The cognitive and visual deficits associated with PD resulted in impaired visual search while driving, and the increased cognitive load during this task worsened their driving safety.

The quantitative effect of an auditory-verbal distracter task on driving performance was not significantly different between Parkinson disease (PD) and control groups. However, a significantly larger subset of drivers with PD had worsening of their driving safety errors during distraction. Measures of cognition, motor function, and sleepiness predicted effects of distraction on driving performance within the PD group.

Navigating a new route during automobile driving uses the driver's cognitive resources and has the potential to impair driving ability in people with Parkinson's disease (PD). Our aim was to assess navigation and safety errors during a route following task (RFT) in drivers with the illness. Seventy-seven subjects with mild-moderate PD (median Hoehn-Yahr stage = 2.0) and 152 neurologically normal elderly adults, all active and licensed drivers, were tested with a battery of visual, cognitive and motor tests of abilities. Each driver also performed a RFT administered on the road in an instrumented vehicle. Main outcome variables included: number of incorrect turns, times lost and at-fault safety errors. All group comparisons were adjusted for age, gender, education and familiarity with the region. Drivers with PD performed significantly worse on cognitive, visual and motor tests compared to controls, and took longer to finish the RFT. Higher proportions of these drivers made incorrect turns {53.9% in PD versus 21.1% in controls, Odds Ratio (OR) [95% Confidence Interval (CI)] = 2.8 [1.4, 5.7], P = 0.006}, got lost (15.8% versus 2.0%, OR [95%CI] = 4.7 [1.1, 20.0], P = 0.037), or committed at-fault safety errors (84.2% versus 46.7%, OR [95%CI] = 7.5 [3.3, 17.0], P < 0.001). Within the patient group, the navigational and safety errors were predicted by poor performances on cognitive and visual tests, but not by the severity of motor dysfunction. Drivers with PD made more navigation and safety errors than neurologically normal drivers on a RFT that placed demands on driver memory, attention, executive functions and visual perception. The PD group driver safety was degraded possibly due to an increase in the cognitive load in patients with limited reserves. Navigational errors and lower driver safety were associated more with impairments in cognitive and visual function than the motor severity of their disease in drivers with PD.

Objective: To assess driving performance in Parkinson disease (PD) under low-contrast visibility conditions. Methods:Licensed, active drivers with mild to moderate PD (n ϭ 67, aged 66.2 Ϯ 9.0 years, median Hoehn-Yahr stage ϭ 2) and controls (n ϭ 51, aged 64.0 Ϯ 7.2 years) drove in a driving simulator under high-(clear sky) and low-contrast visibility (fog) conditions, leading up to an intersection where an incurring vehicle posed a crash risk in fog.Results: Drivers with PD had higher SD of lateral position (SDLP) and lane violation counts (LVC) than controls during fog (p Ͻ 0.001). Transition from high-to low-contrast visibility condition increased SDLP and LVC more in PD than in controls (p Ͻ 0.01). A larger proportion of drivers with PD crashed at the intersection in fog (76.1% vs 37.3%, p Ͻ 0.0001). The time to first reaction in response to incursion was longer in drivers with PD compared with controls (median 2.5 vs 2.0 seconds, p Ͻ 0.0001). Within the PD group, the strongest predictors of poor driving outcomes under low-contrast visibility conditions were worse scores on measures of visual processing speed and attention, motion perception, contrast sensitivity, visuospatial construction, motor speed, and activities of daily living score. Conclusions:During driving simulation under low-contrast visibility conditions, drivers with Parkinson disease (PD) had poorer vehicle control and were at higher risk for crashes, which were primarily predicted by decreased visual perception and cognition; motor dysfunction also contributed. Our results suggest that drivers with PD may be at risk for unsafe driving in low-contrast visibility conditions such as during fog or twilight. Neurology Reduced contrast sensitivity (CS) is a common feature of Parkinson disease (PD)1-11 and is associated with poor outcomes on driving tests in parkinsonian drivers.12-14 However, there are no published reports on driving under low visibility due to low-contrast lighting conditions in PD. This study evaluates the effect of different environmental visibility settings (high contrast ϭ clear sky, low contrast ϭ fog, as in figure 1) on vehicle control (indexed by SD of lateral position [SDLP] and lane violation counts [LVC]) during uneventful driving, and response to sudden hazards under low-contrast visibility conditions in drivers with PD using a driving simulator.To test driver response to a sudden hazard under low-contrast visibility conditions, we used a collision avoidance scenario at an intersection. [15][16][17] Although intersections constitute only a

Background Mesial temporal lobe epilepsy (mTLE) has been suggested to follow a circadian rhythm. Previous research found an afternoon peak in mTLE seizure occurrence. We evaluated the pattern of seizure occurrence in patients with well-localized mTLE and hypothesized that peak seizure frequency would occur in the afternoon, and that this pattern would not be altered by age, gender, or seizure focus. Methods We retrospectively identified consecutive mTLE patients with a seizure-free outcome following anterior temporal lobectomy from 1993-2004 with video-EEG captured seizures. We recorded and plotted the 24-hour clock time for each seizure and performed cosinor analysis. SAS Proc GLIMMIX was used to fit the linearized transform of the cosinor model. Negative binomial regression fitted by the generalized estimating equations (GEE) method was also performed to estimate and compare the mean seizure rates over a 24-hour day. Results Sixty mTLE patients monitored between 2-16 days were analyzed. Mean (standard deviation), median number of seizures per subject were 10.47(7.86), 9.00. Cosinor plots indicated that the function had two modes: 7-8 a.m. and 4-5 p.m. GEE analysis was consistent with peak seizure frequency occurrence at 6-8 a.m. (p<0.0001) and 3-5 p.m. (p<0.01). Conclusions We found a bimodal pattern of seizure occurrence in human mTLE, with peak seizure frequencies occurring between 6-8 a.m. and 3-5 p.m. confirming an afternoon peak, as well as a previously unsuspected morning peak in seizure occurrence that provides rationale for future investigations of antiepileptic drug chronopharmacology and informs patient counseling regarding patterns of seizure occurrence.