PubMed Health⌕ Search

Biomedical subjects

L J Côté

Publications and source records attributed to L J Côté.

18 recordsLinked to original sources
PubMed2002

The association of incident dementia with mortality in PD.

OBJECTIVE: To evaluate the association of incident dementia with mortality in a cohort of patients with idiopathic PD who were nondemented at baseline evaluation, controlling for extrapyramidal sign (EPS) severity at each study visit. BACKGROUND: The development of dementia has been associated with reduced survival in PD. Because EPS severity is associated with both dementia and mortality in PD, the association of dementia with mortality may be confounded by disease severity. METHODS: A cohort of patients with PD was followed annually with neurologic and neuropsychological evaluations. The association of incident dementia and the total Unified PD Rating Scale (UPDRS) motor score with mortality in PD was examined using Cox proportional hazards models with time-dependent covariates. All analyses were adjusted for age at baseline, sex, years of education, ethnicity, and duration of PD. RESULTS: Of 180 PD patients, 41 (22.8%) died during a mean follow-up period of 3.9 +/- 2.2 years. Among those who died during the study period, 48.8% (20 of 41) became demented during follow-up, as compared to 23.0% (32 of 139) of those who remained alive. Both incident dementia (RR: 2.2, 95% CI: 1.1 to 4.5, p = 0.04) and the total UPDRS motor score at each study visit (RR: 1.04, 95% CI: 1.02 to 1.07, p = 0.001) were associated with mortality in PD when included in the same Cox model. CONCLUSIONS: Incident dementia has an independent effect on mortality when controlling for EPS severity. The development of dementia is associated with a twofold increased mortality risk in PD.

Aged↗
PubMed1995

Neuropsychological characteristics of preclinical dementia in Parkinson's disease.

The goal of this study was to characterize the changes in cognition associated with the earliest, or preclinical, stages of dementia in Parkinson's disease (PD). We administered a comprehensive neuropsychological test battery to a group of initially nondemented PD patients participating in a longitudinal community-based epidemiologic study. We used Cox proportional hazards models to assess the relative risk of incident dementia associated with baseline scores on the neuropsychological tests. Baseline performance on two verbal fluency tasks (letter fluency and category fluency) was significantly and independently associated with incident dementia. Tests of memory, orientation, abstract reasoning, naming, and constructional skill were less sensitive predictors of subsequent dementia. The neuropsychological pattern characterizing the preclinical stages of dementia in PD differed from that described previously in preclinical Alzheimer's disease. Results suggest that poor performance on tests of verbal fluency may represent a distinct characteristic of the preclinical phase of dementia in PD.

Aged↗
PubMed1994

Smoking and Parkinson's disease.

Smoking was examined in relation to Parkinson's disease (PD) in a population-based study in northern Manhattan (New York City) because of its putative "protective effect." Using a case-control design, information on smoking and associated behaviors was obtained in structured interviews after standard diagnostic evaluations in both cases and controls. The overall prevalence of smoking in the population was 43.7%, decreasing to 37% after age 85. Smoking was most frequent in men, Blacks, and in both cases and controls using alcohol once per week or more. Cases had quit smoking more often than controls (87 vs. 64%), and had smoked for significantly fewer years (31 vs. 41 yrs; p < 0.05 for both). The age-at-onset for smokers with PD was similar to age-at-onset for nonsmokers with PD. The odds ratio (OR) for a history of smoking associated with PD was 1.1 (95% CI 0.7-1.8). No protective gradient was associated with heavier smoking patterns. However, the odds that patients with PD were still smoking at the time of the interview were significantly less than those for controls (OR = 0.2; 95% CI 0.1-0.5). These results do not support the hypothesis that smoking protects against PD; rather they strongly imply the converse, that PD reduces smoking.

Aged↗
PubMed1993

Isocratic HPLC assay with electrochemical detection of free gamma-aminobutyric acid in cerebrospinal fluid.

A method for measuring gamma-aminobutyric acid (GABA) in human cerebrospinal fluid (CSF) by isocratic HPLC with electrochemical detection is described. The method is based on precolumn derivatization of GABA with o-phthaldialdehyde (OPA) and tert-butylthiol (t-BT), separation of the GABA-OPA complex on a reversed-phase column, and quantitation by means of a Coulochem electrochemical detector. The method is highly sensitive and specific for GABA. In three samples of human CSF containing low, medium, and high amounts of GABA, the coefficients of variation between and within runs were 4.5% and 3.6%, respectively. The concentration of GABA in 10 neurologically intact subjects was 92.5 +/- 9.4 nmol/L of CSF.

Adolescent↗
PubMed1987

The assessment of cognitive function in the elderly.

Evidence of impaired cognitive function requires careful evaluation to arrive at correct diagnosis and, possibly, treatment. Steps in this evaluation that might be undertaken in primary care are enumerated and discussed. The role of brief formal tests of cognitive functions in such an evaluation is emphasized.

Aged↗
PubMed1975

Biosynthesis of catecholamines in organotypic cultures of peripheral autonomic nervous system: modifications by biopterin and other agents.

Organotypic cultures of chick-embryo sympathetic ganglion chains maintained in vitro for 3-4 weeks rapidly synthesized catecholamines, as demonstrated by the conversion of L-[U-14C]tyrosine to catechol derivatives and by histofluorescence assay. The biosynthesis of catechols from radioactive L-tyrosine leveled off at 6 hr of incubation and dropped slightly at 10 hr. The addition of DL-alpha-methyl-p-tyrosine to the culture medium did not affect protein synthesis, but produced a complete block in the synthesis of catecholamines from L-tyrosine, with consequent loss of fluorescence in the bodies and proximal processes of adrenergic neurons in 2 hr, and essentially complete loss in 6 hr. Our observations suggest that a major portion of the catecholamines were synthesized in the perikarya and transported via neuronal processes to their terminals. The addition of monoamine oxidase inhibitors to the incubation medium produced a moderate to pronounced increase in fluorescence; reserpine caused a rapid and profound loss of catecholamines. When added to the culture medium, crude biopterin produced an increase in the synthesis of catechol derivatives from radioactive L-tyrosine and a marked increase in fluorescence, beginning in the neuronal perikarya. This effect was completely blocked by DL-alpha-methyl-p-tyrosine. The mechanism of biopterin's action in the synthesis of catecholamines in cultures of sympathetic ganglia is not completely elucidated from these studies, but may be related to the role it plays as cofactor for tyrosine hydrocylase.

Animals↗