Annals of the New York Academy of Sciences
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Familial episodic ataxias are inherited channelopathies that manifest as episodes of vertigo and ataxia triggered by emotional stress and physical exertion. Mutations in two neuronal ion-channel genes KCNA1 and CACNA1A abundantly expressed in the cerebellum account for the majority of the identified cases of episodic ataxia. Overlapping features between episodic ataxia and the more common recurrent vertigo and ataxia syndromes, particularly those associated with migraine, suggest shared underlying mechanisms. ⋯ Given the familial aggregation of migraine and migrainous vertigo, our objective was to identify predisposing genetic factors. Preliminary findings demonstrate that migrainous vertigo is genetically heterogeneous and complex. Efforts are ongoing to perform genomewide association studies to identify risk alleles for migrainous vertigo, which may also be relevant to migraine in general.
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The rickettsial diseases of Australia are described in their chronological order of discovery. The include epidemic typhus (R. prowazekii); murine typhus (R. typhi) found Australia-wide; scrub typhus (O. tsutsugamushi) only in tropical, northen Australia; Q. fever (C. burnetti) found Australia-wide; Queensland tick typhus (R. australis) along the east coast of Australia; Flinders Island spotted fever (R. honei) in southeast Australia; Variant Flinders Island spotted fever (R. honei, strain "marmionii") in eastern Australia; Rickettsia felis, Western Australia; eight new RFG rickettsiae from ticks (of unknown pathogenicity); and two nonhuman pathogens in A. platys (dogs) and A. marginale (cattle).
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Ann. N. Y. Acad. Sci. · May 2009
ReviewQ Fever during pregnancy: a cause of poor fetal and maternal outcome.
Q fever is a worldwide zoonosis caused by Coxiella burnetii. Q fever may be present as an acute or a chronic infection and can be reactivated during subsequent pregnancies. Although its exact prevalence remains unknown, it is likely that the number of cases of Q fever in pregnant women is underestimated. ⋯ Such treatment should be used to treat pregnant women with Q fever. Women with previous history of Q fever should have a regular serological follow up. Obstetricians' knowledge about Q fever must be improved.
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Expectations, positive or negative, are modulating factors influencing behavior. They are also thought to underlie placebo effects, potentially impacting perceptions and biological processes. We used sustained pain as a model to determine the neural mechanisms underlying placebo-induced analgesia and affective changes in healthy humans. ⋯ Both dopamine and opioid neurotransmission were related to expectations of analgesia and deviations from those initial expectations. When the activity of the nucleus accumbens was probed with fMRI using a monetary reward expectation paradigm, its activation was correlated with both dopamine, opioid responses to placebo in this region and the formation of placebo analgesia. These data confirm that specific neural circuits and neurotransmitter systems respond to the expectation of benefit during placebo administration, inducing measurable physiological changes.
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Ann. N. Y. Acad. Sci. · Mar 2009
ReviewExploring altered consciousness states by magnetic resonance imaging in brain injury.
Traumatic brain injury (TBI) occurs abruptly, involves multiple specialized teams, calls on the health-care system in its emergency dimension, and engages the well-being of the patient and his relatives for a lifetime period. Clinicians in charge of these patients are faced with issues of uppermost importance: medical issues such as predicting the long-term neurological outcome of the comatose patient; ethical issues because of the influence of intensive care on the long-term survival of patients in a vegetative and minimally conscious state; legal issues because of the law that has set the concept of proportionality of care as the legal rule; and social issues as the result of the very high cost of these pathologies. Today's larger availability of magnetic resonance imaging (MRI) in ventilated patients and the recent improvements in hardware and in imaging techniques that have made the last-developed imaging techniques such as diffusion tensor imaging and magnetic resonance spectroscopy available in brain-trauma patients, are changing the paradigm in neurointensive care regarding outcome prediction. ⋯ This major change opens new challenging ethical questions. This review focuses on the brain explorations that are required, such as MRI, magnetic resonance spectroscopy, and diffusion tensor imaging, to provide the clinician with a multimodal assessment of the brain state to predict outcome of coma. Such an assessment will become mandatory in the near future to answer the crucial question of proportionality of care in these patients.