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The following is a summary of “Signs of hyperpathia in chronic peripheral neuropathic pain,” published in the October 2024 issue of Pain by Carmland et al. 

Neuropathic pain, resulting from a disease or lesion of the somatosensory system, was characterized by spontaneous, evoked, or both types of pain, with hyperpathia defined by the IASP as an abnormal painful reaction to stimuli.   

Researchers conducted a retrospective study to analyze the presence of mechanical hyperpathia in a diverse group of patients with peripheral neuropathic pain and to correlate signs of hyperpathia with other sensory indicators.  

They examined patients using graded pinprick stimuli to create a stimulus–response curve and repetitive pinprick stimuli to evaluate pain increase over time and aftersensations. Patients were then categorized based on the likelihood of having mechanical hyperpathia, identified by either a steep stimulus–response curve or a pronounced response on the repetitive pinprick test. The results were related to mechanical detection, pain thresholds, and other outcomes from comprehensive quantitative sensory testing.   

The results showed that 124 patients with peripheral neuropathic pain were included. Patients exhibiting a steep stimulus–response curve did not overlap with those showing a steep response on the repetitive pinprick test. Both groups more frequently demonstrated decreased detection and pain thresholds rather than increased ones.  

Investigators concluded the challenged concept of hyperpathia and indicated a need for further research to identify the symptoms and signs that may cluster together to form a syndrome. 

Source: onlinelibrary.wiley.com/doi/full/10.1002/ejp.4739