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Biomedical subjects

H R Winn

Publications and source records attributed to H R Winn.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cerebrospinal fluid creatine kinase-BB isoenzyme activity and outcome after subarachnoid hemorrhage.

BACKGROUND: The brain is rich in creatine kinase-BB isoenzyme activity (CK-BB), which is not normally present in cerebrospinal fluid (CSF). Results of previous studies have shown that CK-BB can be detected in the CSF of patients with aneurysmal subarachnoid hemorrhage (SAH), but whether CK-BB levels correlate with patients' neurologic outcomes is unknown. OBJECTIVE: To evaluate the relationship between CSF CK-BB level and outcome after SAH. DESIGN: Prospective observational cohort. SETTING: University-affiliated tertiary care center. PATIENTS: Convenience sample of 30 patients seen for cerebral aneurysm clipping. INTERVENTIONS: We sampled and assayed CSF for CK isoenzymes a median of 3 days after SAH in 27 patients, and at the time of unruptured aneurysm clipping in 3 patients. MAIN OUTCOME MEASURES: Without knowledge of CK results, we assigned the Glasgow Outcome Scale score early (approximately 1 week) and late (approximately 2 months) after surgery. RESULTS: Higher CSF CK-BB levels were associated with higher Hunt and Hess grades at hospital admission (Spearman rank correlation, p = 0.69; P<.001), lower Glasgow Coma Scale scores at hospital admission (p = -0.72; P<.001), and worse early outcomes on the Glasgow Outcome Scale (p = -0.64; P<.001). For patients with a favorable early outcome (Glasgow Outcome Scale score, 3-5), all CK-BB levels were less than 40 U/L. With a cutoff value of 40 U/L, CK-BB had a sensitivity of 70% and a specificity of 100% for predicting unfavorable early outcome (Glasgow Outcome Scale score, 1-2). Having a CK-BB level greater than 40 U/L increased the chance of an unfavorable early outcome, from 33% (previous probability) to 100%, whereas a CK-BB level of 40 U/L or less decreased it to 13%. Similar findings were obtained when considering late outcomes. CONCLUSION: The level of CSF CK-BB may help predict neurologic outcome after SAH.

Adult↗
PubMed1999

Intracranial aneurysms and subarachnoid hemorrhage management of the poor grade patient.

Between 20 and 30% of patients who suffer cerebral aneurysm rupture are in poor clinical grade when first evaluated. Management of these patients is controversial and challenging but can be successful with an aggressive proactive approach that begins with in the field resuscitation and continues through rehabilitation. In this article we review the epidemiology, pathology and pathophysiology, clinical features, evaluation, surgical and endovascular management, critical care, cost, and outcome prediction of patients in poor clinical grade after subarachnoid hemorrhage.

Adult↗
PubMed1999

Endovascular therapy for aneurysmal vasospasm.

Endovascular treatment of cerebral vasospasm induced by subarachnoid hemorrhage has become a useful therapy. The two main treatments that have been used are balloon angioplasty and intra-arterial papaverine infusion. Both treatments have been shown to reverse subarachnoid hemorrhage-induced vascular spasm, increase cerebral blood flow and improve delayed ischemic neurologic deficits induced by vasospasm. Balloon angioplasty is superior to papaverine for treatment of proximal vessel vasospasm by virtue of a more sustained effect on the vessels. Papaverine can be useful as an adjunct to balloon angioplasty and also for the treatment of distal vessels that are not accessible for balloon angioplasty.

Aneurysm, Ruptured↗
PubMed1999

P-selectin blockade following fluid-percussion injury: behavioral and immunochemical sequelae.

Traumatic brain injury (TBI) can cause polymorphonuclear leukocyte (PMN) migration into brain parenchyma, mediating various cytodestructive mechanisms. We examined the effect of blocking leukocyte/endothelial cell adhesion molecules (CAMs) on the anatomic and behavioral sequelae in lateral fluid-percussion injury in rats. Monoclonal antibodies (MAb) directed against a functional (PB1.3) or nonfunctional (PNB1.6) epitope on endothelial P-selectin were used as treatments. Subjects were tested in the Morris water maze (MWM) at 7 and 14 days postinjury then immunohistochemistry was performed using antibodies that recognize ChAT, GFAP and OX-42. A second set of animals underwent myeloperoxidase (MPO) assay in the brain parenchyma and a third set was used to examine neutrophil migration using the MAb RP-3. Time in quadrant, but not escape latency or proximity improved with PB1.3 (p < 0.05). Similarly, PB1.3 reduced MPO levels after injury (p < 0.05), in the ipsilateral cortex. No significant difference occurred in neutrophil counts in cortex, corpus callosum, hippocampus, and thalamus between injured only rats and injured rats treated with PB1.3. Quantitative analysis of cholinergic cells in the medial septum showed a protective effect by PB1.3. Densitometry readings of GFAP and OX-42 immunolabeling revealed no discernible differences between the treated and untreated injured rats. Qualitatively, there was no difference in microglia or astrocyte response to treatment. Treatment with P-selectin blockade in brain-injured rats may reduce PMN migration into brain, help preserve cholinergic immunolabeling of medial septal nucleus neurons, and may alleviate mnemonic deficits.

Animals↗
PubMed1999

Acute traumatic posteroinferior cerebellar artery aneurysms: report of three cases.

OBJECTIVE AND IMPORTANCE: Posterior fossa subarachnoid hemorrhage secondary to blunt head trauma is rarely associated with traumatic aneurysms of the posterior circulation. CLINICAL PRESENTATION: We present three cases of posterior fossa subarachnoid hemorrhage from ruptured posteroinferior cerebellar artery (PICA) aneurysms after blunt head trauma. In each case, there was no associated penetrating injury or cranial fracture. All three patients presented with acute hydrocephalus requiring ventriculostomy. Two of the three patients had a proximal PICA aneurysm visible on emergent angiography. The remaining patient's aneurysm, although not visible on his initial angiogram, was detected on a subsequent angiogram 72 hours later. INTERVENTION: All patients underwent successful surgical clipping of their aneurysms. Two cases required sacrificing of the parent vessels because of the friable nature of the false aneurysms. In each case, severe symptomatic vasospasm occurred, requiring angioplasty. All three patients also required a ventriculoperitoneal shunt for persistent hydrocephalus. CONCLUSION: Features of these three cases and similar cases reported in the literature support the theory that vascular ruptures and traumatic aneurysms of the proximal PICA may be related to anatomic variability of the PICA as it transverses the brainstem. This variability predisposes individuals to vascular lesions, which occur in a continuum based on the severity of the injury. Posterior fossa subarachnoid hemorrhage after head injury requires a high index of suspicion and warrants aggressive diagnostic and therapeutic interventions.

Adolescent↗
PubMed1999

Bacterial meningitis associated with lumbar drains: a retrospective cohort study.

OBJECTIVES: The infective potential of lumbar drainage is an important topic deserving particular study. The aetiology, incidence, and clinical findings associated with bacterial meningitis are described in patients having continuous lumbar CSF drainage to treat communicating hydrocephalus after subarachnoid haemorrhage or CSF leaks after traumatic dural rents. METHODS: Retrospective review of the records of patients with a positive CSF bacterial culture who underwent lumbar drain placement over a 39 month period. RESULTS: Thirteen cases of bacterial meningitis occurred subsequent to the use of 312 lumbar drain kits (4.2%). All meningitic patients had CSF pleocytosis, but not all had peripheral leukocytosis. Fever, peripheral leukocytosis, and CSF pleocytosis did not help to differentiate the presence of bacterial meningitis from other infections. Eight patients had prior CSF drainage procedures, including ventriculostomy (n=5) or lumbar drain (n=5) placements; two patients received both procedures. Six of 13 patients developed their CSF infection within 24 hours of lumbar drain insertion. Six of 13 patients developed meningitis while receiving antibiotics for other reasons. CONCLUSIONS: External lumbar drainage seems to carry a low risk of infectious meningitis and offers a safe alternative to ventriculostomy or serial lumbar punctures. Antibiotics do not seem to protect completely against developing the infection. The infection happens most often with skin organisms. The meningitis often appears within 24 hours after lumbar drain placement. Daily CSF samples should include bacterial cultures but cell counts may not offer any additional useful information in diagnosing the complication. Lumbar drain insertion and management need not be confined to the intensive care unit.

Adult↗
PubMed1999

Resolution of central pain after embolization of an arteriovenous malformation. Case report.

The authors describe a patient with right-sided central pain resulting from a left parietal arteriovenous malformation (AVM). The AVM was treated with staged embolization and stereotactic radiosurgery, and its obliteration was documented on follow-up angiographic studies. Surprisingly, the patient noted complete resolution of her pain syndrome after embolization, which is an extremely rare result. Central pain and its proposed mechanisms are discussed.

Angiography, Digital Subtraction↗
PubMed1999

Side effects and mortality associated with use of phenytoin for early posttraumatic seizure prophylaxis.

OBJECT: The goals of this study were to determine if the use of phenytoin to prevent early posttraumatic seizures following head injury was associated with significant adverse side effects and also to determine if the reduction in early posttraumatic seizures after phenytoin administration was associated with a change in mortality rates in head-injured patients. METHODS: The authors performed a secondary analysis of the data obtained in a prospective double-blind placebo-controlled study of 404 patients who were randomly assigned to receive phenytoin or placebo for the prevention of early and late posttraumatic seizures. The incidence of adverse drug effects during the first 2 weeks of treatment, however, was low and not significantly different between the treated and placebo groups. Hypersensitivity reactions occurred in 0.6% of the patients in the phenytoin-treated group compared with 0% in the placebo group (p = 1.0) during week 1, and in 2.5% of phenytoin-treated compared with 0% of placebo-treated patients (p = 0.12) for the first 2 weeks of treatment. Mortality rates were also similar in both groups. Although the mortality rate was higher in patients who developed seizures, this increase was related to the greater severity of the injuries sustained by these patients at the time of the original trauma. CONCLUSIONS: The results of this study indicate that the incidence of early posttraumatic seizure can be effectively reduced by prophylactic administration of phenytoin for 1 or 2 weeks without a significant increase in drug-related side effects. Reduction in posttraumatic seizure during the 1st week, however, was not associated with a reduction in the mortality rate.

Anticonvulsants↗
PubMed1999

Valproate therapy for prevention of posttraumatic seizures: a randomized trial.

OBJECT: Seizures frequently accompany moderate to severe traumatic brain injury. Phenytoin and carbamazepine are effective in preventing early, but not late, posttraumatic seizures. In this study the authors compare the safety and effectiveness of valproate with those of short-term phenytoin for prevention of seizures following traumatic brain injury. METHODS: The study was a randomized, double-blind, single-center, parallel-group clinical trial. Treatment began within 24 hours of injury. One hundred thirty-two patients at high risk for seizures were assigned to receive a 1-week course of phenytoin, 120 were assigned to receive a 1-month course of valproate, and 127 were assigned to receive a 6-month course of valproate. The cases were followed for up to 2 years. The rates of early seizures were low and similar when using either valproate or phenytoin (1.5% in the phenytoin treatment group and 4.5% in the valproate arms of the study; p = 0.14, relative risk [RR] = 2.9, 95% confidence interval [CI] 0.7-13.3). The rates of late seizures did not differ among treatment groups (15% in patients receiving the 1-week course of phenytoin, 16% in patients receiving the 1-month course of valproate, and 24% in those receiving the 6-month course of valproate; p = 0.19, RR = 1.4, 95% CI 0.8-2.4). The rates of mortality were not significantly different between treatment groups, but there was a trend toward a higher mortality rate in patients treated with valproate (7.2% in patients receiving phenytoin and 13.4% in those receiving valproate; p = 0.07, RR = 2.0, 95% CI 0.9-4.1). The incidence of serious adverse events, including coagulation problems and liver abnormalities, was similar in phenytoin- and valproate-treated patients. CONCLUSIONS: Valproate therapy shows no benefit over short-term phenytoin therapy for prevention of early seizures and neither treatment prevents late seizures. There was a trend toward a higher mortality rate among valproate-treated patients. The lack of additional benefit and the potentially higher mortality rate suggest that valproate should not be routinely used for the prevention of posttraumatic seizures.

Adult↗
PubMed1999

Risk of early closed reduction in cervical spine subluxation injuries.

OBJECT: The authors retrospectively reviewed 121 patients with traumatic cervical spine injuries to determine the risk of neurological deterioration following early closed reduction. METHODS: After excluding minor fractures and injuries without subluxation, the medical records and imaging studies (computerized tomography and magnetic resonance [MR] images) of 82 patients with bilateral and unilateral locked facet dislocations, burst fractures, extension injuries, or miscellaneous cervical fractures with subluxation were reviewed. Disc injury was defined on MR imaging as the presence of herniation or disruption: a herniation was described as deforming the thecal sac or nerve roots, and a disruption was defined as a disc with high T2-weighted signal characteristics in a widened disc space. Fifty-eight percent of patients presented with complete or incomplete spinal cord injuries. Thirteen percent of patients presented with a cervical radiculopathy, 22% were intact, and 9% had only transient neurological deficits in the field. Early, rapid closed reduction, using serial plain radiographs or fluoroscopy and Gardner-Wells craniocervical traction, was achieved in 97.6% of patients. In two patients (2.4%) closed reduction failed and they underwent emergency open surgical reduction. The average time to achieve closed reduction was 2.1+/-0.24 hours (standard error of the mean). The incidence of disc herniation and disruption in the 80 patients who underwent postreduction MR imaging was 22% and 24%, respectively. However, the presence of disc herniation or disruption did not affect the degree of neurological recovery, as measured by American Spinal Injury Association motor score and the Frankel scale following early closed reduction. Only one (1.3%) of 80 patients deteriorated, but that occurred more than 6 hours following closed reduction. CONCLUSIONS: Although disc herniation and disruption can occur following all types of traumatic cervical fracture subluxations, the incidence of neurological deterioration following closed reduction in these patients is rare. The authors recommend early closed reduction in patients presenting with significant motor deficits without prior MR imaging.

Cervical Vertebrae↗
PubMed1998

Suppression of somatosensory evoked potentials by nitric oxide synthase inhibition in rats: methodological differences.

We have previously shown that topically applied N(G)-nitro-L-arginine (L-NNA), a nitric oxide synthase (NOS) inhibitor, suppressed both somatosensory evoked potentials (SEPs) and vascular responses during sciatic nerve stimulation in rats. Due to the normal tight coupling between cerebral blood flow and neuronal activity, we surmise that the vascular response attenuation may be secondary to the SEP decrease. However, a recent study, in which SEPs were recorded with a 'non-contact' electrode placed longitudinally across the cranial window without touching the cortex, did not find a SEP decrease following NOS inhibition. In the present study, we compared SEPs recorded with 'contact' and 'non-contact' electrodes. Regardless of stimulation methods (sciatic nerve or hindpaw), an electrode in contact with the pial surface overlying the hindlimb somatosensory cortex recorded a steady SEP decline during I-NNA application. In contrast, a 'non-contact' electrode did not detect a significant SEP change in the presence of I-NNA. The present results thus confirm the attenuation of SEPs by NOS inhibition.

Animals↗
PubMed1998

Selective loss of hippocampal long-term potentiation, but not depression, following fluid percussion injury.

We investigated the early effects of in vivo fluid percussion injury (FPI) on hippocampal synaptic potentials and excitability. In vitro field potential recordings and immunocytochemistry were performed in the CA1 region in slices from naïve, post-FPI, or sham-operated rats. The following electrophysiological and morphological parameters were affected following FPI: (1) threshold for population spike generation was increased suggesting that post-FPI neurons were hypoexcitable; (2) long-term potentiation (LTP) could not be induced in injured hippocampi; (3) GFAP and inducible NO synthase (iNOS) immunoreactivity were enhanced post-FPI; and (4) following injury, synaptophysin immunoreactivity was enhanced in CA1 stratum radiatum. The effects of FPI on synaptic plasticity were LTP-specific, since long-term depression (LTD) could be equally induced and maintained in post-FPI, sham-operated and control slices. Sham-operated slices were characterized by synaptic excitability indistinguishable from naïve controls, but displayed decreased ability for LTP production and expressed high levels of iNOS. We conclude that FPI causes a selective loss of LTP, possibly due to a previous potentiation induced by trauma as reflected by the increased expression of synaptic proteins. Sham surgical procedures were, however, not without effects on long-term potentiation itself; the latter effects appear to be mediated by an increased production of NO. Our study demonstrates for the first time that hippocampal slices can be used to investigate the correlates of in vivo FPI. Furthermore, we describe LTP-specific deficits in post-traumatic brain injury, suggesting that FPI can selectively erase one of the two main NMDA-dependent forms of synaptic plasticity in the hippocampus.

Animals↗
PubMed1998

Two cases of esophageal carcinoma metastatic to the pineal region with a review of the literature.

BACKGROUND: Metastasis to the pineal region is rare, and there are no previously reported cases of esophageal carcinoma metastatic to the pineal region. CASE DESCRIPTION: We now present two cases of solitary esophageal carcinoma metastatic to the pineal region. In each case there was no evidence of disease progression at the primary site at the time of presentation, and neurologic symptoms were the first indication of recurrent disease. Both patients underwent infratentorial/supracerebellar resection of the pineal lesions and were subsequently referred for radiation therapy. CONCLUSIONS: These two cases emphasize that metastatic disease must be a likely differential consideration in a patient with a CNS lesion and a history of previous malignancy, even if the lesion is in an unusual location.

Adenocarcinoma↗
PubMed1998

Increases in metabolism of valproate and excretion of 6beta-hydroxycortisol in patients with traumatic brain injury.

AIMS: The objectives of this study were to determine the effect of brain trauma on the multiple pathways of metabolism of valproate and to evaluate the use of the urinary 6beta-hydroxycortisol to cortisol ratio in predicting changes in hepatic metabolism induced by brain injury. METHODS: Fourteen patients with severe head injuries received a 15 mg kg(-1) loading dose and a maintenance dose of valproate to maintain therapeutic plasma concentrations. A minimum of one steady state trough blood sample and one dosage interval urine were collected during days 3-6 and during days 7-14 post-injury. Total and unbound valproate plasma concentrations were determined by gas chromatography-flame ionization detection (GC-FID) with and without ultrafiltration. Urinary valproate metabolites were measured by gas chromatography/mass spectrometry (GC-MS) (n = 10). Urinary 6beta-hydroxycortisol and cortisol concentrations were determined by high performance liquid chromatography (h.p.l.c.) (n = 14). Total intrinsic clearance (CL[int]) for valproate and individual formation clearances (CL[f]) to its major metabolites were calculated. Data obtained during baseline (days 3-6) were averaged for each patient and were compared with averaged data obtained from days 7 to 14 using a paired t-test. RESULTS: Statistically significant increases in the CL(int), CL(f) of VPA glucuronide, 2-ene-VPA, and 4-OH-VPA pathways and the 6beta-hydroxycortisol to cortisol ratio were found. The percent change in the 6beta-hydroxycortisol to cortisol ratio correlated significantly with the changes in the CL(int) of valproate. CONCLUSIONS: Brain trauma results in induction of multiple pathways of valproate metabolism and increases in the 6beta-hydroxycortisol to cortisol ratio, suggesting a non-specific enzyme induction in response to head injury.

Adult↗