NeuroTalk Support Groups - Parkinson's along with Tourette's Syndrome‏

http://www.neurology.org/content/49/6/1699.short
Coexistence of tics and parkinsonism: Evidence for non-dopaminergic mechanisms in tic pathogenesis

R. Kumar, MD, FRCPC and A. E. Lang, MD, FRCPC

This is not a recent article but might be helpful.
To read the Full Text, one needs to register.

Abstract of the article is at the link above and also in PubMed.

This title actually uses the term "parkinsonism" but I note the article concerns Parkinson's Disease.

[I have a few other bits of info. but will have to go hunt them down. I would also suggest searching Dr. Joseph Jankovic. The TSA-USA used to have some info. on their website regarding PD and TS. I'll look there later also.]

Added:

This article references the above article [18]

Medscape Reference
http://emedicine.medscape.com/articl...overview#a0104

Tourette Syndrome and Other Tic Disorders
Author: William C Robertson Jr, MD; Chief Editor: Amy Kao, MD

Quote:

Dopamine - clinical observations
Tics are not abated with the subsequent development of Parkinson disease.[18] However, in Parkinson disease, dopamine loss is most evident in posterior putamen,[19] whereas caudate and ventral striatum are more implicated in TS.

Furthermore, dopamine receptor agonists have also been used to successfully treat tics, and patients whose tics improved with an agonist had evidence of prolactin inhibition, consistent with a postsynaptic effect.[20, 21, 22] With adequate carbidopa pretreatment, a single dose of levodopa was followed by diminished, not worsened, tic severity.[20]

Added later:

This one is really old.
http://www.ncbi.nlm.nih.gov/pubmed/3504234
Mov Disord. 1986;1(1):79-83.
Tics in a patient with Parkinson's disease.
Shale H, Fahn S, Mayeux R.

Abstract

Quote:

A patient with Gilles de la Tourette syndrome later developed Parkinson's disease in middle age. This was accompanied by a marked reduction in the frequency of tics but levodopa toxicity exacerbated the tics. The dopamine hypothesis of tic disorders is supported by this observation.