Pallidal deep brain stimulation modulates excessive cortical high β phase amplitude coupling in Parkinson disease

Mahsa Malekmohammadi, Nicholas AuYong, Joni Ricks-Oddie, Yvette Bordelon, Nader Pouratian

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


Objective: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) are equally efficacious in the management of Parkinson disease (PD). Studies of STN-DBS have revealed a therapeutic reduction in excessive cortical β-γ phase-amplitude coupling (PAC). It is unclear whether this is specific to STN-DBS and potentially mediated by modulation of the hyperdirect pathway or if it is a generalizable mechanism seen with DBS of other targets. Moreover, it remains unclear how cortical signals are differentially modulated by movement versus therapy. To clarify, the effects of GPi-DBS and movement on cortical β power and β-γ PAC were examined. Methods: Right sensorimotor electrocorticographic signals were recorded in 10 PD patients undergoing GPi-DBS implantation surgery. We evaluated cortical β power and β-γ PAC during blocks of rest and contralateral hand movement (finger tapping) with GPi-DBS off and on. Results: Movement suppressed cortical low β power (P = 0.008) and high β-γ PAC (P = 0.028). Linear mixed effect modeling (LMEM) showed that power in low and high β bands are differentially modulated by movement (P = 0.022). GPi-DBS also results in a significant suppression of high β-γ PAC but without power modulation in either β sub-band (P = 0.008). Cortical high β-γ PAC is significantly correlated with severity of bradykinesia (Rho = 0.59, P = 0.045) and changes proportionally with therapeutic improvement (Rho = 0.61, P = 0.04). Conclusions: Similar to STN-DBS, GPi-DBS reduces motor cortical β-γ PAC, like that also reported with dopaminergic mediations, suggesting it is a generalizable symptom biomarker in PD, independent of therapeutic target or proximity to the hyperdirect pathway.

Original languageEnglish (US)
Pages (from-to)607-617
Number of pages11
JournalBrain Stimulation
Issue number3
StatePublished - May 1 2018
Externally publishedYes


  • Deep brain stimulation
  • Globus pallidus internus
  • Motor cortex
  • Parkinson disease
  • Phase amplitude coupling

ASJC Scopus subject areas

  • Biophysics
  • Neuroscience(all)
  • Clinical Neurology


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