Driver reaction time before and after treatment for lumbar radiculopathy

Prospective observational pilot study. OBJECTIVE.: To investigate the effect of right and left radiculopathy on driver reaction time (DRT), and the effect of selective nerve root block (SNRB) on DRT.

The effect of many orthopedic procedures on DRT has already been assessed. To date the effect of radiculopathy and SNRB on DRT has not been studied.

DRTs of 20 radiculopathic patients (10 right, 10 left) were measured using a custom-built car simulator. Each patient was tested pre-SNRB, immediately post-SNRB, and 2 and 6 weeks post-SNRB. As controls 20 age- and sex-matched normal subjects were tested once. Full departmental, institutional, and ethical committee approval were obtained.

Mean DRT of the control group was 452 milliseconds. Mean DRT of patients with right or left radiculopathy pre-SNRB was 521 milliseconds (P < 0.045) and 535 milliseconds (P < 0.018), respectively. In the right radiculopathic group, the measurements immediately post-SNRB, 2 weeks, and 6 weeks were 656 milliseconds (P < 0.005), 589 milliseconds (P < 0.019), and 564 milliseconds (P < 0.10), respectively. The delay immediately and at 2 weeks post-SNRB translates into an increase in stopping distance of 3.8 and 1.9 m, respectively at the speed of 100 km/h. In the left radiculopathic group, the measurements immediately post-SNRB, 2 weeks, and 6 weeks were 585 milliseconds (P < 0.037), 534 milliseconds, and 530 milliseconds, respectively. The delay immediately post-SNRB translates into an increase in stopping distance of 1.4 m at the speed of 100 km/h.

The study identified significant DRTs' changes both in radiculopathy and after SNRB. Right and left radiculopathic patients should be advised about the possible changes in their DRTs post-SNRB. Future research with regard to the suitability for radiculopathic patients to drive and the best time to resume driving post-SNRB is needed.