Alonso-Frech F, Zamarbide I, Alegre M, Rodriguez-Oroz MC, Guridi J, Manrique M, et al. Slow oscillatory activity and levodopa-induced dyskinesias in Parkinson's disease. Brain 2006 Jul;129(Pt 7):1748-1757.
The pathophysiology of levodopa-induced dyskinesias (LID) in Parkinson’s disease is not well understood.
We have recorded local field potentials (LFP) from macroelectrodes implanted in the subthalamic nucleus
(STN) of 14 patients with Parkinson’s disease following surgical treatment with deep brain stimulation. Patients
were studied in the ‘Off’ medication state and in the ‘On’ motor state after administration of levodopa–
carbidopa (po) or apomorphine (sc) that elicited dyskinesias in 11 patients. The logarithm of the power
spectrum of the LFP in selected frequency bands (4–10, 11–30 and 60–80 Hz) was compared between the
‘Off’ and ‘On’ medication states. A peak in the 11–30 Hz band was recorded in the ‘Off’ medication state
and reduced by 45.2% (P < 0.001) in the ‘On’ state. The ‘On’ was also associated with an increment of 77. 6%
(P < 0.001) in the 4–10 Hz band in all patients who showed dyskinesias and of 17.8% (P < 0.001) in the 60–80 Hz
band in the majority of patients. When dyskinesias were only present in one limb (n = 2), the 4–10 Hz peak was
only recorded in the contralateralSTN. These findings suggest that the 4–10 Hz oscillation is associated with the
expression of LID in Parkinson’s disease.