Open AccessDiagnosing small fiber neuropathy in clinical practice: a deep phenotyping study
Author(s) -
Nadine Egenolf,
Caren Meyer zu Altenschildesche,
Luisa Kreß,
Katja Eggermann,
Barbara Namer,
Franziska Gross,
Alexander Klitsch,
Tobias Malzacher,
Daniel Kampik,
Rayaz A. Malik,
Ingo Kurth,
Claudia Sommer,
Nurcan Üçeyler
Publication year - 2021
Publication title -
therapeutic advances in neurological disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.684
H-Index - 50
eISSN - 1756-2864
pISSN - 1756-2856
DOI - 10.1177/17562864211004318
Subject(s) - medicine , sudomotor , axon reflex , neurological examination , nerve fiber , skin biopsy , quantitative sensory testing , physical examination , pathology , neurology , gold standard (test) , medical history , dermatology , biopsy , surgery , sensory system , reflex , anatomy , neuroscience , biology , psychiatry
Background and aims: Small fiber neuropathy (SFN) is increasingly suspected in patients with pain of uncertain origin, and making the diagnosis remains a challenge lacking a diagnostic gold standard.Methods: In this case–control study, we prospectively recruited 86 patients with a medical history and clinical phenotype suggestive of SFN. Patients underwent neurological examination, quantitative sensory testing (QST), and distal and proximal skin punch biopsy, and were tested for pain-associated gene loci. Fifty-five of these patients additionally underwent pain-related evoked potentials (PREP), corneal confocal microscopy (CCM), and a quantitative sudomotor axon reflex test (QSART).Results: Abnormal distal intraepidermal nerve fiber density (IENFD) (60/86, 70%) and neurological examination (53/86, 62%) most frequently reflected small fiber disease. Adding CCM and/or PREP further increased the number of patients with small fiber impairment to 47/55 (85%). Genetic testing revealed potentially pathogenic gene variants in 14/86 (16%) index patients. QST, QSART, and proximal IENFD were of lower impact.Conclusion: We propose to diagnose SFN primarily based on the results of neurological examination and distal IENFD, with more detailed phenotyping in specialized centers.