Primers and Assay-IDs of the TaqMan assays used.

<p><b>Abbreviations:</b></p><p>IL: interleukin; TNF: tumor necrosis factor-alpha.</p

Boxplots show the intraepidermal nerve fiber density (IENFD) in affected versus unaffected skin of patients with postherpetic neuralgia (PHN).

<p>In affected skin IENFD is lower than in corresponding (contralateral) unaffected skin (*p<0.05). The horizontal black line in the box marks the median value.</p

Pain distribution in patients with painful radiculopathy.

<p>Criteria for the selection of painful radiculopathy were the following: Leg pain had to be the predominant complaint whereas back pain was absent or of minor intensity. In order to select patients with neuropathic painful radiculopathy with the highest probability only patients who marked their most prominent pain (in red) in the following areas were included: (Foot) OR (foot AND shank) OR (foot AND shank AND thigh).</p

Subgroups of patients based on sensory symptoms.

<p>To identify relevant subgroups of patients who are characterized by a characteristic symptom constellation a hierarchical cluster analysis was performed. The clusters are represented by the patterns of questionnaire scores (adjusted individual mean), thus showing the typical pathological structure of the respecting group. By using this approach five clusters with distinct symptom profiles could be detected in the RAD cohort. Sensory profiles show remarkable differences in the expression of the symptoms. Subgroup 5 was unique for patients with painful radiculopathy. RAD = painful radiculopathy.</p

Pain and sensory symptoms in patients with painful radiculopathy (RAD).

<p>*mean ± standard deviation. Score >3, strongly, very strongly.</p

Distribution of sensory symptom profiles (clusters) in patients with painful radiculopathy (RAD).

<p>Subgroup 1 to 4 occurred also in patients with DPN and PHN (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0018018#pone.0018018-Baron2" target="_blank">[5]</a>). Subgroup 5 was unique for patients with painful radiculopathy. Numbers represent frequencies in percent.</p

Demographic and clinical characteristics of patients with painful radiculopathy (RAD).

<p>*mean ± standard deviation. BMI, body mass index; P25/P75, 25% and 75% percentiles;</p><p>n.s., not significant.</p><p>**mean ± standard deviation.</p

Subgroups of patients based on their sensory symptoms.

<p>To identify relevant subgroups of patients who are characterized by a characteristic symptom constellation a hierarchical cluster analysis was performed. The clusters are represented by the patterns of questionnaire scores (A: adjusted individual mean; B: non-adjusted values), thus showing the typical pathological structure of the respecting group. By using this approach five clusters with distinct symptom profiles could be detected in the cohort. Sensory profiles show remarkable differences in the expression of the symptoms. Subgroup 5 does not show any outstanding symptoms and low prevalence of symptoms in general.</p

Differences in PD-Q scores after IVD-surgery.

<p>The pie-chart depicts the proportion of patients with and without IVD-surgery scoring “positive”, “unclear” or “negative” in the PD-Q. There are no significant differences between the respective groups (χ²-Test, p = 0.2215).</p

Differences in PD-Q scores in the subgroups.

<p>The different scores calculated from the PD-Q are shown, revealing the proportion of positive, i.e. neuropathic and negative, i.e. non-neuropathic as well as unclear results. Patients from clusters 3 and 4 showed the tendency to score more neuropathic than those from clusters 1, 2 and 5.</p