Treating intracranial dural arteriovenous fistulas with gamma knife radiosurgery: A single-center experience.

OBJECTIVE: We evaluated the effectiveness and safety of gamma knife radiosurgery (GKRS) for the treatment of intracranial dural arteriovenous fistulas (dural AVFs) over the past 10 years. MATERIALS AND METHODS: The records of 21 patients diagnosed with dural AVFs between 2004 and 2014 and treated with GKRS were reviewed retrospectively. Complete obliteration (CO) was defined as total symptom relief plus confirmation through magnetic resonance imaging or conventional angiography. RESULTS: The median follow-up was 70.5 months (range 3-136 months). Five patients underwent embolization (2 after GKRS). One patient underwent GKRS twice. The CO rate was 47%, and partial to CO rate was 88%. The complete symptom resolution rate was 77%, and all patients achieved partial to complete symptom resolution. The CO rates for Borden Type I and Type II/III dural AVFs were 66.7% and 25% (P = 0.153), respectively, and complete symptom-free rates were 76.9% and 75.0% (P = 1.000%), respectively. The median duration between initial GKRS and complete symptom resolution was 14.3 months. The median treatment to image-free durations for Borden Type I and Type II/III dural AVFs were 25.9 and 60.4 months (P = 0.028), respectively, and treatment to symptom-free durations were 10.6 and 36.7 months (P = 0.103), respectively. One patient had a recurrent hemorrhage. Two patients experienced brain edema after stereotactic radiosurgery and one patient experienced cystic formation after GKRS. The morbidity rate was 19% (four patients) and there was no mortality. CONCLUSION: Treatment with GKRS for dural AVFs offers a favorable rate of obliteration. Patients with dural AVFs that are refractory or not amenable to endovascular or surgical therapy may be safely and effectively treated using GKRS.

Volume-staged gamma knife surgery for the treatment of large skull base meningioma surrounding the optical apparatus: A snowman-shape design.

BACKGROUND: In cases of meningioma surrounding the optical apparatus, this study sought to reduce the incidence of radiation-induced optical neuropathy resulting from gamma knife surgery (GKS) by dividing the treatment volume into 2 or 3 fractions. METHODS: Four patients with a large skull base meningioma (1 male and 3 females; median age: 42 years; range: 33-43 yrs) were treated using volume-staged GKS. In stage I, the large basal part of the tumor (13.2 mL; range: 3.9-54.7 mL) was treated with a marginal dose of 13.5 Gy (range: 12-15 Gy). In stage II, treatment focused on the smaller upper portion of the tumor located close to the optical apparatus (4.3 mL; range: 1.5-16.2 mL), and the marginal dose was 9 Gy (range: 8-10 Gy). RESULTS: All patients tolerated the treatments well, and tumors regressed over a median follow-up period of 100.5 months (range: 42-122 mos). Specifically, a 34-46% reduction in tumor volume was observed. All four patients presented improvements in the neurological deficits observed prior to GKS treatment, albeit to varying degrees. No adverse effects of radiation or new visual deterioration were observed during the follow-up period. Furthermore, no evidence of new endocrine dysfunction or new cranial nerve neuropathy was observed within a follow-up period of 100.5 months. CONCLUSION: The application of volume-staged GKS using snowman-shape design appears to be an effective approach to control tumor growth when treating benign meningiomas surrounding the optical apparatus. This approach enables the application of higher radiation dosages to facilitate tumor control while still preserving optic nerve function.

Upfront Gamma Knife Surgery for Giant Central Neurocytoma.

BACKGROUND: In this report, we present the results of using upfront Gamma Knife surgery (GKS) in the management of giant central neurocytoma (CNC) (volume >50 mL) without the initial removal of the tumor mass. CASE DESCRIPTIONS: Two patients underwent GKS for histologically proven CNC. Clinical and imaging studies were performed to evaluate the response to treatment. GKS involved delivery doses of 12 or 13 Gy to the tumor margin at the isodose line of 50%. Tumor response to GKS appeared as early as 4-6 months after GKS, at which point a dramatic reduction in volume was observed. No adverse effects of radiation or new neurologic deficits were observed in either of the cases. In case 1, we observed a reduction in tumor volume from 69 to 20 mL at 6 months and a further reduction to 10.3 mL at 86 months. In case 2, we observed a reduction in tumor volume from 62 to 31 mL at 4 months with a further reduction to 22.5 mL at 30 months. The female patient (case 1) showed mild weakness in the right lower limb after the minimal surgical removal of tumor using the cortical approach. No additional neurologic deficits were observed after GKS. The young male patient (case 2) presented a complete recovery without any signs of headache at 3 months after GKS. CONCLUSIONS: Based on this initial experience, it appears that GKS is an effective treatment for CNC and may be used for upfront management in cases of indolent clinical symptoms, even when the tumor is very large.

Prognostic factors of paranasal sinusitis with intracranial invasion: A 14-year review of cases at Hualien Buddhist Tzu Chi Hospital.

Intracranial invasion of paranasal sinusitis is an emergency condition that requires surgical and medical intervention in order to avoid further deterioration. We surveyed patients at the Buddhist Tzu Chi Hospital (Hualien, Taiwan) who had paranasal sinusitis with intracranial invasion. A total of 505 patients with paranasal sinusitis were surveyed at Hualien Buddhist Tzu Chi Hospital over a 14-year period (2000-2013). Data on clinical presentations, microbiology, host factors, postinterventional morbidity, and postinterventional mortality are presented. Of the 505 patients, nine had intracranial invasions (incidence rate, 1.8%). The mortality rate was high among these patients (44.4%, 4/9). Among the various risk factors identified, diabetes had the greatest influence (66.7%, 6/9), which in combination with an immunocompromised condition and cirrhosis is indicative of a poor prognosis.

Acute respiratory distress syndrome and lung injury: Pathogenetic mechanism and therapeutic implication.

To review possible mechanisms and therapeutics for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). ALI/ARDS causes high mortality. The risk factors include head injury, intracranial disorders, sepsis, infections and others. Investigations have indicated the detrimental role of nitric oxide (NO) through the inducible NO synthase (iNOS). The possible therapeutic regimen includes extracorporeal membrane oxygenation, prone position, fluid and hemodynamic management and permissive hypercapnic acidosis etc. Other pharmacological treatments are anti-inflammatory and/or antimicrobial agents, inhalation of NO, glucocorticoids, surfactant therapy and agents facilitating lung water resolution and ion transports. ß-adrenergic agonists are able to accelerate lung fluid and ion removal and to stimulate surfactant secretion. In conscious rats, regular exercise training alleviates the endotoxin-induced ALI. Propofol and N-acetylcysteine exert protective effect on the ALI induced by endotoxin. Insulin possesses anti-inflammatory effect. Pentobarbital is capable of reducing the endotoxin-induced ALI. In addition, nicotinamide or niacinamide abrogates the ALI caused by ischemia/reperfusion or endotoxemia. This review includes historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

A retrospective survey of patients with malignant gliomas treated in the neuro-oncological care system under the Universal National Health Insurance program in Taiwan.

In 1995 a government-supported Universal National Health care system was implemented in Taiwan, which in 2008 was available to 98% of the population. This system offers affordable, rapid medical attention. A multi-center retrospective study was conducted to assess the prognosis of malignant glioma patients under this system. In 2005 and 2006, patients at 14 independent neuro-oncology centers with newly diagnosed malignant glioma were enrolled. The patient profile, pathology, treatment modalities, and prognosis were collected by questionnaire at each center. The Taiwan Neuro-Oncology Society was responsible for the data analysis. The overall median survival period, 1-year survival rate, and 2-year survival rate for patients with World Health Organization grade III glioma were 33.8 months, 81.4%, and 58.2%, respectively, and 15 months, 57.3%, and 33.9% in patients with grade IV glioma. The median survival period, 1-year survival rate, and 2-year-survival rate in patients receiving temozolomide adjuvant therapy was 36 months, 84.2%, and 61.8%, respectively, for patients with grade III glioma and 19.8 months, 73.1%, and 43.7%, for patients with grade IV glioma. The universal health care system in Taiwan offers a comparable prognosis with an affordable premium relative to other large series in developed countries.

White Matter tract involvement in brain tumors: a diffusion tensor imaging analysis.

BACKGROUND: Characterization of WM alteration using MR imaging is important in the pre- and intraoperative assessment of brain tumors. This study characterizes the extent and severity of WM tract alterations near brain tumors using DTI in an effort to determine preoperative viability or resectability of the adjacent WM tracts. Fractional anisotropy is an important DTI-derived metric of MR imaging. METHODS: Twenty-one patients underwent MR DTI. Eighty-six WM tracts composed of 43 WM lesions paired with 43 contralateral WM hemispheric controls were categorized using FA. Neuroradiologists categorized the WM tracts as edematous, displaced, disrupted, or infiltrated with tumor using directionally encoded color maps. A mixed model analysis was used to compare FA. RESULTS: Of the lesioned tracts, 5 were scored as edema, 9 as infiltration, 18 as displacement, and 11 as disruption. A significant DeltaFA(%) was found between the lesioned and contralateral hemispheres only in WM disruption (P = .0056). Both edema FA and disruption FA are significantly less than displacement FA (P < .05). The FA change (DeltaFA(%) = [FA(lesion) - FA(normal)]/FA(normal) x 100%) on the lesioned side was calculated. A DeltaFA% less than -30% is likely to be associated with WM disruption. A positive DeltaFA% is likely to be associated with edema or displacement, and a DeltaFA% between 0% and -30% is likely to be associated with WM displacement or infiltration. CONCLUSIONS: Quantitative analysis of DTI data may provide insight as to whether WM tracts are salvageable preoperatively.

Efficacy of anterior cervical fusion: comparison of titanium cages, polyetheretherketone (PEEK) cages and autogenous bone grafts.

This retrospective study was designed to analyze and compare the efficacy and outcomes of anterior cervical fusion using titanium cages, polyetheretherketone (PEEK) cages and autogenous tricortical bone grafts. Fifty-five patients who underwent segmental anterior discectomy with a follow-up period up to 12 months enrolled in this study. They were divided into three groups: titanium cage with biphasic calcium phosphate ceramic (Triosite; Zimmer, Berlin, Germany) in group A (n=27); PEEK cage with Triosite in group B (n=9); and autogenous tricortical iliac crest bone graft in group C (n=19). The fusion rates after 6 months were 37.21% in group A , 93.3% in group B, and 84.85% in group C. The fusion rates after 1 year in groups A, B, and C were 46.51%, 100% and 100%, respectively. The PEEK cage is a viable alternative to autogenous tricortical bone grafts in anterior cervical fusion.

Protective effects of propofol on acute lung injury induced by oleic acid in conscious rats.

OBJECTIVES: Oleic acid has been used to induce acute lung injury (ALI) in animals. In patients with acute respiratory distress syndrome (ARDS), the blood level of oleic acid was increased. The mechanism and therapeutic regimen of ARDS and oleic acid-induced ALI remain undefined. In the present study, we investigated the oleic acid-induced changes in lung variables for the measure of ALI, inflammatory mediators, and neutrophil-derived substances. We evaluated the effects of pretreatment and posttreatment with propofol. DESIGN: Randomized, controlled animal study. SETTING: University research laboratory. SUBJECTS: Fifty adult male Sprague-Dawley rats weighing 250-300 g. INTERVENTIONS: We employed a conscious and unrestrained rat model. Oleic acid at a dose of 100 mg/kg was administered intravenously. Propofol (30 mg/kg) was given by intravenous infusion (6 mg/kg/min for 5 mins) 30 mins before (pretreatment) and 30 mins after (posttreatment) oleic acid. MEASUREMENTS AND MAIN RESULTS: We monitored the arterial pressure, heart rate, and blood gas. The lung weight changes, exhaled nitric oxide, protein concentration in bronchoalveolar lavage, and Evans blue content in lung tissue were determined. The plasma nitrate/nitrite, methylguanidine, cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and interleukin-10), neutrophil elastase, myeloperoxidase, malondialdehyde, and sodium- and potassium-activated adenosine triphosphatase (Na+-K+-ATPase) were detected. Histopathological examination of the lung was performed. Oleic acid caused systemic hypotension and severe ALI as evidenced by the increases in the extent of ALI, impairment of pulmonary functions (blood gas variables), and lung pathology. In addition, oleic acid significantly increased inflammatory mediators and neutrophil-derived factors but depressed Na+-K+-ATPase. The inducible nitric oxide synthase was up-regulated. Pre- or posttreatment with propofol was capable of reversing the oleic acid-induced changes and attenuating the extent of ALI. CONCLUSIONS: Oleic acid resulted in sepsis-like responses including ALI, inflammatory reaction, and increased neutrophil-derived factors. It depressed the Na+-K+-ATPase activity but up-regulated inducible nitric oxide synthase. Treatment with propofol abrogated or reversed the oleic acid-induced changes.

Successful treatment of meningitis caused by multidrug-resistant Acinetobacter baumannii with intravenous and intrathecal colistin.

Multidrug-resistant Acinetobacter baumannii is an emergent nosocomial pathogen. A 61-year-old woman developed meningitis caused by MDRAB 27 days after receiving a surgical intervention for invasive meningioma. The patient failed to respond to high doses of meropenem and sulbactam treatment and the organism persisted in the cerebrospinal fluids for two months. The regimen was changed to intravenous and intrathecal colistin for 28 days and the patient responded well. Administration of colistin both intravenously and intrathecally could be a suitable option as a salvage therapy for meningitis due to multidrug-resistant A. baumannii.

Niacinamide abrogates the organ dysfunction and acute lung injury caused by endotoxin.

Poly (ADP-ribose) synthabse (PARS) or polymerase (PARP) is a cytotoxic enzyme causing cellular damage. Niacinamide inhibits PARS or PARP. The present experiment tests the effects of niacinamide (NCA) on organ dysfunction and acute lung injury (ALI) following lipopolysaccharide (LPS). LPS was administered to anesthetized rats and to isolated rat lungs. In anesthetized rats, LPS caused systemic hypotension and increased biochemical factors, nitrate/nitrite (NOx), methyl guanidine (MG), tumor necrosis factoralpha (TNFalpha), and interleukin-1beta (IL-1beta). In isolated lungs, LPS increased lung weight (LW) to body weight ratio, LW gain, protein and dye tracer leakage, and capillary permeability. The insult also increased NOx, MG, TNFalpha, and IL-1beta in lung perfusate, while decreased adenosine triphosphate (ATP) content with an increase in PARP activity in lung tissue. Pathological examination revealed pulmonary edema with inflammatory cell infiltration. These changes were abrogated by posttreatment (30 min after LPS) with NCA. Following LPS, the inducible NO synthase (iNOS) mRNA expression was increased. NCA reduced the iNOS expression. Niacinamide exerts protective effects on the organ dysfunction and ALI caused by endotoxin. The mechanisms may be mediated through the inhibition on the PARP activity, iNOS expression and the subsequent suppression of NO, free radicals, and proinflammatory cytokines with restoration of ATP.

Endotoxin-induced acute lung injury and organ dysfunction are attenuated by pentobarbital anaesthesia.

1. Acute lung injury (ALI) as a result of sepsis is a major cause of mortality. Certain anaesthetic agents have been reported to suppress pro-inflammatory cytokines and inducible nitric oxide (NO) synthase (iNOS) activities. We investigated the effects of pentobarbital on ALI and organ functions after the administration of endotoxin. 2. Intravenous (i.v.) pentobarbital (20 or 40 mg/kg) was administered 5 min after lipopolysaccharide (LPS; 10 or 30 mg/kg via i.v. infusion). To avoid hypoxia and/or hypercapnia following anaesthesia, we installed a special chamber connected to a rodent ventilator to provide ventilation with 95% oxygen content and 5% nitrogen. The animal was kept at eucapnic conditions (arterial PCO2 at an average of 38 +/- 2 mmHg). 3. We monitored the arterial pressure (AP) and heart rate (HR). Acute lung injury was evaluated by lung weight changes, protein concentration in bronchoalveolar lavage, and Evans blue leakage. Plasma nitrate/nitrite, methyl guanidine and biochemical factors were determined. Pathological and immunofluorescent examinations were performed to observe the lung changes and to determine the activities of pro-inflammatory cytokines, nitrotyrosine and iNOS. 4. Lipopolysaccharide caused dose-dependent systemic hypotension with an increase in the extent of ALI. The lung pathology included oedema and inflammatory cell infiltration. Accompanying the ALI, LPS elevated plasma nitrate/nitrite, methyl guanidine, blood urea nitrogen, lactic dehydrogenase, creatinine phosphokinase, glutamic transaminase and amylase. The lung tissue content of tumour necrosis factor-alpha, interleukin-lbeta, iNOS and nitrotyrosine was increased following LPS administration. These changes were abrogated by pentobarbital anaesthesia. 5. Our results indicated that pentobarbital anaesthesia significantly augmented the LPS-induced systemic hypotension. However, it attenuated the LPS-induced ALI and organ dysfunctions. This agent also improved the survival rate following LPS at high and low doses. This mechanism may be related to the inhibitory effects on the increases in the production or activity of NO, free radicals, pro-inflammatory cytokines, nitrotyrosine and iNOS.

Inhibition of inducible nitric oxide synthase attenuates acute endotoxin-induced lung injury in rats.

1. In the present study, we investigated the effects of the inducible nitric oxide (iNOS) inhibitors S-methylisothiourea (SMT) and l-N(6)-(1-iminoethyl)-lysine (l-Nil) on endotoxin-induced acute lung injury (ALI), as well as the associated physiological, biomedical and pathological changes, in anaesthetized Sprague-Dawley rats and in rat isolated perfused lungs. 2. Endotoxaemia was induced by an intravenous (i.v.) infusion of lipopolysaccharide (LPS; Escherichia coli 10 mg/kg). Lipopolysaccharide produced systemic hypotension and tachycardia. It also increased the lung weight/bodyweight ratio, lung weight gain, exhaled nitric oxide (NO), the protein concentration in bronchoalveolar lavage and microvascular permeability. 3. Following infusion of LPS, plasma nitrate/nitrite, methyl guanidine, pro-inflammatory cytokines (tumour necrosis factor-alpha and interleukin-1beta) were markedly elevated. Pathological examination revealed severe pulmonary oedema and inflammatory cell infiltration. Pretreatment with SMT (3 mg/kg, i.v.) or l-Nil (3 mg/kg, i.v.) significantly attenuated the LPS-induced changes and ALI. 4. The results suggest that the inflammatory responses and ALI following infusion of LPS are due to the production of NO, free radicals and pro-inflammatory cytokines through the iNOS system. Inhibition of iNOS is effective in mitigating the endotoxaemic changes and lung pathology. Inhibitors of iNOS may be potential therapeutic agents for clinical application in patients with acute respiratory distress syndrome.

A severe vicious cycle in uncontrolled subarachnoid hemorrhage: the effects on cerebral blood flow and hemodynamic responses upon intracranial hypertension.

In subarachnoid hemorrhage (SAH), Cushing postulated that the increase in systemic arterial pressure (SAP) in response to elevation of intracranial pressure (ICP) was beneficial to cerebral perfusion. However, in uncontrolled SAH, the increased SAP may cause more bleeding into the subarachnoid space and further increase the ICP. We created an animal model to simulate SAH by connecting a femoral arterial catheter to the subarachnoid space. The global cerebral blood flow (CBF) was measured with a venous outflow method. The purposes were to observe the CBF change under the simulated SAH, and to evaluate the effects of an adrenergic blocker and a vasodilator. In addition, spectral analysis of the aortic pressure and flow was employed for the analysis of hemodynamic changes at various ICP levels. When the femoral arterial blood was allowed to flow into the subarachnoid space, the ICP was elevated. The Cushing response to increased ICP caused an increase in SAP. A vicious cycle was generated between ICP and SAP. The CBF under the vicious cycle was greatly depressed. The dog developed pulmonary edema (PE) within 5 mins. An alpha-adrenergic blocker (phentolamine) and a vasodilator (nitroprusside) were beneficial to the reduction of SAP and ICP, improvement of CBF, and prevention of PE. Hemodynamic analysis revealed that graded increases in ICP caused increases in SAP, total peripheral resistance, arterial impedance, and pulse reflection with decreases in stroke volume, cardiac output and arterial compliance. The hemodynamic changes may contribute to acute left ventricular failure that leads to pressure and volume loading in the lung circulation, and finally acute PE.

Microelectrode recording can be a good adjunct in magnetic resonance image-directed subthalamic nucleus deep brain stimulation for parkinsonism.

BACKGROUND: The contribution of MER to improving bilateral STN-DBS is debatable. To resolve the controversy and elucidate the role of MER in DBS, we compared the outcome of bilateral STN-DBS surgery with and without MER in parkinsonian patients. METHODS: From February 2002 to November 2002, the first 7 of 13 consecutive parkinsonian patients received STN-DBS without MER (group A), and the last 6 received STN-DBS with MER (group B). Pre- and postoperative assessments included scoring of UPDRS with video taping, and MR images. RESULTS: The mean Hoehn and Yahr stage was 3.6 in group A and 4.0 in group B. The mean follow-up was 7.4 months for group A and 5.3 months for group B. The mean coordinates of the tip of the permanent electrode relative to the mid-commissural point were x = 8.1 mm, y = 4.3 mm, and z = 5.9 mm for group A and x = 10.6 mm, y = 4.1 mm, and z = 6.9 mm for group B. When levodopa was withdrawn from group A for 12 hours at follow-up, the postoperative UPDRS total score improved by 27.6% (P = .01) and the motor score by 25.4% (P = .02); their LEDD decreased by 17.5% (P = .03). In group B, the postoperative UPDRS total score improved by 49.3% (P = .00002) and the motor score by 45.2% (P = .0004); LEDD decreased by 48.5% (P = .01). CONCLUSIONS: Although STN-DBS is a promising surgical modality for advanced parkinsonian patients, there is an inevitable learning curve associated with adopting this new procedure. Intraoperative MER is an effective way to ensure correct electrode placement in the STN. With the assistance of intraoperative MER, the outcome of STN-DBS can be improved significantly.

Sympathetic and parasympathetic activities evaluated by heart-rate variability in head injury of various severities.

OBJECTIVE: To investigate the autonomic function in patients with brain damage of various extents. The purposes were to correlate the parameters derived from spectral analysis of the heart-rate variability (HRV) with the classic Glasgow coma scale (GCS), and to evaluate the possible clinical application of HRV in the autonomic functions in patients with various severities of brain-stem injury. METHODS: A total of 90 patients was divided into 5 groups based on the GCS: I: 15, II: 9-14, III: 4-8, no pupil dilatation, IV: 4-8, pupil dilatation, and V: 3, brain death. Electrocardiogram was recorded for frequency-domain analysis of RR intervals. HRV were categorized into the low-frequency (LF, 0.04-0.15Hz) and high-frequency power (HF, 0.15-0.40Hz), LF to HF power ratio (LF/HF), normalized powers (LF and HF%). These HRV parameters were correlated with the severity of brain damage. RESULTS: The LF, HF, LF%, and LF/HF in Group I were essentially similar to those in the normal subjects. LF and HF decreased from Group I to IV. All parameters were nearly absent in Group V. CONCLUSIONS: The increases in LF% and LF/HF with the decrease in HF indicate augmented sympathetic and attenuated parasympathetic drive. These changes were related to the severity of brain-stem damage. Both LF and HF were nearly abolished in brain death. SIGNIFICANCE: Our analysis indicates that HRV may be an useful tool for evaluating the autonomic functions in patients with brain damage of various degrees.

Primary angiosarcoma of the cranial vault: a case report and review of the literature.

BACKGROUND: Angiosarcoma is a rare neoplasm. It is most likely to affect the scalp in elderly people and involvement of the cranium is uncommon. We report a case of primary malignant angiosarcoma of the cranial vault. CASE DESCRIPTION: An 82-year-old man presented with right hemiparesis, deformity of the cranium and mildly swollen scalp. Further studies disclosed bilateral parietal lesions, with destruction of the dura matter and infiltration of the brain parenchyma. Thrombocytopenia was found. Faint enhancement of the lesions was seen on magnetic resonance imaging (MRI) after i.v. administration of contrast medium with gadolinium. The tumor was excised including the affected portion of the skull and dura matter. Histologic examination revealed typical pictures of angiosarcoma with immunohistochemical evidence of factor VIII-related antigen. Postoperative radiotherapy was employed. The patient remained well at 10 months postoperative follow up. CONCLUSION: Primary angiosarcoma of the cranium is sometimes difficult to differentiate from trauma on clinical examination. We review the literature pertaining to the pathogenesis, clinical course and treatment of this condition. Determination of platelet count may be helpful in monitoring the progression of the disease. The tumor may show faint enhancement on MRI.

Cough induced by ossification of the ligamentum flavum in the high cervical spine. Case report.

The authors report a very rare case of high cervical ossification of the ligamentum flavum (OLF) in a 40-year-old woman who developed an intractable cough after a traffic accident. The patient's symptoms subsided immediately after decompressive laminectomy and removal of the lesion. To the authors' knowledge, this is the first reported case of high cervical OLF in a patient who presented with a cough. The pathophysiological mechanism underlying the cough was determined to be symptomatic of high cervical spine OLF.

Acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) can be associated with various disorders. Among these, coronavirus infection may cause life-threatening severe acute respiratory syndrome (SARS). In this review, we present animal models and techniques for the study of ARDS, and discuss the roles and possible mechanisms of various chemical factors, including nitric oxide (NO). Our early work revealed that cerebral compression elicits severe hemorrhagic pulmonary edema (PE), leading to central sympathetic activation that results in systemic vasoconstriction. The consequence of systemic vasoconstriction is volume and pressure loading in the pulmonary circulation. Vasodilators, but not oxidant radical scavengers, are effective in the prevention of centrogenic PE. In isolated perfused lung, exogenous and endogenous NO enhances lung injury following air embolism and ischemia/reperfusion. In contrast, NO synthase (NOS) inhibitors reverse such lung injury. Although NO is important in maintaining vasodilator tone, hypoxia-induced pulmonary vasoconstriction is accompanied by an increase instead of a decrease in NO release. In animal and isolated lung studies, endotoxin produces acute lung injury that is associated with increases in cytokines and inducible NOS mRNA expression, suggesting that NO is toxic to the lung in endotoxin shock. Recently, we reported several rare cases that indicate that ARDS in patients with Japanese B encephalitis, lymphangitis with breast cancer and fat embolism is caused by different mechanisms. Our early and recent studies on ARDS and PE may provide information for clinical practice and the understanding of the pathogenesis of SARS.