Evaluation of the finger wrinkling test: a pilot study.
OBJECTIVE
Tilt table testing mainly evaluates the systemic cardiovascular part of the autonomic nervous system, while it is assumed that the finger wrinkling test assesses the peripheral part of the autonomic nervous system. In this study we explored whether the finger wrinkling test could be a useful test for autonomic dysfunction and whether the clinical evaluation of wrinkling can be improved by digital analysis of photographs.


METHODS
As much as 20 healthy subjects and 15 patients underwent tilt table testing and finger wrinkling testing. During the finger wrinkling test the right hand was immersed in water at 40 degrees C. The degree of wrinkling was assessed with a 5-point clinical scale at baseline, 5, 15 and 30 min of immersion. Photographs were taken at the same intervals. Several features were evaluated using digital analysis: length and gradient of automatically detected wrinkle and mean, maximum, minimum, variance and derivative of grey value of pixels.


RESULTS
Clinical scoring of wrinkling allowed differentiation between healthy subjects and patients with a normal and an abnormal response to tilt table testing. Relevant features obtained with digital analysis were mean grey value and the gradient of automatically detected wrinkle. McNemar's test showed no difference in test results between the tilt table test and the finger wrinkling test with a kappa of 0.68.


CONCLUSIONS
The finger wrinkling test can be used as a screening test before tilt table testing. Visual evaluation of wrinkling is still superior to digital analysis of photographs.
van Barneveld
S
S
Department of Clinical Neurophysiology, Medisch Spectrum Twente, Haaksbergerstraat 55, 7513 ER, Enschede, The Netherlands. sylvia_van_barneveld@hotmail.com
van der Palen
J
J
van Putten
M J A M
MJ
D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000503:physiopathology*; D005260:Female; D005385:Fingers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010781:Photography; D010865:Pilot Projects; D012867:Skin / Q000473:pathology*; D018667:Tilt-Table Test
Biomed Pharmacother. 2001 Oct;55(8):475-8
11686582
Muscle Nerve. 1997 Aug;20(8):919-37
9236782
Clin Auton Res. 2004 Apr;14(2):125-31
15095056
Muscle Nerve. 2003 Mar;27(3):307-11
12635117
Europace. 2004 Nov;6(6):467-537
15519256
Clin Neurophysiol. 2009 May;120(5):953-8
19375384
Br Med J. 1977 Feb 26;1(6060):551-2
843801
Diabetes Care. 1984 May-Jun;7(3):224-7
6734390
J Neurol Neurosurg Psychiatry. 2008 Jul;79(7):835-7
18270233
Aust N Z J Surg. 2000 Jan;70(1):57-9
10696945