Walking Speed and PARKINSON’S DISEASE
Researchers at the University of Michigan headed by Nicolaas Bohnen have found that the speed of walking in PARKINSON’S DISEASE depends not only on lack of dopamine but can also be affected by lack of acetylcholine. This suggests that “the clinical heterogeneity of PARKINSON’S DISEASE results from variable involvement of different brain systems”, according to Dr. Bohnen.
In a study that involved 125 subjects with PARKINSON’S DISEASE, they found 38 of them lacked acetylcholine in addition to lack of dopamine. When they compared the speed of walking to a control group of 32 non-Parkinsonian subjects, they found the group lacking dopamine walked only slightly slower than the control group. The speed of the group lacking both acetylcholine and dopamine was markedly slower.
They also compared cognitive function in relation to speed of walking and found that the lack of acetylcholine “may reflect the impact of impaired cognitive processing during ambulation.” The cognitive scores of subjects with lack of acetylcholine and dopamine were lower than those with lack of dopamine only, but non Parkinsonian subjects scored higher than both groups of subjects with PARKINSON’S DISEASE.
The results of this study indicate that people with PARKINSON’S DISEASE whose problems with walking speed do not improve on dopamine replacement therapy may have a form of PARKINSON’S DISEASE that is a multisystem neurodegenerative disorder.
Nicolaas I. Bohnen, MD, PhD, Kirk A. Frey, MD, PhD, Stephanie Studenski, MD, MPH, Vikas Kotagal, MD, Robert A. Koeppe, PhD, Peter J.H. Scott, PhD, Roger L. Albin, MD Martijn L.T.M. Müller, PhD;Gait speed in Parkinson disease correlates with cholinergic degeneration Published online before print September 27, 2013, doi: 10.1212/WNL.0b013e3182a9f558Neurology 10.1212/WNL.0b013e3182a9f558
review by Marcia McCall