Increased serum concentrations of tissue plasminogen activator correlate with an adverse clinical outcome in patients with bacterial meningitis

Movement Disorder in Demyelinating Disease: Tracing the Charcot's Foot Print

Movement disorders may be one of the neurological manifestations of demyelinating disorders. They can manifest in Parkinsonism or a wide spectrum of hyperkinetic movement disorders including tremor, paroxysmal dyskinesia, dystonia, chorea, and ballism. Some of these disorders occur during an acute episode of demyelination, whereas others can develop later or even may precede the onset of the demyelinating disorders. The pathophysiology of movement disorders in demyelination is complex and the current evidence indicates a wide involvement of different brain networks and spinal cord. Treatment is mainly symptomatic and oral pharmacological agents are the mainstay of the management. Botulinum toxin and neurosurgical interventions may be required in selected patients.

Mini-Review: Bioactivities of Bacterial Cell Envelopes in the Central Nervous System

During acute bacterial meningitis, recognition of the bacterial envelope by immune cells of the central nervous system (CNS) generates a robust response that is essential to clear bacteria. This response is further amplified during treatment when lytic antibiotics, required for cure, also generate a burst of highly inflammatory cell envelope debris. Different peptidoglycan (PG) subcomponents interact with neurons, glia, and the blood brain barrier resulting in the entire symptom complex of meningitis. Recently, this CNS-cell envelope signaling axis has been extended to non-inflammatory recognition of cell wall components circulating from endogenous bacteria to the brain resulting in both benefit and chronic damage. This review will describe the molecular details of a broad array of cell envelope-induced responses in the CNS and what current strategies can be implemented to improve clinical outcome.

A Pragmatic Biomarker-Driven Algorithm to Guide Antibiotic Use in the Pediatric Intensive Care Unit: The Optimizing Antibiotic Strategies in Sepsis (OASIS) Study

BACKGROUND.

Biomarkers that identify critically ill children with systemic inflammatory response syndrome (SIRS) at low risk for bacterial infection may help clinicians reduce unnecessary antibiotic use.

METHODS.

We conducted a prospective cohort study of children with SIRS and suspected infection admitted to a pediatric intensive care unit from January 5, 2012 to March 7, 2014. We enrolled patients upon initiation of new antibiotics (Time 0) and measured a panel of 8 serum biomarkers daily over 72 hours. Microbiology, imaging, and clinical data were reviewed to classify bacterial infections using Centers for Disease Control and Prevention definitions. We identified cut points of biomarker combinations to maximize the negative predictive value (NPV) and specificity for bacterial infection. Excess antibiotics were calculated as days of therapy beyond day 2 after SIRS onset in patients without bacterial infection.

RESULTS.

Infections were identified in 46 of 85 patients: bacterial (n = 22) and viral (24), whereas 39 patients had no infection identified. At Time 0, C-reactive protein (CRP) <5 mg/dL plus serum amyloid A <15.0 µg/mL had an NPV of 0.92 (95% confidence interval [CI], 0.79-1.0) and specificity of 0.54 (95% CI, 0.42-0.66) to identify patients without bacterial infection, whereas CRP <4 mg/dL plus procalcitonin <1.75 ng/mL had an NPV of 0.90 (95% CI, 0.79-1.0) and specificity of 0.43 (95% CI, 0.30-0.55). Patients without bacterial infection received a mean of 3.8 excess days of therapy.

CONCLUSIONS.

Early measurement of select biomarkers can identify children with SIRS in whom antibiotics might be safely discontinued when there is no other objective evidence of infection at 48 hours.

Spinal segmental myoclonus as an unusual presentation of multiple sclerosis

Background

Unusual presentations of multiple sclerosis (MS) at onset may post a diagnostic dilemma to the treating neurologists. Spinal myoclonus is rare in MS and may lead to perform extensive investigations to rule out other etiologies affecting the spinal cord.

Case presentation

We described a 31-year-old male who presented with involuntary brief jerky movements of the left shoulder and arm with significant wasting of shoulder muscles. In retrospect, the patient had a progressive right leg weakness one year prior to his presentation. Needle electromyography confirmed the presence of rhythmic irregular burst discharges in motor units of muscles expanding from the third to the sixth cervical region with normal nerve conduction parameters. There was no evidence of cortically generated myoclonic jerks using time-locked electroencephalogram. Magnetic Resonance Imaging of the brain and cervical cord along with the presence of oligoclonal bands in cerebral spinal fluid confirmed the diagnosis of MS. Based on the history and progressive clinical features, a diagnosis of primary progressive MS was established.

Conclusion

Spinal myoclonus can be the presenting manifestation of MS in association with demyelinating plaques in the root exit zones of the spinal cord. Spinal myoclonus may pose a diagnostic challenge when it presented at the disease onset and especially in patients with progressive course at onset. Our patient represents the first reported primary progressive MS case in the literature with spinal myoclonus presentation.

The effect of recombinant tissue plasminogen activator on MMP-2 and MMP-9 activities in vitro

One of the most significant side effects during recombinant tissue plasminogen activator (rtPA) for acute stroke treatment is intracranial bleeding. Gelatinases [matrix metalloproteinase (MMP)-2 and MMP-9] are one of the agents involved in the blood-brain barrier destruction resulting in secondary bleeding into the ischemic area during stroke. Previous papers revealed that patients with high baseline MMP-9 serum level have higher risk of intracranial bleeding after thrombolytic therapy. Our objective was to evaluate rtPA influence on serum MMP-2 and MMP-9 activities in vitro. Nine sera obtained from healthy donors were applied for experiment. The commercially available rtPA (Actylise) were diluted with included solvent and additionally with phosphate-buffered saline (PBS) to get concentrations: 2, 4, 8, and 16 μg/ml. Next, 100 μl of serum was mixed with equal proportion with different concentrations of rtPA to obtain final rtPA concentrations: 1, 2, 4, and 8 μg/ml. The sera together with rtPA were incubated for 1 or 2 hours at 37 °C. The activity of gelatinases was estimated with zymography. The activities of MMP-9 (92 kDa) and MMP-2 (72 kDa) were increased by incubation with rtPA in a dose-dependent manner. Simultaneously, the activity of band at 200 kDa (MMP-9/MMP-9 homodimer) was decreased. The activity of gelatinases incubated for 2 hours was elevated in comparison with 1-hour incubation; however, the increase was observed even for sample without rtPA. In conclusion, this study showed that rtPA can increase the biological activity of MMP-2 and MMP-9 on posttranslational level.

Pathogenesis and pathophysiology of pneumococcal meningitis

Pneumococcal meningitis continues to be associated with high rates of mortality and long-term neurological sequelae. The most common route of infection starts by nasopharyngeal colonization by Streptococcus pneumoniae, which must avoid mucosal entrapment and evade the host immune system after local activation. During invasive disease, pneumococcal epithelial adhesion is followed by bloodstream invasion and activation of the complement and coagulation systems. The release of inflammatory mediators facilitates pneumococcal crossing of the blood-brain barrier into the brain, where the bacteria multiply freely and trigger activation of circulating antigen-presenting cells and resident microglial cells. The resulting massive inflammation leads to further neutrophil recruitment and inflammation, resulting in the well-known features of bacterial meningitis, including cerebrospinal fluid pleocytosis, cochlear damage, cerebral edema, hydrocephalus, and cerebrovascular complications. Experimental animal models continue to further our understanding of the pathophysiology of pneumococcal meningitis and provide the platform for the development of new adjuvant treatments and antimicrobial therapy. This review discusses the most recent views on the pathophysiology of pneumococcal meningitis, as well as potential targets for (adjunctive) therapy.

Coagulation, coma, and outcome in bacterial meningitis--an observational study of 38 adult cases

OBJECTIVES

The purpose of this study was to evaluate the epidemiology of intravascular coagulation in bacterial meningitis and to recognise the associations with disease severity and outcome.

METHODS

Thirty-eight consecutively admitted adult patients with microbiologically proven bacterial meningitis were observed prospectively for platelets count (PLT), platelets-decline (dPLT), prothrombin ratio (PTr), INR, and D-dimer levels during the first three days in relation to disease severity (Glasgow Coma Scale--GCS, APACHE-III) and outcome (Glasgow Outcome Scale--GOS).

RESULTS

The prevalence of activated coagulation measured by abnormal laboratory results varied respectively: PTr--30%, INR--36%, PLT--38%, dPLT--50%, and D-dimer--88%. Patients with GCS <9 at admission presented with laboratory results suggesting triggered coagulation: dPLT 48 vs. 15%/day (p=0.0246), INR 1.6 vs. 1.12 (p=0.0014), PTr 76 vs. 93% (p=0.0020). An unfavourable outcome (GOS 1-4) was observed in 42% of patients and was associated with: PLT <170 or >265 G/L (OR--24.4; p=0.0006), PTr <82% (OR--5.00; p=0.0388), INR >1.1 (OR--5.04; 0.0336), and D-dimer >850 ng/ml (OR--24.0; p=0.0033).

CONCLUSIONS

Coagulation was activated in a majority of patients with bacterial meningitis and related to coma and unfavourable outcome.

Procoagulant and fibrinolytic activity in cerebrospinal fluid from adults with bacterial meningitis

OBJECTIVES

This study investigated levels of coagulation and fibrinolysis factors in cerebrospinal fluid (CSF) from adults with bacterial meningitis in relation to development of brain infarction.

METHODS

CSF was collected from 92 adults with community-acquired bacterial meningitis, who participated in the prospective Dutch Meningitis Cohort Study; 8 patients with viral meningitis and 9 healthy control subjects. Levels of proteins involved in the coagulation cascade were determined by means of immunoassays.

RESULTS

Bacterial meningitis was accompanied by local activation of coagulation, as shown by significantly higher CSF soluble tissue factor (P<0.001) and prothrombin fragment F1+2 concentrations (P<0.001) as compared to viral meningitis patients and controls. This was accompanied by a significantly higher D-dimer formation (P<0.001). In addition, in bacterial meningitis fibrinolysis was attenuated, since CSF plasminogen activator inhibitor (PAI)-1 levels were significantly higher as compared to the controls (P=0.02). In patients with bacterial meningitis who developed brain infarction, CSF PAI-1 levels were higher than in those without infarction (P=0.04).

CONCLUSIONS

Activation of coagulation and attenuation of fibrinolysis in the CSF are important features of bacterial meningitis; the net effect on fibrin turnover may contribute to the development of brain infarction.

Thyroid diseases and cerebrovascular disease

BACKGROUND AND PURPOSE

Acute cerebral ischemia has been described in different diseases of the thyroid gland, and not only as a result of thyrotoxic atrial fibrillation and cardioembolic stroke. The purpose of this review is to summarize the studies on the relationship between thyroid diseases and cerebrovascular diseases, discussing the main findings for overt hyperthyroidism and hypothyroidism, as well as for subclinical thyroid dysfunction.

SUMMARY OF REVIEW

In overt hyperthyroidism, cardioembolic stroke is clearly associated to thyrotoxic atrial fibrillation, and in subclinical hyperthyroidism with serum thyroid-stimulating hormone levels <0.1 mU/L, the incidence of atrial fibrillation is increased. Although in vitro and in vivo studies indicate a hypercoagulability state in hyperthyroidism, there is insufficient evidence to prove that this state leads to an increased risk of cardiac emboli. However, the hypothesis that overt hyperthyroidism may cause acute cerebral venous thrombosis is intriguing. Possible associations between hyperthyroidism and Moyamoya or Giant cell arteritis have only been described in case reports. There is enough evidence that overt hypothyroidism is associated with several traditional and newer atherosclerotic risk factors, especially hypertension, hyperlipidemia, and hyperhomocysteinemia. For subclinical hypothyroidism, these associations are less certain. Hypothyroidism has been associated with signs of aortic or coronary atherosclerosis, but no case-control or cohort studies have ever investigated hypothyroidism as a possible risk factor for atherothrombotic stroke.

CONCLUSIONS

Hyperthyroidism is associated with atrial fibrillation and cardioembolic stroke. Hypothyroidism is associated with a worse cardiovascular risk factor profile and leads to progression of atherosclerosis. Associations between hyperthyroidism and acute cerebral venous thrombosis, Moyamoya, and Giant cell arteritis have been suggested, but sound evidence is lacking. Additional studies are needed to clarify these issues.