MRI-Based Predictors of Hemorrhagic Transformation in Patients With Stroke Treated by Intravenous Thrombolysis.

Background: Clinical and biological risk factors for hemorrhagic transformation (HT) after intravenous thrombolysis (IT) have been well-established in several registries. The added value of magnetic resonance imaging (MRI) variables has been studied in small samples, and is controversial. We aimed to assess the added value of MRI variables in HT, beyond that of clinical and biological factors. Methods: We enrolled 474 consecutive patients with brain infarction treated by IT alone at our primary stroke center between January 2011 and August 2017. Baseline demographic, clinical, biological, and imaging characteristics were collected. MRI variables were: brain infarction volume in cm3; parenchymal fluid attenuated inversion recovery (FLAIR) hyperintensity; FLAIR hyperintense vessel signs; number of microbleeds; subcortical white matter hyperintensity; and thrombus length. Results: Overall, 301 patients were included out of 474 (64%). The main causes of exclusion were combined thrombectomy (n = 98) and no MRI before IT (n = 44). In the bivariate analysis, HT was significantly associated with the presence of more FLAIR hyperintense vessel signs, thrombus length (>8 mm), and larger brain infarction volume (diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) < 500 × 10-6 mm2/s). In the multivariable analysis, only brain infarction volume was significantly associated with HT. The discrimination value of the multivariable model, including both the DWI volume and the clinical model (area under the receiver operating characteristic curve, 0.80; 95% confidence interval 0.74-0.86), was improved significantly compared with the model based only on clinical variables (P = 0.012). Conclusions: Brain infarction volume on DWI was the only MRI variable that added value to clinico biological variables for predicting HT after IT.

Artery of Percheron infarction as an unusual cause of coma: three cases and literature review.

OBJECTIVE: Stroke due to occlusion of the artery of Percheron (AOP), an uncommon anatomic variant supplying the bilateral medial thalami, may raise diagnostic challenges and cause life-threatening symptoms. Our objective here was to detail the features and outcomes in three patients who required intensive care unit (ICU) admission and to review the relevant literature. METHODS: Description of three cases and literature review based on a 1973-2013 PubMed search. RESULTS: Three patients were admitted to our ICU with sudden-onset coma and respiratory and cardiovascular dysfunctions requiring endotracheal mechanical ventilation. Focal neurological deficits, ophthalmological signs (abnormal light reflexes and/or ocular motility and/or ptosis), and neuropsychological abnormalities were variably combined. Initial CT scan was normal. Cerebral MRI demonstrated bilateral paramedian thalamic infarction, with extension to the cerebral peduncles in two patients. Consciousness improved rapidly and time to extubation was 1-4 days. All three patients were discharged alive from the hospital and two had good 1-year functional outcomes. Similar clinical features and outcomes were recorded in the 117 patients identified in the literature, of whom ten required ICU admission. CONCLUSIONS: Bilateral paramedian thalamic stroke due to AOP occlusion can be life threatening. The early diagnosis relies on MRI with magnetic resonance angiography. Recovery of consciousness is usually rapid and mortality is low, warranting full-code ICU management.

Determinants of recovery from severe posterior reversible encephalopathy syndrome.

OBJECTIVE: Few outcome data are available about posterior reversible encephalopathy syndrome (PRES). We studied 90-day functional outcomes and their determinants in patients with severe PRES. DESIGN: 70 patients with severe PRES admitted to 24 ICUs in 2001-2010 were included in a retrospective cohort study. The main outcome measure was a Glasgow Outcome Scale (GOS) of 5 (good recovery) on day 90. MAIN RESULTS: Consciousness impairment was the most common clinical sign, occurring in 66 (94%) patients. Clinical seizures occurred in 57 (81%) patients. Median mean arterial pressure was 122 (105-143) mmHg on scene. Cerebral imaging abnormalities were bilateral (93%) and predominated in the parietal (93%) and occipital (86%) white matter. Median number of brain areas involved was 4 (3-5). Imaging abnormalities resolved in 43 (88%) patients. Ischaemic and/or haemorrhagic complications occurred in 7 (14%) patients. The most common causes were drug toxicity (44%) and hypertensive encephalopathy (41%). On day 90, 11 (16%) patients had died, 26 (37%) had marked functional impairments (GOS, 2 to 4), and 33 (56%) had a good recovery (GOS, 5). Factors independently associated with GOS<5 were highest glycaemia on day 1 (OR, 1.22; 95%CI, 1.02-1.45, p = 0.03) and time to causative-factor control (OR, 3.3; 95%CI, 1.04-10.46, p = 0.04), whereas GOS = 5 was associated with toxaemia of pregnancy (preeclampsia/eclampsia) (OR, 0.06; 95%CI, 0.01-0.38, p = 0.003). CONCLUSIONS: By day 90 after admission for severe PRES, 44% of survivors had severe functional impairments. Highest glycaemia on day 1 and time to causative-factor control were strong early predictors of outcomes, suggesting areas for improvement.

Cryptococcal neuroradiological lesions correlate with severity during cryptococcal meningoencephalitis in HIV-positive patients in the HAART era.

Cryptococcal meningoencephalitis has an overall global mortality rate of 20% in AIDS patients despite antifungals. There is a need for additional means of precise assessment of disease severity. We thus studied the radiological brain images available from 62 HIV-positive patients with cryptococcocal meningoencephalitis to analyse the brain lesions associated with cryptococcosis in relationship with disease severity, and the respective diagnostic contribution of magnetic resonance (MR) versus computed tomography (CT). In this retrospective multicenter analysis, two neuroradiologists blindly reviewed the brain imaging. Prospectively acquired clinical and mycological data were available at baseline and during follow-up. Baseline images were abnormal on 92% of the MR scans contrasting with 53% of the CT scans. MR/CT cryptococcosis-related lesions included mass(es) (21%/9%), dilated perivascular spaces (46%/5%) and pseudocysts (8%/4%). The presence compared to absence of cryptococcosis-related lesions was significantly associated with high serum (78% vs. 42%, p = 0.008) and CSF (81% vs. 50%, p = 0.024) antigen titers, independently of neurological abnormalities. MR detected significantly more cryptococcosis-related lesions than CT for 17 patients who had had both investigations (76% vs. 24%, p = 0.005). In conclusion, MR appears more effective than CT for the evaluation of AIDS-associated cerebral cryptococcosis. Furthermore, brain imaging is an effective tool to assess the initial disease severity in this setting. Given this, we suggest that investigation for cryptococcosis-related lesions is merited, even in the absence of neurological abnormality, if a high fungal burden is suspected on the basis of high serum and/or CSF antigen titers.

[Imaging of meningitis complications]. / Imagerie des complications des méningites.

The authors describe the radiological pattern of meningitis neurological complications. These complications are vascular lesions, arteritis and thrombophlebitis, brain swelling, hydro-cephalus, extra-cerebral collections, neuritis and labyrinthitis. When meningitis complication is suspected, MRI must be the first neuroradiological investigation.