Cobalt-57 SPET in relapsing-progressive multiple sclerosis: a pilot study

Multiple sclerosis (MS) is predominantly a progressive immune-mediated disease of the white matter in the brain. We used single photon emission tomography (SPET) and cobalt-57 (57Co) as a calcium (Ca) analogue to visualize brain tissue damage, based on the fact that Ca influx occurs in both cell death and T-lymphocyte activation in MS. The aim of this study was to determine if 57Co-SPET detects MS lesions and, if so, to compare this with clinical data on the patient. Five MS patients underwent neurological examination including Expanded Disability Status Scale (EDSS) assessment and 57Co-SPET, using a single-headed camera. All available data were compared. The lesions were recognized as areas of increased signal intensity, although the poor count rate did not allow any statistical quantification. A relationship between one 57Co-SPET parameter (cobalt plaque load) and EDSS was demonstrated. In conclusion, this pilot study suggests that 57Co-SPET using a single-headed camera is not an appropriate imaging modality in MS. To obtain a more favourable signal-to-noise ratio, the use of a multi-headed camera, the administration of a higher activity of 57Co and a longer acquisition time are recommended. Validation of this method among a larger group of patients and a comparison with healthy volunteers is needed.