Truths, errors, and lies around “reflex sympathetic dystrophy” and “complex regional pain syndrome”

Abstract

The shifting paradigm of reflex sympathetic dystrophy-sympathetically maintained pains-complex regional pain syndrome is characterized by vestigial truths and understandable errors, but also unjustifiable lies. It is true that patients with organically based neuropathic pain harbor unquestionable and physiologically demonstrable evidence of nerve fiber dysfunction leading to a predictable clinical profile with stereotyped temporal evolution. In turn, patients with psychogenic pseudoneuropathy, sustained by conversion-somatization-malingering, not only lack physiological evidence of structural nerve fiber disease but display a characteristically atypical, half-subjective, psychophysical sensory-motor profile. The objective vasomotor signs may have any variety of neurogenic, vasogenic, and psychogenic origins. Neurological differential diagnosis of "neuropathic pain" versus pseudoneuropathy is straight forward provided that stringent requirements of neurological semeiology are not bypassed. Embarrassing conceptual errors explain the assumption that there exists a clinically relevant "sympathetically maintained pain" status. Errors include historical misinterpretation of vasomotor signs in symptomatic body parts, and misconstruing symptomatic relief after "diagnostic" sympathetic blocks, due to lack of consideration of the placebo effect which explains the outcome. It is a lie that sympatholysis may specifically cure patients with unqualified "reflex sympathetic dystrophy." This was already stated by the father of sympathectomy, René Leriche, more than half a century ago. As extrapolated from observations in animals with gross experimental nerve injury, adducing hypothetical, untestable, secondary central neuron sensitization to explain psychophysical sensory-motor complaints displayed by patients with blatantly absent nerve fiber injury, is not an error, but a lie. While conceptual errors are not only forgivable, but natural to inexact medical science, lies particularly when entrepreneurially inspired are condemnable and call for peer intervention.

Complex regional pain syndrome – diagnostic, mechanisms, CNS involvement and therapy

“…These observations in connection with normal neurophysiological test results in CRPS I led to the hypothesis that CRPS is primarily a psychogenic disorder. 122,123 However, well designed studies and comprehensive reviews of the available literature have suggested that psychological symptoms are the result and not the cause of CRPS.…”

“…137,151 Some authors even discard the concept that the sympathetic nervous system is actively involved in the generation of pain. 122,152 They claim that interventions that block sympathetic activity lack speci®city, and argue that the techniques and results of sympathetic blockade have rarely been adequately evaluated and are in most cases not placebo-controlled.…”

Das komplexe regionale Schmerzsyndrom

“…Hierbei sind depressive und Angststörungen am häu-figsten, so dass eine entsprechende psychologische Betreuung wichtig ist. Einige Untersucher behaupten, dass es sich beim CRPS insgesamt um eine psychogene Erkrankung handelt, zumal sich neurophysiologisch keine Auffälligkeiten finden [99,141] Neben der klinischen Untersuchung gibt es technische Zusatzuntersuchungen, die ergänzende diagnostische Informationen über die autonomen,motorischen und sensiblen Störungen liefern, ohne dass bisher ein diagnostischer Goldstandard existiert.…”

Mechanisms of neuropathic pain: Nerve, brain, and psyche: Perhaps the dorsal horn but not the sympathetic system

“…Finally, the objective signs in those patients, typically labeled "RSD" (reflex sympathetic dystrophy), are nonspecific and explainable otherwise. When the concept of SMP collapsed, it carried with it the concept of "RSD" [11,12].…”