Bone atrophy in complex regional pain syndrome patients measured by microdensitometry.
OBJECTIVE
To determine the usefulness of quantitative measurement of bone atrophy in the diagnosis and the long-term follow-up of patients with complex regional pain syndrome (CRPS). The bone-sparing effect of a 5-hydroxytriptamine (5-HT2) antagonist was also studied.


METHODS
Bone mass was measured by computerized micro-densitometry at the middle position of the second metacarpal. The effect of repeated stellate ganglion blocks (SGBs) three times per week with mepivacaine (n = 11), administration of a 5-HT2 antagonist (sarpogrelate hydrochloride, 300 mg a day po) (n = 12), and combined therapy (n = 10) were compared by micro-densitometry and conventional visual analogue scale (VAS) for analgesia after three months of treatment.


RESULTS
In CRPS patients, metacarpal index (cortical bone thickness), maximum bone density (cortical bone density), minimum bone density (trabecular bone density), and average bone density were reduced on the affected side (14.1%, 12.1%, 25.0% and 19.3% respectively). The rate of reduction in bone mass correlated with the duration of the disease (P < 0.05). Therapy with the 5-HT2 receptor antagonist (with or without repeated SGBs) decreased pain intensity (from 6.10 to 3.81 with SGB, from 6.30 to 2.91 without SGB, respectively; P < 0.01) and bone atrophy evaluated by micro-densitometry (P < 0.05). In contrast, repeated SGBs alone reduced pain intensity (from 6.30 to 2.91; P < 0.01) but did not ameliorate bone atrophy.


CONCLUSIONS
Bone micro-densitometry is useful in the assessment and follow-up of CRPS and for evaluation of treatment. The 5-HT2 antagonist, sarpogrelate hydrochloride, is a promising treatment for CRPS patients.
Otake
T
T
Department of Anesthesia and Pain Clinic, Isesaki Municipal Hospital, Japan.
Ieshima
H
H
Ishida
H
H
Ushigome
Y
Y
Saito
S
S
D000284:Administration, Oral; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000627:therapeutic use; D001284:Atrophy; D001340:Autonomic Nerve Block; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000737:chemistry* / Q000187:drug effects; D003720:Densitometry; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D016166:Free Radical Scavengers / Q000627:therapeutic use; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008619:Mepivacaine / Q000627:therapeutic use; D008663:Metacarpus / Q000737:chemistry; D008875:Middle Aged; D010147:Pain Measurement; D012019:Reflex Sympathetic Dystrophy / Q000175:diagnosis / Q000378:metabolism* / Q000517:prevention & control; D012702:Serotonin Antagonists / Q000627:therapeutic use; D013233:Stellate Ganglion; D013386:Succinates / Q000008:administration & dosage / Q000627:therapeutic use
D000779:Anesthetics, Local; D016166:Free Radical Scavengers; D012702:Serotonin Antagonists; D013386:Succinates; C064294:sarpogrelate; D008619:Mepivacaine