Significance of serum neuron-specific enolase in transient global amnesia.

Neuron-specific enolase (NSE) is a glycolytic enzyme, which is associated with neuronal cell dysfunction in the brain. This study evaluated the role of serum NSE levels of patients with transient global amnesia (TGA). In addition, the relationship between serum NSE levels and the clinical features of TGA was explored. Forty-eight patients with TGA were prospectively included, and their serum NSE levels were measured. We investigated serum NSE levels in patients with TGA. In addition, we analyzed the differences in clinical characteristics between patients with elevated and normal serum NSE levels. Of the 48 patients with TGA, 16 patients (33.3%) had elevated serum NSE levels (25.0 ± 11.5 ng/mL), whereas 32 patients (66.7%) showed normal serum NSE levels (12.8 ± 2.1 ng/mL). The patients with elevated serum NSE levels exhibited higher levels of cognitive impairment than those with normal serum NSE levels (4/16 vs. 1/32, p = 0.036). The serum NSE levels showed a relatively high discrimination (AUC 0.684) between patients with and without cognitive impairment, with 80.0% sensitivity and 74.4% specificity at a cut-off value 17.3 ng/mL. A third of all patients with TGA carry elevated serum NSE levels, which suggests that the neuronal cell dysfunction could be associated with TGA pathogenesis. In addition, it might be correlated with cognitive impairment.

Serum cortisol levels in patients with a transient global amnesia.

Transient global amnesia (TGA) can be triggered by a high level of blood cortisol. We assessed whether patients had a higher level of cortisol during the TGA than shortly after. We included 52 patients, 21 with blood collected during the TGA episode and 31 shortly thereafter. We compared these two groups after adjustment for time of blood collection. The cortisol level was significantly higher in the per-ictal group (P=0.03) and negatively correlated with the time elapsed from symptom onset (P=0.005). The results are consistent with of the hypothesis of a hyperreactivity of the hypothalamic-pituitary-adrenal axis.

Myocardial injury in transient global amnesia: a case-control study.

BACKGROUND AND PURPOSE: Elevation of cardiac troponin (cTn), a sensitive biomarker of myocardial injury, is frequently observed in severe acute neurological disorders. Case reports suggest that cardiac dysfunction may also occur in patients with transient global amnesia (TGA). Until now, no study has systematically assessed this phenomenon. METHODS: We performed a case-control study using data of consecutive patients presenting with TGA from 2010 to 2015. Multiple logistic regression analysis accounting for age, sex and cardiovascular risk factors was performed to compare the likelihood of myocardial injury [defined as elevation of cTn > 99th percentile (≥14 ng/L); highly sensitive cardiac troponin T assay] in TGA with three reference groups: migraine with aura, vestibular neuritis and transient ischaemic attack (TIA). RESULTS: Cardiac troponin elevation occurred in 28 (25%) of 113 patients with TGA. Patients with TGA with cTn elevation were significantly older, more likely to be female and had higher blood pressure on admission compared with those without. The likelihood of myocardial injury following TGA was at least more than twofold higher compared with all three reference groups [adjusted odds ratio, 5.5; 95% confidence interval (CI), 1.2-26.4, compared with migraine with aura; adjusted odds ratio, 2.2; 95% CI, 1.2-4.4, compared with vestibular neuritis; adjusted odds ratio, 2.3; 95% CI, 1.3-4.2, compared with TIA]. CONCLUSIONS: One out of four patients with TGA had evidence of myocardial injury as assessed by highly sensitive cTn assays. The likelihood of myocardial injury associated with TGA was even higher than in TIA patients with a more pronounced cardiovascular risk profile. Our findings suggest the presence of a TGA-related disturbance of brain-heart interaction that deserves further investigation.

Cardiac troponin T elevation associated with transient global amnesia: another differential diagnosis of 'troponosis'.

Elevated cardiac troponin (cTn) levels can be detected in a variety of diseases with or without signs of myocardial ischaemia. Acute neurological disorders such as subarachnoid haemorrhage, stroke, transient ischaemic attack, epileptic seizures, and traumatic head injury can cause cTn elevation with and without myocardial wall motion abnormalities. We report a case of transient global amnesia with elevation and dynamic rise of highly sensitive troponin T (hsTnT) without clinical symptoms or signs of ischaemia. Cardiac work up was otherwise normal, with no signs of atherosclerotic coronary artery disease on coronary angiogram. Myocardial systolic function was also normal. In the era of highly sensitive cTn assays, dynamic elevations of cTn are seen in a number of acute conditions unrelated to myocardial ischaemia. Transient global amnesia should be added to the list of acute neurological disorders where cTn release can be present, even in the absence of stress-induced cardiomyopathy.

Recurrent orthostatic global amnesia in a patient with postoperative hyperfibrinogenemia.

Transient global amnesia (TGA) is characterized by sudden, temporary dysfunction of antegrade and recent retrograde memory without other neurologic deficits. Although there is sometimes a precipitating event, the origin of TGA remains controversial. We encountered a patient who developed recurrent TGA when upright, in whom the symptom promptly and regularly resolved when supine. Symptoms began about a week after cardiac surgery concurrent with marked hyperfibrinogenemia and acceleration of the erythrocyte sedimentation rate, and abated without recurrence when these laboratory abnormalities were ameliorated by anticoagulant and corticosteroid therapy. Diagnostic studies, including temporal artery biopsy and cerebral angiography, disclosed no anatomic vascular pathology. This is the first report of TGA associated with postoperative inflammation in which amnesia was provoked by orthostatic positioning. In conclusion, these observations implicate ischemia caused by hemodynamic vascular insufficiency as a possible cause of TGA.

Transient global amnesia in a patient with high and persistent levels of antiphospholipid antibodies.

Cerebrovascular disease is one of the most common symptoms associated with anticardiolipin antibodies (ACA) and lupus anticoagulant (LA), usually in the form of ischemic stroke. However, many other neurologic disorders have been described in patients with antiphospholipid syndrome or ACA. So far, the precise relation between the presence of antibodies and the development of the disease in many of these cases remain unknown. Transient global amnesia (TGA) is an infrequent neurologic disturbance whose precise pathophysiology is not known. It is characterized by a sudden inability to acquire new information, usually lasting no more than 12 h, and it is not accompanied by any other focal neurological signs or symptoms. We report a patient with TGA with persistent and high levels of ACA and LA and suggest that in patients with TGA, investigation of the possible presence of ACA and/or LA may be warranted because a higher prevalence of TGA in the patients with antiphospholipidic syndrome with respect to the general population may lead to further insights into pathogenesis of neurologic disease associated with antiphospholipidic antibodies.