Subthalamic and pallidal oscillatory activity in patients with Neurodegeneration with Brain Iron Accumulation type I (NBIA-I).

Objectives: Neurodegeneration with Brain Iron Accumulation type I (NBIA-I) is a rare hereditary neurodegenerative disorder with pallidal degeneration leading to disabling generalized dystonia and parkinsonism. Pallidal or subthalamic deep brain stimulation can partially alleviate motor symptoms. Disease-specific patterns of abnormally enhanced oscillatory neuronal activity recorded from the basal ganglia have been described in patients with movement disorders undergoing deep brain stimulation (DBS).

Dopamine-dependent scaling of subthalamic gamma bursts with movement velocity in patients with Parkinson's disease.

Gamma synchronization increases during movement and scales with kinematic parameters. Here, disease-specific characteristics of this synchronization and the dopamine-dependence of its scaling in Parkinson's disease are investigated. In 16 patients undergoing deep brain stimulation surgery, movements of different velocities revealed that subthalamic gamma power peaked in the sensorimotor part of the subthalamic nucleus, correlated positively with maximal velocity and negatively with symptom severity.

Cortico-pallidal oscillatory connectivity in patients with dystonia.

Primary dystonia has been associated with an underlying dysfunction of a wide network of brain regions including the motor cortex, basal ganglia, cerebellum, brainstem and spinal cord. Dystonia can be effectively treated by pallidal deep brain stimulation although the mechanism of this effect is not well understood. Here, we sought to characterize cortico-basal ganglia functional connectivity using a frequency-specific measure of connectivity-coherence.

Thalamic gamma oscillations correlate with reaction time in a Go/noGo task in patients with essential tremor.

Intracerebral recordings of neuronal activity in patients undergoing deep brain stimulation have revealed characteristic movement-related desynchronization at frequencies <30 Hz and increased activity in the gamma band (~30-100 Hz) in the basal ganglia and thalamus. Thalamic gamma activity is also found during arousal. Here, we explore oscillatory gamma band activity recorded from the ventralis intermedius nucleus of the thalamus during motor performance in a Go/noGo task in 10 patients with essential tremor after implantation of deep brain stimulation electrodes.

Validity of subthalamic-cortical coherency observed in patients with Parkinson's disease.

Simultaneous magnetoencephalography (MEG) and local field potential (LFP) recordings in patients with Parkinson's disease (PD) undergoing deep brain stimulation (DBS) treatment is a promising tool for both clinical application and basic research. Recordings can be accomplished during the time interval between electrode insertion and its connection to the pulse generator while electrodes are being externalized. In nine PD patients, coherence (COH) between LFP and MEG signals was calculated from the data of a 5-min simultaneous MEG-LFP rest recording.