Neurophysiological aspects of the regulation of the head's position in the normal state and left- and right-sided forms of spasmodic torticollis

• Published in: Human physiology Vol. 35; no. 2; pp. 157 - 162
• Main Authors: Naryshkin, A. G, Skoromets, T. A, Gorelik, A. L, Egorov, A. Yu
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : SP MAIK Nauka/Interperiodica 01.03.2009; SP MAIK Nauka/Interperiodica
• Subjects: Biomedical and Life Sciences; Biomedicine; Brain; Coherence; Control; Disturbances; Frequency ranges; Human Physiology; Life Sciences; Links; Patients; Wakefulness; Spasmodic Torticollis; Cervical Dystonia; Head Turn; Peripersonal Space; Left Turn
• ISSN: 0362-1197; 1608-3164
• DOI: 10.1134/S0362119709020042

We have studied the spatiotemporal distribution of coherent EEG links in 10 healthy right-handed subjects under the conditions of comfortable wakefulness with a straight position of the head and with the head voluntarily turned to fixed left and right positions. The computations were made separately in each standard range of EEG frequencies (Δ, θ, α, and β). The results were compared with the data obtained during studies of right-handed patients with right-sided (RS, n = 9) and left-sided (LS; n = 8) forms of spasmodic torticollis (ST). It has been shown that, upon a voluntary right turn of the head, the number of strong and moderate coherent EEG links in healthy subjects increases considerably more than upon a left turn. This may be accounted for by the greater functional importance of the control of the right part of the visual space as the area of manipulation of the dominant hand. In patients with RS ST, the number of intra- and interhemispheric strong and moderate coherent EEG links increased in all four frequency ranges, as compared to healthy subjects, upon the right turn of the head. In patients with LS ST, the spatial structure of the bioelectric potential field of the brain is less reorganized upon the voluntary left turn of the head as compared to the level of coherent EEG links in healthy subjects. Presumably, this phenomenon reflects a stronger insufficiency of neurophysiological mechanisms of postural control and compensation for its disturbances in patients with the LS form of ST, which results in a more severe disability as compared to patients with right-sided ST.