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Biomedical subjects

B T Andrews

Publications and source records attributed to B T Andrews.

At least 37 records · Page 2Linked to original sources
PubMed1992

Severity and outcome of intracranial lesions in pedestrians injured by motor vehicles.

To evaluate the type and severity of intracranial lesions and the prognosis after closed head trauma in pedestrians injured by motor vehicles, we reviewed the cases of 225 consecutive patients who suffered major head injuries in collisions with motor vehicles. Patients in this series were comatose, had intracranial hematomas requiring surgical removal, or both. The initial Glasgow Coma Scale (GCS) score was 9-15 in 24% of patients, 6-8 in 32%, and 3-5 in 43%. Intracranial hypertension occurred in 40%. Diagnostic studies showed subdural hematomas in 45% of patients, epidural hematomas in 8%, intracerebral hematomas in 10%, and cerebral contusions in 9%. Clinically significant mass lesions were evacuated, and intracranial pressure was monitored and treated aggressively if elevated. After 6 months, 51% of the patients had died, 13% were vegetative or severely disabled, and 35% had a good outcome or moderate disability. These major head injuries in pedestrians struck by motor vehicles were usually severe, included a high incidence of intracranial hematomas and increased intracranial pressure, and frequently had poor outcomes.

Accidents, Traffic↗
PubMed1991

Infarct of the conus medullaris simulating a spinal cord tumor: case report.

A 71-year-old woman had the sudden onset of a neurogenic bladder and a stepwise increase in paraparesis that left her unable to stand or walk. Magnetic resonance imaging showed what appeared to be a tumor in the conus medullaris. After laminectomy, the lesion was localized by ultrasound examination, and a biopsy was performed. The deficits remained unchanged postoperatively. Microscopic examination of the biopsy specimen showed necrosis and pathologic changes consistent with infarction of the conus medullaris. An anomalous arterial supply of the conus medullaris is the most likely cause of this unusual problem. The patient gradually regained her ability to walk, but the neurogenic bladder persists.

Aged↗
PubMed1991

Functional recovery after traumatic transtentorial herniation.

To elucidate the factors associated with functional recovery after traumatic transtentorial herniation, we reviewed the records of 153 consecutive patients admitted with clinical signs of transtentorial herniation (altered level of consciousness, anisocoria or pupillary unresponsiveness, and abnormal motor findings). Overall, 28 patients (18%) had a functional outcome: 14 patients (9%) made a good recovery and 14 were moderately disabled. Sixteen patients (10.5%) were severely disabled or vegetative, and 104 (60%) died. Compared with patients who died or were left severely disabled or vegetative, patients who had a good recovery were younger (21 versus 38 years), were significantly more likely to be children (less than or equal to 17 years old) and have anisocoria and a deteriorating Glasgow Coma Score (GCS), and were significantly less likely to be flaccid or have bilaterally fixed pupils; moderately disabled patients also had a lower median age and a higher frequency of anisocoria. There was no difference in the incidence of significant intracranial hematomas between patients with a functional outcome and those with a nonfunctional outcome. Twenty-seven percent of the 95 patients with anisocoria had a good outcome or moderate disability, whereas only 3.5% of the 58 patients with bilaterally fixed and dilated pupils at admission had a functional recovery (P less than 0.05). Age, level of consciousness, and the degree of residual upper brain stem function at admission appear to be the most important determinants of functional outcome after traumatic transtentorial herniation.

Adolescent↗
PubMed1990

Intraoperative ultrasound imaging of the entire brain through unilateral exploratory burr holes after severe head injury: technical note.

A portable ultrasound unit with a 3.5-MHz probe allows accurate imaging of both cerebral hemispheres and partial imaging of the posterior fossa through unilateral exploratory burr holes or a craniotomy. In patients with clinical signs of transtentorial herniation after severe head injury, this unilateral technique can detect extraaxial and intraparenchymal mass lesions more accurately than is possible with bilateral exploratory burr holes.

Adult↗
PubMed1990

Neurologic complications of cardiac transplantation.

Between 1984 and 1989, orthotopic cardiac transplantations were done in 90 patients from 10 to 65 years of age for end-stage, refractory congestive cardiomyopathy. Two patients had had ischemic strokes 5 months and 18 years, respectively, before transplantation. Six patients (7%) suffered acute neurologic events perioperatively. Three patients suffered cerebral infarctions. In 1 case this occurred 10 days before transplantation--probably as a result of systemic hypoperfusion--with the placement of ventricular assist devices. Two others suffered infarctions 5 and 21 days, respectively, after transplantation, each of probable embolic origin. Two patients had an acute intracerebral hemorrhage 21 and 36 days, respectively, after transplantation; both were located within the basal ganglia and subcortical regions. Both patients had moderate to severe hypertension, and in 1, renal failure and a coagulopathy developed before hemorrhage. Tremor, seizures, and an altered level of consciousness developed in 1 patient as an apparent toxic reaction to cyclosporine treatment. Only 1 patient died as a result of the neurologic complication--of an acute intracerebral hemorrhage. Three patients recovered fully, 2 partially. Only the case of drug toxicity could be directly attributed to the transplantation procedure itself. We conclude that the risk of an acute neurologic insult with orthotopic cardiac transplantation is low but may result from drug toxicity, cerebral ischemia, or hemorrhagic mechanisms.

Adolescent↗
PubMed1989

Stroke associated with cocaine use.

We describe eight patients in whom cocaine use was related to stroke and review 39 cases from the literature. Among these 47 patients the mean (+/- SD) age was 32.5 +/- 12.1 years; 76% (34/45) were men. Stroke followed cocaine use by inhalation, intranasal, intravenous, and intramuscular routes. Intracranial aneurysms or arteriovenous malformations were present in 17 of 32 patients studied angiographically or at autopsy; cerebral vasculitis was present in two patients. Cerebral infarction occurred in 10 patients (22%), intracerebral hemorrhage in 22 (49%), and subarachnoid hemorrhage in 13 (29%). These data indicate that (1) the apparent incidence of stroke related to cocaine use is increasing; (2) cocaine-associated stroke occurs primarily in young adults; (3) stroke may follow any route of cocaine administration; (4) stroke after cocaine use is frequently associated with intracranial aneurysms and arteriovenous malformations; and (5) in cocaine-associated stroke, the frequency of intracranial hemorrhage exceeds that of cerebral infarction.

Adult↗
PubMed1989

Surgical exploration before computed tomography scanning in children with traumatic tentorial herniation.

Seventeen consecutive children with early clinical signs of tentorial herniation after head injury underwent immediate burr-hole exploration before computed tomography scanning. In nine children (53%), a subdural hematoma was discovered and immediately evacuated. In one, a small intracerebral hemorrhage was diagnosed by intraoperative ultrasonography. Postoperative studies showed that no intraaxial or extraaxial hematoma was missed by surgical exploration. Nine children (53%) survived; eight (47%) died. The survival rate was higher among patients with a mass lesion than among those without. Seven children had a good recovery, and two were moderately disabled (mean follow-up, 15.2 months). We conclude that a significant proportion of head-injured children with clinical signs of tentorial herniation have extraaxial hematomas that can be readily identified and evacuated by immediate surgical exploration. The survival rate and extent of recovery in children appear to be better than in similarly injured adults.

Adolescent↗
PubMed1989

Management of cerebral aneurysms: further facts and additional myths.

In 1985 we reviewed 17 misconceptions or myths surrounding the treatment of aneurysmal subarachnoid hemorrhage that may contribute to the dismal outcome from these lesions. Since that time, significant new data, or facts, have become available regarding the influence of early aneurysm surgery on rebleeding, the efficacy of treatments for symptomatic arterial narrowing, improvements in surgical techniques such as temporary arterial clipping, and measures to protect the brain from ischemic injury. However, additional myths have become apparent which continue to limit our ability to improve the outcome of these patients. We review these facts and myths and discuss management of the patient with aneurysmal subarachnoid hemorrhage.

Antifibrinolytic Agents↗
PubMed1989

Treatment of acute traumatic internal carotid artery occlusion with extracranial-to-intracranial arterial bypass: case report.

Ligation of the cervical internal carotid artery resulted in an acute neurological deficit in the dominant hemisphere of a 35-year-old man who suffered a penetrating injury to the neck. Regional cerebral hypoperfusion was suspected because the ischemic symptoms occurred while the patient was fully heparinized. Immediate institution of a barbiturate coma, volume expansion, and placement of a high-flow extracranial-intracranial arterial bypass graft led to rapid recovery of hemispheric function. High-flow extracranial-intracranial bypass grafts appear to be indicated for the treatment of symptomatic cerebral ischemia in selected cases of acute ligation or occlusion of the extracranial carotid artery.

Adult↗
PubMed1989

Use of intraoperative ultrasonography to improve the diagnostic accuracy of exploratory burr holes in patients with traumatic tentorial herniation.

Seventeen head-injured patients with signs of brain stem compression at admission underwent emergency bilateral burr-hole exploration before computerized tomographic (CT) scanning. After exploration of the epidural and subdural spaces, real-time ultrasonography was performed intraoperatively to identify intraaxial hematomas. Epidural or subdural hematomas were identified surgically in 11 patients (65%) and immediately evacuated through a craniotomy; in 2 patients, bilateral subdural hematomas were removed. Ultrasonography showed no evidence of intracerebral mass lesions in 14 (82%) of the 17 patients, demonstrated extensive contusions of the temporal lobe in 2 patients (prompting partial lobectomy in both cases), and revealed a small intraparenchymal hematoma deep within the dominant hemisphere, which was not removed, in 1 patient. The sensitivity of ultrasound images for identifying intraparenchymal lesions was evaluated postoperatively by CT or autopsy. In 15 patients (88%), the results of ultrasonography were confirmed. In 2 (12%), CT scans showed small but significant lesions at the frontal pole missed by ultrasonography; one patient had a residual subdural hematoma, and the other a small intraparenchymal hemorrhage. These results confirm that patients with clinical evidence of brain stem compression soon after head injury often have extraaxial hematomas that can be readily identified by burr-hole exploration. Although intraparenchymal hematomas are rare immediately after head injury, they can usually be identified by intraoperative ultrasonography. This simple technique can reduce the risk of missing intracranial hematomas during emergency burr-hole exploration and improve intraoperative decision making in this population of severely head-injured patients.

Adolescent↗
PubMed1989

Microsurgical anatomy of the venous drainage into the superior sagittal sinus.

Ten unfixed human brains were examined under an operating microscope to evaluate the feasibility of reimplanting the parasagittal veins into the superior sagittal sinus. On average, there were 6.5 veins draining the surface of each hemisphere in the anterior frontal region, 3 veins draining each posterior frontal region, 4 veins draining each parietal region, and 1 vein draining each occipital region. The veins were most frequently 0.1 to 1.0 mm in diameter, but were as large as 3.0 mm in the anterior frontal and occipital regions, 3.5 mm in the parietal region, and 5.0 mm in the posterior frontal region. The mean vein length between the superior sagittal sinus and the first lateral attachment was 3.0 to 7.4 mm; individual veins were as long as 30.0 mm. The 20 hemispheres contained a total of 5 veins in the anterior frontal region, 7 veins in the posterior frontal region, and 8 veins in the parietal region that appeared to have an adequate diameter and length for microsurgical reimplantation into the superior sagittal sinus. The superior sagittal sinus had a mean width of 4.3 mm and depth of 3.6 mm in the midanterior frontal region and enlarged to a mean width of 9.9 mm and depth of 6.8 mm in the midoccipital region. In all sites, the sinus appeared to be structurally compatible with vein reimplantation. In 3 cases, veins 2.8 to 4.6 mm in diameter were reimplanted microsurgically into the sinus; in each case, the anastomosis was technically satisfactory and patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Nonoperative treatment of spinal epidural infections.

Spinal epidural infections were diagnosed before the onset of neurological deficits in six patients and treated nonsurgically. The diagnosis was based on the clinical presentation and on the results of myelography and computerized tomography scanning. Positive cultures were obtained from blood in all six patients, from aspiration of a paraspinous infection in two, and from a skin abscess and a pulmonary empyema in one patient each. Staphylococcus aureus was the causative organism in five cases. All patients were treated with intravenous antibiotics and remained neurologically intact throughout the course of treatment. Five patients have had no recurrence of their symptoms. One patient eventually required surgery for persistent discitis.

Adult↗
PubMed1989

Brain shift, level of consciousness, and restoration of consciousness in patients with acute intracranial hematoma.

Recently, Ropper reported that horizontal brain shift caused by acute unilateral mass lesions correlated closely with consciousness, and suggested that recovery of consciousness was unlikely to occur after surgical evacuation if the shift was insufficient to explain the observed diminution of consciousness. The authors have sought to confirm the correlation of pineal shift with level of consciousness and to assess the prognostic value of brain shift measurements in a prospective study. Forty-six patients (19 with subdural hematoma, 14 with intracerebral hematoma, and 13 with epidural hematoma) were accrued to the study group consecutively. A correlation was found between a decrease in the level of consciousness and a significant increase in the mean lateral brain displacement at the pineal gland (from 3.8 to 7.0 mm) and septum (5.4 to 12.2 mm). When outcome was examined in patients who were stuporous or comatose on admission, a significant increase in septal shift was found among patients with a poor outcome, but there was no significant relationship between outcome and degree of pineal or aqueductal shift. A poor outcome was more likely with effacement of both perimesencephalic cisterns or the ipsilateral cistern, but not the contralateral cistern, although this difference did not reach statistical significance. These results do not substantiate the value of brain shift as an independent prognostic factor after evacuation of an acute unilateral mass lesion. The decision to operate and the determination of prognosis should be based rather on established criteria such as the clinical examination, age of the patient, and the mechanism of injury.

Acute Disease↗
PubMed1988

An epidural intracranial pressure monitor for experimental use in the rat.

We described the construction and use of a simple and reliable catheter system that can be used to monitor intracranial pressure (ICP) from the epidural space in rats in an experimental setting. The catheter system is easily fabricated in the laboratory from readily available materials. The monitor is fitted flush with the inner table through a burr hole in the temporal squama. A side port is used to fill the system with saline and to irrigate the system should be catheter become obstructed. The distal end of the catheter is fitted to a pressure transducer that is connected to a graphic display and recording system. This system was used to record ICP in 30 anaesthetized adult rats. Seven were subjected to baseline ICP recording only and 23 were subjected to baseline recordings followed by epidural balloon compression of the contralateral hemisphere. Baseline ICP varied between 0 and 8 mmHg and respiratory variation could be detected on the tracings for 24 rats (75%). ICP responded directly and sensitively to epidural balloon inflation in all 23 rats tested. In 5 rats that died during balloon inflation, the decrease in ICP after death followed closely the loss of arterial blood pressure. There was a close correlation of numerical values obtained in two rats in which ICP was recorded simultaneously from the epidural catheter and from a catheter in the subarachnoid space at the cisterna magna. In one rat in which ICP increased to more than 70 mmHg, the epidural catheter continued to record ICP accurately while the cisternal catheter became obstructed with herniated brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Computerized cortical surface electroencephalography after temporary middle cerebral artery occlusion in rabbits.

The sensitivity and regional specificity of intraoperative electroencephalographic (EEG) monitoring in cerebral ischemia was evaluated in a new experimental model of temporary focal cerebral ischemia in rabbits. EEG potentials were recorded directly from the cortical surface using a bipolar disc electrode grid and were analyzed by computer. Groups of 5 animals each underwent temporary occlusion of the left middle cerebral arterial trunk for 5, 10, 20, 30, 45, or 60 minutes. EEG data were recorded from the cortex proximal (temporal site) and distal (parasagittal site) to the middle cerebral arterial trunk during occlusion and 2 hours of reperfusion. EEG suppression was detected immediately after occlusion at the temporal site by analysis of power spectra in 29 of 30 rabbits (mean power, 32% of base line), by compressed spectral array (CSA) edge analysis in 23, and by analysis of the conventional EEG wave form in 24. Within 5 minutes after the start of occlusion, all 30 rabbits showed EEG power suppression and 26 showed decrease in the CSA edge frequency or in the routine EEG wave form. By the end of the occlusion period, EEG power at the temporal site had decreased to 20.5% of base line. At the parasagittal site, a lesser degree of EEG suppression was detected; 20 rabbits had an initial loss of EEG power (mean, 85.7% of base line), 13 had decrease in the CSA edge, and 7 had suppression of the EEG wave form. By the end of the occlusion period, spectral power at the parasagittal site had decreased in 25 of 30 rabbits to a mean of 86.9% of base line.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Presentation of type I Chiari malformation after head trauma.

An unusual case of Type I Chiari malformation that became symptomatic after closed head injury is reported. The patient manifested transient upper extremity weakness, persistent lower cranial nerve dysfunction, and cerebellar signs that slowly resolved. Magnetic resonance images showed tonsillar ectopia but no displacement of the brain stem or syringomyelia. Type I Chiari malformation should be included in the differential diagnosis of patients who present with upper extremity weakness, lower cranial nerve palsies, or cerebellar signs after trauma.

Adolescent↗