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Lithium, a drug used to treat bipolar disorders, has a variety of neuroprotective mechanisms including inhibition of glycogen synthase kinase-3 (GSK-3), a major tau kinase. Recently, it has been shown that, in various neurodegenerative proteinopathies, lithium could induce autophagy. To analyze how lithium is therapeutically beneficial in tauopathies, transgenic mice overexpressing human mutant tau (P301L) were treated with oral lithium chloride (LiCl) for 4 months starting at the age of 5 months. At first, we examined the effects of treatment on behavior (using a battery of behavioral tests), tau phosphorylation (by biochemical assays), and number of neurofibrillary tangles (NFTs) (by immunohistopathology). In comparison with control mice, LiCl-treated mice showed a significantly better score in the sensory motor tasks, as well as decreases in tau phosphorylation, soluble tau level, and number of NFTs. Next, we examined lithium effects on autophagy using an antibody against microtubule-associated protein 1 light chain 3 (LC3) as an autophagosome marker. The number of LC3-positive autophagosome-like puncta was increased in neurons of LiCl-treated mice. Neurons containing NFTs were completely LC3-negative, whereas LC3-positive autophagosome-like puncta contained phosphorylated-tau (p-tau). The protein level of p62 was decreased in LiCl-treated mice. These data suggested that oral long-term lithium treatment could attenuate p-tau-induced motor disturbance not only by inhibiting GSK-3 but also by enhancing autophagy in tauopathy model mice.

Tauopathies differ in terms of the brain regions that are affected. In Alzheimer's disease, basal forebrain and hippocampus are mainly involved, while frontotemporal lobar degeneration affects the frontal and temporal lobes and subcortical nuclei including striatum. Over 90% of human cases of tauopathies are sporadic, although the majority of established tau-transgenic mice have had mutations. This prompted us to establish transgenic mice expressing wild-type human tau (Tg601). Old (>14 months old) Tg601 mice displayed decreased anxiety in the elevated plus maze test and impaired place learning in the Morris water maze test. Immunoblotting of brain tissue identified that soluble tau multimer was increased with aging even though insoluble tau was not observed. In the striatum of old Tg601, the level of AT8- or AT180-positive tau was decreased compared with that of other regions, while PHF-1-positive tau levels remained equal. Phosphorylated tau-positive axonal dilations were present mainly in layers V and VI of the prefrontal cortex. Loss of synaptic dendritic spine and decreased immunohistochemical level of synaptic markers were observed in the nucleus accumbens. In vivo 2-[18F]fluoro-2-deoxy-d-glucose positron emission tomography analysis also showed decreased activity exclusively in the nucleus accumbens of living Tg601 mice. In Tg601 mice, the axonal transport defect in the prefrontal cortex–nucleus accumbens pathway may lead to decreased anxiety behavior. Differential distribution of hyperphosphorylated tau may cause region-specific neurodegeneration.

OBJECTIVE: Genetic studies for Parkinson’s disease (PD) which have been increased during last few years have shown that parkin (PARK2), DJ-1 (PARK7) and PINK-1 (PARK6) mutations can cause autosomal recessive early-onset parkinsonism. OBJECTIVE: The aim of this study was to investigate by genetic screening methods, the presence of possible genetic mutations in two siblings who have developed PD. METHODS: In these two brothers, PD started at the age of 48 with cervical dystonia and bradykinesia on the left arm, and 56 with tremor on the right hand, respectively. Although they had a favorable response to levodopa, they developed wearing-off phenomenon without dyskinesia on the 4th year. Besides dystonia, the younger brother experienced psychosis and impulse control disorder, as well. Family history revealed first degree consanguinity and the father had also a diagnosis of PD. PD progressed rather slowly in both, but unfortunately the older brother died due to lung cancer 10 years after the initial diagnosis of PD, while he was on the stage 2 of Hoehn-Yahr scale. The younger brother is still on our follow-up at the 7th year of his PD. Informed consent was obtained and blood samples were sent to the genetic department of Juntendo University in Japan for genetic analysis. Parkin gene mutation and DJ-1 gene mutation were analyzed on the PARK7 locus, by automated direct nucleotide sequencing and performed gene dosage assay using TaqMan real-time quantitive PCR. RESULTS: After excluding the parkin mutation the presence of PARK7 was detected in both siblings with haplotype analysis. DJ-1 gene mutation analysis responsible for PARK7, revealed a deletion on intron 1. CONCLUSION: A rarely encountered PARK7 mutation was identified in two brothers having slowly progressive PD and a favorable response to levodopa, one of whom also had psychotic symptoms. As in the presented cases, the genetic studies performed on early-onset PD patients with positive family history provide significant contributions to the sub-group identification of the disease which exhibits clinical heterogeneity

Background and purposeDementia with Lewy bodies (DLB) needs to be distinguished from Alzheimer's disease (AD) because of important differences in patient management and outcome. Severe cardiac sympathetic degeneration occurs in DLB, but not in AD, offering a potential system for a biological diagnostic marker. The primary aim of this study was to investigate the diagnostic accuracy, in the ante-mortem differentiation of probable DLB from probable AD, of cardiac imaging with the ligand 123I-meta-iodobenzylguanidine (MIBG) which binds to the noradrenaline reuptake site, in the first multicenter study.MethodsWe performed a multicenter study in which we used 123I-MIBG scans to assess 133 patients with clinical diagnoses of probable (n = 61) or possible (n = 26) DLB or probable AD (n = 46) established by a consensus panel. Three readers, unaware of the clinical diagnosis, classified the images as either normal or abnormal by visual inspection. The heart-to-mediastinum ratios of 123I-MIBG uptake were also calculated using an automated region-of-interest based system.ResultsUsing the heart-to-mediastinum ratio calculated with the automated system, the sensitivity was 68.9% and the specificity was 89.1% to differentiate probable DLB from probable AD in both early and delayed images. By visual assessment, the sensitivity and specificity were 68.9% and 87.0%, respectively. In a subpopulation of patients with mild dementia (MMSE ≥ 22, n = 47), the sensitivity and specificity were 77.4% and 93.8%, respectively, with the delayed heart-to-mediastinum ratio.ConclusionsOur first multicenter study confirmed the high correlation between abnormal cardiac sympathetic activity evaluated with 123I-MIBG myocardial scintigraphy and a clinical diagnosis of probable DLB. The diagnostic accuracy is sufficiently high for this technique to be clinically useful in distinguishing DLB from AD, especially in patients with mild dementia.

Background. The minimal clinically important difference (MCID) is the smallest change in an outcome measure that is meaningful for patients. Objectives. To calculate the MCID for Unified Parkinson’s Disease Rating Scale (UPDRS) scores in early Parkinson’s disease (EPD) and for UPDRS scores and “OFF” time in advanced Parkinson’s disease (APD). Methods. We analyzed data from two pivotal, double-blind, parallel-group trials of pramipexole ER that included pramipexole immediate release (IR) as an active comparator. We calculated MCID as the mean change in subjects who received active treatment and rated themselves “a little better” on patient global impression of improvement (PGI-I) minus the mean change in subjects who received placebo and rated themselves unchanged. Results. MCIDs in EPD (pramipexole ER, pramipexole IR) for UPDRS II were −1.8 and −2.0, for UPDRS III −6.2 and −6.1, and for UPDRS II + III −8.0 and −8.1. MCIDs in APD for UPDRS II were −1.8 and −2.3, for UPDRS III −5.2 and −6.5, and for UPDRS II + III −7.1 and −8.8. MCID for “OFF” time (pramipexole ER, pramipexole IR) was −1.0 and −1.3 hours. Conclusions. A range of MCIDs is emerging in the PD literature that provides the basis for power calculations and interpretation of clinical trials.