Szabolcs Szatmári1, Alexandra Pintér2, Tamás Horváth3, Annamária Takáts4, Dániel Bereczki4, Martin Arndt5, Ben Min-Woo Illigens6, Timo Siepmann5
1 János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest
2 Department of Family Medicine, Semmelweis University, Budapest
3 Department of Hydrodynamic Systems, Budapest University of Technology and Economics, Budapest
4 Department of Neurology, Semmelweis University, Budapest
5 Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden
6 Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston
Introduction: Alpha-synuclein accumulation in cutaneous autonomic pilomotor nerve fibers has been linked to autonomic nervous system disturbances even in the early stages of Parkinson’s disease (PD). Currently the proposed method to quantify pilomotor function in PD is the quantitative pilomotor axon-reflex test (QPART).
Aims: to assess the link between structural nerve fiber damage and nerve function in PD, test reproducibility and validity of QPART, and compare the reproducibility of a novel, semi-automated image analysis technique with the recent manual counting method.
Method: 10 patients (4 male, 6 female) with idiopathic PD were recruited. Pilomotor function was evaluated on the forearms after iontophoresis of phenylephrine to elicit a cutaneous axon-reflex mediated response. Silicone impressions of the stimulation area were obtained, scanned and quantified for pilomotor impressions. Based on 40 images a semi-automated image analysis algorithm written in ImageJ was compared with the current method. The number of impressions, QPART enveloping area and circumference were quantified with the two methods. Tests were performed at baseline (visit1) and after 2 weeks (visit2).
Results: Mean age and disease duration were 60 and 5.9 years respectively. Between the automatic and manual methods, at both visits1 and 2 impression-count differed by 3 on the left and 1 on the right side. QPART area differed at visit1 by 23 and 20 mm2 on left and right forearms. At visit2 these differences were 20 and 18 mm2. QPART perimeter difference at visit1 was 3mm at the left and 2mm at the right arm, at visit2 these values were both 2 mm.
Conclusion: Results supporting QPART reproducibility and validity can contribute to introduction of QPART into clinical practice. Thus, QPART could be a non-invasive method of early detection and long-term follow up of pilomotor nerve damage and PD in research as well as in clinical assessment.
Doctoral School: János Szentágothai Doctoral School of Neurosciences
Program: 05. Clinical neurological research
Supervisor: Dániel Bereczki
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