Patterns of three-phase bone scintigraphy according to the time course of complex regional pain syndrome type I after a stroke or traumatic brain injury.

We have proposed to evaluate different patterns represented on 3-phase bone scintigraphy (TPBS) according to the time course of complex regional pain syndrome (CRPS) type I (CRPS-I) after a stroke or traumatic brain injury. TPBS was performed in 50 consecutive patients for the evaluation of CRPS. We divided the patients into CRPS and non-CPRS groups based on the use of International Association for the Study of Pain criteria. We evaluated the changes on TPBS according to clinical stages based on time course. In the early acute stage within 6 weeks, minimal uptake on all TPBS phases was observed in the 90% of the patients in the CRPS-I group and in 75% of the patients in the non-CRPS group. In the acute stage of CRPS in the range of 2 to 20 weeks, moderately increased uptake was seen for 78%, 83%, and 83% of the patients in the CRPS group for the 3 phases, respectively. However, only 16% of the patients in the non-CRPS group had moderately increased uptake as seen on all TPBS phases. In the late stage of more than 21 weeks, there was no distinct difference in uptake between the 2 groups. A sequential change during the time course for the CPRS-I group was statistically significant (P < 0.05). Therefore, performance of follow-up TPBS may be useful to diagnose CPRS-I in uncertain cases of the early acute stage after a stroke or traumatic brain injury.