[Isotope transit in reflex sympathetic algodystrophy].
It has been shown in radioisotope scans made three hours after injection of 99mTc MDP that a significant hyperfixation in bone extremities is present in causalgias, probably due to accelerated osteogenesis. However, this gives no information concerning blood circulation inside bone. Nevertheless, the kinetic activity of tracer in areas of lesion for the initial seconds after injection depends upon the vascularity of this region. The computerized recording of isotope activity forms an early activity curb (isotope transit) which can be compared to the activity curb of the corresponding healthy articulatory region of the other limb or side. This curb breaks down into two parts: first, a rapidly ascending slope that corresponds to infiltration of the periarticular arterial network; second, a slowly ascending slope that corresponds to the tracer diffusion space in bony extremities. Among the 27 cases of causalgia in our series 19 evolved into thermalgias in less than three months. Furthermore, in 18 of these 19 cases the lesion-side activity curb was significantly different from the aspect of the healthy side's curb in that both portions showed a hyperactivity. The initial "arterial" hyperactivity slope probably corresponds to an increase in arterial blood flow (and sometimes circulatory speed) in soft tissues around joints; subsequent hyperactivity, gradually increasing, probably corresponds to an increase in the vascular bed volume and diffusion surface due to functional entry of usually silent intraosseous capillaries. Thus, the causalgia which has become thermalgic has a typical initial isotopic tracing curb: this hyperfixation explains the anatomic and pathophysiologic disorders evidenced by other procedures in this disease.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001842:Bone and Bones / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000378:metabolism; D003201:Computers; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012019:Reflex Sympathetic Dystrophy / Q000000981:diagnostic imaging* / Q000378:metabolism; D013667:Technetium; D013997:Time Factors
D013667:Technetium
Transit isotopique au cours des algodystrophies sympathiques réflexes.