Kiminobu Yonemura

Small centrum ovale infarcts on diffusion-weighted magnetic resonance imaging.

Background and Purpose— A small centrum ovale infarct (SCOI), caused by occlusion of the white matter medullary arteries, is often equated with a lacunar infarct. We sought to clarify the clinical characteristics of a SCOI visualized by diffusion-weighted MRI (DWI) compared with those of a small basal ganglia infarct (SBGI). Methods— Patients with a SCOI (SCOI group; n=38) or SBGI (SBGI group; n=68) ≤15 mm in diameter on conventional MRI and DWI were selected from 582 consecutive patients with acute ischemic stroke. Sex, age, neurological symptoms, vascular risk factors, emboligenic heart disease, arterial occlusive disease in the ipsilateral carotid system, and recurrent stroke within the initial 30 days were compared between the 2 groups. Results— Only 47% of SCOIs but 87% of SBGIs could be identified with the use of conventional MRI, whereas DWI could detect them all. Age, sex, and vascular risk factors were not significantly different between the 2 groups. The SCOI group had more frequently an abrupt onset of symptoms (63% versus 26%;P =0.0002), emboligenic heart diseases (34% versus 12%;P =0.0054), occlusive carotid and/or middle cerebral artery diseases (53% versus 19%;P =0.0004), and recurrent stroke (13% versus 1%;P =0.0216) but less frequently a classic lacunar syndrome (50% versus 81%;P =0.0009) than the SBGI group. On a multivariate analysis, both arterial and heart diseases were independently associated with the SCOI group. Conclusions— Symptomatic SCOIs detected by DWI may be associated with large-vessel and heart diseases and should be distinguished from lacunar infarcts.

Oscillating thromboemboli within the extracranial internal carotid artery demonstrated by ultrasonography in patients with acute cardioembolic stroke

We detected oscillating thromboemboli at the extracranial internal carotid artery (ICA) by duplex carotid ultrasonography in patients with acute cardioembolic stroke. Using B-mode ultrasonography, we evaluated the extracranial ICA in 11 patients with acute cardioembolic ICA occlusion. A homogeneous, elastic, oscillating intraluminal mass echo originating in the extracranial ICA extended distally in 5 (46%) of these patients. The echoes moved quickly and distally during the systolic phase of the cardiac cycle and returned slowly to the original position during the diastolic phase. We performed a postmortem study 24 days after stroke onset in 1 patient with an oscillating intraluminal mass echo that had been demonstrated by duplex ultrasonography. The ICA lumen was obstructed with a fresh string-like thrombus. The findings of oscillating intraluminal mass echo may help establish a diagnosis of acute embolic ICA occlusion.

Lesions visualized by contrast-enhanced magnetic resonance imaging in transient ischemic attacks.

In patients with transient ischemic attacks (TIAs), contrast-enhanced magnetic resonance imaging (MRI) is more sensitive to visualize the recent ischemic lesions than conventional MRI. We examined the clinical characteristics of TIA patients presenting with enhanced lesions visualized by contrast-enhanced MRI. We retrospectively evaluated 64 patients with carotid TIAs. We evaluated the frequency and topography of TIA associated infarcts on contrast-enhanced MRI and compared the clinical background of patients with and without such lesions. Twenty-three patients underwent plain MRI only, while the remaining 41 patients underwent contrast-enhanced MRI. Of the latter 41 patients, 16 had abnormal enhanced lesions (39%: group L), while 25 had no lesions (61%: group NL). In group L, all lesions were spotty, and they were located in the cerebral cortex in 13 patients (81%), the subcortex in two (12%), and the perforator territory in one (6%). Aphasia or confusional state, hypertension, and emboligenic cardiac or arterial disease (stenosis > or =50%) were more frequently observed in group L than in group NL (38 vs. 8%, 81 vs. 48%, and 93 vs. 60%, respectively, P<0. 05). The TIA patients with enhanced lesions on MRI may be associated with an emboligenic cardiac or arterial disease, severe neurologic symptom compared to those without them.

Early neurological deterioration represents recurrent attack in acute small non-lacunar stroke.

The aim of this study was to identify the frequency and possible pathogenic mechanisms of early neurological deterioration in patients with acute small non-lacunar infarction. We studied 46 patients (35 men, 11 women; age, 70.3+/-10.4 years) with acute small non-lacunar infarction. Small non-lacunar infarction was diagnosed using diffusion-weighted magnetic resonance imaging (DWI) as being <15 mm in diameter and located in the cortex and centrum ovale in the middle cerebral artery territory. The patients were divided into two groups; Group D (n=6) had neurological deterioration within 7 days after symptom onset, while Group N (n=40) did not have any neurological deterioration. In Group D, the interval from symptom onset to clinical deterioration was 3.3+/-1.5 days (range 2-6 days). Blood pressure on admission was higher in Group D than in Group N (p<0.05). In Group D, four of these five patients with follow-up DWI had new acute small ischemic lesions in addition to the initial lesions, indicating recurrent attacks of brain infarction. Neurological deterioration occurred within 7 days after symptom onset in 13% of patients. Neurological deterioration was frequently caused by recurrent infarction detected by DWI.

Staphylococcus cohnii as a cause of multiple brain abscesses in Weber-Christian disease

We report a patient with multiple brain abscesses due to Staphylococcus cohnii. While these brain abscesses markedly responded to the antibiotics, this patient was subsequently suffered from subcutaneous inflammatory nodules in the adipose tissue, which diagnosed him as having Weber-Christian disease (WCD). This is the first report that subcutaneous inflammatory nodules in the adipose tissue, which lead the diagnosis of WCD, followed multiple brain abscesses. To our knowledge, S. cohnii has not yet been reported to cause multiple brain abscesses in humans. Although the etiology of WCD is unknown, an immune mechanism has been implicated in the pathogenesis. Therefore, we should notice that patients with WCD could be immunocompromised hosts with a higher risk to suffer from severe opportunistic infections.

Hypertension and Neurovascular Compression of the Left Lateral Medulla oblongata in Ischemic Stroke

Hypertension is a major risk factor for stroke. Neurovascular compression (NC) of the left ventrolateral medulla oblongata may cause arterial hypertension. We evaluated the relationship between the two ischemic stroke patients. We classified 69 patients under 50 years old (49 men and 20 women, aged 43.6 ± 7.3 years) based on magnetic resonance imaging findings as follows: NC patients (n = 38; 10 with NC on the right side, 18 with NC on the left side, and 10 with NC on both sides) and non-NC patients (n = 31). We compared the following clinical characteristics between the two groups: (1) risk factors for stroke, including hypertension, diabetes mellitus, hypercholesterolemia, and smoking and (2) stroke subtype. Hypertension was more frequent in the NC group than in the non-NC group (58 vs. 19%, p = 0.001). Hypertension was more frequent in patients with left-side NC than in those with right-side NC (78 vs. 20%, p = 0.005). No other differences were observed between the two groups. Twelve patients presented with atherothrombotic stroke, 16 with cardioembolic stroke, 24 with lacunar stroke and 17 with stroke of miscellaneous etiology. NC was significantly more common in patients with lacunar stroke as compared with those affected by other stroke subtypes (p = 0.015). We found a significant relationship between hypertension and NC of the ventrolateral medulla oblongata on the left side in ischemic stroke patients younger than 50 years of age. Some patients with lacunar stroke may have hyptertension related to NC.