Biomedical subjects

E Y Uc

Publications and source records attributed to E Y Uc.

6 recordsLinked to original sources

PubMed2006

Driving with distraction in Parkinson disease.

OBJECTIVE: To assess the effects of auditory-verbal distraction on driving performance in Parkinson disease (PD). METHODS: We tested licensed, currently active drivers with mild-to-moderate PD (n = 71) and elderly controls with no neurologic disease (n = 147) on a battery of cognitive, visual, and motor tests. While they drove on a four-lane interstate freeway in an instrumented vehicle, we determined at-fault safety errors and vehicle control measures during a distracter task (Paced Auditory Serial Addition Task [PASAT]) and on an uneventful baseline segment. RESULTS: Compared with controls, drivers with PD committed more errors during both baseline and distraction, and drove slower with higher speed variability during distraction. Although the average effect of distraction on driving performance compared with baseline was not different between the groups, the drivers with PD showed a more heterogeneous response to distraction (p < 0.001): the error count increased in 28.2% of drivers with PD (vs 15.8% in controls), decreased in 16.9% (vs 3.4%), and remained stable in 54.9% (vs 80.8%). The odds of increase in safety errors due to distraction was higher in the PD group even after adjusting for baseline errors, level of engagement in PASAT, sex, and education (odds ratio [95% CI] = 2.62 [1.19 to 5.74], p = 0.016). Decreased performance on tests of cognitive flexibility, verbal memory, postural control, and increased daytime sleepiness predicted worsening of driving performance due to distraction within the PD group. CONCLUSION: 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.

Accidents, Traffic↗

PubMed2005

Visual dysfunction in Parkinson disease without dementia.

OBJECTIVE: To determine the profiles of visual dysfunction and their relationship to motor and cognitive dysfunction and to disability in mild to moderate Parkinson disease (PD) without dementia. METHODS: Seventy-six independently living participants with mild to moderate PD and 161 neurologically normal older adults were studied using a comprehensive battery to assess visual acuity, contrast sensitivity (CS), visual speed of processing and attention, spatial and motion perception, visual and verbal memory, visuoconstructional abilities, executive functions, depression, and motor function. RESULTS: Participants with PD scored significantly worse on all tests of vision and cognition compared with normal elderly persons. Reduced CS contributed to deficits on tests of spatial and motion perception and attention in participants with PD. Impairments in visual attention and spatial perception predicted worse cognitive function. Worse performances on tests of visual speed of processing and attention, spatial and motion perception, visual construction, and executive functions correlated with measures of postural instability and gait difficulty (in the Motor section of the Unified Parkinson's Disease Rating Scale). Impairments in motor function, visual memory, mood, and executive functions predicted worse disability as measured by Schwab-England Activities of Daily Living Scale. CONCLUSIONS: Patients with mild to moderate Parkinson disease showed impaired visual perception and cognition compared with elderly control subjects. Visual dysfunction contributes to parkinsonian disability through its influences on cognition and locomotion.

Aged↗

PubMed2005

Driver landmark and traffic sign identification in early Alzheimer's disease.

OBJECTIVE: To assess visual search and recognition of roadside targets and safety errors during a landmark and traffic sign identification task in drivers with Alzheimer's disease. METHODS: 33 drivers with probable Alzheimer's disease of mild severity and 137 neurologically normal older adults underwent a battery of visual and cognitive tests and were asked to report detection of specific landmarks and traffic signs along a segment of an experimental drive. RESULTS: The drivers with mild Alzheimer's disease identified significantly fewer landmarks and traffic signs and made more at-fault safety errors during the task than control subjects. Roadside target identification performance and safety errors were predicted by scores on standardised tests of visual and cognitive function. CONCLUSIONS: Drivers with Alzheimer's disease are impaired in a task of visual search and recognition of roadside targets; the demands of these targets on visual perception, attention, executive functions, and memory probably increase the cognitive load, worsening driving safety.

Aged↗

PubMed2004

Driver route-following and safety errors in early Alzheimer disease.

OBJECTIVE: To assess navigation and safety errors during a route-following task in drivers with Alzheimer disease (AD). DESIGN/METHODS: Thirty-two subjects with probable AD (by National Institute of Neurological and Communicative Disorders criteria) of mild severity and 136 neurologically normal older adults were tested on a battery of visual and cognitive tests of abilities that are critical to safe automobile driving. Each driver also performed a route-finding task administered on the road in an instrumented vehicle. Main outcome variables were number of 1) incorrect turns; 2) times lost; and 3) at-fault safety errors. RESULTS: The drivers with mild AD made significantly more incorrect turns, got lost more often, and made more at-fault safety errors than control subjects, although their basic vehicular control abilities were normal. The navigational and safety errors were predicted using scores on standardized tests sensitive to visual and cognitive decline in early AD. CONCLUSIONS: Drivers with Alzheimer disease made more errors than neurologically normal drivers on a route-following task that placed demands on driver memory, attention, and perception. The demands of following route directions probably increased the cognitive load during driving, which might explain the higher number of safety errors.

Aged↗

PubMed2000

Niemann-Pick disease type C: two cases and an update.

We describe two patients with juvenile-onset Niemann-Pick disease type C (NPC) to illustrate the variable neurologic features of this condition. One presented with hypersplenism at age 10 and was misdiagnosed with Gaucher disease. He developed complex partial seizures in his teens but remained otherwise neurologically asymptomatic until his mid 30s. At age 45, he had mild dementia and dysarthria, vertical supranuclear ophthalmoplegia, axonal sensorimotor polyneuropathy, and cerebellar ataxia. The second patient presented with rapidly progressive dystonia at age 8, and mild hepatosplenomegaly, vertical supranuclear ophthalmoplegia, severe behavioral disorder, and dementia by age 14. The diagnosis of NPC was based on deficient cholesterol esterification and excessive lysosomal filipin staining in cultured skin fibroblasts. Current notions about diagnosis and pathogenesis of NPC are reviewed.

Adolescent↗

PubMed1995

Expression of mRNAs of multiple growth factors and receptors by astrocytes and glioma cells: detection with reverse transcription-polymerase chain reaction.

1. Although glial cells in culture are known to secrete growth factors and are also known to be responsive to some of them, detailed comparisons are difficult because the bulk of information was based on various animals of origin, developmental stages, growth properties, culture age, and culture conditions. 2. To present a unified picture of the growth factors and their receptors found in glial cells, we surveyed the expression of messenger RNAs of a panel of growth factors and receptors, using reverse transcription-polymerase chain reaction (RT-PCR), in three common glial cell types: rat astrocytes in primary culture, rat glioma line C6, and human glioma line A172. 3. We observed that normal and neoplastic glial cells in culture express multiple growth factors and also possess most of the receptors to the factors, suggesting multiple autocrine functions. In addition, glia produce growth factors known to be capable of acting on neurons, implicating paracrine function involving glia-neuron interaction. Glial cells also produce growth factors and receptors that are capable of communicating with hematopoietic cells, suggesting neuroimmunologic interaction. What is most interesting is that glial cells express receptors for growth factors previously thought to be acting on neurons only. 4. The current study demonstrates the feasibility of screening from a small sample a large number of growth factors and receptors. The method portends future clinical application to biopsy or necropsy samples from brain tumors or pathologic brains suffering from degenerative diseases such as Alzheimer's or Parkinson's disease.

Animals↗