TY  - JOUR
A1  - Egenolf, Nadine
A1  - Altenschildesche, Caren Meyer zu
A1  - Kreß, Luisa
A1  - Eggermann, Katja
A1  - Namer, Barbara
A1  - Gross, Franziska
A1  - Klitsch, Alexander
A1  - Malzacher, Tobias
A1  - Kampik, Daniel
A1  - Malik, Rayaz A.
A1  - Kurth, Ingo
A1  - Sommer, Claudia
A1  - Üçeyler, Nurcan
T1  - Diagnosing small fiber neuropathy in clinical practice: a deep phenotyping study
JF  - Therapeutic Advances in Neurological Disorders
N2  - 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.
KW  - algorithm
KW  - diagnosis
KW  - neurological examination
KW  - skin punch biopsy
KW  - small fiber neuropathy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232019
SN  - 1756-2864
VL  - 14
ER  - 
TY  - JOUR
A1  - Özdağ Acarlı, Ayşe Nur
A1  - Klein, Thomas
A1  - Egenolf, Nadine
A1  - Sommer, Claudia
A1  - Üçeyler, Nurcan
T1  - Subepidermal Schwann cell counts correlate with skin innervation - an exploratory study
JF  - Muscle & Nerve
N2  - Introduction/Aims
Schwann cell clusters have been described at the murine dermis-epidermis border. We quantified dermal Schwann cells in the skin of patients with small-fiber neuropathy (SFN) compared with healthy controls to correlate with the clinical phenotype.
Methods
Skin punch biopsies from the lower legs of 28 patients with SFN (11 men, 17 women; median age, 54 [range, 19-73] years) and 9 healthy controls (five men, four women, median age, 34 [range, 25-69] years) were immunoreacted for S100 calcium-binding protein B as a Schwann cell marker, protein-gene product 9.5 as a pan-neuronal marker, and CD207 as a Langerhans cell marker. Intraepidermal nerve fiber density (IENFD) and subepidermal Schwann cell counts were determined.
Results
Skin samples of patients with SFN showed lower IENFD (P < .05), fewer Schwann cells per millimeter (P < .01), and fewer Schwann cell clusters per millimeter (P < .05) than controls. When comparing SFN patients with reduced (n = 13; median age, 53 [range, 19-73] years) and normal distal (n = 15, median age, 54 [range, 43-68] years) IENFD, the number of solitary Schwann cells per millimeter (p < .01) and subepidermal nerve fibers associated with Schwann cell branches (P < .05) were lower in patients with reduced IENFD. All three parameters correlated positively with distal IENFD (P < .05 to P < .01), whereas no correlation was found between Schwann cell counts and clinical pain characteristics.
Discussion
Our data raise questions about the mechanisms underlying the interdependence of dermal Schwann cells and skin innervation in SFN. The temporal course and functional impact of Schwann cell presence and kinetics need further investigation.
KW  - intraepidermal nerve fiber density
KW  - small-fiber neuropathy
KW  - skin punch biopsy
KW  - Schwann cell
KW  - neuropathic pain
KW  - innervation
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318726
VL  - 65
IS  - 4
SP  - 471
EP  - 479
ER  -