Parkinson’s Disease is characterized by rigid and sluggish movements, as well as tremors and gait problems.  Blocked blood vessels in the brain, often too small to be seen with current medical imaging technologies, may explain the onset of Parkinson’s symptoms, such diminished walking ability and hand tremors.  Aron S. Buchman, from Rush University (Illinois, USA), and colleagues found microscopic infarcts in 57 individuals out of 418 brain autopsies conducted.  The team reports that the presence of such blockages was significantly associated with gait abnormalities similar to those seen in Parkinson’s disease.  As well, signs of arteriolosclerosis invisible with standard imaging were also significantly associated with parkinsonian gait.  The team urges that more aggressive prevention and treatment strategies for vascular risk factors "might decrease the burden of mild age-related parkinsonian signs.”