Table 2.

Results of baseline QST.

Variable	Nerve fibers involved	ARA 290 (n = 21)		Placebo (n = 17)
		Change	Number of patients (%)	Change	Number of patients (%)
Cold detection threshold	Aδ and C	Decrease	19 (91)	Decrease	11 (65)
Warm detection threshold	Aδ and C	Decrease	17 (81)	Decrease	13 (77)
		Increase	1 (5)
Thermal sensory limen	Aδ and C	Decrease	4 (19)	Decrease	4 (24)
		Increase	2 (10)
Paradoxical heat sensation	Aδ	Decrease	8 (38)	Decrease	7 (41)
Cold pain threshold	Aδ and C	Increase	3 (14)	—	0
Heat pain threshold	C	Decrease	3 (14)	Decrease	1 (6)
		Increase	5 (24)
Mechanical detection threshold	Aβ	Decrease	11 (52)	Decrease	10 (59)
Mechanical pain threshold	Aβ	Decrease	11 (52)	Decrease	4 (24)
		Increase	4 (19)	Increase	2 (12)
Mechanical pain sensitivity	Aβ + C	Decrease	2 (10)	Decrease	1 (6)
		Increase	5 (24)
Dynamic mechanical allodynia	Aβ	Increase	11 (52)	Increase	3 (18)
Windup ratio	Aδ and C	Increase	4 (19)	Increase	2 (12)
Vibration detection threshold	Aβ	Decrease	20 (95)	Decrease	15 (88)
Pressure pain threshold	Aδ and C	Decrease	3 (14)	Decrease	1 (6)
		Increase	10 (48)	Increase	7 (41)

Patients in the ARA 290 and placebo groups showed functional impairment of both small nerve fibers (Aδ and C) as well as larger sensory nerve fibers (Aβ). Data are expressed as number of patients deviating beyond the 95% confidence interval of a sex- and age-matched normal population. Test sites of face, hand and foot are pooled for calculation of percentages. “Decrease” indicates a loss of function; “Increase” indicates a gain in function compared with a normal population. For example, a decreased CDT means that a patient required a lower temperature stimulus than normal to determine that an object was cold (that is, a decrease in sensitivity).