格林巴利综合征 (Guillain-Barre syndrome)MRI病例图片影像诊断分析周围神经 2011-01-10
【临床病史】：患者，10岁男孩，近期病毒感染，出现下肢麻痹和反射减弱。CSF检查提示蛋白含量增高，不伴有脑脊液细胞增多。10-year-old male with recent viral infection is admitted with lower extremity paralysis and hyporeflexia. CSF findings reveal elevated protein level without pleocytosis.
【影像表现】：Figure 1,Figure 2,Figure 3and Figure 4: When compared with pre-contrast T1 weighted sagittal images (Figure 3), post-gadolinium sagittal T1-weighted images demonstrate enhancement and thickening of the cauda equina (Figure 4).对比平扫T1和增强矢状位T1显示马尾增厚强化。
【影像诊断】：Guillain-Barre syndrome 格林巴利综合征
Differential diagnosis of abnormal intrathecal nerve root enhancement includes: 异常的鞘内神经根强化鉴别诊断包括：1.AIDS-related polyradiculopathy AIDS相关的多发性神经根病；2.Arachnoiditis 蛛网膜炎；3.Sarcoidosis 结节病；4.Metastatic disease 转移性病变。
Guillain Barre syndrome is a heterogeneous grouping of immune-mediated processes generally characterized by motor, sensory, and autonomic dysfunction. Classically, GBS is an acute inflammatory demyelinating polyneuropathy characterized by progressive symmetric ascending muscle weakness, paralysis, and hyporeflexia with or without sensory or autonomic symptoms; however, variants involving the cranial nerves or pure motor involvement are not uncommon. 格林巴利综合征是一种免疫介导的多类型病变，一般特征为运动、感觉及自主功能障碍。典型的情况下，GBS是一种急性炎症性脱髓鞘性多发性神经病，表现为急性进行性对称的逐步向上延伸的肌无力、瘫痪和反射减弱，伴有或不伴有感觉或自主功能障碍。然而其他类型-颅神经或单纯的运动神经受累并非罕见。
MRI of the thoracolumbar spine is performed in cases of equivocal CSF and EEG findings or atypical clinical presentation. MRI findings include abnormal thickening and enhancement of the intrathecal nerve roots and cauda equina. The enhancement of only anterior spinal nerve roots is strongly suggestive of Guillain Barre syndrome. MRI is a sensitive but non-specific examination. 当CSF和EEG检查疑诊或临床症状不典型时需要行胸腰椎MR扫描。MRI表现包括异常增粗强化的鞘内神经根和马尾。仅仅是前方的神经根强化强烈的提示GBS。MRI是一种敏感但并不特异的检查。 【讨论】：Guillain Barre syndrome (GBS) is an acute inflammatory demyelinating polyneuropathy (AIDP). It is an autoimmune disease affecting the peripheral nervous system, usually triggered by an acute infectious process. It is frequently severe and usually presents as an ascending paralysis beginning as weakness in the legs that spreads to the upper limbs and the face along with complete loss of deep tendon reflexes. Hypo- or areflexia, autonomic dysfunction and cranial nerve involvement is commonly associated. It is generally preceded by an antecedent bacterial or viral infection. Nearly 40% of patients are seropositive for Campylobacter jejuni. Diagnosis is based on clincial signs and symptoms, lumbar puncture and electrophysiologic crtieria. CSF findings include elevated protein level without pleocytosis. Nerve conduction findings suggestive of GBS include nerve conduction slowing, conduction block, prolonged distal latency, and prolonged or absent F waves. Therapeutic options include supportive measures, plasmapharesis, and immunoglobulin.
Although ascending paralysis is the most common form of spread in GBS, other variants also exist. Miller Fisher syndrome (MFS) is a rare variant of GBS and manifests as a descending paralysis, proceeding in the reverse order of the more common form of GBS. It usually affects the ocular muscles first and presents as opthalmoplegia, ataxia and areflexia. Anti-GQ1b antibodies are found in 90% of cases. Acute motor axonal neuropathy (AMAN), also known as Chinese Paralytic Syndrome, attacks motor nodes of Ranvier and is prevalent in China and Mexico. The disease can be seasonal and recovery can be rapid. Anti-GD1a antibodies are often present. Acute motor sensory neuropathy (AMSAN) is similar to AMAN but also affects sensory nerves with severe axonal damage. Recovery can be incomplete.
Radiologic studies are typically performed in order to exclude other causes. MR of the spine is performed to define infiltrative etiologies such as tranverse myelitis and compressive causes of polyradiculopathy. In cases of equivocal CSF or nerve conduction findings or atypical clinical findings, MRI of the spine can confirm or exclude the diagnosis. Findings usually include thickening and enhancement of the nerve roots that surround the medullary cone and extend along the length of the cauda equina. In GBS, there is lymphocytic and macrophagic infiltration around endoneural vessels with associated demyelination of the affected nerves. The abnormal enhancement of the intrathecal nerve roots is suggestive of blood brain barrier breakdown. Differential diagnosis of abnormal intrathecal nerve root enhancement includes AIDS-related polyradiculopathy in patients affected by CMV, arachnoiditis, sarcoidosis, and metastatic disease, The most common site of enhancement in GBS may be anterior nerve roots rather than posterior nerve roots. MRI is a sensitive but non-specific examination. Motor weakness and sensory change are correlated with patterns of nerve root enhancement and nerve conduction findings.
放射学检查通常被用于除外其他病变。脊髓MR被用于明确病因学。当CSF和EEG检查疑诊或临床症状不典型时，脊髓MRI扫描可以证实或排除诊断。影像表现包括环绕脊髓圆锥的增粗强化的神经根并沿着马尾纵向扩展，在GBS，环绕神经管的淋巴和巨噬细胞浸润伴随受累神经的脱髓鞘改变。鞘内的神经根异常强化提示血脑屏障被破坏，鞘内神经根异常强化的鉴别诊断包括包括巨细胞病毒感染所致的AIDS相关性多发性神经根病、蛛网膜炎、结节病和转移性病变。GBS中最常见的强化部位可能是前根而不是后根。MRI是一种敏感但非特异性的检查。运动虚弱和感觉异常与神经根强化的形式和神经传递改变向关联。(参考来源:,医影志ACR, November, 2009,作者:freemanpyw编译)