There may be some overlap with other articles being mentioned here, but these are ones I have found that might be of interest. None of these provide any direct connection to Parkinson's Disease. And, I don't know enough about PD to even know which ones might be most relevant.

What this does show is that gluten sensitivity is responsible for wide ranging and severe neurological problems, there is evidence of autoimmune mechanisms, and this area of exploration is in its infancy....and new connections are being made every day.

The first article that Dr. Hadjivassiliou wrote on the subject was written just a decade ago... in 1996. My daughter was born in 1996. Based upon his research, my daughter has been gluten free since 2001. She did have a positive antigliadin IgG blood test , but that was discounted as meaningless by the GI doctor. We took a leap of faith when we embarked on a gluten free diet, based mostly on a couple of articles of Dr. H. She had neurological, gastrointestinal and skin symptoms...that have all resolved on a strict gluten free diet. She is mostly casein free as well as that causes her GI symptoms. Only gluten seemed to cause the neurological symptoms in her, but I've heard many accounts of casein sensitivity being involved in neurological symptoms. Gluten ataxia is just now be accepted into mainstream medicine~ ten years later. And, it doesn't stop there.

Does cryptic gluten sensitivity play a part in neurological illness? Feb 1996
They actually included Parkinson's disease patients in this one, and did not find any big correlation. No correlation was found with MS in this study either, yet I've known many diagnosed with MS who have "lost" their MS diagnosis while on various combinations of gluten free, casein free, and legume free diets. It might also be a matter of diagnostic confusion as there can be a lot of symptom overlap, and an absence of absolutely definitive diagnostic criteria in many conditions.

Other articles of possible interest....

Dietary treatment of gluten neuropathy, Sept 2006

Autoantibody targeting of brain and intestinal transglutaminase in gluten ataxia, Feb 2006

Cerebellar abnormalities on proton MR spectroscopy in gluten ataxia, July 2005 - free full text

Choreic syndrome and coeliac disease: a hitherto unrecognised association, Apr 2004

Dietary treatment of gluten ataxia. Sept 2003

Celiac disease presenting with motor neuropathy: Effect of gluten free-diet.

Cognitive impairment and celiac disease.

Anti-ganglioside antibodies in coeliac disease with neurological disorders.

Neuromuscular disorder as a presenting feature of coeliac disease. Dec 1997 -

Immune cross-reactivity in celiac disease: anti-gliadin antibodies bind to neuronal synapsin I.

Symptomatic myoclonus.

Myopathy associated with gluten sensitivity.

Paroxysmal nonkinesigenic dystonia and celiac disease.

Celiac disease can be associated with severe neurological symptoms

Atypical neurological involvement associated with celiac disease.

Sporadic cerebellar ataxia associated with gluten sensitivity.

Choreic syndrome and coeliac disease: A hitherto unrecognised association.

Gait and Balance Dysfunction in Adults.

Cortical myoclonus and cerebellar pathology.