Laser Doppler Flare Imaging and Quantitative Thermal Thresholds Testing Performance in Small and Mixed Fiber Neuropathies.
BACKGROUND
Small fiber neuropathy might be a part of typical mixed small and large fiber neuropathy, or a distinct entity, affecting exclusively small nerve fibers.


OBJECTIVE
Explore the utility of small nerve fiber testing in patients with clinical presentation suggesting small fiber neuropathy, with and without evidence for concomitant large fiber neuropathy.


METHODS
Patients attending the neuromuscular clinic from 2012 to 2015 with a clinical presentation suggesting small nerve fiber impairment, who had Laser Doppler flare imaging (LDIFlare) and quantitative thermal testing (QTT) were evaluated for this study. Patients with clinical or electrophysiological evidence for concomitant large fiber neuropathy were not excluded.


RESULTS
The sensitivities of LDIFlare, cooling and heat threshold testing were 64%, 36%, and 0% respectively for clinically highly suggestive small fiber neuropathy, 64%, 56%, and 19% respectively for mixed fiber neuropathy, and 86%, 79%, and 29% respectively for diabetic mixed fiber neuropathy.


CONCLUSIONS
LDIFlare and cooling thresholds testing are non-invasive small nerve fiber testing modalities, with moderate performance in patients with small and mixed fiber neuropathy, and excellent performance in diabetic mixed fiber neuropathy.
Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada.
Alon
http://orcid.org/0000-0002-9020-2399
A
Abraham
Department of Neurology, King Fahad Hospital of the University, University of Dammam, Dammam, Saudi Arabia.
Majed
M
Alabdali
Department of Neurology, King Fahad Hospital of the University, University of Dammam, Dammam, Saudi Arabia.
Abdulla
A
Alsulaiman
Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada.
Ari
A
Breiner
Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada.
Carolina
C
Barnett
Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada.
Hans D
HD
Katzberg
Division of Endocrinology and Metabolism, Department of Medicine, Mount Sinai Hospital and Lunenfeld Tanenbaum Research Institute, University of Toronto, Toronto, Canada.
Leif E
LE
Lovblom
Division of Endocrinology and Metabolism, Department of Medicine, Mount Sinai Hospital and Lunenfeld Tanenbaum Research Institute, University of Toronto, Toronto, Canada.
Bruce A
BA
Perkins
Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada.
Vera
V
Bril
D003929:Diabetic Neuropathies / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D000071075:Small Fiber Neuropathy / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013697:Thermosensing / Q000502:physiology