Residency Program of Neurology, Università Degli Studi di Milano, Milan, Italy.
Department of Neurology, IRCCS Istituto Auxologico Italiano, Piazzale Brescia, 20, Milan, 20149, Italy.
BMC Neurol. 2024 Sep 2;24(1):309. doi: 10.1186/s12883-024-03799-6.
Bibrachial amyotrophy associated with an extradural CSF collection and infratentorial superficial siderosis (SS) are rare conditions that may occasionally mimic ALS. Both disorders are assumed to be due to dural tears.
A 53-year-old man presented with a 7-year history of slowly progressive asymmetric bibrachial amyotrophy. Initially, a diagnosis of atypical motor neuron disease (MND) was made. At re-evaluation 11 years later, upper limb wasting and weakness had further progressed and were accompanied by sensorineural hearing loss. MRI of the brain and spine demonstrated extensive supra- and infratentorial SS (including the surface of the whole spinal cord) as well as a ventral longitudinal intraspinal fluid collection (VLISFC) extending along almost the entire thoracic spine. Osteodegenerative changes were observed at C5-C7 level, with osteophytes protruding posteriorly. The bony spurs at C6-C7 level were hypothesized to have lesioned the dura, causing a CSF leak and thus a VLISFC. Review of the MRI acquired at first evaluation showed that the VLISFC was already present at that time (actually beginning at C7 level), whereas the SS was not. 19 years after the onset of upper limb weakness, the patient additionally developed parkinsonism. Response to levodopa, brain scintigraphy with I-ioflupane and brain MRI with nigrosome 1 evaluation were consistent with idiopathic Parkinson's disease (PD). On the latest follow-up 21 years after symptom onset, the VLISFC was unchanged, as were upper arm weakness and wasting.
Based on the long-term follow-up, we could establish that, while the evidence of the VLISFC was concomitant with the clinical presentation of upper limb amyotrophy and weakness, the radiological signs of SS appeared later. This suggests that SS was not per se the cause of the ALS-like clinical picture, but rather a long-term sequela of a dural leak. The latter was instead the causative lesion, giving rise to a VLISFC which compressed the cervical motor roots. Dural tears can actually cause several symptoms, and further studies are needed to elucidate the pathophysiological correlates of "duropathies". Finally, as iron metabolism has been implicated in PD, the co-occurrence of PD with SS deserves further investigation.
与硬脊膜外脑脊髓液（CSF）积聚和颅后窝表浅铁沉积症（SS）相关的双侧上肢下运动神经元病（UMN）较为罕见，偶尔可能类似于肌萎缩侧索硬化症（ALS）。这两种疾病均被认为是由于硬脊膜撕裂引起的。
一名 53 岁男性，表现为进行性双侧上肢肌无力 7 年，最初诊断为非典型运动神经元病（MND）。11 年后再次评估时，上肢肌肉萎缩和无力进一步进展，并伴有感音神经性听力损失。头颅和脊柱 MRI 显示广泛的颅后窝和颅上 SS（包括整个脊髓表面）以及沿着几乎整个胸段脊髓延伸的腹侧长脊髓内液性聚集（VLISFC）。C5-C7 水平观察到退行性骨改变，骨赘向后突出。C6-C7 水平的骨赘被认为损伤了硬脊膜，导致 CSF 漏，从而形成 VLISFC。回顾首次评估时获取的 MRI 显示，当时已经存在 VLISFC（实际上从 C7 水平开始），而 SS 尚未出现。上肢无力发作 19 年后，患者另外出现帕金森病。左旋多巴反应、I-ioflupane 脑闪烁扫描和黑质 1 评估的脑 MRI 结果与特发性帕金森病（PD）一致。症状发作后 21 年的最新随访中，VLISFC 无变化，上臂无力和萎缩也无变化。
根据长期随访，我们可以确定，尽管 VLISFC 的证据与上肢肌无力和无力的临床表现同时存在，但 SS 的影像学征象出现较晚。这表明 SS 本身并不是 ALS 样临床症状的原因，而是硬脊膜漏的长期后遗症。后者是导致 VLISFC 的致病病变，压迫颈髓运动神经根。硬脊膜撕裂实际上可能引起多种症状，需要进一步研究阐明“硬脊膜病”的病理生理学相关性。最后，由于铁代谢与 PD 有关，PD 与 SS 同时发生值得进一步研究。
