Characterizing the Normative Voice Tremor Frequency in Essential Vocal Tremor

Conflicting results on the existence of tremor-related cortical activity in essential tremor (ET) have raised questions on the role of the cortex in tremor generation. Here we attempt to address these issues. We recorded 64 channel surface EEGs and EMGs from forearm muscles in 15 patients with definite ET. EEG and EMG power spectra, relative power of the rhythmic EMG activity, relative EEG power at the tremor frequency, and EEG–EMG and EEG–EEG coherence were calculated and their dynamics over time explored. Corticomuscular delay was studied using a new method for narrow-band coherent signals. Corticomuscular coherence in the contralateral central region at the tremor frequency was present in all patients in recordings with a relative tremor EMG power exceeding a certain level. However, the coherence was lost intermittently even with tremors far above this level. Physiological 15- to 30-Hz coherence was found consistently in 11 patients with significantly weaker EMG activity in this frequency range. A more frontal (mesial) hot spot was also intermittently coupled with the tremor and the central hot spot in five patients. Corticomuscular delays were compatible with transmission in fast corticospinal pathways and feedback of the tremor signal. Thus the tremor rhythm is intermittently relayed only in different cortical motor areas. We hypothesize that tremor oscillations build up in different subcortical and subcortico-cortical circuits only temporarily entraining each other.

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Validation of a new tool for automatic assessment of tremor frequency from video recordings

Journal of Neuroscience Methods ◽

10.1016/j.jneumeth.2011.02.033 ◽

2011 ◽

Vol 198 (1) ◽

pp. 110-113 ◽

Cited By ~ 10

Author(s):

Zdenka Uhríková ◽

Otakar Šprdlík ◽

Martina Hoskovcová ◽

Arnošt Komárek ◽

Olga Ulmanová ◽

...

Keyword(s):

Automatic Assessment ◽

Video Recordings ◽

Tremor Frequency

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Comparative measures of vocal tremor and vocal vibrato

Journal of Voice ◽

10.1016/s0892-1997(87)80040-1 ◽

1987 ◽

Vol 1 (2) ◽

pp. 162-167 ◽

Cited By ~ 37

Author(s):

Lorraine A. Ramig ◽

Thomas Shipp

Keyword(s):

Vocal Tremor

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Primidone Therapy for Essential Vocal Tremor

JAMA Otolaryngology–Head & Neck Surgery ◽

10.1001/jamaoto.2015.2849 ◽

2016 ◽

Vol 142 (2) ◽

pp. 117 ◽

Cited By ~ 15

Author(s):

Andrew Nida ◽

Josie Alston ◽

John Schweinfurth

Keyword(s):

Vocal Tremor

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Common features of the reservoir-associated seismic activities

Bulletin of the Seismological Society of America ◽

10.1785/bssa0620020481 ◽

1972 ◽

Vol 62 (2) ◽

pp. 481-492 ◽

Cited By ~ 1

Author(s):

Harsh K. Gupta ◽

B. K. Rastogi ◽

Hari Narain

Keyword(s):

Main Shock ◽

Detailed Examination ◽

Factors Affecting ◽

B Values ◽

Common Features ◽

Rate Of Increase ◽

Tremor Frequency ◽

Earthquake Sequences ◽

Largest Aftershock ◽

Frequency Magnitude

abstract A detailed examination of the behavior of earthquakes associated with over a dozen artificial lakes shows that, in all cases, the tremors were initiated or their frequency increased considerably following the lake filling and that their epicenters were mostly located within a distance of 25 km from the lakes. Among the factors affecting the tremor frequency are the rate of increase of water level, duration of loading, maximum levels reached, and the period for which the high levels are retained. The study of these reservoir-associated earthquake sequences reveals that the ratio of the largest aftershock to the main shock is high (about 0.9), and the b values are also high in the frequency-magnitude relation, which is contrary to the normal earthquakes of the concerned regions.

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