Alzheimer's disease cerebrospinal fluid biomarker in cognitively normal subjects

In a large multicentre study, Toledo et al. examine core Alzheimer's disease CSF biomarkers in 1233 cognitively normal subjects aged 40-85 years. Alzheimer disease-like changes in Aβ1-42 are seen as early as middle age, while APOE genotype strongly modifies age-related effects on both Aβ1-42 and phosphorylated/total ta

Levodopa-Induced Dyskinesia Is Associated with Increased Thyrotropin Releasing Hormone in the Dorsal Striatum of Hemi-Parkinsonian Rats

Background Dyskinesias associated with involuntary movements and painful muscle contractions are a common and severe complication of standard levodopa (L-DOPA, L-3,4-dihydroxyphenylalanine) therapy for Parkinson's disease. Pathologic neuroplasticity leading to hyper-responsive dopamine receptor signaling in the sensorimotor striatum is thought to underlie this currently untreatable condition. Methodology/Principal Findings Quantitative real-time polymerase chain reaction (PCR) was employed to evaluate the molecular changes associated with L-DOPA-induced dyskinesias in Parkinson's disease. With this technique, we determined that thyrotropin releasing hormone (TRH) was greatly increased in the dopamine-depleted striatum of hemi-parkinsonian rats that developed abnormal movements in response to L-DOPA therapy, relative to the levels measured in the contralateral non-dopamine-depleted striatum, and in the striatum of non-dyskinetic control rats. ProTRH immunostaining suggested that TRH peptide levels were almost absent in the dopamine-depleted striatum of control rats that did not develop dyskinesias, but in the dyskinetic rats, proTRH immunostaining was dramatically up-regulated in the striatum, particularly in the sensorimotor striatum. This up-regulation of TRH peptide affected striatal medium spiny neurons of both the direct and indirect pathways, as well as neurons in striosomes. Conclusions/Significance TRH is not known to be a key striatal neuromodulator, but intrastriatal injection of TRH in experimental animals can induce abnormal movements, apparently through increasing dopamine release. Our finding of a dramatic and selective up-regulation of TRH expression in the sensorimotor striatum of dyskinetic rat models suggests a TRH-mediated regulatory mechanism that may underlie the pathologic neuroplasticity driving dopamine hyper-responsivity in Parkinson's disease.Morris K. Udall Center for Excellence in Parkinson’s Research at MGH/MITNational Institutes of Health (U.S.) (NIH NS38372)American Parkinson Disease Association, Inc.University of Alabama at BirminghamMassachusetts General HospitalNational Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (NIDDK/NIH grant R01 DK58148)National Institute of Neurological Disorders and Stroke (U.S.) (R01 NINDS/NIH grant NS045231)Stanley H. and Sheila G. Sydney FundMichael J. Fox Foundation for Parkinson's Researc

Optimización del manejo clínico de opicapona en la enfermedad de Parkinson. Recomendaciones de expertos españoles

[EN] Motor fluctuations are frequently seen in Parkinson disease patients on chronic treatment with levodopa. Management of motor fluctuation includes the addition of catechol-O-methyl transferase (COMT) inhibitors. Opicapone is a recent and selective third-generation COMT inhibitor which achieves marked increase in the bioavailability of levodopa. We present a consensus of a group of Spanish neurologists with extensive experience in the clinical management of motor fluctuations. The clinical experience of this group of experts is in line with clinical trials and confirms that opicapone is an effective drug in the control of motor fluctuations, regardless of the daily levodopa dose, or the use of other antiparkinsonian drugs. However, in the opinion of these experts, the ideal patient with Parkinson’s disease to initiate treatment with opicapone is the one with mild motor fluctuations, since the ratio between clinical efficacy and adverse effects is more favorable. In general, it is an easy-to-use drug both in those first treated with a COMT inhibitor or those already on entacapone. In any case, the secondary side effects are easily managed.[ES] Las fluctuaciones motoras constituyen una importante complicación en los pacientes con enfermedad de Parkinson tratados con levodopa. Entre las opciones terapéuticas para el manejo de las fluctuaciones motoras se cuenta con los inhibidores de la catecol-O-metil-transferasa (COMT), incluyendo la opicapona. La opicapona muestra una elevada afinidad por la COMT y consigue un aumento marcado de la biodisponibilidad de la levodopa. Se presenta el consenso de un grupo de expertos españoles en la enfermedad de Parkinson con experiencia en el tratamiento clínico de fluctuaciones motoras y el empleo de opicapona. La experiencia de este grupo de expertos, en consonancia con los ensayos clínicos, confirma que la opicapona es un fármaco eficaz en el control de las fluctuaciones motoras de la enfermedad de Parkinson, con independencia de la dosis de levodopa recibida o de la utilización de otros fármacos antiparkinsonianos. No obstante, a juicio de estos expertos, el paciente ideal para iniciar el tratamiento con opicapona es el que presenta fluctuaciones motoras leves, ya que muestra una mejor relación entre eficacia clínica y efectos adversos. En general, la opicapona es un fármaco de fácil manejo, tanto en pacientes que requieren opicapona como primer inhibidor de la COMT como en los previamente tratados con entacapona, o en los que están en tratamiento concomitante con otros fármacos antiparkinsonianos. En cualquier caso, los efectos secundarios son fácilmente corregibles