The subthalamic nucleus (STN) is a pivotal point of the basal ganglia function and dysfunction. Its crucial engagement with the neurosurgical procedure of deep brain stimulation (DBS) that alleviates ...medically intractable Parkinsonian tremor augments the need to refine our current understanding of it. Intranuclear recordings, received from a patient during surgery, are processed to acquire both local field potentials (LFPs) and the spiking activity of the cells inside the nucleus. Under the physiologically justified assumption that the LFPs constitute the input of the cells inside the nucleus whereas the spikes are the output, an input output system analysis of the STN is straightforward. Primary results show that a non-linear Hammerstein-Wiener model is able to simulate the STN output with a reasonable accuracy.
Deep brain stimulation (DBS) is considered a surgical treatment alternative for Parkinson disease (PD) patients with intractable tremor or for those patients who are affected by long-term ...complications of levodopa therapy such as motor fluctuations and severe dyskinesias. However, the susceptible accuracy of placement of the DBS electrode inside the brain nucleus determines the therapeutic efficacy of the method. Unlike normal cases, untreated Parkinsonian states in basal ganglia structures produce oscillations at various frequencies, the most prominent of which is a synchronization in the beta frequency band recorded in the subthalamic nucleus (STN). The actual frequency range and the strength of the beta peak vary among patients. We propose that an on-line spectral analysis of the population activity, as evidenced by microelectrode recordings (MERs) could form a neurophysiological biomarker for confirmation of the on-target placement of the electrode within the STN.
