Factors associated with recurrent transient global amnesia: systematic review and pathophysiological insights.

The examination of the risk factors that affect the recurrence of transient global amnesia (TGA) may shed light on the pathophysiological substrate of the disease. A systematic review was performed to identify the factors associated with the recurrence of TGA. MEDLINE, EMBASE, CENTRAL and PsycINFO were meticulously searched. Observational controlled studies involving patients with single (s-TGA) and recurrent TGA (r-TGA) according to Hodges and Warlow's criteria were retrieved. Differences in the demographic characteristics, personal and family medical history, previous exposure to precipitating events and laboratory findings were examined. Retrieved evidence was assessed in the context of the individual article validity, based on the numerical power and methodological quality of each study. Nine cohort studies with retrospective, prospective or mixed design were retrieved. In total, 1989 patients with TGA were included, 269 of whom suffered from r-TGA (13.5%). R-TGA presented an earlier age of onset. Evidence was suggestive of a relationship between recurrence and a family or personal history of migraine, as well as a personal history of depression. There was weaker evidence that associated recurrence with a positive family history of dementia, a personal history of head injury and hippocampal lesions in diffusion-weighted MRI. On the other hand, no connection was found between recurrence and electroencephalographic abnormalities, impaired jugular venous drainage, cardiovascular risk factors, atrial fibrillation, previous cerebrovascular events, exposure to precipitating events, a positive family history of TGA and hypothyroidism. Important pathophysiological insights that arised from these findings were discussed.

Conventional cardiovascular risk factors in Transient Global Amnesia: Systematic review and proposition of a novel hypothesis.

Transient Global Amnesia (TGA) is an enigmatic amnestic syndrome. We conducted a systematic review to investigate the relationship between the conventional cardiovascular risk factors and TGA. MEDLINE, CENTRAL, EMBASE and PsycINFO were comprehensively searched and 23 controlled observational studies were retrieved. The prevalence of hypertension, diabetes mellitus, dyslipidemia and smoking was lower among patients with TGA compared to Transient Ischemic Attack. Regarding the comparison of TGA with healthy individuals, there was strong evidence suggesting a protective effect of diabetes mellitus on TGA and weaker evidence for a protective effect of smoking. Hypertension was associated with TGA only in more severe stages, while dyslipidemia was not related. In view of these findings, a novel pathophysiological hypothesis is proposed, in which the functional interactions of Angiotensin-II type-1 and N-methyl-D-aspartate receptors are of pivotal importance. The whole body of clinical evidence (nature of precipitating events, associations with migraine, gender-based association patterns) was integrated.

The long-term prognosis of Transient Global Amnesia: a systematic review.

Transient Global Amnesia (TGA) constitutes an enigmatic amnestic condition. In view of the admittedly limited knowledge regarding the nature of TGA, we decided to systematically review existing evidence for the generally regarded benign course of the disease. MEDLINE, EMBASE, CENTRAL and PsycINFO were searched for relevant articles. Observational (case-control, cross-sectional and cohort) controlled studies were retrieved. TGA diagnosis was made according to the diagnostic criteria of Caplan, validated by Hodges and Warlow. The TGA group was compared with either healthy controls (HC) or/and individuals with transient ischaemic attacks (TIA). The long-term risks of dementia, epilepsy, psychological-emotional disturbances, as well as long-term vascular and (vascular or nonvascular) mortality risks, were evaluated. Quality assessment was based on the Newcastle-Ottawa Scale. Literature search provided 12 eligible articles. Retrospective, prospective or mixed cohort designs were implemented in every study. Five articles registered a high quality, five registered a moderate quality, while two articles were assessed as part of the grey literature (conference abstract, abstract in English-article in Spanish). Overall, retrieved evidence was suggestive of similar vascular and mortality risks in TGA patients and HC, while TIA individuals exhibited elevated risks. Moreover, psychological disturbances were comparable between TGA and healthy individuals. On the other hand, studies for dementia and epilepsy obtained contradictory results, indicating both a similar and an increased risk in the TGA group compared to the HC group. Therefore, additional high-quality studies are warranted for the acquisition of more determining conclusions regarding the long-term risk of dementia and epilepsy in TGA.

High prevalence of elevated liver enzymes in blood donors: associations with male gender and central adiposity.

OBJECTIVE: Nonalcoholic fatty liver disease is an increasingly recognized condition, but its exact prevalence is unknown. In this prospective, multicenter study, we evaluated the prevalence of elevated alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl-transpeptidase levels as indirect markers of nonalcoholic fatty liver disease in volunteer blood donors as well as their associations with epidemiological and anthropometrical characteristics. METHODS: Alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl-transpeptidase levels were determined in blood donors from four transfusion centers during the morning sessions of a 3-month period. Cases with positive hepatitis B surface antigen, anti-hepatitis C virus, anti-HIV or elevated liver enzymes and alcohol abuse were excluded. RESULTS: Abnormal liver enzymes were found in 17.6% of 3063 participants (alanine aminotransferase: 14.5%, aspartate aminotransferase: 4.6%, gamma-glutamyl-transpeptidase: 4.7%). Individuals with abnormal compared with those with normal liver enzymes or alanine aminotransferase values were more frequently men and had higher weight, body mass index, waist, hip and neck circumference (P<0.001 for all comparisons). The prevalence of abnormal liver enzymes was also associated with the transfusion center ranging between 8.8 and 22.1% (P<0.001) and alcohol consumption (P=0.001). In multivariate analysis, presence of elevated enzymes was independently associated with male sex, higher weight or body mass index, higher waist circumference and transfusion center. CONCLUSIONS: More than 15% of Greek blood donors exhibit elevated liver enzymes, most likely as a result of unrecognized nonalcoholic fatty liver disease. The prevalence of nonalcoholic fatty liver disease is mainly associated with male sex, obesity and waist circumference, but it may range significantly among different population groups.

A viral kinetic study using pegylated interferon alfa-2b and/or lamivudine in patients with chronic hepatitis B/HBeAg negative.

We studied viral dynamic parameters in 44 chronic hepatitis B/hepatitis B e antigen (HBeAg)(-) patients treated with pegylated interferon alfa-2b (PEG-IFN) 100 or 200 microg weekly or lamivudine 100 mg daily or the combination of PEG-IFN 100 or 200 microg with lamivudine. Patients receiving PEG-IFN monotherapy exhibited viral load oscillations between weekly injections, which were resolved by the addition of lamivudine. The median pharmacological delay was estimated at 4.1, 5.8, and 1.8 hours in PEG-IFN monotherapy, PEG-IFN 100/200 microg + lamivudine, and lamivudine monotherapy, respectively (P = .44). The median half-life of free virus was 12.7 hours (range, 2.4-69.2 hours). The mean antiviral effectiveness of PEG-IFN 100/200 microg monotherapy was lower than that of lamivudine (82.6% vs. 96.4%; P = .005). The mean effectiveness of PEG-IFN 100 microg + lamivudine and PEG-IFN 200 microg + lamivudine was 92.8% and 94.4%, respectively. The half-life of infected cells ranged from 2.7 to 75 days. The median half-life of infected cells in patients receiving the combination regimens of PEG-IFN and lamivudine was similar to that of lamivudine patients (5.0 days vs. 6.0 days, P = .77). In conclusion, the addition of pegylated interferon alfa-2b in lamivudine treatment was found to neither enhance the potency of blocking HBV production nor the decay rates of infected cells. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html).