Association between paroxysmal atrial fibrillation and the left atrial appendage ejection fraction during sinus rhythm in the acute stage of stroke: a transesophageal echocardiographic study.

BACKGROUND: This study aimed to investigate whether left atrial appendage (LAA) dysfunction evaluated by transesophageal echocardiography (TEE) during sinus rhythm is predictable of paroxysmal atrial fibrillation (PAF) as an embolic source in the acute stage of stroke. METHODS AND RESULTS: We measured and analyzed LAA flow velocity (LAA-FV) and LAA ejection fraction (LAA-EF) in 300 acute ischemic stroke patients by TEE. We divided the acute ischemic stroke patients into 3 groups. The atrial fibrillation (AF) group (n=58) comprised patients whose TEE was performed during AF rhythm. The PAF group (n=42) comprised patients with a history of AF but with normal sinus rhythm when TEE was performed. The normal sinus (sinus) group (n=200) did not have any history of AF. We found that mean LAA-FV and LAA-EF values in the PAF group were significantly lower than those in the sinus group (P<.001). The diagnostic accuracy of LAA-FV for the diagnosis of PAF calculated as the area under receiver operating characteristic curves was low (.582, 95% confidence interval [CI]=.498-.665) but that of LAA-EF was modest (.721, 95% CI=.653-.789), with an optimal cutoff point of 49.1%. CONCLUSIONS: LAA dysfunction as determined by TEE (LAA-EF<49.1%) in the acute stage of stroke is predictive of PAF with moderate accuracy. Long-term electrocardiographic monitoring is recommended for cryptogenic stroke patients with LAA dysfunction.

Case reports of unexpected suicides in patients within six months after stroke.

Suicide after stroke is a grievous occurrence. Since the majority of cases under study had shown signs of recovery from stroke, persons surrounding these patients were severely shocked by these suicides. Six patients who attempted suicide within six months after stroke were investigated to determine factors following stroke that relate to suicide in order to prevent future post-stroke suicides. Clinical findings in these six cases were retrospectively analyzed in collaboration with stroke neurologists and coworkers caring for these patients. Four of six patients had sustained a recent infarction extending from the temporal cortex to the parietal cortex. Four of six patients showed depression, and five of six patients showed moderate disability after stroke. Physicians should carefully observe patients with infarction extending from the temporal cortex to the parietal cortex, depression and moderate disability, in order to prevent suicidal behavior.

Isolated anterior cerebral artery territory infarction: dissection as an etiological mechanism.

BACKGROUND: Intracranial arterial lesions are important causes of ischemic stroke, particularly in the Asian population. Of the intracranial lesions, the etiology of isolated anterior cerebral artery (ACA) territory infarction is not fully elucidated. The purpose of this study was to determine the etiological and clinical characteristics of patients with isolated ACA territory infarction, especially those with ACA dissection. METHODS: Of 3,115 consecutive patients with acute ischemic stroke, 42 patients (1.3%, 30 men, 38-88 years old) having an isolated ACA territory infarction were studied. Infarcts were principally verified by diffusion-weighted MRI, and vascular lesions were identified by MRA, CTA, or digital subtraction angiography. Three-dimensional rotational angiography was performed if needed. RESULTS: Eighteen patients (43%) were diagnosed as having ACA dissection. The stroke subtypes of the other 24 patients included cardioembolism for 6 patients and large-artery atherosclerosis for 8. Patients with dissection were younger (p < 0.001) and heavier (p = 0.026), less commonly had heart disease (p = 0.002) and previous stroke (p = 0.002), and had lower initial systolic blood pressure (p = 0.029) and lower levels of D-dimer (p = 0.041) than patients without dissection. Stroke onset more commonly followed physical exertion (p = 0.013) and headache (p = 0.041) in patients with dissection than in patients without dissection. At hospital discharge, the modified Rankin scale score was lower in patients with dissection than in patients without dissection (p = 0.005). CONCLUSIONS: Arterial dissection was the most common vascular lesion underlying an isolated ACA territory infarction in our Japanese cohort. Patients with ACA dissection had unique baseline characteristics and unique conditions at stroke onset.

Paradoxical cerebral embolism causing internal carotid artery occlusion.

Paradoxical cerebral embolism (PCE) is defined to be a pathological condition in which emboli originating from the venous system reach the cerebral arterial circulation via the right-to-left (R-L) shunt. In patients with PCE, emboli originating from the venous system most commonly pass through the patent foramen ovale during Valsalva-provoking activities which increase the right atrial pressure above the left atrial pressure. The size of cerebral infarction caused by PCE is generally small, since the size of emboli which can pass through the R-L shunt is small. Here, we report a case of PCE which occluded the internal carotid artery (ICA).

Microembolic signals within 24 hours of stroke onset and diffusion-weighted MRI abnormalities.

BACKGROUND: The clinical relevance of the microembolic signals (MES) detected by transcranial Doppler sonography (TCD) in acute stroke remains unclear. In a prospective study the authors analyzed the relationship between MES and the findings on diffusion-weighted magnetic resonance imaging (DWI) in acute stroke patients. METHODS: We performed TCD for a period of 30 min to detect MES in patients within 24 h of stroke onset, and DWI was done within the initial 7 days. MES were assessed from Doppler waves obtained from the middle cerebral artery contralateral to the side of the neurological deficits. The acute ischemic lesions observed on DWI were classified by their diameter (small, medium or large) and by their site (cortical, superficial perforator territory, internal borderzone or deep perforator territory). RESULTS: We obtained Doppler waves from 39 vessels in 37 patients; 2 patients had bilateral deficits. MES were detected in 12 vessels (MES-positive group) and not detected in 27 vessels (MES-negative group). No significant differences in clinical features were observed between the 2 groups. The number of small lesions was significantly higher in the MES-positive group than in the MES-negative group (p = 0.02). The numbers of cortical and superficial perforator infarcts were significantly higher in the MES-positive group than in the MES-negative group (p = 0.002 and 0.02, respectively). CONCLUSION: In acute ischemic stroke, MES detected by TCD in the acute phase may produce small cortical and subcortical lesions found on DWI.