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Objective: The study attempted to examine the relationship between neuropsychological functioning and reduced cerebral perfusion pressure (CPP), raised intracranial pressure (ICP), and reduced mean arterial pressure (MAP), monitored during intensive care treatment.Design: This prospective follow-up study included consecutive patients and evaluated outcome at 6 months postinjury by the administration of a neuropsychological test battery.Setting: The study was conducted at the University Hospital of Gent, Belgium.Patients and Participants: Over a 30-month period, 43 patients were included. Inclusion criteria were the following: hospital admission following closed head injury. ICP monitoring, no medical history of central nervous system disease or mental retardation, survival for at least 6 months, and informed consent for participation.Interventions: All patients received the hospital's standard treatment for head injury, which remained unchanged during the study period.Measurements and Results: Reduced CPP was analyzed using the number of observed values below 70 mmhg, raised ICP using the number of values above 20 mmHg, and MAP using the number of values below 80 mmHg. The neuropsychological test battery included 11 measures of attention, information processing, motor reaction time, memory, learning, visuoconstruction, verbal fluency, and mental flexibility. No linear relationships were found between overall neuropsychological impairment and episodes of reduced CPP, raised ICP, or reduced MAP.Conclusions: Although reduced CPP and raised ICP are frequent, often fatal, complications of head injury, in survivors they do not seem to be related to later neuropsychological functioning. [ABSTRACT FROM AUTHOR]

Neuropsychological outcome and recovery of a group of 91 patients with moderate-to-severe head injuries were prospectively investigated over a 2 year period, with evaluations at acute hospital discharge at 6 months and 2 years post-injury. A group of 39 trauma patients with injuries to parts of the body other than the head were used as controls. The head injured group performed significantly worse than the control group at baseline, 6 months and 2 years post-injury. Significant improvement was found during the first 6 months, but also between 6 months and 2 years post-injury. Trauma controls also performed significantly better at 6 months post-injury compared to baseline. Differential practice effects between groups cause difficulties in determining recovery. Within the head injured group, three distinct recovery groups were identified varying as a function of coma-length and coma-duration. The first group is comparable with the trauma controls. The other two groups demonstrate significant neuropsychological impairments at baseline, with one group showing a marked improvement over the 2 year period, and the other group showing only small improvement over this time period. [ABSTRACT FROM AUTHOR]

We present a new methodology for simultaneously assessing competitive market structure and deriving market segments. A hierarchical or ultrametric tree representation is estimated in a maximum likelihood framework from collected paired-comparison choice data. The derived tree portrays both brands and consumers/households/segments as terminal nodes, where the `closer' a brand is to a particular consumer/household/segment in the tree, the higher the predicted probability of that consumer/household/segment choosing that particular brand. This paper initially presents an introduction to the problem of market structure assessment. We review the extensive marketing literature on market structure and survey several competing methodologies. The proposed stochastic ultrametric tree unfolding methodology is technically described and several program options are indicated. An illustration of the proposed methodology is presented with respect to paired comparison choice data collected from a convenience sample involving the over-the-counter analgesics market. Finally, several areas for future research are identified. [ABSTRACT FROM AUTHOR]

Neuropsychological test performance and subjective complaints of 85 patients with moderate to severe head injury were investigated at 6 months postinjury. The neuropsychological test battery included 10 measures of attention, memory, mental flexibility, reaction time, visuoconstruction and verbal fluency. Subjective complaints were assessed using a self-report questionnaire subdivided into four subscales (somatic, cognitive, emotional and behavioural). Ratings were obtained for the pre-injury and current status. Thirty-three trauma patients with injuries to other parts of the body than the head were used as controls. For the head injured, relatives also completed the questionnaire. Head injured patients performed significantly below trauma control patients on nearly all test measures. Head injured patients and their relatives reported a significant increase in subjective complaints since the injury on all four subscales, with no differences between patients' and relatives' reports. These changes were also reported by the trauma controls, but they report fewer changes in somatic and cognitive functioning. Exploratory canonical correlation analyses revealed no correlations between any of the four scales of the questionnaire and the test measures, nor for the head injured, the trauma controls, or the relatives, indicating no relevant relationship between subjective complaints and neuropsychological test performance. [ABSTRACT FROM AUTHOR]