Clinical experience of modified diffusion-weighted imaging protocol for lesion detection in transient global amnesia: an 8-year large-scale clinical study.

BACKGROUND AND PURPOSE: The detection rate of typical transient global amnesia (TGA) lesions on diffusion-weighted imaging (DWI) can be improved, up to 85% with optimal DWI parameters and imaging time. There is limited evidence that these findings are similar to those observed in large-scale consecutive patients with TGA in clinical practice. METHODS: Patients with clinically diagnosed TGA underwent magnetic resonance imaging studies, consecutively, with three sets of DWI parameters (standard clinical DWI protocols, the TGA DWI protocol I and the TGA DWI protocol II) in which the resolution, slice thickness, and the time interval between symptom onset of DWI were varied over an 8-year period. RESULTS: TGA lesion detection rates were up to 88% with a modified TGA DWI protocol. The lesion detection rate was the highest using TGA DWI protocol I, with b = 3,000 s/mm(2), a slice thickness of 3 mm, and performed on the third day after symptom onset, and TGA DWI protocol II, with b = 2,000 s/mm(2) and a slice thickness of 2 mm. CONCLUSIONS: A modified TGA DWI protocols for detecting TGA lesions are useful in large-scale clinical practice for confirming the diagnosis of TGA patients with clinical findings.

Low glomerular filtration rate increases hemorrhagic transformation in acute ischemic stroke.

BACKGROUND: Decreased glomerular filtration rate (GFR) can increase the risk of bleeding tendency and hemorrhagic stroke. However, the relationship between the levels of GFR and hemorrhagic transformation (HT) after acute ischemic stroke is largely unknown. The aim of this study was to assess whether GFR level is associated with HT in acute ischemic stroke. METHODS: We reviewed 770 consecutive patients with acute ischemic stroke within 7 days from September 2007 to February 2012 in a prospective stroke registry database. We calculated the patient's GFR using the Cockcroft-Gault equation, and divided them into 3 groups: ≥60, 30-59 and <30 ml/min/1.73 m(2). HTs were identified by follow-up computed tomography (CT) or magnetic resonance imaging, and were defined as (1) any degree of high density within the area of low attenuation of vascular territory on noncontrast brain CT, or (2) low-signal intensity area in gradient echo within high-signal intensity meaning acute infarct on diffusion-weighted imaging. Multivariable logistic regression analyses were used to estimate the risk of GFR for HT. Stratification analyses were done according to the presence of HT high risk factors: atrial fibrillation (AF), thrombolysis and large size infarction. Additional logistic regression model for symptomatic HTs was established with the same variables. RESULTS: HTs were noted in 131 patients (17.0%) and symptomatic HTs in 63 patients (8.2%). In univariate analysis, HTs were more frequent in patients with AF (51.9 vs. 16.7%, p < 0.001) and large-size infarction (42.0 vs. 5.3%, p < 0.001). The risk of HT was associated with decreased GFR among 3 subgroups classified according to the value of estimated GFR: 49/394 (12.4%) in the GFR ≥60 group, 66/312 (21.2%) in the 30≤ GFR <59 group and 16/64 (25.0%) in the GFR <30 group (p = 0.002). We found a significant association between the GFR <30 group and HTs in acute ischemic stroke (OR 2.90; 95% CI 1.26-6.68, p = 0.012) after adjusting for other risk factors. Moreover, the incidence of HTs was higher in the subgroups without thrombolysis (OR 3.49; 95% CI 1.44-8.46) and without AF (OR 3.44; 95% CI 1.10-10.76). Decreased GFR also had a tendency of increasing symptomatic HTs (OR 2.39; 95% CI 0.72-7.94, p = 0.154). CONCLUSIONS: Low levels of GFR are associated with a high risk of HT after acute ischemic stroke. Further studies are needed to elucidate whether HT in the patients with renal insufficiency are related to a worse outcome after acute ischemic stroke.

Associations of cigarette smoking with intracranial atherosclerosis in the patients with acute ischemic stroke.

BACKGROUND: Although cigarette smoking has been established as an important risk factor for stroke, the effect on the atherosclerotic stenosis, which are based on observational studies, have been controversial. We set out to examine the differences in the risk factors between smokers and nonsmokers and to investigate the association of cigarette smoking with cerebral arterial stenosis. METHODS: A total of 989 consecutive patients with acute noncardioembolic ischemic stroke were prospectively enrolled from June 2004 to January 2010. The risk factor profiles were compared between smokers and nonsmokers. We analyzed the degree of stenosis in all MRA, and evaluated influencing factors in the patients with intracranial atherosclerosis (ICAS) and extracranial atherosclerosis (ECAS) who were randomly matched by age and sex. RESULTS: There were differences in the distribution of risk factors between the 467 (70.0%) nonsmokers and the 215 (30.0%) smokers. Nonsmokers were older (71.7±11.0 versus 61.7±12.0, p<0.001) and had a higher frequency of hypertension than smokers had (75.4% versus 64.0%, p=0.002). When smokers and nonsmokers were age- and sex-matched, smoking was more prevalent in patients with ICAS than with ECAS (32.9% versus 28.2%). Conditional regression analysis revealed that smoking and hypertension increased the odds of ICAS [smoking, odds ratio (OR): 1.83, p=0.026; hypertension, OR: 1.84, p=0.01], whereas hyperlipidemia increased the odds of ECAS (OR: 1.87, p=0.034). CONCLUSION: The distributions of the major risk factors for ischemic stroke were different between smokers and nonsmokers. Cigarette smoking may be more associated with ICAS than with ECAS after adjusting for potential risk factors.

A case of cardiac cephalalgia showing reversible coronary vasospasm on coronary angiogram.

BACKGROUND: Under certain conditions, exertional headaches may reflect coronary ischemia. CASE REPORT: A 44-year-old woman developed intermittent exercise-induced headaches with chest tightness over a period of 10 months. Cardiac catheterization followed by acetylcholine provocation demonstrated a right coronary artery spasm with chest tightness, headache, and ischemic effect of continuous electrocardiography changes. The patient's headache disappeared following intra-arterial nitroglycerine injection. CONCLUSIONS: A coronary angiogram with provocation study revealed variant angina and cardiac cephalalgia, as per the International Classification of Headache Disorders (code 10.6). We report herein a patient with cardiac cephalalgia that manifested as reversible coronary vasospasm following an acetylcholine provocation test.

Transient urinary retention in acute right lateral medullary infarction.

Urinary disturbance has rarely been reported in patients with a medullary lesion. We evaluated a patient with acute infarction in the right lateral medulla who had voiding difficulty as an initial manifestation. Urodynamic study showed detrusor areflexia on voiding, and the voiding symptom completely recovered 2 weeks after the stroke onset. The urinary retention in this patient might be caused by interruption of descending fibers from facilitatory pontine tegmentum micturition centers.