RATIONALE In this case report, we describe a Parkinson's disease (PD) patient with limb-kinetic apraxia (LKA) in whom degeneration of the corticofugal tract (CFT) from the supplementary motor area (SMA) was observed in diffusion tensor tractography (DTT). PATIENT CONCERNS A 63-year-old woman presented with a loss of dexterity in both upper extremities, which indicated LKA, and typical PD-rela...

Objective: One patient received oral levodopa during a study aiming for better understanding of the basal ganglia and of the mechanisms of deep brain stimulation of the subthalamic nucleus (STN DBS) with and without intravenous (IV) levodopa infusion in patients with Parkinson’s disease (PD). The results from oral and IV levodopa treatment are presented. Methods: Five patients with advanced PD ...

The antiparkinsonian and antidyskinetic profile of two N-methyl-D-aspartate (NMDA) receptor antagonists, a competitive antagonist, (R)-4-oxo-5-phosphononorvaline (MDL 100,453), and a novel noncompetitive allosteric site antagonist, 4-hydroxy-N-[2-(4-hydroxyphenoxy)ethyl]-4-(4-methylbenzyl)piper idi ne (Co 101244/PD 174494), was assessed in six levodopa-treated 1-methyl-4-phenyl-tetrahydropyridi...

Over the last decade, hydrogen sulfide (H2S) has emerged as an important endogenous gasotransmitter in mammalian cells and tissues. Similar to the previously characterized gasotransmitters nitric oxide and carbon monoxide, H2S is produced by various enzymatic reactions and regulates a host of physiologic and pathophysiological processes in various cells and tissues. H2S levels are decreased in ...

The present study was aimed at the uptake ofl-3,4-dihydroxyphenylalanine (l-dopa) and its intracellular decarboxylation to dopamine. The accumulation ofl-dopa from the apical side in cells cultured in collagen-treated plastic was found to be a saturable process with a Michaelis constant ( K m) of 123 ± 17 μM and a maximal velocity ( V max) of 6.0 ± 0.2 nmol ⋅ mg protein-1 ⋅ 6 min-1. The uptake ...

CONTEXT Abnormality in interactions between N-methyl-d-aspartate (NMDA) receptor and its signaling molecules occurs in the lesioned striatum in Parkinson's disease (PD) and levodopa-induced dyskinesia (LID). It was reported that Fyn-mediated NR2B tyrosine phosphorylation, can enhance NMDA receptor function. Postsynaptic density protein 95 (PSD-95), one of the synapse-associated proteins, regula...

Abnormal involuntary movements, particularly levodopainduced dyskinesia (LID) and antipsychotic drug-elicited tardive dyskinesia, are among the most difficult to manage adverse effects associated with the treatment of Parkinson’s disease (PD) and schizophrenia, respectively. The mechanisms underlying dyskinesias in levodopa-treated PD have been studied for decades. Over this time, there has bee...