Mwiza Ushe | PubMed Health

PubMed2006

Postural tremor suppression is dependent on thalamic stimulation frequency.

Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) reduces tremor in people with essential tremor (ET), yet the dependence of tremor suppression on stimulation frequency remains unclear. To address this issue, we tested tremor suppression for three 15-second measurements during a variety of stimulation frequencies in 11 ET patients treated with VIM DBS. Stimulation frequencies at or above 100 Hz produced maximal benefit; higher frequencies provided no additional benefit. If this short-term measure predicts long-term response in routine activities at home, then this stimulation frequency setting will prolong battery half-life compared to higher frequency settings. These findings suggest that ET patients treated with VIM DBS may receive adequate benefit from stimulation frequencies about 100 Hz and this setting compared to commonly used higher settings will prolong battery life of surgically implanted pulse generators.

Aged↗

PubMed2004

Effect of stimulation frequency on tremor suppression in essential tremor.

We sought to determine the effect of deep brain stimulation (DBS) frequency on tremor suppression in essential tremor (ET) patients with deep brain stimulators implanted in the ventral intermediate nucleus (VIM) of the thalamus. A uniaxial accelerometer was used to measure tremor in the right upper extremity of subjects with a diagnosis of ET who had DBS electrodes implanted in the left VIM. The root-mean-square acceleration was used as the index of tremor magnitude and normalized to the OFF DBS condition. There was a highly significant inverse sigmoidal relationship between stimulation frequency and normalized tremor acceleration (X(2)/DoF = 0.42, r(2) = 0.997). Tremor acceleration had a nearly linear response to stimulation frequencies between 45 and 100 Hz with little additional benefit above 100 Hz. These findings have two important implications. Clinically, frequency of thalamic stimulation is an important variable for optimal tremor control with maximal benefit achieved with 100 to 130 Hz in most patients. Second, thalamic DBS provides tremor benefit in a graded manner and is not an all-or-nothing phenomenon.

Adult↗