Peak-dose dyskinesias are abnormal movements that usually occur 1 h after oral administration of levodopa, and often complicate chronic treatment of Parkinson's disease. We investigated by PET with [11C]raclopride whether Parkinson's disease progression modifies the striatal changes in synaptic dopamine levels induced by levodopa administration, and whether this modification, if present, could ...

OBJECTIVES Degeneration of nigrostriatal neurons and subsequent striatal dopamine deficiency produce many of the symptoms of Parkinson disease (PD). Initially restoration of striatal dopamine with oral levodopa provides substantial benefit, but with long term treatment and disease progression, levodopa can elicit additional clinical symptoms, reflecting altered effects of levodopa in the brain....

Levodopa, a dopamine precursor, is an effective and well-tolerated dopamine replacement agent used to treat Parkinson's disease (PD). Oral levodopa has been widely used for over 40 years, often in combination with a dopa-decarboxylase inhibitor (DDCI), which reduces many treatment complications, extending its half-life and increasing levodopa availability to the brain. Entacapone, a catechol-O-...

Levodopa medication is the most efficient treatment for motor symptoms of Parkinson's disease (PD). Levodopa significantly alleviates rigidity, rest tremor, and bradykinesia in PD. The severity of motor symptoms can be graded with UPDRS-III scale. Levodopa challenge test is routinely used to assess patients' eligibility to deep-brain stimulation (DBS) in PD. Feasible and objective measurements ...

After 40 years of clinical experience, levodopa remains the gold standard treatment for Parkinson's disease (PD) despite the recent emergence of a host of new therapies. Some physicians are cautious when prescribing levodopa because of its association with motor complications. Evidence now suggests that levodopa-associated complications are a result of deep troughs in delivery of levodopa to th...

Currently, levodopa is the most effective and commonly used medication to control motor symptoms in Parkinson’s disease (PD). However, its long-term use is associated with adverse effects (AEs). Combination therapy of a monoamine oxidase type B inhibitor (MAOBI) with levodopa or a catechol-O-methyl transferase inhibitor (COMTI) with levodopa provides benefits to PD patients. Direct comparison o...

Metabolism of levodopa via the enzyme catechol-O-methyltransferase requires S-adenosylmethionine (SAM) as a methyl donor. SAM caused Parkinson disease (PD)-like symptoms in rodents. Therefore, SAM could contribute to a decreased efficacy of levodopa in the long term. SAM levels were significantly reduced in levodopa-treated PD patients, but they showed increased enzyme methionine adenosyl trans...

D a t a e x t r a c t i o n Studies were rated for quality (class I [highquality randomized controlled trials with blinded outcome assessment] to class IV [uncontrolled studies, case series, case reports, or expert opinion]). M a i n r e s u l t s Selegiline: 2 class-II studies on the neuroprotective effects of selegiline were included. Selegiline improved symptoms, but the evidence was insuffi...

Levodopa is a drug that is commonly used to treat movement disorders associated with Parkinson's disease. Its dosage requires careful monitoring, since the required amount changes over time, and excess dosage can lead to muscle spasms known as levodopa-induced dyskinesia. In this work, we investigate the potential for using epiNet, a novel artificial gene regulatory network, as a classifier for...

A new layered organic-inorganic nanocomposite material with an anti-parkinsonian active compound, L-3-(3,4-dihydroxyphenyl) alanine (levodopa), intercalated into the inorganic interlayers of a Zn/Al-layered double hydroxide (LDH) was synthesized using a direct coprecipitation method. The resulting nanocomposite was composed of the organic moiety, levodopa, sandwiched between Zn/Al-LDH inorganic...