[Dementia with Lewy bodies and Alzheimer's disease: differential diagnosis by cardiac sympathetic innervation MIBG imaging].
Dementia with Lewy bodies (DLB) is the second most common cause of degenerative dementia after Alzheimer's disease (AD). At present, pre-mortem diagnosis of DLB can only be made clinically using the International Consensus Criteria. However, an accurate differential diagnosis between these diseases could improve the therapeutic handling of patients with DLB, due to their supersensitivity to neuroleptic treatment and the difficult treatment of their psychotic symptoms.


OBJECTIVE
To assess the utility of cardiac MIBG imaging as diagnostic study for DLB, to help in the differential diagnosis with AD.


METHODS
Cardiac MIBG imaging was performed in 11 patients with clinical criteria of probable DLB (7 males, mean age 77 years [range 62-89 years], mean MMSE 17 [range 11-28], and in 9 patients with clinical criteria of probable AD (3 males, mean age 79 years [range 61-87 years], mean MMSE 17 [range 4-25]). Planar anterior images of the thorax were acquired at 15 minutes. (early study) and 4 hours (late study) after tracer injection. Myocardial MIBG activity was quantified by means of a heart-to-mediastinum ratio (HMR). A HMR > 1.8 was considered normal.


RESULTS
Respect AD patients, patients with DLB showed decreased HMR in the early study (1.34 +/- 0.27 [range 1.03-1.98] vs. 1.84 +/- 0.22 [range 1.53-2.15], p<0.001) and in the late study (1.22 +/- 0.23 [range 0.95-1.75] vs. 1.73 +/- 0.08 [range 1.59-1.89], p<0.0001).


CONCLUSIONS
Cardiac MIBG imaging could be a useful tool for differential diagnosis between DLB and AD.
Estorch
M
M
Servicio de Medicina Nuclear, Hospital de la Santa Creu i Sant Pau, Universidad Autónoma de Barcelona, Barcelona, España. mestorch@santpau.es
Camacho
V
V
Fuertes
J
J
Rodríguez-Revuelto
A
A
Hernández
M A
MA
Flotats
A
A
Kulisevsky
J
J
Carrió
I
I
D019797:3-Iodobenzylguanidine; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006321:Heart / Q000294:innervation*; D006801:Humans; D007457:Iodine Radioisotopes; D020961:Lewy Body Disease / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging*; D013997:Time Factors
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine