Figure 2. Subgroups of patients based on sensory symptoms.

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.