Pain-related mood influences pain perception differently in fibromyalgia and multiple sclerosis

Figures & data

Table 1 Participants’ characteristics

	Controls	FM	MS-P	MS-NP
Men/women	11/20	0/13	5/6	7/5
Age (range)	49 (35–65)	52.7 (37–76)	50.16 (38–65)	51.08 (36–73)
Education†	2.1 (0.83)	2.08 (0.86)	2.42 (0.79)	2.25 (0.96)
MMSE	28.45 (1.65)	27.03 (2.00)	27.78 (1)	28.75 (1.2)
MOCA	26.45 (2.88)	23.6 (3.00)*	25.5 (3.3)	25.8 (2.5)

Notes: Data represent mean (standard deviation) values. FM = the group of patients with fibromyalgia; MS-P = the group of multiple sclerosis patients with pain; MS-NP = the group of multiple sclerosis patients without pain.

* Significantly differed from controls (P<0.05).

† Education levels: 1= primary education; 2= secondary education; 3= college education.

Abbreviations: MMSE, Mini Mental State Examination; MOCA, Montreal Cognitive Assessment.

Table 2 Pain and mood assessments

	Controls	FM	MS-P	MS-NP
Depression scale	3.46 (2.82)	7.83 (12.57)**	7.07 (4.09)**	2.83 (2.72)
Anxiety scale	4.3 (2.49)	5.28 (1.21)**	5.84 (2.91)**	1 (1.04)*
PCS-CF	24.41 (9.04)	30 (9.78)*	23.6 (12.05)	26 (7)

Notes: Data represents mean (standard deviation) values. FM = the group of patients with fibromyalgia; MS-P = the group of multiple sclerosis patients with pain; MS-NP = the group of multiple sclerosis patients without pain.

* Significantly differed from controls (P<0.05);

** patients with pain significantly differed from controls and MS patients without pain.

Abbreviation: PCS-CF, French Canadian Pain Catastrophizing Scale.

Figure 1 SPQ discrimination score for “self” pain.

Notes: Variability appears in terms of standard errors. ***Significant differences (P<0.0001) were reported.
Abbreviations: FM, fibromyalgia patients; MS-P, multiple sclerosis patients with pain; MS-NP, multiple sclerosis patients with no pain; SPQ, Situational Pain Questionnaire; TM, normal controls.

Figure 2 SPQ response bias for “self” pain.

Notes: Variability appears in terms of standard errors. *Significant differences (P<0.05) were reported.
Abbreviations: FM, fibromyalgia patients; MS-P, multiple sclerosis patients with pain; MS-NP, multiple sclerosis patients with no pain; SPQ, Situational Pain Questionnaire; TM, normal controls.

Table 3 Sensitivity to facial expressions of pain (STEP test)

Score	Controls	FM	MS-P	MS-NP
Discrimination scores
P(A)NS	0.95 (0.03)	0.92 (0.02)*	0.95 (0.008)	0.90 (0.08)*
P(A)NM	0.77 (0.01)	0.70 (0.02)*	0.71 (0.01)*	0.72 (0.06)
Response bias score
BNS	1.3 (0.05)	1.67 (0.1)*	1.46 (0.07)	1.38 (0.1)
BNM	0.94 (0.04)	1.20 (0.1)*	0.90 (0.05)	0.96 (0.06)

Notes: The discrimination score, P(A), indicates the extent to which participants were able to differentiate facial expressions. The response bias (B) score indicates patients’ tendency to infer pain from the facial expressions. Two discriminations scores and two bias scores were analyzed: NS (between “no pain” and “strong pain” expressions) and NM (between “no pain” and “moderate pain” expressions). The data represent mean (errors standard) values.

* Significant differences between patients and controls (P<0.05).

Abbreviations: FM, fibromyalgia patients; MS-P, multiple sclerosis patients with pain; MS-NP, multiple sclerosis patients with no pain.