Neural systemic impairment from whole‐body vibration

Abstract

Insidious brain microinjury from motor vehicle-induced whole-body vibration (WBV) has not yet been investigated. For a long time we have believed that WBV would cause cumulative brain microinjury and impair cerebral function, which suggests an important risk factor for motor vehicle accidents and secondary cerebral vascular diseases. Fifty-six Sprague-Dawley rats were divided into seven groups (n = 8): 1) 2-week normal control group, 2) 2-week sham control group (restrained in the tube without vibration), 3) 2-week vibration group (exposed to whole-body vibration at 30 Hz and 0.5g acceleration for 4 hr/day, 5 days/week, for 2 weeks), 4) 4-week sham control group, 5) 4-week vibration group, 6) 8-week sham control group, and 7) 8-week vibration group. At the end point, all rats were evaluated in behavior, physiological, and brain histopathological studies. The cerebral injury from WBV is a cumulative process starting with vasospasm squeezing of the endothelial cells, followed by constriction of the cerebral arteries. After the 4-week vibration, brain neuron apoptosis started. After the 8-week vibration, vacuoles increased further in the brain arteries. Brain capillary walls thickened, mean neuron size was obviously reduced, neuron necrosis became prominent, and wide-ranging chronic cerebral edema was seen. These pathological findings are strongly correlated with neural functional impairments.

Cumulative Brain Injury from Motor Vehicle-Induced Whole-Body Vibration and Prevention by Human Apolipoprotein A-I Molecule Mimetic (4F) Peptide (an Apo A-I Mimetic)

“…People believe tired drivers are deadly drivers. However, our recent preliminary study results 1–3 on simulated motor vehicle-induced whole-body vibration (MV-WBV) challenge the traditional thinking; our studies suggest that “driver’s fatigue” is actually brain dysfunction and brain impairment resulting from MV-WBV. Here we hypothesize that prolonged MV-WBV induces brain injuries that compromise a driver’s judgment and reactive capabilities and may be one cause of MVAs.…”

“…Seventy-two Sprague-Dawley male rats (weight 250–300 g) were divided into 9 groups (N = 8) 1 : the 2-week normal control group had no treatment 2 ; the 2-week sham control group was restrained in the tube without vibration 3 ; the 2-week vibration group was exposed to WBV at 30 Hz and .5 g acceleration for 4 hours/day, 5 days/week for 2 weeks 4 ; the 4-week sham control group was restrained in the tube without vibration 5 ; the 4-week vibration group was vibrated for 4 weeks 6 ; the 4-week vibration group was treated with 4F-peptide (Ac-DWFKAFYDKVAEKFKEAF-NH2) preconditioning 7 ; the 8-week sham control group was restrained in the tube without vibration 8 ; the 8-week vibration group was vibrated for 8 weeks 9 ; and the 8-week vibration group was treated with 4F-peptide preconditioning. At the end point, all the rats were evaluated by behavioral, physiological, histopathological, and molecular studies of the brain.…”

“…The acceleration was set with a power amplifier (B&K type 2706). Frequency and acceleration was calibrated before beginning the study using an HP 1201 B oscilloscope and a B&K 4384 accelerometer connected to a B&K Integrating Vibration Meter, type 2513, linear vertical oscillations with linear vertical oscillations of 30 Hz and .5 g acceleration (4.9 m/second 2 root mean square acceleration). These vibration parameters were selected to simulate most common MV driving.…”

“…We constructed a classic maze used in our previous study on WBV. 1,2 The maze is constructed from standard ½-inch particle board and consists of a large 23 × 23-inch platform with a series of 6-inch high vertical walls and a transparent ceiling. The channels are 4 inches wide, allowing the rats easy access through the maze.…”

Assessment of vibration exposure and physiological responses of crew members during Infantry Combat Vehicle (ICV) operation: a pilot study

“…Short time exposure to WBV has shown to have physiological effects which includes hyperventilation, chest pain and increased muscle tension 4. Yan et al 19 hypothesised that acute WBV exposure caused insidious brain injury by bringing about cerebrovascular spasm, constriction and increased amount of free radicals leading to neuronal impairment which further causes fatigue. It was observed that with 1 hour exposure, the rms value of HAV was below the EAV and ELV.…”