Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Loss of Microvascular Response to Central Nervous Impulses to Finger Pulp in Systemic Sclerosis.

Bergersen2,  Tone Kristin, Hoffmann-Vold1,  Anna-Maria, Midtvet2,  Oivind, Gran2,  Jan Tore, Mork2,  Cato, Toska3,  Karin

Oslo University Hospital, Oslo, Nydalen, Norway
Oslo University Hospital, Oslo, Norway
University of Oslo, Blindern, Norway

Thickening and fibrosis of digital skin with recurrent digital ulcera are major problems in systemic sclerosis (SSc). Probably, digital ulcera are caused by damage of the microvascular bed (1). Typically, the fingers are more severely affected than the proximal parts of the palm. Blood flow in skin of hands is mainly controlled by the arteriovenous anastomoses (AVAs) located in the palm and nailbeds (2). The vasomotion of the AVAs is controlled by the CNS and is synchronous in all skin areas. We have studied the vasomotor activity in skin of fingers and thenar region in SSc.

Laser Doppler flux (Moor instruments, England) from finger pulp and thenar region were simultaneously recorded together with ipsilateral radial artery blood velocities (ultrasound Doppler, SD100, Vingmed, Norway) and mean arterial blood pressure (Finapres) in 11 patients and in 11 aged matched healthy subjects. The subjects were resting on a bench in thermoneutral condition for 30 min before a 15 min continuous recording was obtained.

The mean duration of SSc was 7.3 yrs (range 2–15 yrs), mean age 55 yrs (range 45–67 yrs). Eight of the patients had previous history of digital ulcera, but none had ongoing ulcera. All patients had Raynauds phenomenon and disturbed microvascular architecture visualized by nailfold capillaroscopy. The blood velocity in the radial artery in both groups showed the typical large fluctuations caused by synchronous opening and closing of the AVAs (2) (Fig. 1A). In the control group, fluctuations in thenar flux and finger pulp flux were closely correlated to the velocity fluctuations in the radial artery (Table 1). In the SSc group, there was also a close correlation between the thenar flux and the velocity fluctuations in the radial artery (Fig 1A and B, Table 1). However, the simultaneous finger pulp flux was statistically significantly less correlated to the velocity in radial artery than the thenar flux (Table 1). Furthermore, in some patients, a positive correlation was seen between finger pulp flux and short-time variability in MAP (Fig. 1 C and D).

Figure 1. Simultaneous blood velocity, flux and MAP in a patient with SSc.

Table 1.

 SScControl group
 median r94% CImedian r94% CI
finger pulp flux - radial artery0.27-0.15, 0.670.870.73, 0.96
thenar flux - radial artery0.770.65, 0.860.900.87, 0.94
Wilcoxon sign test, p0.016 0.81 
r= correlation coefficient, CI=Confidence Interval, significance level p<0.05

In conclusion, the pattern of bursts of efferent sympathetic impulses to skin AVAs is probably unchanged in SSc. However, the AVAs in the SSc finger do have an attenuated response to impulses from the CNS. A positive correlation between perfusion of finger tip and short-time variability in MAP suggest a passive vascular bed where blood flow variations is a result of variations in MAP.

References:

1.Abraham,  et al. Rheumatology.(Oxford) 48 Suppl 3: iii3–iii7, 2009.

2.Bergersen,  et al. Am.J.Physiol.Regul.Integr.Comp.Physiol. 269 : R325–R330, 1995.

To cite this abstract, please use the following information:
Bergersen, Tone Kristin, Hoffmann-Vold, Anna-Maria, Midtvet, Oivind, Gran, Jan Tore, Mork, Cato, Toska, Karin; Loss of Microvascular Response to Central Nervous Impulses to Finger Pulp in Systemic Sclerosis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1220
DOI: 10.1002/art.28986

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