Pure psychiatric presentation of the Lewy body disease is depression--an analysis of 60 cases verified with myocardial meta-iodobenzylguanidine study.

OBJECTIVE: Parkinson's disease (PD), Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) were collectively termed Lewy body disease (LBD). Pure psychiatric presentation (PPP) of the LBD may be the fourth subtype in which psychiatric symptoms without definite parkinsonism and cognitive disturbance lasted for many years. The aim of this study is to localize the presence of the PPP in subjects with low uptake of myocardial meta-iodobenzylguanidine (MIBG).
METHODS: Sixty MIBG-verified patients (28 women and 32 men) were classified into three psychiatric pictures; depression (Group D: 27 patients), isolated visual hallucinations (Group V: 16 patients) and psychosis (Group P: 17 patients). Fifty six cases were examined with single photon emission tomography (SPECT) study of the brains in which hypoperfusion lobes were identified in 37 cases and 19 cases showed no abnormality. After that, we determined final diagnoses; PD, PDD, DLB and PPP with an aid of the DSM-IV, the unified Parkinson's disease rating scale (UPDRS) and Mini-mental state examination (MMSE).
RESULTS: Of Group D patients 40% remained depressive without parkinsonism and about 50% had or developed typical parkinsonism. Most Group P patients developed clinical pictures of PDD or DLB. Statistics provided four combinations: Group V-DLB-occipital lobe hypoperfusion, Group D-PD without SPECT abnormality, Group P-PDD with temporal lobe hypoperfusion and Group D-PPP without SPECT abnormality.
CONCLUSIONS: PPP featured major depressive disorder and can be preparative of incidental LBD and prodromal depression of PD. Psychosis and dementia were of the same quality that characterizes the PDD.