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

Abstract

BackgroundFalanga torture (beatings on the foot soles) produces local chronic pain and severe walking difficulties. We have previously reported signs of neuropathic pain in the feet of falanga victims. The objective here was to clarify underlying pain mechanisms by quantifying sensory impairments in the feet of torture victims who had experienced both generalized torture and those who had been exposed to falanga in addition. An ethnically matched control group was available.MethodsWe employed quantitative sensory testing (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 as were interview data on sensory symptoms. QST included thresholds for touch, cold, warmth, cold-pain, heat-pain, deep pressure pain and wind-up to cutaneous noxious stimuli in the foot soles. Clinical data on anxiety and depression were retrieved.ResultsAlmost all falanga victims had moderate or strong pain in their feet and in twice as large an area of their foot soles as other torture victims. One-third of the latter had no pain in their feet and many reported slight pain; in spite of this, there were no differences in foot sole QST data between the tortured groups. A comparison with normal data indicated that both tortured groups had hypoesthesia for all cutaneous sensory fibre groups except those transmitting cold and heat pain, in addition to deep mechano-nociceptive hyperalgesia.ConclusionA comparison of the QST data between victims having been exposed to generalized torture and victims who in addition had been exposed to falanga, showed no differences on the group level. The sensory disturbances in relation to our control group are compatible with central sensitization and de-sensitization, pointing to a core role of central mechanisms. A further analysis to create individual sensory profiles from our measurements is in progress.

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

“…Seventy-nine consecutively referred patients were identified via the electronic patient records (see Flowchart, in [10]). One senior physician (BHS) screened these medical records according to the exclusion criteria: pathological structural changes in the feet and lower legs from reasons other than falanga, for example, sustained fractures, amputations, extensive scar tissue after burning or cuttings or foreign objects embedded in the feet such as shrapnel or bullets; nerve lesions in the lower legs from causes other than falanga, for example, diabetic or alcoholic polyneuropathy and also injury to the central nervous system such as stroke or spinal fractures.…”

“…For details of the procedures and measurement techniques, we refer the reader to our previous paper [10]. …”

“…For a detailed description of the techniques used to measure the different modalities, see our previous study [10]. Briefly, we measured mechanical detection thresholds (MDT) utilizing Semmes Weinstein monofilaments; cold detection thresholds (CDT) and warm detection thresholds (WDT), and also cold pain thresholds (CPT) and heat pain thresholds (HPT) utilising a thermal stimulator (MEDOC Inc., Israel); and deep mechano-nociceptive thresholds (pressure pain thresholds: PTT) using an electronic pressure algometer (Somedic, Höör, Sweden).…”

“…When examining torture victims with quantitative sensory testing (QST), we recently and remarkably found no obvious differences in sensory function of the foot soles between groups of torture victims with or without exposure to falanga [10]. This was so in spite of the fact that almost all the falanga victims had moderate to strong pain in their feet and in twice as large an area of their foot soles as those torture victims who had not been exposed to falanga.…”

“…The primary objective of the present paper was to extend the group analysis of the QST data from our previous study [10] 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 pain mechanisms [5,12]. …”