Neurocritical care of patients with central nervous system infections

Neurological Complications of Childhood Cancer

Though the treatment of pediatric cancers has come a long way, acute and chronic effects of cancer are still affecting the life of many children. These effects may be caused not only by the malignancy itself but also by the interventions used for the purpose of treatment. This article focuses primarily on the indirect effects of pediatric cancers and their treatment on the central and peripheral nervous system. Chemotherapy, radiation, and stem cell transplantation cause an immune-compromised state and place the patient at risk of infection, the leading cause of mortality in pediatric cancer. The underlying cancer and the treatments also cause neurovascular changes that may lead to neurological sequelae immediately or many years in the future. Chemotherapy and radiation have both immediate and long-term neurotoxic effects on the central and peripheral nervous system. Cancers may also trigger an immune response that damages nervous system components, leading to altered mental status, seizures, abnormal movements, and even psychosis. Knowledge of these effects can help the practitioner be more vigilant for the signs and symptoms of potential neurological complications during the management of pediatric cancers.

Bacterial infections of the central nervous system

Bacterial CNS infections comprise a wide spectrum of diseases, which may be acquired outside or inside the hospital, affect immunocompetent or immunocompromised patients, and be associated with trauma or procedures, as well as other exposures.

Viral encephalitis in the ICU

Viral encephalitis causes an altered level of consciousness, which may be associated with fever, seizures, focal deficits, CSF pleocytosis, and abnormal neuroimaging. Potential pathogens include HSV, VZV, enterovirus, and in some regions, arboviruses. Autoimmune (eg, anti-NMDA receptor) and paraneoplastic encephalitis are responsible for some cases where no pathogen is identified. Indications for ICU admission include coma, status epilepticus and respiratory failure. Timely initiation of anti-viral therapy is crucial while relevant molecular and serological test results are being performed. Supportive care should be directed at the prevention and treatment of cerebral edema and other physiological derangements which may contribute to secondary neurological injury.

Decompressive craniectomy: past, present and future

Decompressive craniectomy (DC)--a surgical procedure that involves removal of part of the skull to accommodate brain swelling--has been used for many years in the management of patients with brain oedema and/or intracranial hypertension, but its place in contemporary practice remains controversial. Results from a recent trial showed that early (neuroprotective) DC was not superior to medical management in patients with diffuse traumatic brain injury. An ongoing trial is investigating the clinical and cost effectiveness of secondary DC as a last-tier therapy for post-traumatic refractory intracranial hypertension. With regard to ischaemic stroke (malignant middle cerebral artery infarction), a recent Cochrane review concluded that DC improves survival compared with medical management, but that a higher proportion of DC survivors experience moderately severe or severe disability. Although many patients have a good outcome, the issue of DC-related disability raises important ethical issues. As DC and subsequent cranioplasty are associated with a number of complications, indiscriminate use of this surgery is not appropriate. Here, we review the evidence and present considerations regarding surgical technique, ethics and cost-effectiveness of DC. Prospective clinical trials and cohort studies are essential to enable optimization of patient care and outcomes.

Neurointensive care of patients with severe community-acquired meningitis

BACKGROUND

Reports about neurointensive care of severe community-acquired meningitis are few. The aims of this retrospective study were to review the acute clinical course, management and outcome in a series of bacterial meningitis patients receiving neurointensive care.

METHODS

Thirty patients (median age 51, range 1-81) admitted from a population of 2 million people during 7 years were studied. The neurointensive care protocol included escalated stepwise treatment with mild hyperventilation, cerebrospinal fluid (CSF) drainage, continuous thiopentotal infusion and decompressive craniectomy. Clinical outcome was assessed using the Glasgow outcome scale.

RESULTS

Twenty-eight patients did not respond to commands on arrival, five were non-reacting and five had dilated pupils. Twenty-two patients had positive CSF cultures: Streptococcus pneumoniae (n=18), Neisseria meningitidis (n=2), β-streptococcus group A (n=1) and Staphylococcus aureus (n=1). Thirty-five patients were mechanically ventilated. Intracranial pressure (ICP) was monitored in 28 patients (intraventricular catheter=26, intracerebral transducers=2). CSF was drained in 15 patients. Three patients received thiopentothal. Increased ICP (>20 mmHg) was observed in 7/26 patients with available ICP data. Six patients died during neurointensive care: total brain infarction (n=4), cardiac arrest (n=1) and treatment withdrawal (n=1). Seven patients died after discharge, three due to meningitis complications. At follow-up, 14 patients showed good recovery, six moderate disability, two severe disability and 13 were dead.

CONCLUSION

Patients judged to have severe meningitis should be admitted to neurointensive care units without delay for ICP monitoring and management according to modern neurointensive care principles.

Efficacy of CMX001 against herpes simplex virus infections in mice and correlations with drug distribution studies

CMX001, an orally active lipid conjugate of cidofovir, is 50 times more active in vitro against herpes simplex virus (HSV) replication than acyclovir or cidofovir. These studies compared the efficacy of CMX001 to acyclovir in BALB/c mice inoculated intranasally with HSV types 1 or 2. CMX001 was effective in reducing mortality using doses of 5 to 1.25 mg/kg administered orally once daily, even when treatments were delayed 48-72 h post viral inoculation. Organ samples obtained from mice treated with CMX001 had titers 3-5 log(10) plaque-forming units per gram of tissue lower than samples obtained from mice treated with acyclovir, including 5 different regions of the brain. Detectable concentrations of drug-related radioactivity were documented in the central nervous system of mice after oral administration of (14)C-CMX001. These studies indicate that CMX001 penetrates the blood-brain barrier, is a potent inhibitor of HSV replication in disseminated infections and central nervous system infections, and is superior to acyclovir.

Wound botulism from heroin skin popping

Following the introduction of black tar heroin mainly from Mexico in the 1980s, cases of wound botulism dramatically increased in the western United States. Contamination with spores of Clostridium botulinum of black tar heroin occurs along the distribution line. The heating of heroin powder to solubilize it for subcutaneous injection ("skin popping") does not kill the spores. The spores germinate in an anaerobic tissue environment and release botulinum toxin type A or B. Unless skin abscesses are found in the patient, the clinical diagnosis is often challenging. Facilitation of the compound muscle action potential by repetitive nerve stimulation at 20 to 50 Hz is an important and rapid diagnostic test. Definite diagnosis is made by detection of botulinum toxin in serum or isolation of C botulinum from the abscess. Early treatment with equine ABE botulinum antitoxin obtained from the Centers for Disease Control and Prevention often shortens the time on a ventilator.

Infektionen

Trotz Weiterentwicklung moderner Antibiotika in den letzten Jahren sind die Letalitätszahlen der bakteriellen (eitrigen) Meningitis weiterhin hoch; Überlebende haben häufig neurologische Residuen. Die ungünstigen klinischen Verläufe der bakteriellen Meningitis sind meist Folge intrakranieller Komplikationen, wie z. B. eines generalisierten Hirnödems, einer zerebrovaskulären arteriellen oder venösen Beteiligung oder eines Hydrozephalus. Als Folge dieser Komplikationen kommt es häufig zu einem Anstieg des intrakraniellen Drucks. Bei schweren, komplizierten klinischen Verläufen der bakteriellen Meningitis kommen oft adjuvante Therapiemaßnahmen (z. B. intravenöse Gabe von hyperosmolaren Substanzen, externe Ventrikeldrainage) zum Einsatz. Bei Nachweis einer meningitisassoziierten septischen Sinus-/Venenthrombose erfolgt die dosisadaptierte intravenöse Heparintherapie.