Annals of neurology
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Annals of neurology · May 2012
Anesthetics isoflurane and desflurane differently affect mitochondrial function, learning, and memory.
There are approximately 8.5 million Alzheimer disease (AD) patients who need anesthesia and surgery care every year. The inhalation anesthetic isoflurane, but not desflurane, has been shown to induce caspase activation and apoptosis, which are part of AD neuropathogenesis, through the mitochondria-dependent apoptosis pathway. However, the in vivo relevance, underlying mechanisms, and functional consequences of these findings remain largely to be determined. ⋯ These findings suggest that desflurane could be a safer anesthetic for AD patients as compared to isoflurane, and elucidate the potential mitochondria-associated underlying mechanisms, and therefore have implications for use of anesthetics in AD patients, pending human study confirmation.
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Annals of neurology · May 2012
Thrombolysis with recombinant tissue plasminogen activator under dabigatran anticoagulation in experimental stroke.
Anticoagulation with dabigatran etexilate (DE) has a favorable risk-to-benefit profile for the prevention of ischemic events in patients with atrial fibrillation compared to warfarin. Whereas warfarin constitutes a strong contraindication for thrombolysis, it is unclear whether patients anticoagulated with DE can be thrombolysed. We compared the risk of thrombolysis-associated hemorrhagic transformation (HT) after pretreatment with DE or warfarin in a mouse model of ischemic stroke. ⋯ Our experimental data suggest that the risk of thrombolysis-associated HT may not be increased under DE pretreatment with standard doses leading to plasma levels of up to 400 ng/ml, a concentration that was not exceeded in the majority of DE trial patients. At higher DE plasma levels, however, the risk of severe HT rises considerably, emphasizing the need for a readily available assay of DE anticoagulant activity.
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Annals of neurology · Apr 2012
Practice GuidelineGuidelines for the determination of brain death in infants and children: an update of the 1987 task force recommendations-executive summary.
To review and revise the 1987 pediatric brain death guidelines. ⋯ (1) Determination of brain death in term newborns, infants, and children is a clinical diagnosis based on the absence of neurologic function with a known irreversible cause of coma. Because of insufficient data in the literature, recommendations for preterm infants <37 weeks gestational age are not included in these guidelines. (2) Hypotension, hypothermia, and metabolic disturbances should be treated and corrected, and medications that can interfere with the neurologic examination and apnea testing should be discontinued allowing for adequate clearance before proceeding with these evaluations. (3) Two examinations including apnea testing with each examination separated by an observation period are required. Examinations should be performed by different attending physicians. Apnea testing may be performed by the same physician. An observation period of 24 hours for term newborns (37 weeks gestational age) to 30 days of age and 12 hours for infants and children (>30 days to 18 years) is recommended. The first examination determines the child has met the accepted neurologic examination criteria for brain death. The second examination confirms brain death based on an unchanged and irreversible condition. Assessment of neurologic function after cardiopulmonary resuscitation or other severe acute brain injuries should be deferred for 24 hours or longer if there are concerns or inconsistencies in the examination. (4) Apnea testing to support the diagnosis of brain death must be performed safely and requires documentation of an arterial PaCO(2) 20mmHg above the baseline and ≥60mmHg with no respiratory effort during the testing period. If the apnea test cannot be safely completed, an ancillary study should be performed. (5) Ancillary studies (electroencephalogram and radionuclide cerebral blood flow) are not required to establish brain death and are not a substitute for the neurologic examination. Ancillary studies may be used to assist the clinician in making the diagnosis of brain death (a) when components of the examination or apnea testing cannot be completed safely due to the underlying medical condition of the patient; (b) if there is uncertainty about the results of the neurologic examination; (c) if a medication effect may be present; or (d) to reduce the interexamination observation period. When ancillary studies are used, a second clinical examination and apnea test should be performed, and components that can be completed must remain consistent with brain death. In this instance, the observation interval may be shortened, and the second neurologic examination and apnea test (or all components that are able to be completed safely) can be performed at any time thereafter. (6) Death is declared when these above criteria are fulfilled.
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Annals of neurology · Apr 2012
FXN methylation predicts expression and clinical outcome in Friedreich ataxia.
Friedreich ataxia (FA) is the most common ataxia and results from an expanded GAA repeat in the first intron of FXN. This leads to epigenetic modifications and reduced frataxin. We investigated the relationships between genetic, epigenetic, and clinical parameters in a large case-control study of FA. ⋯ These novel findings provide compelling evidence for the link between the GAA expansion, the DNA methylation profile, FXN expression, and clinical outcome in FA. Epigenetic profiling of FXN could be used to gain greater insight into disease onset and progression, but also as a biomarker to learn more about specific treatment responses and pharmacological mechanism(s). This work also highlights the potential for developing therapies aimed at increasing frataxin levels to treat this debilitating disease.