引言
尽管椎间盘碎片移位到硬膜外前间隙的上，下或侧位是人们所熟知的，硬膜外后侧腰椎间盘碎片游离却是一种极其罕见的疾病。硬膜外后侧腰椎间盘碎片游离与其他硬膜外后侧占位性病变往往容易混淆。这些硬膜外病变的鉴别诊断包括囊肿、脓肿、肿瘤和血肿。囊肿在T1-加权磁共振成像（MRI）上显示低信号，在T2-加权磁共振成像上显示非常高的信号。存在脓肿和受感染的患者会出现发烧症状，临床化验结果会呈现异常值，提示患者出现了炎症反应。肿瘤在T1和T2加权磁共振成像中表现出不同的强度。然而，肿瘤通常不会表现出自发性改善。硬膜外后侧腰椎间盘碎片游离和血肿的诊断是非常困难的。椎间盘突出症的游离碎片可能会与出现该病症的椎间隙保持接触，然而，不同于椎盘碎片，血肿没有与椎间隙的任何连接。如前所述，根据临床症状和核磁共振表现，我们诊断患者为硬膜外后侧腰椎间盘碎片游离。硬膜外后侧腰椎间盘碎片游离常导致神经根或马尾综合症。据我们所知，所有已报道的56例硬膜外后侧腰椎间盘碎片游离患者，不管症状严重程度如何，均接受了手术治疗。2008年4月至2010年8月，四名硬膜外后侧腰椎间盘碎片游离的患者在唐津红十字会医院接受了治疗。本文报道了四例硬膜外后侧腰椎间盘碎片游离患者，并根据症状的严重程度和病程确定治疗方法。以往的病例报告中硬膜外后侧腰椎间盘碎片游离也是依患者年龄，通过核磁共振成像特性，病变程度，临床症状、治疗过程和疗效进行分析。这是硬膜外后侧游离腰椎间盘碎片自然消退的第一篇病例报告。
病例报告
病例1
一例83岁男性患者，下腰和右前侧大腿疼痛已持续1个月。表现为右侧L3皮节区感觉减退，右腿屈膝力量为5-/5。患者没有发烧，临床化验检查结果正常。磁共振成像显示L2-L3右段的硬膜外后侧间隙有一肿块。病变区的T1-加权磁共振成像表现出低信号，T2-加权磁共振成像则表现出高低混杂信号。注射钆(Gd)后，病变区边缘增强。因病变区与L2-L3椎间盘相连，故诊断为硬膜外后侧腰椎间盘碎片游离。因患者症状均符合神经根病，故给予保守治疗。在门诊随访中，通过口服非甾体类抗炎药(NSAIDs)，症状有所改善。首次就诊约1个月后，所有症状都得到了缓解，2个月后的磁共振成像观察到病变区出现了自然消退(图1)。
Fig. 1. (A, B) Sagittal T1- and T2-weighted magnetic resonance imaging (MRI) showing the lesion in the posterior epidural space at L2-L3. (C, D) The lesion demonstrated rim enhancement on Gd-enhanced MRI. (E, F) The posterior epidural migrated lumbar disc fragments showed spontaneous regression on T2-weighted MRI 2 months after the first visit.
图1. (A，B)矢状面T1-和T2-加权磁共振成像(MRI)显示病变区是在L2-L3硬膜外后侧间隙。(C，D) Gd增强磁共振成像中病变边缘得以加强。(E，F) 首次就诊2个月后，T2-加权磁共振成像显示硬膜外后侧游离腰椎间盘碎片出现了自然消退。
病例2
一名62岁男性患者陈述紧随着下腰部疼痛，其左臀和大腿前侧也出现了疼痛。未发现感觉或运动障碍。患者没有发烧，临床化验检查结果正常。磁共振成像显示硬膜外后侧病变区与L2-L3椎间盘左段相连。注射钆(Gd)后，病变区边缘增强。经诊断病变为硬膜外后侧腰椎间盘碎片游离。因患者症状均符合神经根病，故给予保守治疗。在门诊随访中，通过口服非甾体类抗炎药，症状有所改善。4个月后，磁共振成像观察到病变区出现了自然消退，症状也得到了缓解(图2)。
Fig. 2. (Left) Posterior epidural migrated lumbar disc fragments were observed at L2-L3 on sagittal T2-weighted magnetic resonance imaging (MRI) at the first visit. (Right) Spontaneous regression of the posterior epidural migrated lumbar disc fragments was revealed on sagittal T2-weighted MRI at the final follow-up.
图2. (左) 首次就诊时，矢状面T2-加权磁共振成像(MRI)显示L2-L3段存在硬膜外后侧腰椎间盘碎片游离。(右) 最后一次随访中，矢状面T2-加权磁共振成像显示硬膜外后侧游离腰椎间盘碎片出现了自然消退。
病例3
一名79岁男性患者陈述其左腿疼痛。表现为左侧L4和L5皮节区感觉减退，左脚趾背屈力量为4/5。患者没有发烧，临床化验检查结果正常。磁共振成像显示硬膜外后侧病变区与L4-L5椎间盘左段相连。经诊断病变为硬膜外后侧腰椎间盘碎片游离。因症状符合神经根病，且口服非甾体类抗炎药后骶管阻滞症状得到缓解，因此给予了保守治疗。6个月后，磁共振成像观察到病变区出现了自然消退，症状也得到了缓解(图3)。
Fig. 3. (Left) Posterior epidural migrated lumbar disc fragments were observed at L3-L4 on sagittal T2-weighted magnetic resonance imaging (MRI) at the first visit. (Right) Spontaneous regression of the posterior epidural migrated lumbar disc fragments was observed on sagittal T2-weighted MRI at the finalfollow-up.
图3. (左) 首次就诊时，矢状面T2-加权磁共振成像(MRI)显示L3-L4段存在硬膜外后侧腰椎间盘碎片游离。(右) 最后一次随访中，矢状面T2-加权磁共振成像显示硬膜外后侧游离腰椎间盘碎片出现了自然消退。
病例4
一例53岁男性患者，右腿感觉异常已持续4个月。患者承受重负荷后出现了急性下腰痛，两侧臀部疼痛和间歇性跛行。来我院首次就诊前，患者在家休养了5天，期间症状持续。双腿感觉减退，双脚背屈力量为4/5。未发现膀胱或肠道功能障碍。患者没有发烧，临床化验数据正常。病变区的T1-加权磁共振成像表现出低信号，T2-加权磁共振成像则表现出高低混杂信号。经诊断病变为硬膜外后侧腰椎间盘碎片游离。在门诊随访中，因症状恶化，予以手术治疗。L3-L4段实施了椎板切除术。手术中观察到肿块样病变明显压迫硬膜管，附着于硬膜。肿块被分块切除，L3-L4段实施了椎间盘切除术。切除掉的成分与碎片相匹配。术后患者神经系统症状迅速缓解。术后3个月，双脚背屈完全康复 (图4)。
Fig. 4. (A, B) Posterior epidural migrated lumbar disc fragments were observed at L3-L4 on T2-weighted magnetic resonance imaging at the first visit. (C,D) Magnetic resonance imaging showed the disappearance of the posterior epidural migrated lumbar disc fragments 3 months after surgery.
图4. (A，B) 首次就诊时，T2-加权磁共振成像显示L3-L4段存在硬膜外后侧腰椎间盘碎片游离。(C，D) 术后3个月，磁共振成像显示硬膜外后侧腰椎间盘碎片游离消失。
讨论
1973年，Lombardi报道了首例硬膜外后侧腰椎间盘碎片游离病例。此后，包括此报道，已有60例硬膜外后侧腰椎间盘碎片病例报道。此前的报道包括46例男性和14例女性患者，平均年龄为54.0岁(范围：28-83岁)。2例患者L1-L2段，12例患者L2-L3段，23例患者 L3-L4段，17例患者L4- L5段，以及6例患者L5-S1段经确认出现了硬膜外后侧腰椎间盘碎片游离。与普通腰椎间盘突出症不同，硬膜外后侧腰椎间盘碎片游离经证实发生于脊椎上段。对于主要的临床症状，33例出现了尾马综合症，25例出现了神经根病，2例出现了腰痛。
硬膜外后侧腰椎间盘碎片游离与其他硬膜外后侧占位性病变往往容易混淆。这些硬膜外病变的鉴别诊断包括囊肿、脓肿、肿瘤和血肿。磁共振成像是用于评价脊柱病变的常规诊断工具。此前报道的硬膜外后侧腰椎间盘碎片游离的病例中，主要的诊断工具是磁共振成像：60例中有48例进行了脊柱MRI检查，而这48例中有32例采用了钆注射。基于临床症状和核磁共振结果，囊肿、脓肿和肿瘤较容易诊断。然而，血肿与硬膜外后侧腰椎间盘碎片游离可能很难区分。Komori等人描述血肿的T1-和T2-加权图像通常表现为高信号，然而有时血肿的T1-加权图像会表现出中等信号，信号与椎间盘类似。从而他们总结认为不能完全排除为硬膜外血肿。在以往的报道中，硬膜外后侧腰椎间盘碎片游离的T1-加权磁共振成像趋向于呈现低信号。然而，病变区的T2-加权磁共振成像则表现为高低混杂信号。在32例实施钆增强磁共振成像的病例中，30例的病变区观察到边缘增强，2例观察到弥漫性增强。边缘增强可提示硬膜外后侧腰椎间盘碎片游离的存在。本文中所有病例，病变区的T1-加权磁共振成像表现出低信号，而T2-加权磁共振成像则表现出高低混杂信号。文中四名患者中的两例接受了钆增强磁共振成像，均观察到边缘增强。正如上述磁共振图像结果，文中保守治疗的患者的诊断结果与硬膜外后侧腰椎间盘碎片游离相一致。此外，本文中行手术治疗的病例经诊断病变为硬膜外后侧腰椎间盘碎片游离。
所有已报道的和文中的一例硬膜外后侧腰椎间盘碎片游离患者均进行了手术治疗。仅本报道中三名患者接受了保守治疗，并且症状得到缓解。39例手术治疗的病例完全康复，另16例手术治疗病例病情得到改善。三例接受保守治疗的患者证实已完全康复，这包括口服非甾体类抗炎药和骶管阻滞的患者。手术治疗的病例中，疗效似乎与首诊至术前症状持续时间和术前临床症状表现无关。影响疗效的因素尚未明确。病例报告中需外科治疗的原因是硬膜外后侧腰椎间盘碎片游离导致马尾综合征或神经根病。Sengoz等人认为硬膜外后侧腰椎间盘碎片游离的早期手术治疗是非常重要的，是预防严重神经性损伤的首选。另一方面，腰椎间盘突出症的自然消退已被广泛接受。Haro等人报道称炎症细胞浸润在经韧带型突出或游离型病变中更为显著。一些经韧带型和游离型椎间盘髓核脱出的病例中髓核脱出范围呈现显著进行性减小。硬膜外后侧腰椎间盘碎片游离经诊断属于游离型椎间盘突出症。本文的病例中硬膜外后侧腰椎间盘碎片游离的患者被当成普通腰椎间盘突出症接受了治疗。三个病例的磁共振成像呈现了病变的自然消退和症状缓解。这三个病例的磁共振成像可观察到病变的自然消退与症状缓解，这清楚地显示了硬膜外后侧腰椎间盘碎片游离自然消退的可能性，这在更为常见的游离型腰椎间盘突出症中亦可见。因此，硬膜外后侧腰椎间盘碎片游离的治疗方式应根据患者症状严重程度和病程来决定。然而，如果患者出现急性马尾综合征或神经系统症状恶化，实施早期手术治疗就显得很重要了。
Introduction
Although disc fragments arewell known to migrate to superior, inferior, or lateral sites in the anterior epidural space, posterior epidural migrated lumbar disc fragments is an extremely rare disorder. Posterior epidural migrated lumbar disc fragments are often confused with other posterior epidural space-occupying lesions. The differential diagnosis of these epidural lesions includes cysts, abscesses, tumors, and hematomas. Cysts demonstrate a low-intensity signal on T1-weighted magnetic resonance imaging (MRI) and a very high-intensity signal on T2-weighted MRI. Patients with abscesses and infection exhibit fever and clinical laboratory test results that show abnormal values indicating inflammatory reactions. Tumors demonstrate various intensities on T1- and T2-weighted MRI. However, tumors typically do not show improvement during their natural course. Making a diagnosis between posterior epidural migrated lumbar disc fragments and hematomas is very difficult. Disc herniations with migration may retain contact with the disc space from which they arose, whereas hematomas can be distinguished from disc fragments by the lack of continuity with a disc space. As mentioned previously, we diagnosed our patients with posterior epidural migrated lumbar disc fragments based on the clinical symptoms and MRI findings. Posterior epidural migrated lumbar disc fragments usually cause radiculopathy or cauda equina syndrome. To the best of our knowledge, surgical treatment was performed in all reported 56 cases of posterior epidural migrated lumbar disc fragments, regardless of symptom severity. Between April 2008 and August 2010, four patients with posterior epidural migrated lumbar disc fragments were treated at Karatsu Red Cross Hospital. We herein present four posterior epidural migrated lumbar disc fragment cases in which the treatment was determined according to the severity and course of the patients’ symptoms. Previously reported cases of posterior epidural migrated lumbar disc fragments were also analyzed with respect to age, imaging features on MRI, the level of the lesion, clinical symptoms, treatment, and outcomes. This is the first report of spontaneous regression of posterior epidural migrated lumbar disc fragments.
Case report
Case 1
An 83-year-old man presented with a 1-month history of low back pain and right anterior thigh pain. Hypesthesia of the L3 dermatome on the right side and 5- of 5 strength on knee extension of the right leg were revealed. The patient did not have a fever, and the clinical laboratory data were normal. Magnetic resonance imaging demonstrated a mass in the posterior epidural space on the right side at the L2-L3 level. The lesion exhibited low- to isointensity on T1-weighted MRI and high and low intensities on T2-weighted MRI. After gadolinium (Gd) injection, the lesion demonstrated rim enhancement. The lesion was diagnosed as a posterior epidural migrated lumbar disc fragment because it was attached to the L2-L3 disc. Conservative treatment was administered because the symptoms were consistent with radiculopathy. The symptoms improved after oral administration of nonsteroidal anti-inflammatory drugs (NSAIDs) during outpatient clinic follow-up. All symptoms were relieved approximately 1 month after the first visit, and spontaneous regression of the lesion was observed on MRI 2 months later (Fig. 1).
Case 2
A 62-year-old man complained of left buttock and anterior thigh pain followed by low back pain. No sensory or motor disturbances were observed. The patient did not have a fever, and the clinical laboratory data were normal. Magnetic resonance imaging showed a posterior epidural lesion attached to the L2-L3 disc on the left side. The lesion exhibited rim enhancement after Gd injection. The lesion was diagnosed as a posterior epidural migrated lumbar disc fragment. Conservative treatment was administered because the symptoms were consistent with radiculopathy. The symptoms improved after the oral administration of NSAIDs during the outpatient clinic follow-up. A spontaneous regression of the lesion was observed on MRI 4 months later with the relief of all symptoms (Fig. 2).
Case 3
A 79-year-old man complained of left leg pain. Hypesthesia of the L4 and L5 dermatome on the left side and 4 of 5 strength on dorsiflexion of the left toes were revealed. The patient did not have a fever, and the clinical laboratory data were normal. Magnetic resonance imaging revealed a proximal migrated posterior epidural lesion attached to the L4-L5 disc on the left side. The lesion was diagnosed as a posterior epidural migrated lumbar disc fragment. Conservative treatment was administered because the symptoms were consistent with radiculopathy and were relieved by an oral administration of NSAIDs after a caudal block. A spontaneous regression of the lesion was observed on MRI 6 months later with the relief of symptoms (Fig. 3).
Case 4
A 53-year-old man presented with a 4-month history of right leg paresthesia. Acute low back pain, bilateral buttock pain, and neurogenic claudication appeared after the patient lifted a heavy load. The symptoms persisted during rest at home for 5 days before the first visit to our hospital. Hypesthesia was revealed in both legs, and 4 of 5 strength on dorsiflexion was observed in both feet. No bladder or bowel dysfunction was observed. The patient did not have a fever, and the clinical laboratory data were normal. The lesion exhibited low- to isointensity on T1-weighted MRI and high and low intensities on T2-weighted MRI. The lesion was diagnosed as a posterior epidural migrated lumbar disc fragment. Surgical treatment was performed because the symptoms worsened during outpatient clinic follow-up. L3-L4 laminotomy was performed. Intraoperatively, the mass-like lesion clearly compressed the dural tube and was adhered to the dura matter. The mass was removed piece by piece, and L3-L4 discectomy was performed. The removed materials were matched for disc fragments. The patient’s neurologic symptoms were rapidly relieved after surgery. A full recovery with dorsiflexion of both feet was observed 3 months after surgery (Fig. 4).
Discussion
Lombardi reported the first case of posterior epidural migrated lumbar disc fragments in 1973. Since then, 60 cases of posterior epidural migrated lumbar disc fragments have been reported, including the present report. Previous reports include 46 male and 14 female patients with a mean age of 54.0 years (range 28-83 years). The location of the posterior epidural migrated lumbar disc fragments was confirmed at L1-L2 in 2 patients, at L2-L3 in 12 patients, at L3-L4 in 23 patients, at L4-L5 in 17 patients, and at L5-S1 in 6 patients. The presence of posterior epidural migrated lumbar disc fragments was confirmed in the upper level compared with ordinary lumbar disc herniation. Regarding the primary clinical symptoms, cauda equine syndrome was observed in 33 cases, radiculopathy in 25 cases, and lumbago in 2 cases.
Posterior epidural migrated lumbar disc fragments are often confused with other posterior epidural space-occupying lesions. The differential diagnosis of these epidural lesions includes cysts, abscesses, tumors, and hematomas. Magnetic resonance imaging is a routine diagnostic tool used in the evaluation of spinal lesions. In the previously reported posterior epidural migrated lumbar disc fragment cases, the primary diagnostic tool was MRI: 48 of 60 cases involved MRI of the spine, whereas Gd was injected in 32 of these 48 cases. Cysts, abscesses, and tumors can be easily diagnosed based on clinical symptoms and MRI findings. However, it may be rather difficult to distinguish between hematomas and posterior epidural migrated lumbar disc fragments. Komori et al. described hematomas as normally showing high-intensity signal on T1- and T2-weighted images, whereas sometimes exhibiting intermediate intensity signal on T1-weighted views, similar to disc materials. They concluded that epidural hematomas cannot be ruled out completely. In previous reports, posterior epidural migrated lumbar disc fragments tended to demonstrate low- to isointensity signals on T1-weighted MRI. However, on T2-weighted MRI, the lesions demonstrated low- to high-intensity signals. Gd-enhanced MRI was performed in 32 cases, of which, rim enhancement of the lesion was seen in 30 cases and diffuse enhancement was observed in 2 cases. Rim enhancement might indicate the presence of vascular proliferation surrounding posterior epidural migrated lumbar disc fragments. In all our cases, the lesions were low- to isointense on T1-weightedMRI, where as showing high and low intensities on T2-weighted MRI. Two of our four patients underwent Gd-enhanced MRI, and rim enhancement was observed in all these cases. As to the aforementioned MRI findings, our conservatively treated patients exhibited findings compatible with a diagnosis of posterior epidural migrated lumbar disc fragments. In addition, the lesion in our surgically treated case was proven to be a posterior epidural migrated lumbar disc fragment.
All previous and one present patient with posterior epidural migrated lumbar disc fragments underwent surgical treatment. Only the present three patients underwent conservative treatment and obtained symptom relief. Complete recovery was seen in the 39 surgically treated cases, and improvement was seen in the 16 surgically treated cases. The three patients who underwent conservative treatment, including the oral administration of NSAIDs and a caudal block, were confirmed to have achieved a complete recovery. In the surgically treated cases, the outcomes appear to be unrelated to both the duration from the onset of symptoms until surgery and the clinical symptoms present before surgery. The factors affecting the outcomes remain unclear. The reason for surgical treatment in the reported cases was that posterior epidural migrated lumbar disc fragments usually cause cauda equina syndrome or radiculopathy. Sengoz et al. described early surgical treatment for posterior epidural migrated lumbar disc fragments as being important, as a first choice for preventing severe neurologic deficits. On the other hand, the spontaneous regression of lumbar disc herniations is a widely accepted observation at present. Haro et al. reported that the infiltration of inflammatory cells is more prominent in transligamentous extrusion or sequestration-type lesions. Significant and progressive decreases in the size of herniated nucleus pulposus in some cases of transligamentous and sequestration-type herniated nucleus pulposus have been demonstrated. The diagnosis of posterior epidural migrated lumbar disc fragments falls under the sequestrated type of disc herniation. In the present cases, the posterior epidural migrated lumbar disc fragments were treated as ordinary lumbar disc herniations, and spontaneous regression of the lesions with relief of symptoms was observed on MRI in three cases. The spontaneous lesion regression on MRI with symptom relief observed in these three cases clearly demonstrates the possibility of spontaneous regression of posterior epidural migrated lumbar disc fragments, such as that seen with the more common sequestrated lumbar disc herniations. Consequently, the treatment for posterior epidural migrated lumbar disc fragments should therefore be determined based on the severity and course of the patient’s symptoms. However, providing early surgical treatment is important if the patient has acute cauda equina syndrome or the neurologic symptoms worsen over time.
由MediCool医库软件 王露黔 编译
原文来自：Spontaneous regression of posterior epidural migrated lumbar disc fragments: case series
Spine J. 2015Jun 1;15(6):e57-62.
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