Morphometry of dermal nerve fibers in human skin.

Neuromuscular Diseases Unit, IRCCS Foundation, Carlo Besta Neurological Institute, Via Celoria, 11, 20133, Milan, Italy.
Neurology (Impact Factor: 8.25). 07/2011; 77(3):242-9. DOI: 10.1212/WNL.0b013e318225ab51
Source: PubMed

ABSTRACT We aimed to assess the innervation density of dermal nerves in human skin biopsies by bright-field immunohistochemistry.
The size of dermal area where nerve length was quantified was validated in 30 skin biopsy sections (5 controls and 5 patients with small-fiber neuropathy [SFN]). It was obtained dividing an area of 200-μm depth from the dermal-epidermal junction into 4 equal portions. The length of dermal nerves (DNFL) was measured into 150 sections (25 controls and 25 patients with SFN) and values per millimeter of epidermis (DNFL/mm) and dermal area (DNFL/mm2) were obtained. Age- and gender-matched normative values of intraepidermal nerve fiber (IENF) density were used as gold standard to calculate the performance of dermal nerve morphometry.
Patients showed significantly lower DNFL (1.96 mm ± 0.96 SD), DNFL/mm (0.65 ± 0.29 SD), and DNFL/mm2 (3.75 ± 1.7 SD) than controls (DNFL 3.52 mm ± 1.31 SD, 5th percentile 2.05; DNFL/mm 1.25 ± 0.39, 5th percentile 0.71; DNFL/mm2 7.07 ± 2.41 SD, 5th percentile 3.95). Sensitivity, specificity, and percentage of individuals correctly classified were 75.8%, 73.9%, and 74.8% for DNFL, 75%, 80%, and 77.7% for DNFL/mm, and 75.8%, 80.2%, and 78.1% for DNFL/mm2. Receiver operator characteristic area analysis confirmed the excellent discrimination (0.8-0.9) between patients and controls. Dermal nerve morphometry significantly correlated with IENF density. Spearman rank correlation demonstrated good agreement for interobserver analysis (0.87-0.89), and between DNFL and IENF densities (0.71-0.73; p < 0.0001).
We provided a reliable method to quantify the innervation density of dermal nerves that might improve the diagnostic yield of skin biopsy.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: Age and gender-matched reference values are essential for the clinical use of quantitative sensory testing (QST). To extend the standard test sites for QST according to the German Research Network on Neuropathic Pain to the trunk, we collected QST profiles on the back in 162 healthy subjects. Sensory profiles for standard test sites were within normal inter-laboratory differences. QST revealed lower sensitivity on the upper back than the hand, and higher sensitivity on the lower back than the foot, but no systematic differences between these trunk sites. Age effects were significant for most parameters. Females exhibited lower pressure pain thresholds (PPT) than males, which was the only significant gender difference. Values outside the 95%-CI of healthy subjects (considered abnormal), required temperature changes of >3.3-8.2°C for thermal detection. For cold pain thresholds, confidence intervals extended mostly beyond safety cut-offs, hence only relative reference data (left-right differences, hand-trunk differences) were sufficiently sensitive. For mechanical detection and pain thresholds, left-right differences were 1.5-2.3 times more sensitive than absolute reference data. The most sensitive parameter was PPT, where already side-to-side differences >35% were abnormal. Compared to trunk reference data, patients with postherpetic neuralgia exhibited thermal and tactile deficits and dynamic mechanical allodynia mostly without reduced mechanical pain thresholds. This pattern deviates from other types of neuropathic pain. QST reference data for the trunk will also be useful for patients with postthoracotomy pain or chronic back pain.
    Pain 02/2014; · 5.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The neuroanatomical morphology of nerve fibers is an important description for understanding the pathological aspects of nerves. Different from the traditional automatic nerve morphometry methods, a molecular hyperspectral imaging system based on an acousto-optic tunable filter (AOTF) was developed and used to identify unstained nerve histological sections. The hardware, software, and system performance of the imaging system are presented and discussed. The gray correction coefficient was used to calibrate the system's spectral response and to remove the effects of noises and artifacts. A spatial-spectral kernel-based approach through the support vector machine formulation was proposed to identify nerve fibers. This algorithm can jointly use both the spatial and spectral information of molecular hyperspectral images for segmentation. Then, the morphological parameters such as fiber diameter, axon diameter, myelin sheath thickness, fiber area, and g-ratio were calculated and evaluated. Experimental results show that the hyperspectral-based method has the potential to recognize and measure the nerve fiber more accurately than traditional methods.
    Applied Optics 06/2013; 52(17):3891-901. · 1.69 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to estimate dermal nerve fiber length (DNFL) using a stereological sampling technique in comparison with a previously reported manual estimation. DNFL was analyzed in skin punch biopsy specimens from 24 healthy volunteers and 18 patients with small fiber neuropathy (SFN) using global spatial sampling that yields unbiased and reliable length estimation. The estimation was carried out in 50-µm biopsy sections after immunostaining with anti-protein gene product (PGP) 9.5 antibodies. The length of the PGP9.5-positive dermal nerves from the dermal-epidermal junction and 200 µm down was measured (DNFL mm(-2) ). Results were compared with our previously reported manual method. Patients showed a significantly (p < 0.0001) lower DNFL (105 mm(-2) ± 6.4 SD) than healthy subjects (246 mm(-2) ± 8.39 SD). Moderate correlation with age was observed for both healthy subjects (Pearson's r = -0.33) and patients (Pearson's r = -0.59). A significant (p < 0.001) correlation between global spatial sampling and manual estimation was observed in both patients and healthy subjects (Pearson's r = 0.62 and 0.61, respectively). These findings provide further evidence on the reliability of dermal nerve morphometry in human skin and strengthen the hypothesis that dermal nerve fibers undergo significant degeneration in SFN.
    Journal of the Peripheral Nervous System 03/2013; 18(1):48-53. · 2.57 Impact Factor


Available from
May 19, 2014