title: Brain SPECT can differentiate between essential tremor and early-stage tremor-dominant Parkinson's disease.
abstract: There are no confirmatory or diagnostic tests or tools to differentiate between essential tremor (ET) and tremor in idiopathic Parkinson's disease (PD). Although a number of imaging studies have indicated that there are differences between ET and PD, the functional imaging study findings are controversial. Therefore, we analyzed regional cerebral blood flow (CBF) by perfusion brain single-photon emission computed tomography (SPECT) to identify differences between ET and tremor-dominant Parkinson's disease (TPD). We recruited 33 patients with TPD, 16 patients with ET, and 33 healthy controls. We compared the severity of tremor symptoms by comparing the Fahn-Tolosa-Marin rating scale (FTM) score and the tremor score from Unified Parkinson's Disease Rating Scale (UPDRS) between TPD and ET patients. Subjects were evaluated by neuropsychological assessments, MRI and perfusion SPECT of the brain. Total FTM score was significantly higher in ET patients than TPD patients. However, there was no significant difference in FTM Part A scores between the two patient groups, while the scores for FTM Part B and C were significantly higher in ET patients than TPD patients. Brain SPECT analysis of the TPD group demonstrated significant hypoperfusion of both the lentiform nucleus and thalamus compared to the ET group. Brain perfusion SPECT may be a useful clinical method to differentiate between TPD and ET even during early-phase PD, because the lentiform nucleus and thalamus show differences in regional perfusion between these two groups during this time period. Additionally, we found evidence of cerebellar dysfunction in both TPT and ET.
authors.affiliation: Department of Neurology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 271 Cheonbo-ro, Uijeongbu 480-717, Republic of Korea.
authors.forename: In-Uk
authors.initials: IU
authors.lastname: Song
authors.affiliation: Department of Neurology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 271 Cheonbo-ro, Uijeongbu 480-717, Republic of Korea. Electronic address: pjw516@catholic.ac.kr.
authors.forename: Jeong-Wook
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Neurology, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 271 Cheonbo-ro, Uijeongbu 480-717, Republic of Korea.
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Chung
authors.affiliation: Department of Nuclear Medicine, College of Medicine, The Catholic University of Korea, Uijeongbu, Republic of Korea.
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Chung
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003937:Diagnosis, Differential; D020329:Essential Tremor / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014202:Tremor / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology
keywords: Essential tremor; Parkinson’s disease; Perfusion SPECT