Early predictors of mortality and morbidity after severe closed head injury.

Mortality and morbidity of 158 patients with severe head injury were studied in relation to age, and early (24-h) clinical and computed tomography data. For comparison of outcome data in survivors, a group of 32 patients with traumatic injuries to parts of the body other than the head was used as controls. Within the head-injured group, the mortality rate was 51%. Logistic regression analyses combined 13 out of 16 predictors into a model with an accuracy of 93%, a sensitivity of 90%, and a specificity of 95%. These include age, Glasgow Coma Scale (GCS) score, pupillary reactivity, blood pressure, intracranial pressure, blood glucose, platelet count, body temperature, cerebral lactate, and subdural, intracranial, subarachnoid, and ventricular hemorrhage. At 6 months postinjury, head-injury survivors and trauma controls were evaluated with the Glasgow Outcome Scale (GOS), a neuropsychological test battery and the Sickness Impact Profile (SIP). Head-injury survivors had a higher proportion of disabilities and neuropsychological dysfunctions than trauma controls. They also report more quality of life-related functional limitations on the SIP scales for mobility, intellectual behavior, communication, home management, eating, and work. Linear regression analysis resulted in age being the only important predictor of outcome on the GOS, the GCS score being the best predictor of neuropsychological functioning, and pupillary reactivity being the most predictive for self-reported quality of life as measured by SIP. Those factors important for predicting mortality (clinical variables such as ICP or blood glucose level, and CT observations) failed to show any significant relationship with morbidity.

Cerebral perfusion pressure and intracranial pressure in relation to neuropsychological outcome.

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.

Subjective complaints versus neuropsychological test performance after cardiopulmonary bypass.

The study by Newman et al. (Journal of Psychosomatic Research, 1989) compared subjective reports of cognition with assessed cognitive performance in patients one year after coronary artery bypass surgery. The current study reinvestigated this relation in a larger and more heterogeneous group--90 cardiac patients six months after cardiopulmonary bypass--using a more extensive checklist of subjective complaints and different neuropsychological tests. In agreement with previous research, the patients who reported complaints in specific cognitive areas were not found to have impaired cognitive functions as assessed with appropriate neuropsychological tests. The patients who reported deterioration in cognition after surgery were found to have higher levels of depression and state anxiety. These differences were significant for almost all evaluated cognitive functions. An alternative explanation of the relationship between mood and cognitive complaints based on personality traits, i.e., neuroticism, is offered.

Personality change following head injury: assessment with the NEO Five-Factor Inventory.

We evaluated personality change following head injury in 68 patients at 6 months postinjury using the NEO Five-Factor Inventory to assess the five personality dimensions of the Five-Factor Model of Personality. All items had to be rated twice, once for the preinjury and once for the current status. Twenty-eight trauma patients with injuries to other parts of the body than the head were used as controls. For the head-injured group, 63 relatives also completed the questionnaire. The results showed no differences between the ratings of head-injured patients and the ratings of trauma control patients. Both groups showed significant change in the personality dimensions Neuroticism, Extraversion, and Conscientiousness. Compared to their relatives, head-injured patients report a smaller change in Extraversion and Conscientiousness. Changes were not reported on the Openness and Agreeableness scales, by neither the head-injured or their relatives, nor by the trauma controls.

Short-term and long-term neuropsychological consequences of cardiac surgery with extracorporeal circulation.

OBJECTIVE: Cognitive dysfunction after extracorporeal circulation is a major continuing problem in modern cardiac surgery. We designed this prospective study to update the incidence of postoperative neuropsychological changes after routine cardiopulmonary bypass (CPB) and to identify perioperative variables associated with these complications. METHODS: We assessed the patients with a comprehensive neuropsychological test battery 1 day before, 7 days after (n = 109) and 6 months after (n = 91) cardiopulmonary bypass. We used patients undergoing major vascular or thoracic surgery as a surgical control group (n = 20). RESULTS: Repeated measures multivariate analysis of variance (using surgical group as a between-subjects factor) on the group data revealed significant changes early after surgery compared with the preoperative performance (P = 0.001). The early changes are characterized by a significant decrease of visual attention and verbal memory performance (univariate F-tests, always P < 0.05). Cardiac patients showing cognitive impairment after cardiac surgery had lower preoperative ejection fractions (P = 0.014) and a more complicated medical history (P = 0.046). At 6-month follow-up, the patients performed significantly better than before surgery (P < 0.001). CPB patients showing persistent cognitive impairment at follow-up were significantly older at the time of surgery (P = 0.005). Individual comparisons revealed that 45% of the patients undergoing CPB showed evidence of cognitive impairment soon after surgery. In 12% of the patients, the cognitive sequelae persisted at follow-up. Both group data and individual incidence rates revealed neither significant pre-post differences between the surgical groups nor a time-by-group interaction effect. Variables directly associated with CPB were not significantly associated with the occurrence of cognitive impairment after surgery. CONCLUSIONS: We conclude that an important proportion of the cognitive impairment after cardiac surgery is likely to be due to nonspecific effects of surgery.

Course of neuropsychological recovery from moderate-to-severe head injury: a 2-year follow-up.

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.

Subjective complaints versus neuropsychological test performance after moderate to severe head injury.

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.

Prospective evaluation of verbal memory performance after cardiopulmonary bypass surgery.

One hundred and four patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) and a surgical control group undergoing major vascular or thoracic surgery (n = 18) were tested with the Auditory Verbal Learning Test (AVLT) at the following intervals: 1 day before, 1 week after, and 6 months after surgery. Early after surgery a significant decline in AVLT-performance was found, characterized by a smaller carry-over of learned words on subsequent acquisition trials. Six-month follow-up data revealed significant improvement in the delayed retention of words as compared to the preoperative assessment. No surgical group differences or time by group interaction effects were found. In the CPB group, deeper levels of hypothermia, reflecting longer and more extensive cardiac surgery, were associated with reduced improvement on retest.

Perceptual scaling of synthesized musical timbres: common dimensions, specificities, and latent subject classes.

To study the perceptual structure of musical timbre and the effects of musical training, timbral dissimilarities of synthesized instrument sounds were rated by professional musicians, amateur musicians, and nonmusicians. The data were analyzed with an extended version of the multidimensional scaling algorithm CLASCAL (Winsberg & De Soete, 1993), which estimates the number of latent classes of subjects, the coordinates of each timbre on common Euclidean dimensions, a specificity value of unique attributes for each timbre, and a separate weight for each latent class on each of the common dimensions and the set of specificities. Five latent classes were found for a three-dimensional spatial model with specificities. Common dimensions were quantified psychophysically in terms of log-rise time, spectral centroid, and degree of spectral variation. The results further suggest that musical timbres possess specific attributes not accounted for by these shared perceptual dimensions. Weight patterns indicate that perceptual salience of dimensions and specificities varied across classes. A comparison of class structure with biographical factors associated with degree of musical training and activity was not clearly related to the class structure, though musicians gave more precise and coherent judgments than did non-musicians or amateurs. The model with latent classes and specificities gave a better fit to the data and made the acoustic correlates of the common dimensions more interpretable.