Follow-up of pain processing recovery after ketamine in hyperalgesic fibromyalgia patients using brain perfusion ECD-SPECT.
OBJECTIVE
The aim of this study was to determine whether the follow-up of pain processing recovery in hyperalgesic fibromyalgia (FM) could be objectively evaluated with brain perfusion ethyl cysteinate dimer single photon computerized tomography (ECD-SPECT) after administration of ketamine.


METHODS
We enrolled 17 hyperalgesic FM women patients (48.5 +/- 11 years, range 25-63). After treatment with subcutaneous ketamine, 11 patients were considered as "good responders", with a decrease in pain intensity, evaluated by visual analog scale (VAS), greater than 50%. On the other hand, six patients were considered as "poor responders". A voxel-based analysis of regional cerebral blood flow (rCBF) was conducted (p (voxel) < 0.001uc), in the two subgroups of patients, before and after treatment, in comparison to a group of ten healthy subjects, matched for age and gender.


RESULTS
In comparison to baseline brain SPECT, midbrain rCBF showed a greater increase after ketamine in the responder group than in the nonresponder group (p (cluster) = 0.016c). In agreement with the clinical response, the change in midbrain rCBF after ketamine was highly correlated with the reduction of VAS pain score (r = 0.7182; p = 0.0041).


CONCLUSIONS
This prospective study suggests that blockade of facilitatory descending modulation of pain with ketamine can be evaluated in the periaqueductal grey with brain perfusion SPECT.
Guedj
Eric
E
Service Central de Biophysique et de Médecine Nucléaire, Assistance Publique des Hôpitaux de Marseille, Centre Hospitalo-Universitaire de la Timone, 264 rue Saint Pierre, Marseille Cedex 5, France. eric.guedj@ap-hm.fr
Cammilleri
Serge
S
Colavolpe
Cécile
C
de Laforte
Catherine
C
Niboyet
Jean
J
Mundler
Olivier
O
D000328:Adult; D000368:Aged; D000778:Anesthetics, Dissociative / Q000627:therapeutic use; D001921:Brain / Q000000981:diagnostic imaging*; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D005356:Fibromyalgia / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005500:Follow-Up Studies; D006801:Humans; D006930:Hyperalgesia / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D007649:Ketamine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010146:Pain / Q000000981:diagnostic imaging / Q000517:prevention & control; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods*; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome
D000778:Anesthetics, Dissociative; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D007649:Ketamine; C059659:technetium Tc 99m bicisate; D003545:Cysteine