Department of Internal Medicine, University Hospital, Angers, 49000, France.
Department of Neurology, Referral center for neuromuscular diseases, University Hospital, Angers, 49000, France.
Eur J Intern Med. 2020 Sep;79:58-62. doi: 10.1016/j.ejim.2020.05.004. Epub 2020 May 27.
To distinguish large (LFN) and small fiber neuropathies (SFN) in Sjögren's syndrome (SS) requires electroneuromyography (EMG) first, but this is time-consuming and has sometimes a limited accessibility, which can lead to a diagnostic delay. We aimed to identify clinical features that could distinguish SFN from sensitive LFN in SS.
The study included patients with SS who were monitored in the internal medicine and neurology departments at Angers University Hospital between 2010 and 2016, and who were tested for suspected peripheral neuropathy. Patients with clinical motor involvement were excluded. LFN diagnosis was based on EMG. SFN diagnosis was based on intraepidermal nerve fiber density on skin biopsies in patients with no abnormality on EMG.
LFN and SFN were diagnosed respectively in 22 (6.9%) and 17 (5.4%) patients among 317 patients with SS. Prevalence of anti-SSA antibodies was lower in the SFN group compared to the LFN group (p=0.002). The types of paresthesia did not differ between the 2 groups. After adjustment for age and sex, SFN was associated with dysautonomia (p=0.01, OR 8.4 [CI 95%: 1.7-42.4]) and without length-dependent topography (p=0.03, OR 0.2 [0.04-0.8] in comparison with the LFN group.
An association of non-length-dependent pattern and dysautonomia seems to predict the absence of LFN in SS and encourages the search for SFN. In contrary, patients with length-dependent involvement and without dysautonomia should be prioritized for EMG.
在干燥综合征（SS）中，要区分大纤维神经病（LFN）和小纤维神经病（SFN），首先需要进行电神经肌图（EMG）检查，但这既费时又有时无法广泛获得，这可能导致诊断延迟。我们旨在确定可将 SFN 与 SS 中的敏感 LFN 区分开的临床特征。
这项研究纳入了 2010 年至 2016 年期间在昂热大学附属医院内科和神经科接受监测的 SS 患者，这些患者接受了疑似周围神经病的检查。排除了有临床运动受累的患者。LFN 诊断基于 EMG。SFN 诊断基于 EMG 无异常患者的皮肤活检中的表皮内神经纤维密度。
在 317 例 SS 患者中，分别诊断出 LFN 和 SFN 分别为 22 例（6.9%）和 17 例（5.4%）。SFN 组患者的抗 SSA 抗体阳性率低于 LFN 组（p=0.002）。两组患者的感觉异常类型无差异。在校正年龄和性别后，SFN 与自主神经功能障碍相关（p=0.01，OR 8.4 [95%CI：1.7-42.4]），并且没有长度依赖性分布（p=0.03，与 LFN 组相比，OR 0.2 [0.04-0.8]）。
非长度依赖性模式和自主神经功能障碍的关联似乎可预测 SS 中不存在 LFN，并鼓励寻找 SFN。相反，具有长度依赖性受累且无自主神经功能障碍的患者应优先进行 EMG 检查。
