Correlation between pretreatment and follow-up infarct volume using CT perfusion imaging: the Bayesian versus singular value decomposition method.

PURPOSE: Pretreatment ischemic core volume is conceptually equal to follow-up infarct volume (FIV) in patients with successful recanalization. However, there is sometimes an absolute volume difference (AD) between pretreatment core volume and FIV. The aim was to compare the AD values between the Bayesian and the singular value decomposition (SVD) methods with time from onset-to-imaging in acute ischemic stroke (AIS) patients undergoing mechanical thrombectomy. METHODS: Consecutive AIS patients were included if they had the following: (1) anterior large vessel occlusion (internal carotid or middle cerebral artery); (2) within 24 h of onset; (3) pretreatment CT perfusion (CTP); (4) successful recanalization (mTICI ≥ 2b); and (5) 24-h diffusion-weighted imaging (DWI). FIV was measured on 24-h DWI. The AD value between FIV and the pretreatment core volume was calculated for Bayesian and SVD methods. Spearman's rank correlation coefficient (rho) was calculated as appropriate. RESULTS: In the 47 patients enrolled (25 men; median age 78 years; median baseline National Institutes of Health Stroke Scale, 22), the median time from onset-to-imaging and onset-to-recanalization was 136 and 220 min, respectively. Shorter onset-to-imaging time was correlated with a larger AD value, and more trend was seen in the SVD method (rho = - 0.28, p = 0.05) compared with the Bayesian method (rho = - 0.08). A larger pretreatment core volume was correlated with a larger AD value, and this tendency was slightly stronger for the SVD (rho = 0.63, p < 0.01) than for the Bayesian (rho = 0.32, p = 0.03) method. CONCLUSIONS: The Bayesian method might be more correlated with FIV than the SVD method in patients with a large ischemic lesion immediately after stroke onset, but not perfect.

Acute Stroke Caused by Progressive Intracranial Artery Stenosis Due to Varicella Zoster Virus Vasculopathy after Chemotherapy for Malignant Lymphoma.

Decreased cell-mediated immunity can reactivate Varicella zoster virus (VZV), which can lead to various neurological complications, including vasculopathy. We herein report the case of a patient with acute stroke with progressive internal carotid artery stenosis due to VZV vasculopathy after chemotherapy for malignant lymphoma. Treatment for VZV vasculopathy improved the stenosis and prevented recurrent stroke. VZV vasculopathy is an important treatable cause of stroke in immunosuppressed patients.

Improving Acute In-Hospital Stroke Care by Reorganization of an In-Hospital Stroke Code Protocol.

BACKGROUND AND PURPOSE: Delays in recognition and assessment of in-hospital strokes (IHS) can lead to poor outcomes. The aim was to examine whether reorganized IHS code protocol can reduce treatment time. METHODS: IHS code protocol was developed, educational workshops were held for medical personnel. In the protocol, any medical personnel should directly consult a stroke neurologist before any diagnostic studies. Time intervals were compared between the pre- and post-implementation periods and between direct consultation with a stroke neurologist (DC group) and non-DC group in the post-implementation period. RESULTS: A total of 145 patients were included (pre, 42; post, 103). Time from recognition to stroke neurologist assessment (91 vs. 35 min, p = 0.002) and time from recognition to neuroimaging (123 vs. 74, p = 0.013) were significantly lower in the post-implementation period. Time from stroke neurologist assessment to groin puncture was significantly lower (135 vs. 81, p = 0.037). In the post-implementation period, DC group showed significant time savings from last known well (LKW) to recognition (93 vs. 260, p = 0.001), LKW to stroke neurologist assessment (145 vs. 378, p = 0.001), and recognition to stroke neurologist assessment (16 vs. 76, p < 0.001) compared with non-DC group. CONCLUSIONS: Reorganization of IHS code protocol reduced time from stroke recognition to assessment and treatment time. Reorganized IHS code and direct consultation with a stroke neurologist improved the initial response time.

[A case of bilateral medial medullary and left tegmentum of pontine infarction in whom DSA-MR fusion imaging identified infarct-relevant arteries].

We herein reported a patient with acute ischemic stroke in the bilateral medial medullary and the left tegmentum of the pons who presented with various neurological symptoms. Fusing digital subtraction angiography (DSA) and MRI (DSA-MR fusion imaging) could reveal the infarct-relevant arteries. A 41-year-old male presented with headache, bilateral arm's dysesthesia, quadriplegia, left Horner's syndrome, upbeat nystagmus, internuclear ophthalmoplegia and left peripheral facial paralysis. Diffusion weighted MRI (DWI) revealed the high intensity lesion in the bilateral medial medullary and the left tegmentum of the pons. MRA showed right vertebral artery (VA) occlusion. A high intensity on T1 weighted imaging was shown on the right VA vessel wall. DSA-MR fusion imaging revealed the anterior spinal artery (ASA) occlusion proximal to the infarction. The stenosis was located at the origin of the right VA perforating branch distributing into the infarct lesion. The steno-occlusive lesion of ASA and VA perforating branch due to VA dissection resulted in infarction in the pontomedullary junction and caused various neurological symptoms. DSA-MR fusion imaging would prove the radiological anatomy of infarct-relevant arteries and clarify the etiology of ischemic stroke.

[A case of definite diagnosis of branch atheromatous disease confirmed by digital subtraction angiography-3 tesla magnetic resonance fusion imaging].

We herein experienced one patient with typical branch atheromatous disease (BAD) type infarction. Digital subtraction angiography (DSA) and MRI fusion imaging revealed the relationship between atheromatous plaque and perforating branches. A 66-year-old male presented acute onset of dysarthria, the left side hemiparesis and sensory disturbance. Diffusion-weighted MR imaging (DWI) showed the right pontine acute infarction. We started to treat with dual antiplatelet therapy. However, the left-side hemiparesis was worsening on 4 days after admission. DWI showed infarct growth and plaque imaging revealed the atheromatous plaque in the basilar artery. We fused DSA and MRI T2 weighted imaging (DSA-MR fusion imaging) to illustrate the relationship between the atheromatous plaque and the perforating branches. DSA-MR fusion imaging showed that the paramedian artery and the short circumferential artery ran around and into the pontine infarct lesion. Additionally, one of the paramedian arteries was occluded. Those neuroradiological findings coincided with the pathological concept of BAD. DSA-MR fusion imaging can prove the pathological concept of BAD.