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Biomedical subjects

G L Rockswold

Publications and source records attributed to G L Rockswold.

At least 19 recordsLinked to original sources
PubMed2001

Effects of hyperbaric oxygenation therapy on cerebral metabolism and intracranial pressure in severely brain injured patients.

OBJECT: Hyperbaric oxygenation (HBO) therapy has been shown to reduce mortality by 50% in a prospective randomized trial of severely brain injured patients conducted at the authors' institution. The purpose of the present study was to determine the effects of HBO on cerebral blood flow (CBF), cerebral metabolism, and intracranial pressure (ICP), and to determine the optimal HBO treatment paradigm. METHODS: Oxygen (100% O2, 1.5 atm absolute) was delivered to 37 patients in a hyperbaric chamber for 60 minutes every 24 hours (maximum of seven treatments/patient). Cerebral blood flow, arteriovenous oxygen difference (AVDO2), cerebral metabolic rate of oxygen (CMRO2), ventricular cerebrospinal fluid (CSF) lactate, and ICP values were obtained 1 hour before and 1 hour and 6 hours after a session in an HBO chamber. Patients were assigned to one of three categories according to whether they had reduced, normal, or raised CBF before HBO. In patients in whom CBF levels were reduced before HBO sessions, both CBF and CMRO2 levels were raised 1 hour and 6 hours after HBO (p < 0.05). In patients in whom CBF levels were normal before HBO sessions, both CBF and CMRO2 levels were increased at 1 hour (p < 0.05), but were decreased by 6 hours after HBO. Cerebral blood flow was reduced 1 hour and 6 hours after HBO (p < 0.05), but CMRO2 was unchanged in patients who had exhibited a raised CBF before an HBO session. In all patients AVDO2 remained constant both before and after HBO. Levels of CSF lactate were consistently decreased 1 hour and 6 hours after HBO, regardless of the patient's CBF category before undergoing HBO (p < 0.05). Intracranial pressure values higher than 15 mm Hg before HBO were decreased 1 hour and 6 hours after HBO (p < 0.05). The effects of each HBO treatment did not last until the next session in the hyperbaric chamber. CONCLUSIONS: The increased CMRO2 and decreased CSF lactate levels after treatment indicate that HBO may improve aerobic metabolism in severely brain injured patients. This is the first study to demonstrate a prolonged effect of HBO treatment on CBF and cerebral metabolism. On the basis of their data the authors assert that shorter, more frequent exposure to HBO may optimize treatment.

Adolescent↗
PubMed1999

Inhibition of microglial cell RANTES production by IL-10 and TGF-beta.

Using human fetal microglial cell cultures, we found that the gram-negative bacterial cell wall component lipopolysaccharide (LPS) stimulated RANTES (regulated upon activation of normal T cell expressed and secreted) production through the protein kinase C signaling pathway and that activation of transcription nuclear factor (NF)-kappaB was required for this effect. Similarly, the proinflammatory cytokines interleukin (IL)-1beta and tumor necrosis factor-alpha dose-dependently stimulated microglial cell RANTES production via NF-kappaB activation. Anti-inflammatory cytokines, IL-10, and transforming growth factor (TGF)-beta sequentially inhibited LPS- and cytokine-induced microglial cell NF-kappaB activation, RANTES mRNA expression, and protein release. Proinflammatory cytokines but not LPS also stimulated RANTES production by human astrocytes. These findings demonstrate that human microglia synthesize RANTES in response to proinflammatory stimuli, and that the anti-inflammatory cytokines IL-10 and TGF-beta down-regulate the production of this beta-chemokine. These results may have important therapeutic implications for inflammatory diseases of the brain.

Cell Lineage↗
PubMed1999

Light deprivation soon after frontal brain trauma accelerates recovery from attentional deficits and promotes functional normalization of basal ganglia.

BACKGROUND: Light deprivation significantly accelerates recovery from attention deficits (neglect) after cortical ablation in rats. We hypothesized that light deprivation would improve recovery after traumatic contusive brain injury (TBI) and do so by enhancing dopaminergic function in the ipsilateral basal ganglia. METHODS: Adult rats received left frontal contusion injury and were placed into darkness or standard light/dark cycling for 48 hours. Neurologic evaluation included attentional and sensorimotor tasks. Amphetamine-induced production of the immediate early gene protein product Fos was quantified to determine neuronal dopaminergic response in caudate-putamen (striatum). RESULTS: Unilateral frontal TBI produced severe contralateral deficits in all tasks. Postoperative light deprivation resulted in improved recovery from attentional but not sensorimotor deficits. Five days after injury, ipsilateral striatal Fos expression was reduced by 51% in TBI rats experiencing normal light cycling (p < 0.006). In contrast, postoperative light deprivation normalized striatal Fos expression. By 6 weeks, all TBI rats demonstrated nearly full recovery and striatal Fos expression was symmetrical between the two striata. CONCLUSION: Postoperative light deprivation may improve recovery from TBI-induced attention deficits by normalizing basal ganglia function.

Amphetamine↗
PubMed1999

The effects of acute and chronic alcohol ingestion on outcome following multiple episodes of mild traumatic brain injury in rats.

OBJECTIVE: Recent studies suggest that in some circumstances, alcohol intoxication at the time of severe head injury may be neuroprotective. The objective of this study was to determine the effect of acute and chronic alcohol ingestion on outcome in rodents sustaining multiple episodes of mild traumatic brain injury while intoxicated. METHOD: For two weeks before experimentation, adult male Sprague-Dawley rats received intoxicating levels of 95% ethanol (3 g/kg) or normal saline (NS) every other day by orogastric instillation. On the day of experimentation, the animals were randomized to receive alcohol or NS. Two hours later, the animals received either mild (1.2 +/- 0.4 ATA) fluid percussion injury (FPI) or no injury. The injured animals received a total of three episodes of FPI (once every four days). Mean reflex recovery time (RRT) was determined (seconds +/- SEM) immediately after each episode. Mean latency time (seconds +/- SEM) for Morris Water Maze (MWM) performance was assessed at post-trauma days 11-19. RESULTS: The chronic alcohol-exposed (CA) and the non-alcohol-exposed (NA) animals intoxicated when injured had prolonged escape, righting, and corneal RRTs after each FPI compared with the nonintoxicated injured animals and the non-injured shams. However, the CA animals had significantly shorter RRTs when compared with the NA rats. All the injured animals had MWM deficits on testing days 1-6 compared with the noninjured controls. On the last two MWM testing days, the injured NA animals had significantly better MWM performance than the injured CA rats. CONCLUSIONS: The injured intoxicated CA animals had a more rapid recovery of reflexes compared with the injured intoxicated NA animals. Despite initial MWM deficits, the injured NA rodents eventually began to learn the MWM. The injured CA rats never learned the maze. Under the conditions of this study, acute alcohol intoxication at the time of multiple episodes of minor head trauma did not provide neuroprotection for NA or CA rodents.

Acute Disease↗
PubMed1998

Cytokine regulation of human microglial cell IL-8 production.

IL-8 involvement in neutrophil activation and chemotaxis may be important in inflammatory responses within the central nervous system, secondary to meningitis, encephalitis, and traumatic injury. The source of IL-8 within the brain during these inflammatory processes, however, is unknown. To explore the role of microglia in the production of IL-8, human fetal microglia, which are the resident macrophages of the brain, were treated with LPS and pro- and anti-inflammatory cytokines to determine their effects on IL-8 production. We found that IL-8 protein levels increased in response to LPS or IL-1 beta, or to TNF-alpha, which also corresponded to elevated IL-8 mRNA levels by RT-PCR. Pretreatment with IL-4, IL-10, or TGF-beta 1 potently inhibited the stimulatory effects of these proinflammatory agents. These findings indicate that human microglia synthesize IL-8 in response to proinflammatory stimuli, and that anti-inflammatory cytokines down-regulate the production of this chemokine. These results may have important therapeutic implications for certain central nervous system insults involving inflammation.

Age Factors↗
PubMed1998

Assessment of the relationship between timing of fixation of the fracture and secondary brain injury in patients with multiple trauma.

BACKGROUND: It has been suggested that early fixation of a fracture is deleterious to eventual neurologic outcome. We undertook this study to determine whether the timing of fracture fixation is correlated to neurologic outcome. METHODS: We retrospectively reviewed patients with severe head and orthopedic injuries requiring fracture fixation. Patients were divided into two groups: early fracture fixation (< 24 hours after injury) and late fracture fixation (> 24 hours after injury). RESULTS: One hundred twenty-three patients met entry criteria. During fracture fixation, the early group had a significant 2-, 3-, and 2-fold increase in crystalloid, blood infusion, and blood loss, respectively. There was no difference in oxygen saturation and systolic blood pressure or episodes of cranial hypertension or hypoperfusion. There was no difference in outcomes as measured by in-hospital complications, stay in the intensive care unit or hospital, mortality rates, hospital discharge or follow-up Glasgow Coma Scores, or long-term orthopedic or neurologic results. CONCLUSIONS: Patients undergoing fracture fixation with severe head injury mandate monitoring of intracranial pressure and perfusion and tailored fluid resuscitation to meet specific organ end points. Integrating end organ perfusion and pressure with meticulous fluid status during the definitive repair phase may reduce the exposure to secondary brain injury in patients undergoing early fracture fixation.

Adult↗
PubMed1997

Thoracoscopic sympathectomy for palmar hyperhidrosis. A case report.

Palmar hyperhidrosis is a disabling condition that manifests itself as excessive sweating of the hands. Although the exact cause is unknown, several medical and surgical therapies are available to treat it. Recent developments in surgical technique have made the less invasive thoracoscopic sympathectomy a viable alternative to the open sympathectomy for medically refractory cases. We believe that thoracoscopic sympathectomy is a safe and effective treatment for palmar hyperhidrosis.

Adult↗
PubMed1995

Effect of hypoxia or hyperbaric oxygen on cerebral edema following moderate fluid percussion or cortical impact injury in rats.

This study was designed to evaluate the production of cerebral edema [as measured by tissue specific gravity (SpG)] following moderate fluid percussion (FP) and cortical impact (CI) injury in rodents. To determine the effects of a secondary systemic insult, hypoxia (13% oxygen for 30 min) was added to some experimental groups immediately after head injury. To determine the effects of hyperbaric oxygen (HBO) on injured cortical tissue, additional animal groups were exposed to HBO (1.5 atm, for 60 min), beginning 4 h after head trauma. Both injury models produced equal amounts of tissue edema at the site of injury (mean SpG +/- SEM = 1.035 +/- 0.001), when measured 6 h posttrauma. There was no significant edema at the tissue sites immediately adjacent to the trauma sites. The addition of hypoxia to either injury system did not increase edema formation beyond that produced by injury alone. HBO reduced the water content of the trauma site in animals that had received FP, but not in animals receiving CI. We conclude that with the injury parameters used in this protocol, both FP and CI appear to produce focal cerebral edema at the site of trauma. Hypoxia does not worsen edema. HBO appears to reduce edema produced by FP, but not by CI.

Animals↗
PubMed1995

Spinal tuberculosis: a diagnostic and management challenge.

The authors reviewed 29 cases of spinal tuberculosis treated from 1973 to 1993 with an average follow-up time of 7.4 years. Clinical findings included back pain, paraparesis, kyphosis, fever, sensory disturbance, and bowel and bladder dysfunction. Twenty-two patients (76%) presented with neurological deficit; 12 (41%) were initially misdiagnosed. Sixteen patients (55%) had predominant vertebral body involvement; nine had marked bone collapse with neurological compromise. Eleven individuals (39%) had intraspinal granulomatous tissue causing neurological dysfunction in the absence of bone destruction, and two (7%) had intramedullary tuberculomas. All patients received antituberculous medications: 13 were initially treated with bracing alone, eight underwent laminectomy and debridement of extra- or intradural granulomatous tissue, and eight underwent anterior, posterior, or combined fusion procedures. No patient with neurological deficit recovered or stabilized with nonoperative management. Thirteen patients were readmitted with progression of inadequately treated osteomyelitis; 12 (92%) of these required new or more radical fusion procedures. Anterior fusion failure was associated with marked preoperative kyphosis and multilevel disease requiring a graft that spanned more than two disc spaces. Courses of antibiotic medications shorter than 6 months were invariably associated with disease recurrence. It was concluded that 1) patients should receive at least 12 months of appropriate antituberculous therapy; 2) individuals with neurological deficit should undergo surgical decompression; 3) laminectomy and debridement are adequate for intraspinal granulomatous tissue in the absence of significant bone destruction; 4) when vertebral body involvement has produced wedging and kyphosis, aggressive debridement and fusion are indicated to prevent delayed instability and progression of disease.

Adolescent↗
PubMed1993

Patients who talk and deteriorate.

Patients who "talk and deteriorate" are defined as those who utter recognizable words at some time after head injury and then deteriorate to a severe head-injured condition (Glasgow Coma Scale score of 8 or less) within 48 hours of injury. They represent a very small but important subgroup of patients with brain injury. In approximately 75% of these patients, the cause of this deterioration is intracranial hematoma. Despite the fact that talking indicates nonlethal impact brain injury, deterioration is a marker of poor prognosis. Outcome depends on early recognition of deterioration and rapid removal of mass lesions. The challenge for emergency physicians is to distinguish patients at risk for deterioration from the many patients evaluated after head injury.

Brain Injuries↗
PubMed1992

Results of a prospective randomized trial for treatment of severely brain-injured patients with hyperbaric oxygen.

The authors enrolled 168 patients with closed-head trauma into a prospective trial to evaluate the effect of hyperbaric oxygen in the treatment of brain injury. Patients were included if they had a total Glasgow Coma Scale (GCS) score of 9 or less for at least 6 hours. After the GCS score was established and consent obtained, the patient was randomly assigned, stratified by GCS score and age, to either a treatment or a control group. Hyperbaric oxygen was administered to the treatment group in a monoplace chamber every 8 hours for 1 hour at 1.5 atm absolute; this treatment course continued for 2 weeks or until the patient was either brain dead or awake. An average of 21 treatments per patient was given. Outcome was assessed by blinded independent examiners. The entire group of 168 patients was followed for 12 months, with two patients lost to follow-up study. The mortality rate was 17% for the 84 hyperbaric oxygen-treated patients and 32% for the 82 control patients (chi-squared test, 1 df, p = 0.037). Among the 80 patients with an initial GCS score of 4, 5, or 6, the mortality rate was 17% for the hyperbaric oxygen-treated group and 42% for the controls (chi-squared test, 1 df, p = 0.04). Analysis of the 87 patients with peak intracranial pressures (ICP) greater than 20 mm Hg revealed a 21% mortality rate for the hyperbaric oxygen-treated patients, as opposed to 48% for the control group (chi-squared test, 1 df, p = 0.02). Myringotomy to reduce pain during hyperbaric oxygen treatment helped to reduce ICP. Analysis of the outcome of survivors reveals that hyperbaric oxygen treatment did not increase the number of patients in the favorable outcome categories (good recovery and moderate disability). The possibility that a different hyperbaric oxygen treatment paradigm or the addition of other agents, such as a 21-aminosteroid, may improve quality of survival is being explored.

Adult↗
PubMed1991

A pilot study of hyperbaric oxygen in the treatment of human stroke.

We administered hyperbaric oxygen or air in a double-blind prospective protocol to 39 patients with ischemic cerebral infarction. We interrupted the study when we noticed what appeared to be a trend favoring the air-treated patients, whose neurological deficits were less severe (mean +/- SEM score on graded neurological examination: air, 25.6 +/- 4.9; oxygen, 34.5 +/- 7.5) and whose infarcts were smaller (air, 29.0 +/- 12.2 cm3; oxygen, 49.2 +/- 11.7 cm3) at 4 months. The trend, we decided, was probably an artifact of the randomization process. Nevertheless, we chose not to resume the trial because the treatment was difficult to administer by schedule (for various reasons the treatment protocol was broken in 15 of the 39 patients), was poorly tolerated (eight of the 39 patients refused to continue treatments), and did not produce dramatic improvement.

Adult↗
PubMed1990

Halo immobilization and surgical fusion: relative indications and effectiveness in the treatment of 140 cervical spine injuries.

In the management of cervical spine injuries, it is not always clear when to use halo immobilization alone, surgical fusion alone, or a combination of the two. To investigate the relative effectiveness of each of these approaches, we reviewed the medical records of 140 patients with cervical spine injuries treated with either halo immobilization or surgical fusion, or both. Seventy (50%) of the patients were neurologically intact on admission (two of these were paraplegic from previous injuries). Halo immobilization was used as the primary treatment in 99 patients, and yielded a successful fusion rate of 78%. Within this group, the 26 patients with hyperflexion-anterior subluxation injuries had only a 54% successful fusion rate, while the rate for the 73 with non-flexion injuries was 87% (Chi-square = 11.36; p = 0.0008). Surgical fusion was used as the primary treatment in 41 patients and as a subsequent treatment in the 22 for whom halo immobilization did not bring about fusion. Of these 63 patients treated with surgical fusion, six remained unstable after the surgery; five of these six had sustained a hyperflexion-anterior subluxation. One patient experienced neurologic deterioration after surgical fusion. There were three deaths in the entire series. Excluding fusion failure, complications with halo immobilization were frequent (25%) but usually minor; with surgical fusion, less frequent (6%) but usually more severe. We draw the following conclusions. 1) Halo immobilization brings about satisfactory healing for most fracture types. 2) Both halo immobilization and surgical fusion have relatively high failure rates in the treatment of hyperflexion-anterior subluxation injury, with or without bilaterally locked facets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Incidence and diagnosis of C7-T1 fractures and subluxations in multiple-trauma patients: evaluation of the advanced trauma life support guidelines.

A 5-year retrospective review was done to evaluate C-7 and C7-T1 cervical spine injuries and to assess the advanced trauma life support guidelines for cervical spine evaluation. Eighteen fractures of C-7 and four fracture-dislocation at C7-T1 were identified. Nineteen of the patients had neck pain, tenderness, or neurologic findings on initial examination. Three patients were awake and asymptomatic. The initial diagnosis could be made from lateral cervical spine x-ray film in only three of the 22 patients. In the remaining patients, the diagnosis was made by either swimmer's view (7 of 8 positive), oblique views (1 of 1 positive), flexion-extension views (2 of 3 positive), or computed tomography (CT) scan (7 of 7 positive). In two patients, the diagnosis was not made in the first 24 hours. Follow-up x-ray films were positive in 3 of 22 lateral cervical spine films, 10 of 14 swimmer's views, 2 of 3 oblique views, 2 of 3 flexion-extension views, and 14 of 20 CT scans. The data support the advanced trauma life support recommendation for liberal use of cervical spine radiologic screening. We recommend that the screening examination consist of a lateral cervical spine film, and a swimmer's view, if necessary, to visualize C-7 and the C7-T1 interspace. We further recommend that strong consideration be given to the use of a five-view trauma series. CT scan should be viewed as complementary to conventional film techniques.

Adolescent↗
PubMed1988

Radiation-induced meningiomas in pediatric patients.

Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature.

Brain Neoplasms↗
PubMed1988

A clinical comparison of subarachnoid catheters to ventriculostomy and subarachnoid bolts: a prospective study.

A subarachnoid catheter (SAC) technique of continuous intracranial pressure (ICP) monitoring is presented and compared to intraventricular catheters (IVC's) and subarachnoid bolts (SAB's) in 40 neurosurgical patients. Thirty-one patients were monitored simultaneously with SAC's and IVC's and nine patients with SAC's and SAB's, and the ICP waveforms and measurements were compared. The duration of monitoring ranged from 15 hours to 11 days, and the initial ICP from 2 to 117 torr. A total of 42 SAC's were placed; two that entered brain parenchyma were redirected. One SAC placement was associated with an intracerebral hematoma. There were no infections. For the 31 patients with SAC's and IVC's, there were 2706 pairs of ICP measurements with a mean difference of -0.12 torr and a standard deviation of 5.29 torr. The waveforms from the SAC's and IVC's were indistinguishable. For the nine patients with SAC's and SAB's, there were 773 pairs of ICP measurements with a mean difference of 1.24 torr and a standard deviation of 32.83 torr. The SAB waveforms were of varying quality and all dampened with time. The paired t-test (ts) demonstrated no statistically significant difference between SAC's and IVC's (ts = - 1.19). An analysis of variance demonstrated the scatter of the measurements obtained from SAB's to be 38.5 times that of SAC's, p less than 0.00005. The SAB is shown to be relatively inaccurate with a wide range of variance, while the SAC is demonstrated to be an accurate, reliable, and safe method of continuous ICP measurement and an acceptable alternative to ventriculostomy.

Adolescent↗