PET of the Brain with 2-18F-2-desoxi-D-Glucose in Differential Diagnosis of Dystonia and Essential Tremor

The purpose.The purpous of the present study is to compare the data of brain PET wih 2-18F-2-desoxi-D-glucose (18-FDG) of patients with dystonia with the results of patients with essential tremor (ET) by analyzing the data with the help of the new calculation method of Z-score of PET results.Materials and methods. In 2010 in journal “Medical Visualization” we published results of PET study with 18-FDG of brain of 11 patients, which have been divided in two groups: the group with dystonia – 7 patients and the group with essential tremor – 4 patients. Glucose metabolism was studied by means of Siemens Exacthigh resolution tomograph. The results were presented in semi quantitative form of percentage of change of glucose metabolism, without comparison with the healthy control. The calculation has been done by means of software package SPM2, installated to the personal computer (OS Windows 2000). Later the Advantage Workstation of the same tomograph, used for the study, was equipped by software package Cortex ID that allows automatic structural and functional analyzes of PET visualization of the brain in comparison with the scans of control group of the same age. The results of such comparison are calculated by this program in the equation of Z-score, that is calculated automatically by special program for each brain zone. In present study we applied Z-score for analyzing again the comparison of the PET results of these two disorders. The group of essential tremor remained the same and included 4 patients studied before. As to the second group of dystonia, we added to it 3 new patients, studied since aforementioned study of 2010, the whole group of D rising up to ten patients. In order to level the conditions of our research, we also compared the former group of dystonia of 7 patients with the group of essential tremor by means of Z-score method.Results. We have detected reliable difference between the group of dystonia and the group of essential tremor, presented in the form of different changes of glucose metabolism in 4 brain zones – left thalamus, right nucleus lentiformis, girus cingularis and the pons. Such result has not changed when we also compared the former staff of dystonia group of 7 patients with essential tremor group.Conclusion.The study has confirmed efficacy PET in differential diagnosis of extrapyramidal disorders and of Z-score method in PET investigations by means of establishing of the correspondence of cinical heterogeneity to PET heterogeneity.