Spinal Excitability in Patients with Painful Chronic Pancreatitis

Figures & data

Figure 1 Overview of data available for each measure.

Abbreviations: CP, chronic pancreatitis; QST, quantitative sensory testing; NWR, nociceptive withdrawal reflex; SEPs, somatosensory evoked potentials; CPM, conditioned pain modulation; EEG, electroencephalography; EMG, electromyography.

Table 1 Basic Demography of Included Chronic Pancreatitis Patients (n = 17) and Healthy Controls (n = 20)

	Chronic Pancreatitis	Healthy Controls
Age (years), mean ± SD	52.5 ± 16.5	46.8 ± 13.3
Male gender, n (%)	9 (53)	12 (60)
Height (cm), mean ± SD	169.5 ± 10.4	178.8 ± 9.7
Weight (kg), mean ± SD	71.3 ± 20.4	80.2 ± 12.8
BMI (kg/m^2), mean ± SD	24.5 ± 4.9	25.1 ± 3.1
Active smoking, n (%)	10 (59)	4 (29)
Alcohol >14units/week, n (%)	0 (0)	0 (0)
Systolic blood pressure (mmHg), mean (SD)	131 ± 20	136 ± 23
Diastolic blood pressure (mmHg), mean ± SD	76 ± 14	80 ± 14
Pulse (/min), mean ± SD	80 ± 13	69 ± 11
Disease duration (years), mean ± SD	9 ± 8	–
Risk/etiology of chronic pancreatitis, n (%) according to TIGAR-O^a
Toxic-metabolic	5 (29)	-
Idiopathic	4 (24)
Genetic	2 (12)
Autoimmune	1 (6)
Recurrent/severe acute pancreatitis	5 (29)
Obstructive	0 (0)

Notes: ^aWhitcomb DC, Pancreatitis: TIGAR-O version 2 Risk/Etiology Checklist with topic reviews, updates, and use primers. Clin Transl Gastroenterol. 2019; 10(6):1–14.

Figure 2 (A) Median pain detection thresholds in patients with chronic pancreatitis (n = 17) and healthy controls (n = 20), Whiskers mark interquartile range, (B) Median pain tolerance thresholds in patients with chronic pancreatitis (n = 17) and healthy controls (n = 20), Whiskers mark interquartile range.

Figure 3 (A) Self-reported pain during cold pressor test in chronic pancreatitis patients (n = 17) and healthy controls (n = 20), VAS = visual analogue scale, (B) Coldpressor endurance time in chronic pancreatitis patients (n = 17) and healthy controls (n = 20).

Figure 4 (A) Boxplot of reflex thresholds measured in mA during the nociceptive withdrawal reflex in patients with chronic pancreatitis (n = 14) and healthy controls (n = 20), (B) Boxplot of reflex AUC per subject measured using electromyography during elicitation of the nociceptive withdrawal reflex in patients with chronic pancreatitis (n = 12) and healthy controls (n = 19).

Abbreviation: AUC, area under the curve.

Table 2 Correlations Between Nociceptive Withdrawal Reflex Findings (Reflex Threshold, Reflex Area Under the Curve), Clinical Characteristics and Quantitative Sensory Testing Measures in Patients with Painful CP^a

Measure	Reflex Threshold	Reflex AUC
Age	ρ = −0.41, P = 0.15	ρ = 0.19, P = 0.56
Disease duration	ρ = 0.61, P = 0.02^b	ρ = 0.04, P = 0.91
Brief Pain Inventory Pain Severity score	ρ = 0.70, P = 0.02^c	ρ = −0.49, P = 0.22
Brief Pain Inventory Pain Interference score	ρ = 0.18, P = 0.61	ρ = −0.38, P = 0.35
Temporal summation – T10 abdomen	ρ = −0.26, P = 0.36	ρ = 0.15, P = 0.65
Temporal summation – C5	ρ = −0.14, P = 0.63	ρ = 0, P = 1
Pressure detection thresholds summarized	ρ = −0.19, P = 0.52	ρ = 0.01, P = 0.97
Pressure tolerance thresholds summarized	ρ = 0.07, P = 0.82	ρ = −0.01, P = 0.98
VAS during cold pressor (AUC)	ρ = 0.25, P = 0.39	ρ = −0.08, P = 0.80
Cold pressor endurance time	ρ = 0.71, P = 0.004^d	ρ = 0.37, P = 0.24

Notes: Bold text marks statistical significance, ρ refers to Spearman’s rank correlation coefficient. ^bData available for 14 patients, ^cData available for 10 patients, ^dData available for 14 patients.

Abbreviations: ^aAUC, area under the curve; VAS, visual analogue scale.

Figure 5 (A) Scatterplot of reflex thresholds and cold pressor endurance time in patients with painful chronic pancreatitis (n=14), (B) Reflex thresholds in patients with painful chronic pancreatitis colored according to whether they were able to endure the cold pressor test for 180 seconds (n=7) or less (n=7).