1/5. Distinct behavioral and EEG topographic correlates of loss of consciousness in absences.PURPOSE: To describe the behavioral and EEG topographic correlates of absences with 3-Hz generalized spike-waves and partitioned impairment of consciousness. methods: Two adult women had so-called "phantom" absences, characterized by brief and mild impairments of consciousness that were previously inconspicuous to both patient and physician. Neuropsychological examination was performed under video-EEG monitoring during absence status. EEG topographic mapping of spike-wave discharges was obtained in the two cases. RESULTS: Only mild attentional and executive disturbances were observed during absence status despite prolonged discharges. Spike-wave bursts were associated with selective impairment in the initiation of response and self-generated action, whereas short-term storage of external information during discharges was fully preserved. This is consistent with a predominant involvement of frontomesial cortex demonstrated by topographic mapping of spike-wave discharges in the two cases. By contrast, in two other patients with typical absences and a complete lack of retention for information given during the discharges, topographic mapping found a more lateral frontal involvement by spike-wave activity. CONCLUSIONS: Different types of absence seizures may impair distinct components of conscious behavior. A predominant involvement of frontomesial thalamocortical circuitry may underlie an "inconspicuous" disorder of consciousness as seen in phantom absences with selective loss of initiation and goal-oriented behavior, whereas involvement of more lateral frontal areas in typical absences may additionally disrupt working memory processes.- - - - - - - - - - ranking = 1keywords = physician (Clic here for more details about this article) |
2/5. Algorithm for evaluation and disposition of a single episode of loss of consciousness.The presentation of a solitary episode of loss of consciousness in aviators presents a challenge to the aerospace physician, who has certain vital obligations to fulfill: to find the cause of loss of consciousness; to find the likely pathology; and to make a decision about fitness for flying duties. Evaluation of loss of consciousness focuses on three systems: the cardiovascular system; the central nervous system; and the mental functioning. If an abnormality is found in any of the three systems, specific evaluation and treatment is warranted. However, if no pathophysiology is found, aeromedical disposition of such a case is determined by three questions. Is it a case of syncope? If it is indeed syncope, is it vaso-vagal syncope (VVS) or something more sinister? If it is VVS, is it likely to recur in flight? VVS may be a one-time occurrence due to sudden cessation of blood supply to the brain and is the most common cause of loss of consciousness. Correct diagnosis of VVS, while a daunting task, can be made possible by proper attention to history, clinical examination, and relevant clinical investigations. Once diagnosed, a single episode of VVS is considered compatible with flying duties. Two cases of loss of consciousness in different settings have been presented to highlight the dilemmas faced by an aerospace physician. An algorithm for evaluation of cases with a solitary episode of loss of consciousness is also suggested.- - - - - - - - - - ranking = 2keywords = physician (Clic here for more details about this article) |
3/5. Prolonged unconsciousness in a patient with End-stage Renal disease.patients with End-stage Renal disease being immunocompromised; are prone to a variety of infections, sometimes, rare ones, more than the general population. This fact should alert the physicians to be more vigilant and have a broader scope when considering the etiology of infections in such patients. We report the case of a 65-year-old man who had a very stormy hospital stay secondary to cerebral nocardiosis with multiple brain abscesses, prolonged unconsciousness and neurological deficits. However, the patient was treated successfully, surgically and chemotherapeutically. He was discharged home in a good condition.- - - - - - - - - - ranking = 1keywords = physician (Clic here for more details about this article) |
4/5. Concussion in sports. Guidelines for the prevention of catastrophic outcome.Concussion (defined as a traumatically induced alteration in mental status, not necessarily with loss of consciousness) is a common form of sports-related injury too often dismissed as trivial by physicians, athletic trainers, coaches, sports reporters, and athletes themselves. While head injuries can occur in virtually any form of athletic activity, they occur most frequently in contact sports, such as football, boxing, and martial arts competition, or from high-velocity collisions or falls in basketball, soccer, and ice hockey. The pathophysiology of concussion is less well understood than that of severe head injury, and it has received less attention as a result. We describe a high school football player who died of diffuse brain swelling after repeated concussions without loss of consciousness. Guidelines have been developed to reduce the risk of such serious catastrophic outcomes after concussion in sports.- - - - - - - - - - ranking = 1keywords = physician (Clic here for more details about this article) |
5/5. prazosin-induced first-dose phenomenon possibly associated with hemorrhagic stroke: a report of three cases.A small initial dose of prazosin ranging from 0.5 to 1 mg has been recommended to avoid the first-dose phenomenon characterized by a sudden and severe drop in blood pressure after the administration of the first dose of prazosin. However, even with an initial dose of 0.5 mg, hypotension with consciousness disturbance developed in three hypertensive patients with recent cerebral hemorrhage. We present this report to alert physicians and pharmacists about the potential risk of the first-dose phenomenon even at the recommended initial doses of prazosin in hypertensive patients who have suffered a recent stroke.- - - - - - - - - - ranking = 1keywords = physician (Clic here for more details about this article) |