Biomedical subjects

Peter Houx

Publications and source records attributed to Peter Houx.

7 recordsLinked to original sources

PubMed2006

Neurocognitive fitness in the sub-acute stage after mild TBI: the effect of age.

OBJECTIVE: Age is assumed to be a negative prognostic factor in recovery from moderate-to-severe traumatic brain injury (TBI). Little is known on cognitive performance after mild TBI in relation to age in the sub-acute stage after injury. METHOD: Ninety-nine mild TBI subjects (age 15-75) were compared with 91 healthy control subjects (age 14-74) in a case-control design. Patients were matched on age, sex and level of education, with control subjects. Mean interval between injury and cognitive assessment was 13 days. Neurocognitive test battery contained tests of verbal memory, selective attention, general speed of information processing and verbal fluency. RESULTS: An overall effect was found of a single mild TBI on neurocognitive performance in the sub-acute stage after injury. Age did not add significantly to the effect of mild TBI on cognitive functioning. CONCLUSION: Patients suffering from mild TBI are characterized by subtle neurocognitive deficits in the weeks directly following the trauma. The notion that elderly subjects have a worse outcome in the sub-acute period after mild TBI is at least not in line with the results of this study.

Adolescent↗

PubMed2005

S-100B concentration is not related to neurocognitive performance in the first month after mild traumatic brain injury.

The serum concentration of S-100B is reported to reflect the severity of brain damage. The purpose of this study was to determine whether elevated serum S-100B concentrations were related to neuropsychological test performance of patients in the subacute phase of recovery from mild traumatic brain injury (TBI). S-100B concentrations were measured in blood samples taken within 6 h after TBI. Serum S-100B was estimated using an immunoluminometric assay. Cognitive speed and memory were assessed with neuropsychological tests at a median of 13 days (range 7-21 days) after injury. The two groups, formed on a median split of initial serum S-100B concentrations (>or<0.22 microg/l) did not differ in age or education. The neuropsychological performance of the TBI patients was also compared with that of a healthy control group. Cognitive speed and memory performance of mild TBI patients were inferior compared to those of healthy subjects. There were no significant differences within the TBI group when serum S-100B concentration was taken into consideration. The findings suggest that serum S-100B levels after mild TBI are not predictive of neuropsychological performance in the subacute stage of recovery.

Adolescent↗

PubMed2004

Cross-national comparison and validation of the Alzheimer's Disease Assessment Scale: results from the European Harmonization Project for Instruments in Dementia (EURO-HARPID).

BACKGROUND: The Alzheimer's Disease Assessment Scale (ADAS) is often used in international multicenter trials. Use across countries presupposes correct translation and adaptation of the scale, and maintenance of its psychometric properties. OBJECTIVES: To compare the various translations of the ADAS used in Western Europe, to design internationally harmonized translations and to validate these. SETTING: International cooperative study in eight European countries. METHODS: An inventory was made of existing versions of the ADAS-Cog used in eight European countries, and adaptations were made. The concurrent validity of the harmonized versions of the ADAS was tested in 283 patients with probable or possible Alzheimer's disease. The Nurses Observation Scale for Geriatrics (NOSGER), CAMCOG-R and MMSE was used to assess concordance between cognitive and behavioral measures. RESULTS: Differences between the versions mainly involved object naming, items for verbal memory, such as the number of trials allowed, the imagery value of the words selected as targets or distractors, and the number of parallel versions. These differences were eliminated by adapting and harmonizing the various versions of the ADAS-Cog. Thereafter, only small differences between the different countries were found, and patterns of correlation between ADAS-Cog, and the NOSGER, CAMCOG-R and MMSE were consistent. CONCLUSIONS: The study underlines the need to use harmonized versions of instruments for rating dementia in multinational studies. The findings indicate that the harmonization of the ADAS-Cog was successful.

Aged↗

PubMed2003

Cross-national comparisons of the Cambridge Cognitive Examination-revised: the CAMCOG-R: results from the European Harmonization Project for Instruments in Dementia.

BACKGROUND: Transnational and psychometrically appropriate versions of instruments used in the diagnosis of dementia are essential for comparing information between different countries. The Cambridge Examination for Mental Disorders of the Elderly incorporates a brief neuropsychological test battery, Cambridge Cognitive Examination (recently revised version), which provides objective data on performance across a number of cognitive domains. OBJECTIVE: To harmonise the Cambridge Cognitive Examination between seven European countries. METHOD: 40 patients with probable or possible Alzheimer's disease of each of the seven countries were administered the Cambridge Cognitive Examination. The Nurse Observation Scale for Geriatrics was used to assess concordance between cognitive and behavioural measures. RESULTS: Only small differences between the various Cambridge Cognitive Examination versions were found, and patterns of correlation between Cambridge Cognitive Examination and the Nurse Observation Scale for Geriatrics were consistent. CONCLUSION: These findings indicate that the harmonisation of the Cambridge Cognitive Examination was successful.

Aged↗

PubMed2002

Association between high-density lipoprotein and cognitive impairment in the oldest old.

Low high-density lipoprotein cholesterol is associated with an increased risk for cardiovascular disease and stroke. At the same time, cardiovascular disease and stroke are important risk factors for dementia. We assessed the association between total and fractionated cholesterol and cognitive impairment and explored whether observed associations were dependent on or independent of atherosclerotic disease. In a population-based study, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were measured in 561 subjects 85 years old and grouped in three equal strata representing decreasing serum concentrations. History of cardiovascular disease and stroke was determined. All subjects completed the Mini-Mental State Examination (MMSE), and the presence of dementia was determined. Median MMSE scores were significantly lower in subjects with low high-density lipoprotein cholesterol (25 points vs 27 points, p < 0.001). No differences in MMSE scores were found for other lipids and lipoproteins. MMSE scores in subjects with and without cardiovascular disease were 26 and 27 points (p = 0.007), respectively, and in subjects with and without stroke were 21 and 26 points (p < 0.001), respectively. The associations between low MMSE scores and low high-density lipoprotein cholesterol remained significant after subjects with cardiovascular disease or stroke were excluded. In a comparison of subjects with low high-density lipoprotein cholesterol with subjects with high high-density lipoprotein cholesterol, the odds ratio for dementia was 2.3 (95% confidence interval, 1.2-4.3), and in subjects without cardiovascular disease or stroke, it was 3.7 (95% confidence interval, 1.3-10.1). All odds ratios were unaffected by education, low-density lipoprotein cholesterol, triglycerides, and survival. Low high-density lipoprotein cholesterol is associated with cognitive impairment and dementia. At least part of the association between high-density lipoprotein cholesterol and cognitive function is independent of atherosclerotic disease.

Aged↗

PubMed2002

Engaged lifestyle and cognitive function in middle and old-aged, non-demented persons: a reciprocal association?

Some studies have shown that cognitive function is positively affected by an engaged and active lifestyle. However, a recent study found evidence for an opposite causal direction, i.e., persons with good cognitive function more often start to engage in leisure-time activities. Here, we longitudinally examine the causal direction of the association between an engaged lifestyle and cognitive function in middle and old-aged Dutch men and women. The participants in the prospective cohort study "Maastricht Aging Study" (MAAS) were recruited from a register of 15 family practices in the South of the Netherlands. There were 830 non-demented men and women, aged 49 to 81 in 1993-1995 (baseline phase). They were re-examined three years later (follow-up phase). During both phases, all persons reported on their participation in mental, social, and physical activities. Six separate neuropsychological tests, including the Mini-Mental State Examination, were used to define cognitive function at baseline and follow-up. All three activities measured were negatively related to cognitive decline between both phases. Effects were moderate, but consistent. Persons participating in all three activities were particularly protected against longitudinal decline. Furthermore, persons with the best baseline cognitive performance were more likely to increase their number of activities during follow-up compared with persons with the poorest scores. In summary, an engaged lifestyle and cognitive function mutually influence each other in middle and old aged, non-demented persons. This reciprocal association is characterized by simultaneous positive effects of leisure-time activities and good cognitive function on cognitive function and leisure-time activities, respectively. This reciprocal association may create a self-reinforcing, beneficial or adverse life-course in middle and old age.

Age Factors↗

PubMed2002

Postoperative cognitive dysfunction in middle-aged patients.

BACKGROUND: Postoperative cognitive dysfunction (POCD) after noncardiac surgery is strongly associated with increasing age in elderly patients; middle-aged patients (aged 40-60 yr) may be expected to have a lower incidence, although subjective complaints are frequent. METHODS: The authors compared the changes in neuropsychological test results at 1 week and 3 months in patients aged 40-60 yr, using a battery of neuropsychological tests, with those of age-matched control subjects using Z-score analysis. They assessed risk factors and associations of POCD with measures of subjective cognitive function, depression, and activities of daily living. RESULTS: At 7 days, cognitive dysfunction as defined was present in 19.2% (confidence interval [CI], 15.7-23.1) of the patients and in 4.0% (CI, 1.6-8.0) of control subjects (P < 0.001). After 3 months, the incidence was 6.2% (CI, 4.1-8.9) in patients and 4.1% (CI, 1.7-8.4) in control subjects (not significant). POCD at 7 days was associated with supplementary epidural analgesia and reported avoidance of alcohol consumption. At 3 months, 29% of patients had subjective symptoms of POCD, and this finding was associated with depression. Early POCD was associated with reports of lower activity scores at 3 months. CONCLUSIONS: Postoperative cognitive dysfunction occurs frequently but resolves by 3 months after surgery. It may be associated with decreased activity during this period. Subjective report overestimates the incidence of POCD. Patients may be helped by recognition that the problem is genuine and reassured that it is likely to be transient.

Adult↗