EEG abnormalities have been reported for both dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Although it has been suggested that variations in mean EEG frequency are greater in the former, the existence of meaningful differences remains controversial. No evidence is as yet available for Parkinson's disease with dementia (PDD). The aim of this study was to evaluate whether EEG abnormalities can discriminate between DLB, AD and PDD in the earliest stages of dementia and to do this 50 DLB, 50 AD and 40 PDD patients with slight cognitive impairment at first visit (MMSE ≥ 20) were studied. To improve clinical diagnostic accuracy, special emphasis was placed on identifying cognitive fluctuations and REM-sleep behaviour disorder. EEG variability was assessed by mean frequency analysis and compressed spectral arrays (CSA) in order to detect changes over time from different scalp derivations. Patients’ initial diagnoses were revised at a 2-year follow-up visit with neuroimaging evaluation. Initial diagnoses were confirmed in 36 DLB, 40 AD and 35 PDD patients. The most relevant group differences were observed between the AD and DLB patients in EEGs from posterior derivations (P<0.001). Dominant frequencies were 8.3 ± 0.6 Hz for the AD group and 7.4 ± 1.6 Hz for the DLB group, in which most of the patients (88%) exhibited a frequency band of 5.6–7.9 Hz. Dominant frequency variability also differed between the AD (1.1 ± 0.4 Hz) and DLB groups (1.8 ± 1.2 Hz, P<0.001). Of note, less than a half (46%) of the patients with PDD exhibited the EEG abnormalities seen in those with DLB. Graded according to the presence of alpha activity, five different patterns were identified on EEG CSA from posterior derivations. A pattern with dominant alpha bands was observed in patients with AD alone while, in those with DLB and PDD, the degree to which residual alpha and 5.6–7.9 bands appeared was related to the presence and severity of cognitive fluctuations. At follow-up, EEG abnormalities from posterior leads were seen in all subjects with DLB and in three-quarters of those with PDD. Of interest, in four patients initially labelled as having AD, in whom the occurrence of fluctuations and/or REM-sleep behaviour disorder during the 2-year follow-up had made the diagnosis of AD questionable, the initial EEG was characterized by the features observed in the DLB group. If revised consensus criteria for DLB diagnosis are properly applied (i.e. emphasizing the diagnostic weight of fluctuations and REM sleep behaviour disorder), EEG recording may act to support discrimination between AD and DLB at the earliest stages of dementia, since characteristic abnormalities may even precede the appearance of distinctive clinical features.
1 August 2012 in Journal of Clinical Psychopharmacology
The primary aim of the present study was to compare the effects of agomelatine (AGO) and venlafaxine XR (VLX) on anhedonia in patients with major depressive disorder. Secondary end points were to test its antidepressant and anxiolytic efficacy.Sixty patients were enrolled and randomly assigned to two different treatments: AGO (25-50 mg/d; n = 30 subjects) or VLX (75-150 mg/d, n = 30 subjects). Psychopathological assessment was performed at baseline and after 8 weeks of treatment with the Snaith Hamilton Rating Scale (SHAPS), the Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Clinical Global Impression for anhedonia, depression, anxiety, and global improvement, respectively.Both groups showed a significant reduction in time for the SHAPS, the Hamilton Depression Rating Scale, and the Hamilton Anxiety Rating Scale. A significant between-group difference was observed for SHAPS scores: patients treated with AGO showed a more relevant reduction compared with that in VLX-treated patients. Moreover, only patients treated with AGO showed a statistically significant improvement in Clinical Global Impression scores.In this study, AGO showed significantly greater efficacy on anhedonia and similar antidepressant efficacy to the serotonin-norepinephrine reuptake inhibitor VLX in patients with major depressive disorder during an 8-week treatment period. Anhedonia has been considered a potential trait marker related to vulnerability for depression. Therefore, the efficacy of AGO on this dimension holds particular importance in the treatment of patients with anhedonic features.
22 March 2007 in International Journal of Geriatric Psychiatry