[Rhinocerebral mucormycosis]. / Une mucormycose rhinocérébrale.

INTRODUCTION: Mucormycosis is a rare and acute fungal infection which is frequently lethal. The rhinocerebral form is usually seen in diabetics, but other localizations may occur in severely immunocompromised subjects. OBSERVATION: We report the case of a sphenoidal sinusitis associated with a probable cavernous sinus thrombosis and carotid artery thrombosis with middle cerebral artery territory infarction. Diagnosis was made on histological examination following sphenoidotomy. Early medical and surgical treatment led to a good outcome. CONCLUSION: The diagnosis of rhinocerebral mucormycosis should be considered in the clinical setting of necrotic sinusitis and acute neurologic deficit in diabetic patients. Early diagnosis and treatment are crucial factors leading to a good outcome.

[Cerebral venous thrombosis presenting as subarachnoid hemorrhage]. / Thrombophlébite cérébrale révélée par une hémorragie sous-arachnoïdienne.

Headache of subacute onset, associated with other signs of increased intracranial pressure, represents the most frequent symptom of cerebral thrombophlebitis. We report a case of subarachnoid hemorrhage as a rare presentation of cerebral thrombophlebitis. Unfractionated intravenous heparin treatment resulted in resolution of subarachnoid hemorrhage on control brain CT scan and quick clinical recovery.

The delayed perfusion sign at MRI.

PURPOSE: Effective collateral blood flow seem to be an important factor associated with a small infarct volume and a good clinical outcome. We aimed to assess leptomeningeal collateral blood flow on source perfusion-weighted images in patients with acute stroke. MATERIALS AND METHODS: 29 patients with proximal middle cerebral artery occlusion (MCA alone, n=17; MCA + internal carotid artery [ICA] occlusion, n=12) were evaluated with MRI at baseline before thrombolytic therapy, and at day 60. Clinical evaluation was performed at days 0 and 60 with the National Institutes of Health Stroke Scale (NIHSS) score, and at day 60 with the modified Rankin score. We assessed (on source images of the dynamic contrast-enhanced T2*-weighted perfusion [PWI] sequence) the presence of a hypointensity consistent with delayed contrast arrival within the global perfusion deficit (delayed perfusion sign). We analyzed the extent of the area demonstrating such delayed perfusion (DP area) on source images of the PWI sequence, and compared it with the global perfusion (GP) abnormality shown by time-to-peak maps. We calculated the Spearman rank correlation coefficient between the DP/GP ratio and: 1. age; 2. clinical scores; 3. site of occlusion [MCA alone versus ICA+MCA occlusion]; 4. DWI lesion size at day 0, and T2WI lesion size at day 60; 5. PWI-derived parameters (time-to-peak [TTP], relative cerebral blood volume [rCBV], relative cerebral blood flow [rCBF], and peak height). All tests were bilateral and a p value<0.05 was considered as significant. RESULTS: Delayed perfusion areas of various size were found within the global perfusion deficit in all patients. High DP/GP ratio values were significantly correlated with: 1. better clinical scores at day 0 and day 60 (all p<=0.04); 2. smaller lesions at day 0 DWI and at day 60 T2WI (all p<=0.004); 3. ICA patency (r=0.49, p=0.01); 4. lower TTP delays, and higher values of rCBV, rCBF, and peak height. CONCLUSION: These preliminary data suggest that a delayed contrast filling observed on native perfusion-weighted images may be a marker of leptomeningeal collateral blood flow, and may lead to better clinical and morphological outcomes in acute ischemic stroke.

Baseline magnetic resonance imaging parameters and stroke outcome in patients treated by intravenous tissue plasminogen activator.

BACKGROUND AND PURPOSE: We designed a prospective sequential pretreatment and posttreatment MRI study to assess the relation between neuroimaging parameters and clinical outcome in patients treated with intravenous recombinant tissue-type plasminogen activator (rtPA). METHODS: Patients with symptoms of acute hemispheric ischemic stroke were recruited. The National Institutes of Health Stroke Scale (NIHSS) score was assessed at baseline and at days 1, 7, and 60, and the modified Rankin scale (mRS) at day 60, by which outcome was classified in terms of independence (mRS score 0, 1, or 2) or severe disability or death (mRS score 3 through 6), was assigned. Multimodal stroke MRI was performed at presentation and repeated at day 1. MRI procedures included magnetic resonance angiography, T2* gradient-echo sequence, echoplanar imaging, and isotropic diffusion- (DWI) and perfusion-weighted (PWI) imaging. Patients were treated with intravenous rtPA after MRI completion. RESULTS: Twenty-nine patients (16 men and 13 women; mean+/-SD age, 65+/-14 years) underwent MRI; the mean time from symptom onset to treatment was 255+/-62 minutes. Twenty-six patients had a vessel occlusion, and 15 patients experienced a partial (Thrombolysis in Myocardial Infarction [TIMI]-2) or total (TIMI-3) recanalization at day 1, whereas 11 patients had a persistent occlusion. Mean NIHSS scores at day 60 were 5.7+/-5.4 if recanalization had occurred and 14+/-2 in cases of persistent occlusion. According to the mRS, 13 patients were independent (mRS 0 through 2), whereas severe disability or death (mRS 3 through 6) was observed in 15 patients. A better outcome was observed when recanalization was achieved (r=-0.68, P=0.0002). PWI volume and time to peak (TTP) within the DWI lesion assessed before therapy were correlated with day-60 NIHSS score (PWI volume: r=0.51, P=0.006, TTP: r=0.35, P=0.07). The day-0 DWI abnormality volume was well correlated with day-60 NIHSS score (r=0.58, P=0.001). Multiple regression linear analysis showed that 2 factors mainly influenced clinical outcome: (1) recanalization, with a high correlation with NIHSS score at day 60 (P=0.0001) and (2) day-0 DWI lesion volume, which is closely associated with day-60 NIHSS score (P=0.03). CONCLUSIONS: Baseline DWI volume and recanalization are the main factors influencing clinical outcome after rtPA for ischemic stroke.

[Comparison of different techniques for the detection of heterogeneous resistance to methicillin in Staphylococcus aureus]. / Etude comparative de différentes techniques pour la détection de la résistance hétérogène à la méticilline chez Staphylococcus aureus.

The methods for detection of methicillin resistant S. aureus (MRSA) can fail to detect resistance because phenotypic expression is often heterogeneous (40% of strains). Seventy four strains of S. aureus [4 methicillin susceptible strains, 10 homogeneous MRSA (Ro) and 60 heterogeneous MRSA (Rh)] were isolated from different french hospitals in Paris. These strains were tested by different methods: oxacillin screen plate with 6 micrograms/ml oxacillin and 4% NaCl, agar diffusion method with 5 micrograms oxacillin disk tested either at 30 degrees C on Mueller-Hinton medium or at 37 degrees C on Mueller-Hinton plus 5% NaCl, BBL Crystal MRSA ID system tested with two inocula (0.5 and 1 McFarland equivalent bacterial suspension) at 37 degrees C for 4 h and 5 h. Dot-blot hybridization was performed under stringent condition with the mecA probe. The accuracy of the different methods for the detection of methicillin resistance is equivalent, except for the BBL crystal system with a 0.5 McFarland inoculum wich detects the resistance with an accuracy of 86% for Ro strains and 69% for Rh strains. In other respects, there was a close correlation with the detection of the phenotypic resistance and the presence of mecA gene. So this study demonstrates that these various methods can be used for the detection of methicillin resistant S. aureus. For a rapid detection (below 5 h) the BBL crystal system with a 1 McFarland inoculum can be used; the agar diffusion method remains a good method provided some conditions (inoculum, incubation temperature, addition of salt, incubation period); the oxicillin screnn plate is a very attractive method for it is easy and reliable.