Objective: To record the possible effect of acute deep brain stimulation (DBS) of the globus pallidus internus (GPI) on the neuronal activity of the ventralis oralis anterior (VOA) nucleus of the thalamus.
Methods: Under general propofol anaesthesia, extracelullar single unit recordings were performed in VOA of a post-anoxic dystonic patient previously implanted with GPI located electrodes for chronic DBS.
Results: Neurons recorded in the VOA could be classified in two cell subpopulations: a high firing rate (16.5 Hz) and low burst index (BI; 15.6) type and a low firing rate (5.5 Hz) and high BI (35.6) type. GPI electrical stimulation reduced the frequency and increased the BI of the high firing rate cells while leaving the other cell type unchanged.
Conclusion: These results demonstrate that pallidal DBS is able to inhibit a subpopulation of motor thalamic cells and question the pathophysiological model of dystonia based on a low firing rate of GPI cells.