Does subthalamic nucleus deep brain stimulation affect the static balance at different frequencies?

PURPOSE: To investigate the effects of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) with different stimulation frequencies on static balance.

MATERIALS AND METHODS: Twenty patients (15 males and 5 females), aged between 43 and 81 (mean: 60.05±7.4) years, who had been diagnosed with idiopathic Parkinson's disease (PD) and undergone STN-DBS surgery were included in the study. Static balance was assessed with TecnoBody Rehabilitation System at four different frequencies: 230, 130, 90 and 60Hz and off-stimulation. Static balance tests were 'stabilometric test, stabilometric compared bipedal closed/opened eye, stabilometric compared mono pedal (right/left foot)'. These tests reported the centre of pressure data 'ellipse area, perimeter, front/back and mediolateral standard deviations'.

RESULTS: There were no statically differences between the static balance test results at any frequency (p>0.05), but results were found better at 90Hz. Stabilometric compared bipedal opened eye forward-backward standard deviation result was significant between off-stimulation and 130Hz (p=0.04). Different frequency stimulation affected the static balance categories percentage with no statistical significance between off-stimulation and others (all p>0.05).

CONCLUSION: This study showed that STN-DBS did not affect the static balance negatively. Low-frequency (LF) stimulation improved the static equilibrium. Posturography systems will give more precise and quantitative results in similar studies with wide frequency ranges.