86 Table 4 Percentage abnormalities for each parameter per group, measured at both feet. Next, the percentage of abnormalities according to the New Besta criteria are displayed. The New Besta criteria are here defined as small fiber neuropathy (SFN) based on symptoms of SFN in combination with at least 2 clinical signs of SFN and abnormal thermal threshold testing (TTT). Abnormal TTT is defined as at least 1 abnormal parameter measured at both feet with and WDT with the method of limits (MLi) and method of levels (MLe). CDT = cold detection threshold; WTD = warm detection threshold; MLi = method of limits; MLe = method of levels; TSL = thermal sensory limen; PHS = paroxysmal heat sensations; CPT = cold pain threshold; HPT = heat pain threshold; TTT = thermal threshold testing. As shown by the results of all TTT measurements at both feet, over 70% of participants in all groups showed at least one abnormal parameter. Increasing the cutoff value from 1 to 2 abnormalities in all TTT parameters except for MLe in both feet improved the results to 64% abnormal QST in patients with sarcoidosis and SFN, 27% abnormal QST in patients with sarcoidosis without SFN and 25% abnormal QST in healthy controls. Diagnostic accuracy Table 5 shows the reliability of combining different QST parameters, based on the corresponding optimal cutoff value. Measuring TTT according to the new Besta criteria7 results in a sensitivity of 60% and a specificity of 55% when using the cutoff value of 1 abnormal parameter. Combining all TTT measurements at both hands and feet resulted in a minor improvement of specificity to 63% at a cutoff of 5 abnormalities. Measuring all parameters at both feet except for MLe reduced the labor intensiveness with a minor improvement of sensitivity to 65%, while specificity improved to 73% with a cutoff of 2 abnormalities. Measurements at the hands showed lower sensitivity and specificity and measuring one hand or foot also resulted in lower sensitivity and specificity (not displayed in Table 4). The SFNSL questionnaire had a sensitivity of 70% and specificity of 66%. Combining all TTT parameters measured at both feet, except for MLe, with the SFNSL improved the sensitivity to 73% and the specificity to 69%. Percentage abnormal Healthy Controls (n=20) Sarcoidosis without SFN (n=49) Sarcoidosis with probable SFN (n=48) CDT MLi 5% 16% 42% WDT MLi 5% 8% 23% CDT MLe 50% 29% 25% WDT MLe 30% 10% 15% TSL 5% 14% 35% PHS 30% 20% 44% CPT 10% 12% 4% HPT 15% 14% 8% New Besta (≥1 abnormal) 55% 47% 60% TTT feet all (≥1 abnormal) 70% 71% 73% TTT feet without MLe (≥1 abnormal) 40% 57% 67% TTT feet without MLe (≥2 abnormal) 25% 27% 64% 5 90 5
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