PubMed Health⌕ Search

Biomedical subjects

D Hovda

Publications and source records attributed to D Hovda.

7 recordsLinked to original sources
PubMed2001

Early predictors of mortality in penetrating compared with closed brain injury.

INTRODUCTION: Although brain injury incidence rates have been decreasing, the proportion of these injuries which are penetrating has been increasing. This study compares mortality amongst persons with penetrating and closed brain injuries and explores the relationship of early predictors of mortality. METHODS: The study included 795 moderately or severely brain injured individuals identified through the UCLA Brain Injury Research Centre. Logistic regression was used to predict mortality by GCS level and brain injury type, controlling for age, gender, and presence of multiple trauma. RESULTS: Of the 795 individuals, 110 had penetrating and 685 had closed brain injury. Case fatality rates were higher for penetrating than closed injuries for all GCS, gender, age, and cause of injury categories. When controlling for GCS level at admission, age, gender, and multiple trauma, those with penetrating injuries were 6.6 (95% CI = 3.9-11.1) times more likely to die. CONCLUSIONS: As the pool of information about survival and recovery from penetrating injuries grows, decisions regarding clinical care and prevention activities can be more appropriately focused.

Adolescent↗
PubMed1998

Depression, cognition, and functional correlates of recovery outcome after traumatic brain injury.

The present study investigated the prevalence and magnitude of depressive symptomatology in a sample of patients who had sustained traumatic brain injury (TBI) six months earlier. Depression was examined as a function of recovery outcome status, and its association with neuropsychological functioning, personal competency, and employability was also explored. Subjects were 100 patients who had previously sustained moderate-to-severe TBI who were enrolled as research subjects in the UCLA Brain Injury Research Center, and 30 matched control subjects who had sustained traumatic injuries other than to the head six months prior to evaluation. The results showed a significant association between depression and recovery status as measured by the Glasgow Outcome Scale (GOS). A significant majority of depressed subjects were found in the poorer GOS outcome groups (severe and moderate disability), compared to TBI subjects who had good GOS outcomes, and control subjects. This association was also reflected in the magnitude of the mean depression scores on two self-report measures of depression. However, no association was found between depression status and performance on the neuropsychological measures. Effects of depression were found only on an examiner-rated Patient Competency scale, and a metacognition measure based on self-report. These results are discussed in terms of brain injury severity, recovery status, and metacognition issues in TBI and other disorders.

Activities of Daily Living↗
PubMed1998

Neuropsychological, psychosocial and vocational correlates of the Glasgow Outcome Scale at 6 months post-injury: a study of moderate to severe traumatic brain injury patients.

Traumatic brain injury (TBI) subjects at Glasgow Outcome Scale levels 3 (severe disability), 4 (moderate disability), 5 (good recovery), and an other-injury control group (OIC) were compared in terms of neuropsychological, psychosocial, and vocational functioning 6 months after injury. Subjects were a sample of 100 patients with a moderate to severe traumatic brain injury (TBI) and a matched sample of 30 other-injury control subjects (OIC) enrolled in the UCLA Brain Injury Research Center study of TBI outcome. Overall, the results showed a systematic decrease in mean neuropsychological test performance as a function of increasing GOS severity, as well as an increased prevalence of symptoms of depression and lower ratings on measures assessing employability and capacity for self care. TBI patients in the 'severe' and 'moderate disability' groups were distinctly inferior to the 'good recovery' and 'OIC' groups, who were quite similar to each other in terms of cognitive, psychosocial, and vocational outcomes. The results demonstrate overall support for the predictive and concurrent validity of the GOS 6 months post injury. Despite these results, which strengthen the utility and appeal of the GOS for multicentre studies, concerns still remain regarding GOS category 4 (moderate disability), which was shown to lack sufficient discriminability in this study.

Activities of Daily Living↗
PubMed1995

Posttraumatic cerebral arterial spasm.

Posttraumatic cerebral arterial spasm (vasospasm) has been demonstrated in the past by angiography, and recently by transcranial Doppler ultrasonography. Posttraumatic vasospasm is a delayed complication that involves the large basal intracranial arteries (e.g., internal carotid, middle cerebral, basilar) and occurs in 25-40% of head trauma patient. The time course of posttraumatic vasospasm resembles that of vasospasm associated with aneurysmal subarachnoid hemorrhage with onset occurring 2 or more days after injury. A study of the relationship of admission CT scan findings to the incidence of vasospasm suggests that intradural bleeding, which extends into the CSF (subarachnoid, intraventricular, and subdural hemorrhage), plays a role in the pathogenesis of posttraumatic arterial spasm. The preliminary results of a large prospective study of head trauma patients suggest that vasospasm may be an important determinant of outcome from severe head injury.

Brain Injuries↗
PubMed1994

A universal, multi-modality localization system for animal radiosurgery.

We have developed a stereotactic localization system allowing a radiosurgical approach in a number of animal models. The system utilizes fixation adapters specially designed for a particular animal, which in turn are attached to a common Brown-Roberts-Wells (BRW) compatible Delrin head ring. Each fixation adapter is constructed using materials compatible with CT, MRI, PET, and angiographic imaging studies. With such a system, radiographic localization, computerized treatment planning, and stereotactic radiation delivery can subsequently be performed in a manner identical to the procedures used for humans.

Animals↗
PubMed1989

MR imaging of experimental demyelination.

Seventeen rabbit sciatic nerves undergoing experimental demyelination and 17 control nerves were imaged in vivo with a 0.3-T MR imaging system using a silicone chamber wrapped around the nerves to isolate them from surrounding tissues. Three pulse sequences were used for each nerve: (1) spin-echo 500/28 (TR/TE), (2) spin-echo 2000/56, and (3) inversion recovery 1000/300/30 (TR/TI/TE). Image intensity data were acquired for each nerve by placing a region of interest over the nerve and measuring pixel brightness within the region of interest by means of a computer algorithm. The mean signal intensity of the experimental nerve was then compared with the mean signal intensity of the contralateral control nerve on the same image. Histologic sections of the nerves were stained with Loyez's stain for myelin and thionin for glial cells. MR findings were then compared with histopathologic data. Experimental nerves showed distinct stages of demyelination. Two fundamental observations were surmised from the data: (1) Perceptible MR signal changes are associated with early nerve degeneration, in which there is demyelination in the absence of glial cell proliferation; these changes are appreciated as increased intensity on heavily T2-weighted sequence. In these nerves no signal changes are seen on T1-weighted sequences. (2) Perceptible MR signal changes are associated with more advanced nerve degeneration, in which there is an increase in the number of glial cells in the absence of further demyelination; these changes are appreciated as decreased intensity on T1-weighted sequences and markedly increased intensity on T2-weighted sequences, respectively. The results show that MR can distinguish stages of demyelination in degenerating nerves, thereby providing a powerful method for the diagnosis and characterization of demyelinating disease.

Animals↗