Assisted Suicide in Parkinsonian Disorders.

Background: Due to the high prevalence of suicidal ideation in Parkinson's Disease (PD) and exploratory data indicating a similar prevalence in atypical Parkinsonian disorders (APD), we sought to determine the frequency of assisted suicide (AS) as well as factors driving these decisions in PD and APD. Methods: Retrospective chart analysis (2006-2012) at a Swiss Right-to-Die organization. Patients with PD and APD who completed AS were analyzed concerning disease state, symptom burden, medication, and social factors. Results: We identified 72 patients (PD = 34, PSP = 17, MSA = 17, CBS = 4; 7.2% of all AS cases), originating mainly from Germany (41.7%), Great Britain (29.2%), and the US (8.3%). Predominant symptoms at the time of application were immobility (PD/APD: 91%/97%), helplessness (63%/70%), pain (69%/19%), dysarthria (25%/32%), and dysphagia (19%/59%). APD patients generally showed a higher symptom burden and a higher frequency of diagnosed depression (8.8%/28.9%). While most patients with diagnosed depression received antidepressants (80%), other symptoms such as pain (59%) were treated less consistently. Of note, time from diagnosis to application differed greatly between PD (8.5 ± 6.8 years) and APD (1.5 ± 1.3 years, p < 0.0001). Conclusions: In our analysis, Parkinsonian disorders appeared to be overrepresented as a cause of AS considering the prevalence of these diseases. The observation that assisted suicide is sought early after initial diagnosis in APD implies the need for early comprehensive psychological support of these patients and their relatives.

Low-degree trisomy 21 mosaicism promotes early-onset Alzheimer disease.

Trisomy-21 mosaicism (mT21) with subclinical intellectual development disorder or physical phenotype has very rarely been associated with early-onset cognitive decline. Notably, early-onset Alzheimer's disease (EOAD) patients' family histories frequently suggest genetic causes other than autosomal-dominant APP/PSEN-1/2 mutations. We present an EOAD patient in his late fifties newly diagnosed with low-degree mT21 (13%/21% blood lymphocytes/ectodermal cells). We applied fluorescence in-situ hybridization to confirm a diagnosis of mT21. Multimodal positron-emission-tomography applying 18F-fluodesoxyglucose (metabolism), 18F-florbetaben (amyloid-ß deposits) and 18F-PI-2620 (tau-deposits) tracers was used to confirm a diagnosis of EOAD according to the ATN-criteria of AD. Initial PET-studies revealed marked cerebral amyloid-ß- and tau-pathology and parietotemporal hypometabolism, confirming EOAD according to the ATN-criteria of AD. A marked cognitive decline was accompanied by an increase in tau pathology in follow-up studies. This is the first case demonstrating that a low-degree APP gene-dose increase suffices to cause EOAD with prominent amyloid-ß/tau pathology.

Binding of Metal-Ion-Induced Tau Oligomers to Lipid Surfaces Is Enhanced by GSK-3ß-Mediated Phosphorylation.

While fibrillar deposits of hyperphosphorylated protein tau are a key hallmark of several neurodegenerative diseases such as Alzheimer's disease, small oligomers have been speculated to be the key toxic aggregate species. Trivalent metal ions were shown to promote tau oligomer formation in vitro. However, little is known about potential intercellular spreading mechanisms or toxic modes of action of such oligomers. We investigated interactions of tau monomers and Fe3+/Al3+-induced oligomers with small unilamellar vesicles derived from 1-palmitoyl-2-oleoyl-phosphatidylcholine (neutral, liquid-crystalline phase) and dipalmitoyl-phosphatidylcholine (neutral, gel-phase). We further evaluated the influence of glycogen synthase kinase 3ß (GSK-3ß)-mediated tau phosphorylation applying the single-particle fluorescence spectroscopy techniques fluorescence correlation spectroscopy, fluorescence intensity distribution analysis, and scanning for intensely fluorescent targets. In these experiments, no binding to neutral lipid surfaces was observed for tau monomers. In contrast, metal-ion-induced tau oligomers showed a gain of function in binding to neutral lipid surfaces. Of note, tau phosphorylation by GSK-3ß increased both oligomer formation and membrane affinity of the resulting oligomers. In conclusion, our data imply a pathological gain of function of metal-ion-induced oligomers of hyperphosphorylated tau, enabling membrane binding irrespective of surface charge even at nanomolar protein concentrations.