[Two adult patients with acute necrotizing encephalopathy following influenza virus infection].

Influenza encephalopathy is characterized by high fever, disturbance of consciousness following influenza virus infection. We encountered 2 adult patients with influenza-associated acute necrotizing encephalopathy (Case 1, a 70-year-old woman with diabetes; Case 2, a 49-year-old woman with multiple myeloma), showing hemorrhagic lesions in the bilateral thalamus. Case 1 presented with fever and disturbance of consciousness followed by status epilepticus, and Case 2 developed fever and drowsiness as initial manifestation. Influenza type A was positive in Case 1 and influenza type B was positive in Case 2. In the acute phase, 2 patients required respiratory ventilation and were treated with anti-influenza drug, steroid and immunoglobulin. Cognitive impairment remained in the both patients in the chronic phase. When acute necrotizing encephalopathy is suspected, intensive treatment should be started as early as possible to improve clinical outcome of patients.

Suitable methods of measuring acceleration time in the diagnosis of internal carotid artery stenosis.

PURPOSE: To enhance the utility of acceleration time (AcT) in the diagnosis of internal carotid artery (ICA) stenosis, we assessed the value of AcT measurements with different waveform patterns. METHODS: Ninety-three patients with acute atherothrombotic cerebral infarction were enrolled, and they underwent both carotid ultrasonography and digital subtraction angiography (DSA). AcT was determined by a conventional procedure (using the first peak point or the bending point) and the peak systolic velocity (PSV) procedure. The AcT ratio was calculated as (AcT of ICA)/(AcT of the ipsilateral common carotid artery). We evaluated the correlation of stenosis rate as assessed by the North American Symptomatic Carotid Endarterectomy Trial method using DSA (DSA-NASCET) with the AcT of ICA (ICA-AcT), the AcT ratio measured by the conventional procedure (conventional AcT ratio), and the AcT ratio measured by the PSV procedure (PSV AcT ratio). The area under receiver operating characteristic curves (AUC) for DSA-NASCET was calculated based on the ICA-AcT and AcT ratio. RESULTS: Forty-five vessels had 50% or greater ICA stenosis. DSA-NASCET was positively correlated with the conventional AcT ratio (r = 0.723), conventional ICA-AcT (r = 0.638), and PSV AcT ratio (r = 0.245). The corresponding AUCs for ICA stenosis ≥ 50% were 0.971, 0.886, and 0.572, respectively. CONCLUSION: We demonstrated the usefulness of the conventional procedure for diagnosing stenosis of ICA origin using AcT and showed that the AcT ratio was a more beneficial parameter than AcT.

Usefulness of acceleration time ratio in diagnosis of internal carotid artery origin stenosis.

PURPOSE: The acceleration time (AcT) ratio of the internal carotid artery (ICA) is increased in ICA stenosis. However, there are few reports that have directly compared the AcT ratio to digital subtraction angiography (DSA) findings. METHODS: We evaluated 177 vessels with DSA and carotid artery ultrasonography. The AcT ratio was calculated as AcT of the ICA (ICA-AcT)/AcT of the ipsilateral common carotid artery (CCA). We evaluated the correlation of DSA-NASCET stenosis with the origin of the ICA or the peak systolic velocity (ICApsv) in the stenotic region, ICApsv/peak systolic velocity of the CCA (CCApsv), ICA-AcT, and AcT ratio. Sensitivity and specificity for stenosis ≥ 70% were calculated based on the ICApsv, ICApsv/CCApsv, ICA-AcT, and AcT ratio. RESULTS: Using NASCET criteria, 34 vessels had 70% or greater stenosis. DSA-NASCET showed a significant positive correlation with ICApsv, ICApsv/CCApsv, ICA-AcT, and AcT ratio (p < 0.0001). When the cut-off value for ICApsv was set at 176 cm/s, ICApsv/CCApsv at 2.42, ICA-AcT at 0.095 s, and the AcT ratio at 1.35, the sensitivity was 97.1, 97.1, 82.4, and 97.1%, and the specificity was 94.4, 91.0, 83.2, and 83.2%, for DSA-NASCET ≥ 70%, respectively. CONCLUSION: The AcT ratio is a beneficial parameter for evaluating ICA stenosis as well as ICApsv and ICApsv/CCApsv.