Kerry Mallon

Quantitative assessment of driving performance in Parkinson’s disease

Objectives: The primary aim of this study was to determine how Parkinson’s disease (PD) affects driving performance. It also examined whether changes in driver safety were related to specific clinical disease markers or an individual’s self rating of driving ability. Methods: The driving performance of 25 patients with idiopathic PD and 21 age matched controls was assessed on a standardised open road route by an occupational therapist and driving instructor, to provide overall safety ratings and specific driving error scores. Results: The drivers with PD were rated as significantly less safe (p<0.05) than controls, and more than half of the drivers with PD would not have passed a state based driving test. The driver safety ratings were more strongly related to disease duration (r = −0.60) than to their on time Unified Parkinson’s Disease Rating Scale (r = −0.24). Drivers with PD made significantly more errors than the control group during manoeuvres that involved changing lanes and lane keeping, monitoring their blind spot, reversing, car parking, and traffic light controlled intersections. The driving instructor also had to intervene to avoid an incident significantly more often for drivers with PD than for controls. Interestingly, driver safety ratings were unrelated to an individual’s rating of their own driving performance, and this was the case for all participants. Conclusions: As a group, drivers with PD are less safe to drive than age matched controls. Standard clinical markers cannot reliably predict driver safety. Further studies are required to ascertain whether the identified driving difficulties can be ameliorated.

The On-Road Difficulties of Older Drivers and Their Relationship with Self-Reported Motor Vehicle Crashes

OBJECTIVES: To quantify the driving difficulties of older adults using a detailed assessment of driving performance and to link this with self‐reported retrospective and prospective crashes.

Glaucoma and Driving: On-Road Driving Characteristics

Purpose To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Methods Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Results Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Conclusions Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness.

Corrections: Quantitative assessment of driving performance in Parkinson's disease

www.jimmunol.org/cgi/doi/10.4049/jimmunol.1090082 FIGURE 1. Identification of LDGs in lupus PBMC fractions. Healthy control or SLE PBMCs were stained for markers of the monocyte or granulocyte lineages and analyzed by FACS. A, Gates that contained predominantly lymphocytes, monocytes, and granulocytes were established in dual-log scattergrams. Granulocytes (blue) and monocytes (pink) are distinguished based on CD14, CD15, CD86, and MHC class II expression. Monocytes express high levels of CD14 and are positive for CD86 and MHC class II, whereas CD15 is weak or absent. Granulocytes present in the PBMC fraction are CD15, CD14, and negative for CD86 and MHC class II. Similar results were seen in two additional controls and five additional SLE patients. B, Analysis of CD86 and CD16 revealed several subpopulations. Most healthy control monocytes display the resting phenotype of CD86CD16 (light blue), whereas SLE monocytes have the more activated phenotype of CD86CD16 (blue). The CD16 cells can be divided based on CD86 expression. The CD16/CD86 pool (yellow) likely represents LDGs, whereas the CD/CD86 population (pink) possibly reflects conjugates of CD16 granulocytes and CD86 monocytes.