The role of SPECT-DaTSCAN in the diagnosis of isolated tremor syndromes

Objectives: The purpose of our study was to determine the probability of developing Parkinson's disease in various syndromes of isolated tremor. Material and methods: We performed a retrospective analysis of the diagnostic process in patients with isolated upper limb tremor where single-photon emission computed tomography (SPECT)-DaTSCAN was performed. Twenty-four consecutive subjects (9 males, 15 females) with isolated tremor of one or both upper limbs were studied. The patients were referred for SPECT by neurologists from various centres. Cases of diagnosed structural, metabolic or drug-induced tremor were not included in the study. All patients were examined by a movement disorder specialist before and 1-3 years after SPECT-DaTSCAN. All subjects were classified according to the Consensus Statement on the Classification of Tremors (2018). Results: The lowest probability of developing Parkinson's disease was found in patients with rest and action (postural and kinetic) tremor, both unilateral and bilateral. The risk was also low in subjects with postural and kinetic tremor. In cases of a combination of rest and postural tremor (both unilateral and bilateral), the likelihood of neurodegenerative parkinsonism was high. Conclusion: Performing SPECT-DaTSCAN in selected cases of isolated of tremor with a high probability of Parkinson's disease avoids the unnecessary use of drugs recommended in the therapeutic algorithms applicable in essential tremor.