neurologisch - Österreichische Gesellschaft für Neurologie

NEUROLOGIE AKTUELL
Autonome Störungen
Häufig werden PatientInnen
mit Schweißsekretionsstörungen
in Labors für autonome
Funktionsdiagnostik vorgestellt.
Wenn man als Ursache eine
„Small fibre“-Neuropathie
vermutet, so ist die Sicherung der
Diagnose eine Herausforderung.
Zur Verfügung stehen die
quantitative sensorische Testung
(QST) oder der quantitative
sudomotorische Axonreflextest
(QSART). Eine exaktere Diagnose
ist allerdings über die Hautbiopsie
möglich. Während QST und
QSART nur in wenigen Labors
zur Verfügung steht, wird die
Hautbiopsie von DermatologInnen
häufig durchgeführt.
Dr. Casanova-Mollá und Dr. Josep
Valls-Solé haben die Diagnostik
der Hautbiopsie in den letzten
Jahren verfeinert und präsentieren
eine kurzen Überblick über diese
Technik.
Dr. Walter Struhal
Cutaneous nerve evaluation
Among the different techniques used for the assessment of painful peripheral neuropathies,
the skin biopsy has experienced the biggest growth over the past 15 years. It allows
us to identify the axons of the sensory nerve endings in the skin. The most commonly
used marker is pan-axonal protein gene product 9.5 (PGP 9.5), a ubiquitin C-terminal hydroxylase
that is found in axons. 1 Quantitative and qualitative evaluations of cutaneous
nerves can give support to the clinical diagnosis of small-fibre neuropathies. 2, 3 However,
as it is applicable to other peripheral neuropathies, to autonomic disorders, and to the
study of neuropathic pain, this makes the skin biopsy a powerful tool for the future.
The quantification of intra-epidermal nerve
fibres (IENFs) follows specific precepts that
have been defined through a consensus of
experts. The recommendations published by
the European Federation of Neurological Societies
Task Force 4 have been found to be
very reliable, and to have high inter-observer
and intra-observer agreement coefficients. 5
Briefly, IENFs are counted only when they
cross or originate at the dermal–epidermal
junction, with secondary branching excluded
from this quantification. The skin surface is
measured and the mean of three skin sections
provides the IENF density (IENFD) per linear
millimetre for the subject under study. Normative
values have been published, as adjusted
for age and gender. 6, 7 The IENFD cutoff
values of 7.63 /mm and