Abstract：
OBJECTIVE: We aimed to investigate to what extent small fiber tests were abnormal in an unselected retrospective patient material with symptoms suggesting that small fiber neuropathy (SFN) could be present, and to evaluate possible gender differences.
METHODS: Nerve conduction studies (NCS), skin biopsy for determination of intraepidermal nerve fiber density (IENFD) and quantitative sensory testing (QST) were performed. Z-scores were calculated from reference materials to adjust for the effects of age and gender/height.
RESULTS: Two hundred and three patients, 148 females and 55 males had normal NCS and were considered to have possible SFN. 45.3 % had reduced IENFD, 43.2 % of the females and 50.9 % of the males. Mean IENFD was 7.3 ± 2.6 fibers/mm in females and 6.1 ± 2.3 in males (p<0.001), but the difference was not significant when adopting Z-scores. Comparison of gender differences between those with normal and abnormal IENFD were not significant when Z-scores were applied. QST was abnormal in 50 % of the patients (48.9 % in females and 52.9 % in males). In the low IENFD group 45 cases out of 90 (50 %) were recorded with abnormal QST. In those with normal IENFD 51 of 102 (50 %) showed abnormal QST.
CONCLUSIONS: Less than half of these patients had reduced IENFD, and 50 % had abnormal QST. There were no gender differences. A more strict selection of patients might have increased the sensitivity, but functional changes in unmyelinated nerve fibers are also known to occur with normal IENFD. Approval to collect data was given by the Norwegian data protection authority at University Hospital of North Norway (Project no. 02028).
METHODS: Nerve conduction studies (NCS), skin biopsy for determination of intraepidermal nerve fiber density (IENFD) and quantitative sensory testing (QST) were performed. Z-scores were calculated from reference materials to adjust for the effects of age and gender/height.
RESULTS: Two hundred and three patients, 148 females and 55 males had normal NCS and were considered to have possible SFN. 45.3 % had reduced IENFD, 43.2 % of the females and 50.9 % of the males. Mean IENFD was 7.3 ± 2.6 fibers/mm in females and 6.1 ± 2.3 in males (p<0.001), but the difference was not significant when adopting Z-scores. Comparison of gender differences between those with normal and abnormal IENFD were not significant when Z-scores were applied. QST was abnormal in 50 % of the patients (48.9 % in females and 52.9 % in males). In the low IENFD group 45 cases out of 90 (50 %) were recorded with abnormal QST. In those with normal IENFD 51 of 102 (50 %) showed abnormal QST.
CONCLUSIONS: Less than half of these patients had reduced IENFD, and 50 % had abnormal QST. There were no gender differences. A more strict selection of patients might have increased the sensitivity, but functional changes in unmyelinated nerve fibers are also known to occur with normal IENFD. Approval to collect data was given by the Norwegian data protection authority at University Hospital of North Norway (Project no. 02028).
摘要：
目的：我们的目的是调查在未选择的回顾性患者材料中小纤维测试异常的程度，这些患者的症状表明可能存在小纤维神经病变（SFN），并评估可能的性别差异。
方法：神经传导研究（NCS），进行皮肤活检以确定表皮内神经纤维密度（IENFD）和定量感觉测试（QST）。根据参考材料计算Z得分，以调整年龄和性别/身高的影响。
结果：两百三例患者，148名女性和55名男性具有正常的NCS并且被认为具有可能的SFN。45.3%的人减少了IENFD，女性占43.2%，男性占50.9%。平均IENFD在女性为7.3±2.6纤维/mm，在男性为6.1±2.3（p<0.001），但采用Z评分时差异不显著。应用Z评分时，IENFD正常和异常者之间的性别差异比较不显着。50％的患者QST异常（女性为48.9％，男性为52.9％）。在低IENFD组中，90例中有45例（50％）记录了QST异常。在IENFD正常的患者中，有102个（50％）的51个显示QST异常。
结论：这些患者中不到一半的IENFD降低，50%有QST异常。没有性别差异。更严格的患者选择可能会增加敏感性，但已知正常IENFD也会发生无髓神经纤维的功能变化。挪威北挪威大学医院的挪威数据保护机构批准了收集数据的工作（项目编号：02028).
方法：神经传导研究（NCS），进行皮肤活检以确定表皮内神经纤维密度（IENFD）和定量感觉测试（QST）。根据参考材料计算Z得分，以调整年龄和性别/身高的影响。
结果：两百三例患者，148名女性和55名男性具有正常的NCS并且被认为具有可能的SFN。45.3%的人减少了IENFD，女性占43.2%，男性占50.9%。平均IENFD在女性为7.3±2.6纤维/mm，在男性为6.1±2.3（p<0.001），但采用Z评分时差异不显著。应用Z评分时，IENFD正常和异常者之间的性别差异比较不显着。50％的患者QST异常（女性为48.9％，男性为52.9％）。在低IENFD组中，90例中有45例（50％）记录了QST异常。在IENFD正常的患者中，有102个（50％）的51个显示QST异常。
结论：这些患者中不到一半的IENFD降低，50%有QST异常。没有性别差异。更严格的患者选择可能会增加敏感性，但已知正常IENFD也会发生无髓神经纤维的功能变化。挪威北挪威大学医院的挪威数据保护机构批准了收集数据的工作（项目编号：02028).
