Abstract：
BACKGROUND: Anti-immunoglobulin-like cell adhesion molecule 5 (IgLON5) disease is a rare autoimmune encephalitis that can mimic progressive supranuclear palsy or corticobasal syndrome. Moreover, anti-IgLON5 disease can present with symptoms characteristic of multiple system atrophy (MSA), such as cerebellar ataxia and autonomic dysfunction. However, the clinical features of anti-IgLON5 disease resembling MSA have not been well established.
METHODS: We enrolled 35 patients with suspected MSA for whom anti-IgLON5 antibody tests were requested. We evaluated immunoglobulin G (IgG) against IgLON5 using cell-based assays. We also summarized the clinical characteristics of patients who were positive for anti-IgLON5 antibodies.
RESULTS: We identified serum and cerebrospinal fluid anti-IgLON5 antibodies in three patients. These patients had many clinical features characteristic of MSA, including parkinsonism, cerebellar ataxia, severe orthostatic hypotension, acute respiratory failure, sleep parasomnia, vocal cord paralysis, and pyramidal tract signs. Clinical features atypical for MSA were myorhythmia, horizontal eye movement restriction, fasciculations, and painful muscle cramps.
CONCLUSIONS: Anti-IgLON5 disease may be an important differential diagnosis of MSA. A comprehensive physical examination, including assessments of eye movement, lower motor neuron signs, and atypical involuntary movements, is important to avoid misdiagnosis.
METHODS: We enrolled 35 patients with suspected MSA for whom anti-IgLON5 antibody tests were requested. We evaluated immunoglobulin G (IgG) against IgLON5 using cell-based assays. We also summarized the clinical characteristics of patients who were positive for anti-IgLON5 antibodies.
RESULTS: We identified serum and cerebrospinal fluid anti-IgLON5 antibodies in three patients. These patients had many clinical features characteristic of MSA, including parkinsonism, cerebellar ataxia, severe orthostatic hypotension, acute respiratory failure, sleep parasomnia, vocal cord paralysis, and pyramidal tract signs. Clinical features atypical for MSA were myorhythmia, horizontal eye movement restriction, fasciculations, and painful muscle cramps.
CONCLUSIONS: Anti-IgLON5 disease may be an important differential diagnosis of MSA. A comprehensive physical examination, including assessments of eye movement, lower motor neuron signs, and atypical involuntary movements, is important to avoid misdiagnosis.
摘要：
背景：抗免疫球蛋白样细胞粘附分子5（IgLON5）疾病是一种罕见的自身免疫性脑炎，可以模拟进行性核上性麻痹或皮质基底综合征。此外，抗IgLON5疾病可呈现多系统萎缩（MSA）的症状特征，如小脑共济失调和自主神经功能障碍。然而,类似于MSA的抗IgLON5疾病的临床特征尚未明确。
方法：我们招募了35例疑似MSA患者，他们要求进行抗IgLON5抗体检测。我们使用基于细胞的测定法评估了针对IgLON5的免疫球蛋白G（IgG）。我们还总结了抗IgLON5抗体阳性患者的临床特征。
结果：我们在3例患者中鉴定了血清和脑脊液抗IgLON5抗体。这些患者具有许多MSA的临床特征，包括帕金森病,小脑共济失调,严重的直立性低血压，急性呼吸衰竭,睡眠失眠症，声带麻痹,和锥体束的迹象。MSA不典型的临床特征是肌律紊乱，水平眼球运动限制，束感，疼痛的肌肉痉挛.
结论：抗IgLON5病可能是MSA的重要鉴别诊断。全面体检,包括对眼球运动的评估，较低的运动神经元标志，和非典型的不自主运动，重要的是要避免误诊。
方法：我们招募了35例疑似MSA患者，他们要求进行抗IgLON5抗体检测。我们使用基于细胞的测定法评估了针对IgLON5的免疫球蛋白G（IgG）。我们还总结了抗IgLON5抗体阳性患者的临床特征。
结果：我们在3例患者中鉴定了血清和脑脊液抗IgLON5抗体。这些患者具有许多MSA的临床特征，包括帕金森病,小脑共济失调,严重的直立性低血压，急性呼吸衰竭,睡眠失眠症，声带麻痹,和锥体束的迹象。MSA不典型的临床特征是肌律紊乱，水平眼球运动限制，束感，疼痛的肌肉痉挛.
结论：抗IgLON5病可能是MSA的重要鉴别诊断。全面体检,包括对眼球运动的评估，较低的运动神经元标志，和非典型的不自主运动，重要的是要避免误诊。
