Dopamine D2 receptor imaging with iodine-123-iodobenzamide SPECT in idiopathic rotational torticollis.

UNLABELLED

The cause of idiopathic rotational torticollis (IRT) is not completely understood to date. However, basal ganglia are believed to be involved in the pathophysiology of IRT. To elucidate this disorder further, the value of iodobenzamide (IBZM) SPECT was studied for the evaluation of striatal dopamine D2 receptors in these patients.

METHODS

Striatal dopamine D2 receptor density was assessed in 10 patients with IRT using 123I-IBZM SPECT. The images were interpreted by a nuclear medicine physician initially to determine IBZM binding within the striatum and the cerebellum and, secondly, interstriatal IBZM binding. The results were correlated with the clinical parameters of the patients and compared with the results obtained from normal controls.

RESULTS

No difference was found in average, specific striatal IBZM binding (basal ganglia/cerebellum ratio) between patients and controls. However, interstriatal analysis of IBZM binding revealed a significantly higher binding in the striatum contralateral to the direction of the torticollis (p = 0.026, by chi-square test).

CONCLUSION

It was concluded that the striatal dopamine D2 receptor status is altered in patients with IRT.