Levodopa responsiveness in disorders with parkinsonism: A review of the literature

Abstract

A literature review was conducted to investigate whether or not levodopa (LD) responsiveness (LR) is a useful criterion in the diagnosis of parkinsonian disorders. Although LR does appear to differ among the parkinsonian disorders, there is considerable confusion in the literature. While most patients with Parkinson's disease (PD) have a sustained benefit from LD, a small minority of patients with documented PD do not respond. The literature suggests that the LR rate is higher for multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) than based on published diagnostic criteria. Magnitude and duration of response to LD and tolerability (time course, type and distribution of dyskinesias, mental effects and motor worsening) may be useful features in distinguishing PD, MSA, PSP, and CBD. Efforts should be directed toward better defining LR when used for diagnostic purposes and in scientific publications.

Functional Neuroimaging in Parkinson's Disease

“…A major feature of LID appears to be overactivity of the direct striatal pathway, but the pathophysiology of LID is complex, likely involving both pre-and postsynaptic alterations in the nigrostriatal system (Cenci and Lundblad 2006;Cenci and Lindgren 2007). Presynaptic dopaminergic denervation is presumed to be necessary for the development of LID, illustrated by the fact that healthy subjects with an intact presynaptic dopaminergic system do not develop LID (Constantinescu et al 2007). Moreover, the development of LID presumably relates to an interaction between the endogenous dopaminergic denervation and application of levodopa, an exogenous dopamine precursor (Cenci and Lundblad 2006).…”

Differential diagnostic value of eye movement recording in PSP-parkinsonism, Richardson's syndrome, and idiopathic Parkinson's disease

“…Although most patients with PSP do not benefit from treatment with levodopa, about 30 % of patients have some improvement initially or at early stages of the disease [3]. Recent studies [15] suggested a further differentiation of the PSP syndrome into (i) Richardson's syndrome (RS) which corresponds well to 'classical' PSP, and (ii) into a syndrome formerly characterised as atypical PSP with asymmetric onset, tremor and initial response to levodopa, which now is described as PSP-parkinsonism (PSP-P).…”

Progressive supranuclear palsy: new concepts

“…Considering side effects, LD-induced dyskinesias seems to be rare, however, some can develop worsening of motor features and dystonia 33 . A retrospective study involving 12 autopsy-confirmed cases of PSP, found a positive response in four of 11 patients using LD, and in two of 6 using dopamine agonist.…”

“…Drugs directed to systems other than dopaminergic, such as serotonergic, noradrenergic, and cholinergic, were also tried in PSP. Serotoninergic drugs, such as selective serotonin reuptake inhibitors, 5-hydroxytryptophan, and methysergide have no confirmed benefit in PSP 31,33 , neither have cholinergic drugs, such as AChE inhibitors, and muscarinic agonists 36 . Concerning cognitive deficit in PSP, rivastigmine lead to a slight improvement in specific function in a small series with five cases 37 .…”