Cardiac (123)I-metaiodobenzylguanidine imaging allows early identification of dementia with Lewy bodies during life.
OBJECTIVE
Differential diagnosis between dementia with Lewy bodies (DLB) and other neurodegenerative diseases with cognitive impairment represents a clinical challenge. Due to the overlapping of symptoms, the clinical diagnosis can be modified during the prolonged follow-up of these diseases. The purpose of this study was to assess the ability of cardiac metaiodobenzylguanidine (MIBG) imaging for early identification of DLB.


METHODS
Since January 2003, all patients with neurodegenerative diseases with cognitive impairment at their first visit at the Memory Unit and clinical criteria of DLB were consecutively recruited and underwent a cardiac (123)I-MIBG study. The heart-to-mediastinum ratio (HMR) and the washout rate (WR) of cardiac MIBG uptake were obtained.


RESULTS
Sixty-five patients were included. After a clinical follow-up of 4 years, the progress of the disease procured a definite diagnosis in 44 (68%) patients: 19 DLB, 12 Alzheimer disease (AD), and 13 other neurodegenerative diseases with cognitive impairment. HMR was significantly decreased in DLB with respect to the other neurodegenerative diseases. WR was only significantly different between DLB and AD. The HMR cut off point of 1.36 differentiated DLB from the other dementias with a sensitivity of 94% and a specificity of 96% with an accuracy of 95%.


CONCLUSIONS
Cardiac MIBG imaging performed at the time of the first clinical diagnosis of DLB can help early clinical identification or exclusion of this disease.
Department of Nuclear Medicine, Hospital de la Santa Creu i Sant Pau, Autonomous University of Barcelona, C. Sant Antoni M. Claret 167, Barcelona, Spain. mestorch@santpau.cat
Montserrat
M
Estorch
Valle
V
Camacho
Pilar
P
Paredes
Elisabet
E
Rivera
Ato
A
Rodríguez-Revuelto
Albert
A
Flotats
Jaume
J
Kulisevsky
Ignasi
I
Carrio
D019797:3-Iodobenzylguanidine; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000150:complications / Q000175:diagnosis; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D005500:Follow-Up Studies; D006321:Heart; D006801:Humans; D007457:Iodine Radioisotopes; D020961:Lewy Body Disease / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000150:complications / Q000175:diagnosis; D015203:Reproducibility of Results; D013997:Time Factors
D007457:Iodine Radioisotopes; D019797:3-Iodobenzylguanidine