Objective: To evaluate effects of acute levodopa administration on frequency content of intracranial local field potentials in a dystonic young adult.

Background: Levodopa is the standard for medical management of the motor features of movement disorders such as Parkinson’s disease (PD) and dystonia. However, long-term use of levodopa is associated with reduced duration of response and dyskinesia development [1]. These complications result from the pulsatile stimulation of dopamine receptors induced by short-acting dopaminergic drugs, whereas more continuous administration of levodopa is thought to better approximate healthy brain and reduce the risk of motor complications [1,2]. Pharmacotherapy is often used in conjunction with deep brain stimulation (DBS), since combination therapy may optimize response [3]. To optimize the delivery of dopaminergic drugs and adjust for DBS effects, it is important to develop tools to monitor duration of action and hence timing of combined treatment strategies. The first step in this process is to characterize the acute effects of dopaminergic drugs such as levodopa on neural activity.

Method: A single subject with dystonia secondary to cerebral palsy underwent placement of stereotactic electroencephalographic (sEEG) electrodes in the internal globus pallidus (GPi) of basal ganglia and ventralis oralis anterior/posterior (VoaVop) nuclei of thalamus bilaterally to determine optimal DBS targets. Intracranial signals were recorded fifteen minutes before and forty-five minutes after enteral dose of carbidopa/levodopa 25/100 mg, in four separate trials. Frequency content of all signals was calculated in the following bands: delta (1-3 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-30 Hz), and gamma (30-50 Hz). Bandpower is reported as the percentage contribution of each band to summed power across all bands.

Results: The average contribution of alpha band power pre-levodopa was noted to be 6.9% in GPi and 7.2% in VoaVop. Post-levodopa administration, the ratios of alpha band power increased to 10.1% and 12.2%, respectively.

Conclusion: Levodopa is shown to affect the oscillatory neural activity in both basal ganglia and thalamic nuclei, with an increase in alpha band power. Further assessment of levodopa’s effects on neural activity is indicated to help better understand its mechanism of action and to identify possible biomarkers for pharmacodynamic monitoring.

References: [1] Stoker, T. B., Torsney, K. M., & Barker, R. A. (2018). Emerging treatment approaches for Parkinson’s disease. In Frontiers in Neuroscience. https://doi.org/10.3389/fnins.2018.00693
[2] Olanow, C. W., Obeso, J. A., & Stocchi, F. (2006). Continuous dopamine-receptor treatment of Parkinson’s disease: scientific rationale and clinical implications. In Lancet Neurology. https://doi.org/10.1016/S1474-4422(06)70521-X
[3] Oertel, W., & Schulz, J. B. (2016). Current and experimental treatments of Parkinson disease: A guide for neuroscientists. In Journal of Neurochemistry. https://doi.org/10.1111/jnc.13750

« Back to 2023 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/increased-alpha-power-in-basal-ganglia-and-thalamus-following-levodopa-administration-in-a-dystonic-young-adult/