Spinner Robert J, Amrami Kimberly K, Kliot Michel, Johnston Shawn P, Casañas Joaquim
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
J Neurosurg. 2006 Apr;104(4):551-7. doi: 10.3171/jns.2006.104.4.551.
Unlike the more commonly noted paralabral cysts (extraneural ganglia), which are well known to result in suprascapular nerve compression, only four cases of suprascapular intraneural ganglia have been reported. Because of their rarity, the pathogenesis of suprascapular intraneural ganglia has been poorly understood and a pathoanatomical explanation has not been provided. In view of the growing literature demonstrating strong associations between paralabral cysts and labral (capsular) pathology, joint connections, and joint communications, the authors retrospectively reviewed the magnetic resonance (MR) imaging studies and postoperative results in the two featured patients to test a hypothesis that suprascapular intraneural ganglia would have analogous findings.
Two patients who presented with suprascapular neuropathy were found to have intraneural ganglia. Connections to the glenohumeral joint could be established in both patients through posterior labrocapsular complex tears. In neither patient was the joint connection identified preoperatively or intraoperatively, and cyst decompression was performed by itself without attention to the labral tear. The suprascapular intraneural ganglia extended from the glenohumeral joint as far proximally as the level of the nerves' origin from the upper trunk in the supraclavicular fossa. Although both patients experienced symptomatic improvement after surgery, neurological recovery was incomplete. In both cases, postoperative MR images revealed cyst persistence. In addition, previously unrecognized superior labral anteroposterior (SLAP) Type II lesions (tears of the superior labrum extending anteroposterior and involving the biceps anchor at the labrum without actual extension into the tendon) were visualized. In one patient with a persistent cyst, an MR arthrogram was obtained and demonstrated a communication between the joint and the cyst.
The findings in these two patients support the synovial theory for intraneural ganglia. Based on their experience with intraneural ganglia at other sites, the authors believe that suprascapular intraneural ganglia arise from the glenohumeral joint, egress through a superior (posterior) labral tear, and dissect within the epineurium along an articular branch into the main nerve, following the path of least resistance. Furthermore, these two cases of intraneural ganglia with SLAP lesions are directly analogous to the many cases of paralabral cysts associated with these types of labral tears. By better understanding the origin of this unusual type of ganglia and drawing analogies to the more common extraneural cysts, surgical strategies can be formulated to address the underlying pathoanatomy, improve operative outcomes, and prevent recurrences.
与更常见的盂唇旁囊肿（神经外神经节）不同，盂唇旁囊肿众所周知会导致肩胛上神经受压，而肩胛上神经内神经节仅有4例报道。由于其罕见性，肩胛上神经内神经节的发病机制尚未得到充分理解，也未提供病理解剖学解释。鉴于越来越多的文献表明盂唇旁囊肿与盂唇（关节囊）病变、关节连接和关节相通之间存在密切关联，作者回顾性分析了两名典型患者的磁共振（MR）成像研究及术后结果，以验证肩胛上神经内神经节会有类似表现的假设。
两名表现为肩胛上神经病变的患者被发现患有神经内神经节。通过后方盂唇关节囊复合体撕裂，在两名患者中均能建立与盂肱关节的连接。术前或术中均未发现关节连接，且仅进行了囊肿减压，未关注盂唇撕裂情况。肩胛上神经内神经节从盂肱关节向近端延伸至锁骨上窝中上干神经起始水平。尽管两名患者术后症状均有改善，但神经功能恢复不完全。在两例病例中，术后MR图像显示囊肿持续存在。此外，还发现了之前未被识别的上盂唇前向后方（SLAP）Ⅱ型损伤（上盂唇前后向撕裂，累及盂唇处的肱二头肌附着点，但未实际延伸至肌腱）。在一名囊肿持续存在的患者中，进行了MR关节造影，显示关节与囊肿相通。
这两名患者的发现支持神经内神经节的滑膜理论。基于他们在其他部位神经内神经节的经验，作者认为肩胛上神经内神经节起源于盂肱关节，通过上方（后方）盂唇撕裂处穿出，沿着关节分支在神经束膜内沿阻力最小的路径向主神经内蔓延。此外，这两例伴有SLAP损伤的神经内神经节病例与许多与这类盂唇撕裂相关的盂唇旁囊肿病例直接类似。通过更好地理解这种不寻常类型神经节的起源，并与更常见的神经外囊肿进行类比，可以制定手术策略来处理潜在的病理解剖结构，改善手术效果并预防复发。
