Pain when walking: individual sensory profiles in the foot soles of torture victims - a controlled study using quantitative sensory testing

Abstract

BackgroundWith quantitative sensory testing (QST) we recently found no differences in sensory function of the foot soles between groups of torture victims with or without exposure to falanga (beatings under the feet). Compared to matched controls the torture victims had hyperalgesia to deep mechano-nociceptive stimuli and hypoesthesia to non-noxious cutaneous stimuli. The purpose of the present paper was to extend the group analysis into individual sensory profiles of victims’ feet to explore possible relations between external violence (torture), reported pain, sensory symptoms and QST data to help clarify the underlying mechanisms.MethodsWe employed interviews and assessments of the pain and sensory symptoms and QST by investigators blinded to whether the patients, 32 male torture victims from the Middle East, had (n=15), or had not (n=17) been exposed to falanga. Pain intensity, area and stimulus dependence were used to characterize the pain. QST included thresholds for touch, cold, warmth, cold-pain, heat-pain, deep pressure pain and wind-up to cutaneous noxious stimuli. An ethnically matched control group was available.The normality criterion, from our control group data, was set as the mean +/− 1.28SD, thus including 80% of all values.QST data were transformed into three categories in relation to our normality range; hypoesthesia, normoesthesia or hyperesthesia/hyperalgesia.ResultsMost patients, irrespective of having been exposed to falanga or not, reported severe pain when walking. This was often associated with hyperalgesia to deep mechanical pressure. Hypoesthesia to mechanical stimuli co-occurred with numbness, burning and with deep mechanical hyperalgesia more often than not, but otherwise, a hypoesthesia to cutaneous sensory modalities did not co-occur systematically to falanga, pain or sensory symptoms.ConclusionIn torture victims, there seem to be overriding mechanisms, manifested by hyperalgesia to pressure pain, which is usually considered a sign of centralization. In addition there was cutaneous hypoesthesia, but since there was no obvious correlation to the localization of trauma, these findings may indicate centrally evoked disturbances in sensory transmission, that is, central inhibition. We interpret these findings as a sign of changes in central sensory processing as the unifying pathological mechanism of chronic pain in these persons.

Sensory functions in the foot soles in victims of generalized torture, in victims also beaten under the feet (falanga) and in healthy controls – A blinded study using quantitative sensory testing

“…The findings are compatible with central sensitization and de-sensitization, pointing to a core role of central mechanisms. One way to strengthen the analysis is to create sensory profiles from our data on the individual level, which has been done in the subsequent paper [66]. …”

“…It may also be that individual variations make the heterogeneity within groups too big to demonstrate group differences. We will therefore continue the QST analysis by producing individual sensory profiles for all participants, containing both sensory symptoms and QST data [49,53,57,58,65,66]. …”

Rehabilitation need for migrant populations: physiotherapy treatment of the PostTraumatic Stress Disorder and chronic pain from torture results

“…DISCUSSION: We found clear clinical signs of nerve injury in the feet. The sensory findings indicated 2 neuropathic pain mechanisms, one dominated by a peripheral pain generator and other by irritative phenomena (dysesthesia, allodynia (Prip, Persson, & Sjölund, 2011)particularly the impact of neuropathic pain resulting from falanga (beatings under the feet (Prip, Persson, & Sjölund, 2012a) (Prip, Persson, & Sjölund, 2012b). All the included patients suffered from long-term outcomes related to the various kind of torture they had underwent in the previous years (from 5 to 30 years before) in their homelands.…”

Special Considerations for the Treatment of Pain from Torture and War

“…These studies consider the immediate effects of physical trauma, the longer term type of pain, the mechanisms in soft tissue, connective tissue and nervous tissue likely to contribute, and secondary effects. For example, falanga often leaves a neuropathic pain (with signs on quantitative sensory testing: [16]) in the sole of the foot that may worsen with weight bearing or may be more problematic when not bearing weight, such as in bed, a deep pain that extends up the leg when walking and distorted gait to avoid contact of the sole of the foot with the ground that can then affect knee and hip [17–19]. Suspension by the arms, often extended behind the body, can produce abnormal sensory symptoms such as a feeling of heaviness of the arm, and avoidance of use, as well as pain and instability in the shoulder that is most probably a combination of overload of the joint tissues with partial lesion of the brachial plexus [20].…”