Tremor-correlated neuronal activity in the subthalamic nucleus of Parkinsonian patients

• Published in: Neuroscience letters Vol. 442; no. 3; pp. 195 - 199
• Main Authors: Amtage, Florian, Henschel, Kathrin, Schelter, Björn, Vesper, Jan, Timmer, Jens, Lücking, Carl Hermann, Hellwig, Bernhard
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 19.09.2008; Elsevier
• Subjects: Adult; Aged; Biological and medical sciences; Coherence; Deep Brain Stimulation; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Electromyography; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Microelectrodes; Middle Aged; Muscle, Skeletal - innervation; Muscle, Skeletal - physiopathology; Neurology; Neurons - physiology; Parkinson Disease - complications; Parkinson Disease - physiopathology; Parkinson Disease - therapy; Parkinson's disease; Rest tremor; Spike activity; Stereotaxic Techniques; Subthalamic nucleus; Subthalamic Nucleus - physiopathology; Tremor - etiology; Tremor - physiopathology; Tremor - therapy; Vertebrates: nervous system and sense organs; Wrist - innervation; Subthalamic nucleus; Parkinson's disease; Spike activity; Deep brain stimulation; Rest tremor; Coherence; Human; Nervous system diseases; Subthalamic nucleus,Deep brain stimulation,Coherence,Spike activity,Parkinson's disease,Rest tremor; Central nervous system disease; Central nervous system; Parkinson disease; Degenerative disease; Encephalon; Cerebral disorder; Extrapyramidal syndrome
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2008.06.087

Tremor in Parkinson's disease (PD) is generated by an oscillatory neuronal network consisting of cortex, basal ganglia and thalamus. The subthalamic nucleus (STN) which is part of the basal ganglia is of particular interest, since deep brain stimulation of the STN is an effective treatment for PD including Parkinsonian tremor. It is controversial if and how the STN contributes to tremor generation. In this study, we analyze neuronal STN activity in seven patients with Parkinsonian rest tremor who underwent stereotactic surgery for deep brain stimulation. Surface EMG was recorded from the wrist flexors and extensors. Simultaneously, neuronal spike activity was registered in different depths of the STN using an array of five microelectrodes. After spike-sorting, spectral coherence was analyzed between spike activity of STN neurons and tremor activity. Significant coherence at the tremor frequency was detected between EMG and neuronal STN activity in 76 out of 145 neurons (52.4%). In contrast, coherence in the beta band occurred only in 10 out of 145 neurons (6.9%). Tremor-coherent STN activity was widely distributed over the STN being more frequent in its dorsal parts (70.8–88.9%) than in its ventral parts (25.0–48.0%). Our results suggest that synchronous neuronal STN activity at the tremor frequency contributes to the pathogenesis of Parkinsonian tremor. The wide-spread spatial distribution of tremor-coherent spike activity argues for the recruitment of an extended network of subthalamic neurons for tremor generation.