深筋膜前长为１．５ｃｍ、１．１ｃｍ和１．２ｃｍ。其神经支在神经束间或神经旁相互吻合构成丰富的血管网,并借分支与筋膜     

Multiple Neurovascular Abnormalites of a Single Cadaver-A Case Report

Neurovascular variations are of interest to anatomists, clinicians, anaesthesiologists and especially to the surgeons.During routine dissection of a 65 years old male cadaver in Kolkata Medical College; it was found that there was no standard formation of lateral cord of brachial plexus on right side because anterior division of upper trunk continued as Musculocutaneous nerve and the Median nerve was formed medial to the first part of Axillary artery just below and behind the Clavicle by the fibres of anterior division of middle trunk via lateral root and anterior division of lower trunk via medial root. About 1.5cm distal to its formation Median nerve gave a branch which crossed the second part of the Axillary artery and supplied the Coracobrachialis muscle in addition to Musculocutaneous nerve. A single Pectoral nerve was formed by union of two nerves arising from anterior division of middle and lower trunk respectively. The Musculocutaneous nerve of opposite limb was formed by union of two nerves arising from the lateral cord of brachial plexus. In posterior thoracic wall, a left sided Azygos vein and multiple communicating veins between Azygos and Hemiazygos vein were found. An altered relation between Tibial nerve and Posterior Tibial blood vessel and an abnormal termination of latter were encountered in right lower limb.     

Development of the spinal nerves in the mouse with special reference to innervation of the axial musculature

Development of the mouse spinal nerves was studied. On E11 (11th day of gestation), the primitive spinal nerve fascicle extended ventrally in the anterior half of the sclerotome. Spinal nerves in the forelimb region united with each other to form the primitive brachial plexus. Their terminal segment was covered by a peculiar cell mass. On E12, five primary branches developed along the primitive spinal nerve trunk. The ramus dorsalis was originally a cutaneous nerve, supplying two series of branches to the skin of the back. The medial series was derived from the dorsal ramus of C2–C8, and the lateral series from C8 and the more caudal dorsal rami. Nerves of the former series took the presegmental course through the intermyotomic space, while those of the latter the postsegmental course. The ramus cutaneus lateralis was a nerve that took the presegmental course to become cutaneous. The ramus intercostalis externus was a muscle branch whose distribution was restricted within the segment. The ramus anterior was a muscle branch from the end of the primitive spinal nerve trunk. The ramus visceralis connected a thoracic nerve with the para-aortic sympathetic cell cord. On E13–16 the ramus anterior secondarily gave off a cutaneous branch (ramus cutaneus anterior). The ramus intercostalis externus extended ventrally deep to the intercostalis externus muscle, crossing just caudal to the ramus cutaneus lateralis that secondarily gave off branches to the obliquus externus abdominis muscle.     

以前臂内侧皮神经及营养血管为蒂的前臂内侧皮瓣的应用解剖

目的　为带前臂内侧皮神经及其营养血管筋膜皮瓣提供形态学基础。方法　在 32侧成人上肢标本上 ,观测前臂内侧皮神经营养血管及其周围皮肤的血供情况。结果　前臂内侧皮神经近侧的血供来源于尺侧返动脉混合肌皮支 ,起始处外径为 0 .8mm ,穿出深筋膜前长度为 1.1cm ;中部主要来自尺动脉近中段和远中段的粗大皮支 ,起始处外径均为 0 .7mm ,穿出深筋膜前长度均为 1.0cm ;远侧有尺动脉腕上皮支 ,起始处外径为 0 .9mm ,穿出深筋膜前长度均为 1.0cm ;远侧有尺动脉腕上皮支 ,起始处外径为 0 .9mm ,穿出深筋膜前长为 2 .6cm。其神经旁血管网与神经皮穿支及神经内血管广泛吻合组成了皮神经血管轴。结论　可设计成带前臂内侧皮神经及营养血管为蒂筋膜上瓣 ,顺行或逆行转位修复邻近部位的软组织缺损。     

带臂外侧上皮神经及其营养血管筋膜皮瓣的应用解剖

目的:为带臂外侧上皮神经及其营养血管筋膜皮瓣提供解剖学基础.方法:32例经灌注红色乳胶的成人上肢标本,对臂外侧上皮神经及其营养血管等进行了较详细的应用解剖学研究.结果:臂外侧上皮神经在均由腑神经发出,起点横径为1.5±0.4mm,在三角肌深方斜向外下3.6±1.1cm从该肌后缘中1/3浅出肌间隔,分为上支和下支,分布于三角肌后部、外侧部和臂外侧上部.该神经的营养血管起源于旋肱后动脉,起点外径为0.9±0.4mm;其行程、分支和分布均同在神经,供血范因为14.8×9.8cm~2,并与周围的皮动脉存在丰富吻合.结论:带臂外侧上皮神经及其营养血管筋膜皮 瓣可视受区需要设计成游离瓣或旋转瓣,用于修复邻近部位、手或颌面部缺损.     

Superficial temporal artery as an external landmark for deeper-lying brain structures

Additional localizing superficial landmarks for intracranial structures can be of use to the neurosurgeon. This study was performed to evaluate the usefulness of the superficial temporal artery (STA) as an external landmark for deeper brain structures. Thirteen adult cadavers (26 sides) underwent latex injection of their STA bilaterally. Dissections were next carried out to identify this vessel. Once the STA and its frontal and parietal branches were skeletonized, craniectomies were performed and the underlying dura mater excised. Measurements were made between the frontal and parietal branches of the STA and deeper brain structures. The STA was found to branch on average 3 cm superior to the tragus. The bifurcation of the STA was found to commonly bifurcate at the level of the floor of the middle cranial fossa or superior temporal gyrus. The Sylvian fissure was found at a mean of 2 cm superior to the STA bifurcation. The angle between the frontal branch of the STA and the zygomatic arch had a mean of 37 degrees. The angle between the frontal and parietal branches of the STA had a mean of 87 degrees. At the level of the glabella, the frontal branch of the STA was on average 3 cm posterior to the frontal pole. The temporal tip was located a mean of 3.2 cm anterior to the frontal branch of the STA. The plane of the foramen of Monro was found to lie at a mean distance of 2.3 cm posterior to the frontal branch of the STA. The parietal branch of the STA was noted to travel more or less parallel with the central sulcus in all specimens and to travel an average of 2 cm posterior to this sulcus. At the level of the lateral attachment of the tentorium cerebelli, the parietal branch of the STA was found to travel a mean of 4.8 cm anterior to the entrance of the vein of Labbé into the transverse sinus. The parietal branch of the STA was also found to travel a mean of 4.2 cm anterior to the angular gyrus and 3.9 cm anterior to the supramarginal gyrus. Palpation or Doppler identification of the STA and its branches with subsequent mapping on the lateral cranium may prove useful as an additional superficial landmark for the neurosurgeon.     

第9、10肋间神经外侧皮支营养血管皮瓣的解剖与临床应用

目的：为季肋部皮神经营养血管皮瓣提供解剖学基础。方法：在17例34侧成人躯干标本上，观察了第9、10肋间神经外侧皮支及其营养血管的来源、走行及分布规律；在临床上，应用第9肋间神经外侧皮支皮神经营养血管皮瓣修复组织缺损2例。结果：第9、10肋间神经外侧皮支从腋中线前后相应肋间穿出深筋膜，分为前、后支，呈节段性、重叠性分布于侧胸腹部皮肤。皮神经营养血管相互间形成丰富的吻合。临床应用取得了满意的疗效。结论：以第9、10肋间神经外侧皮支营养血管为蒂，可以设计皮神经营养血管皮瓣。     

骨盆后环骨折神经损伤的临床解剖学研究

目的：了解骨盆后环骨折易损神经的相对解剖位置及其与骨折的关系。方法：解剖20具骨盆标本，神经外膜下置管造影CT扫描5例，测量腰区各神经的走行特点、与骨盆壁和骶髂关节的距离。结果：腰4腰骶干支、腰5神经和腰骶干与骶骨翼的距离不超过1cm，距离骶髂关节不超过2．5cm。闭孔神经、股神经、股外侧皮神经与骨壁的距离依次渐远。CT测量结果和人工测量结果无显著性差异。结论：腰4腰骶干支、腰5神经和腰骶干是与骨盆壁和骶髂关节的关系最为紧密的神经，它们在骨盆后环骨折及其治疗时最易受损。