Clinical and physical aspects of total body irradiation for bone marrow transplantation in Nijmegen.

Eighty-nine patients were transplanted with allogeneic bone marrow after a standard conditioning regimen consisting of cyclophosphamide and fractionated total body irradiation (2 x 4.5 Gy) with average dose rates of 4.1 and 12.

Divided attention 5 to 10 years after severe closed head injury.

The ability to divide attention of persons who had sustained a severe Closed Head Injury 5 to 10 years before (chronic CHI patients), was examined in a dual-task experiment administered to 15 CHI patients and 34 control subjects. Both the patient group and the control group consisted of active licenced drivers at the time of the investigation. One task was a compensatory tracking task requiring lane tracking, a basic skill or car driving.

Age differences in divided attention in a simulated driving task.

The ability of young, middle-aged, and old adults to divide attention was examined using a dual task experiment involving two continuous performance tasks. The first task was a compensatory tracking task modeled after the important everyday activity of car driving. The second task was a self-paced visual choice-reaction time task requiring analysis of a small visual display presented in such a way that no eye movements were required when the two tasks had to be performed simultaneously.

Nuclear magnetic resonance relaxation in experimental brain edema: effects of water concentration, protein concentration, and temperature.

Proton relaxation times T1 and T2 of macromolecular solutions, bovine brain tissues, and experimental cat brain edema tissues were studied as a function of water concentration, protein concentration, and temperature. A linear relation was found between the inverse of the weight fraction of tissue water and the spin-lattice relaxation rate, R1, based on a fast proton exchange model for relaxation. This correlation was also found for the spin-spin relaxation rate, R2, of gray matter samples and macromolecular solutions at low concentrations.

Fitness to drive a car after recovery from severe head injury.

Driving skills in relation to residual psychologic impairments were studied in a sample of patients who had survived severe head injuries several years earlier. Daytime driving was studied in an instrumented car that recorded lateral position control on a highway track and during rides in the subjects' own cars with a professional observer. In comparison with a control group matched by age and driving experience, the patients performed worse on both driving tasks.

Acquired brain damage and driving: a review.

Five issues in evaluating driving ability after brain damage were addressed through a review of the literature. Some preliminary conclusions were reached: (1) about half of all subjects studied still hold a valid driver's license; (2) brain-damaged drivers could not, in general, be seen as risky drivers, although some individuals show decreased driving skill and risky behavior in traffic; and (3) statistics show no increase in traffic violations or accidents in groups of neurologic patients with acquired brain lesions or diseases. Frequently noted problems of brain-damaged drivers include poor judgment of traffic situations, impulsivity, and visuospatial impairments.

Sustained attention and sustained effort after closed head injury: detection and 0.10 Hz heart rate variability in a low event rate vigilance task.

In closed head injury patients impaired sustained attention has been used to explain poor performance of complex tasks. However, this basic capacity was never adequately investigated. We investigated sustained attention in an auditory vigilance task and found no evidence at all for an impairment.

A computerized method for rapid quantification of gallbladder volume from real-time sonograms.

A computerized method that requires only 1-2 minutes to quantify gallbladder volume from real-time sonograms is described. This time is considerably shorter than that required using the hand-calculation method. There was a highly significant correlation between gallbladder volumes calculated by computer and hand (r = 0.

Four years experience with a mercury shielded irregular field system (MSIFS).

A mercury shielded irregular field system (MSIFS) has been in use in our department since January 1979. The system is described and illustrated. Experience in treating 225 patients demonstrated that the system is accurate and reproducible.

Visuo-motor behaviour in pre-school children in relation to sex and neurological status: an experimental study on the effect of 'time-pressure'.

A detailed analysis was made of the visuo-motor behaviour of 139 pre-school children during a spatial-constructive task with and without time-pressure. The study focused mainly on sex differences and the implications of minor neurological dysfunctions for children's visuo-motor behaviour. Between sexes only minor differences in behavioural organization and efficiency were found.