Physiology of Midbrain Head Movement Neurons in Cervical Dystonia

• Type of Material: Article
• Authors: Alexey Sedov, Russian Academy of Sciences; Valentin Popov, Russian Academy of Sciences; Vladimir Shabalov, Burdenko Scientific Research Neurosurgery Institute; Svetlana Raeva, Russian Academy of Sciences; Hyder A Jinnah, Emory University; Aasef Shaikh, Emory University
• Language: English
• Date: 2017-06-01
• Publisher: Wiley
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2017 International Parkinson and Movement Disorder Society
• Final Published Version (URL): http://dx.doi.org/10.1002/mds.26948
• Title of Journal or Parent Work: Movement Disorders
• ISSN: 0885-3185
• Volume: 32
• Issue: 6
• Start Page: 904
• End Page: 912
• Grant/Funding Information: Funding support: Aasef Shaikh was supported by Dystonia Medical Research Foundation Clinical Fellowship Award, and Dystonia Coalition/Dystonia Medical Research Foundation Career Development Award.; Aasef Shaikh was supported by Dystonia Medical Research Foundation Clinical Fellowship Award, and Dystonia Coallition/Dystonia Medical Research Foundation Career Development Award.; Buz Jinnah is the recipient of NIH grant U54NS065701.; H.A. Jinnah is the recipient of NIH grants U54NS065701 and TR001456.
• Keywords: CAJAL INC; Clinical Neurology; SPASMODIC TORTICOLLIS; interstitial nucleus of Cajal; NECK MUSCLE ELECTROMYOGRAPHY; Science & Technology; VESTIBULAR RESPONSES; Life Sciences & Biomedicine; MONKEY SUPERIOR COLLICULUS; SPATIAL ORIENTATION; GAZE SHIFTS; BASAL GANGLIA; Neurosciences & Neurology; head tremor; dystonic tremor; FASTIGIAL NUCLEUS; INTERSTITIAL NUCLEUS
• Research Categories: Biology, Neuroscience; Physics, General; Chemistry, Physical

Abstract

Background: Early theories for cervical dystonia, as promoted by Hassler, emphasized the role of the midbrain interstitial nucleus of Cajal. Focus then shifted to the basal ganglia, and it was further supported with the success of deep brain stimulation. Contemporary theories suggested the role of the cerebellum, but even more recent hypotheses renewed interest in the midbrain. Although the pretectum was visited on several occasions, we still do not know about the physiology of midbrain neurons in cervical dystonia. Methods: We analyzed the unique database of pretectal neurons collected in the 1970s and 1980s during historic stereotactic surgeries aimed to treat cervical dystonia. This database is valuable because such recordings could otherwise never be obtained from humans. Results: We found the following 3 types of eye or neck movement sensitivity: eye-only neurons responded to pure vertical eye movements, neck-only neurons were sensitive to pure neck movements, and the combined eye-neck neurons responded to eye and neck movements. There were the 2 neuronal subtypes: burst-tonic and tonic. The eye-neck or eye-only neurons sustained their activity during eccentric gaze holding. In contrast, the response of neck-only and eye-neck neurons exponentially decayed during neck movements. Conclusions: Modern quantitative analysis of a historic database of midbrain single units from patients with cervical dystonia might support novel hypotheses for normal and abnormal head movements. This data, collected almost 4 decades ago, must be carefully viewed, especially because it was acquired using a less sophisticated technology available at that time and the aim was not to address specific hypothesis, but to make an accurate lesion providing optimal relief from dystonia.