[Paraplegia associated with intramedullary spinal cord and epidural abcesses, meningitis and spondylodiscitis (Staphylococcus aureus)]. / Paraplégie flasque due à des abcès intramédullaires et épiduraux à staphylocoques dorés. Méningite et spondylodiscite associées.

INTRODUCTION: Intramedullary spinal cord abscesses are rare, frequently associated with meningitis, sometimes with epidural abscesses. They are frequently responsible for paraplegia. Staphylococcus aureus is the predominant organism. MRI shows an intramedullary collection giving a low-intensity signal on T1-weighted images with peripheral contrast uptake on enhanced TI-weighted studies and a high-intensity signal on T2-weighted images with generally extended adjacent medullary edema. They may be multiple. CASE REPORT: We report the case of a man who presented meningitis with intramedullary and epidural abscesses. The number of the lesions did not allow chirurgical drainage. The paraplegia did not resolve despite appropriate antibiotic therapy. CONCLUSION: Appropriate antibiotic therapy and early surgical drainage, if feasible, are key factors for better outcome and prognosis.

Thrombolysis rate and impact of a stroke code: a French hospital experience and a systematic review.

BACKGROUND: Intravenous rt-PA is effective in hyperacute ischemic stroke (HAIS) but is administered only in few patients. OBJECTIVES: To report the thrombolysis rate in our stroke unit using a stroke code (SC) protocol with a prenotification system and to analyze the SC impact on the thrombolysis rate in a systematic review. METHODS: We report, from 2005 to 2009, the intravenous rt-PA rate in our prospective registry of hyperacute strokes suspicions. The systematic review was conducted in searching PubMed and EMBASE for prospective studies reporting thrombolysis rates and their use of a SC. We categorized SC between those with a prenotification by the Emergency Medical Services and those with only an in-hospital SC system. RESULTS: Among the 1450 stroke patients hospitalized in our stroke unit, 349 were admitted via the SC protocol as suspicions of hyperacute strokes. Intravenous rt-PA rates were: 12.9% of the ischemic strokes, 36% of the suspicions of hyperacute strokes and 59.6% of the HAIS. We found 23 studies reporting thrombolysis rates ranging from 10.3% to 58% of HAIS. Ten studies gave data concerning the use of a SC in case of HAIS. Thrombolysis rate was higher in hospitals with a prenotification system (54.7%) compared with both those with no specific organization (18.2%) (OR=5.43, 95% CI: 3.84-7.73) and those with an in-hospital restricted SC (37.9%) (OR=1.97, 95% CI: 1.53-2.54). CONCLUSIONS: Thrombolysis rate of HAIS is improved by a SC, especially when a prenotification system of thrombolysis candidates by Emergency Medical Services to the stroke unit is used.

Cerebrovascular disease related to COL4A1 mutations in HANAC syndrome.

BACKGROUND: COL4A1 mutations cause familial porencephaly, infantile hemiplegia, cerebral small vessel disease (CSVD), and hemorrhagic stroke. We recently described hereditary angiopathy with nephropathy, aneurysm, and muscle cramps (HANAC) syndrome in 3 families with closely localized COL4A1 mutations. The aim of this study was to describe the cerebrovascular phenotype of HANAC. METHODS: Detailed clinical data were collected in 14 affected subjects from the 3 families. MRI and magnetic resonance angiography (MRA) were performed in 9 of them. Skin biopsies were analyzed by electron microscopy in affected subjects in the 3 families. RESULTS: Only 2 of 14 subjects had clinical cerebrovascular symptoms: a minor ischemic stroke at age 47 years and a small posttraumatic hemorrhage under anticoagulants at age 48 years. MRI-MRA showed cerebrovascular lesions in 8 of 9 studied subjects (mean age 39.4 years, 21-57 years), asymptomatic in 6 of them. Unique or multiple intracranial aneurysms, all on the carotid siphon, were observed in 5 patients. Seven patients had a CSVD characterized by white matter changes (7/7) affecting subcortical, periventricular, or pontine regions, dilated perivascular spaces (5/7), and lacunar infarcts (4/7). Infantile hemiplegia, major stroke, and porencephaly were not observed. Skin biopsies showed alterations of basement membranes at the dermoepidermal junction associated with expansion of extracellular matrix between smooth vascular cells in the arteriolar wall. CONCLUSION: The cerebrovascular phenotype in hereditary angiopathy with nephropathy, aneurysm, and muscle cramps syndrome associates a cerebral small vessel disease and a large vessel disease with aneurysms of the carotid siphon. It is consistent with a lower susceptibility to hemorrhagic stroke than in familial porencephaly, suggesting an important clinical heterogeneity in the phenotypic expression of disorders related to COL4A1 mutations.

MRI and FDG PET/CT findings in a case of probable Heidenhain variant Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is a neurodegenerative disease caused by the accumulation of a pathogenic isoform of a prion protein in neurons that is responsible for subacute dementia. The Heidenhain variant is an atypical form of CJD in which visual signs are predominant. This is a report of the case of a 65-year-old man with probable CJD of the Heidenhain variant, with topographical concordance between findings on magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) photopenic areas on positron emission tomography (PET)/computed tomography (CT) for cortical parietooccipital lesions.

[Cerebral infarction related to intracranial radiation arteritis twenty-four years after encephalic radiation therapy]. / Infarctus cérébral secondaire à une artériopathie radique intracrânienne, vingt-quatre ans après une irradiation encéphalique.

We report a case of a resolutive late cerebral ischemic event, related to radiation induced vasculopathy of the left posterior cerebral artery, documented by MRI, situated in the irradiated volume 24 years before, for an astrocytome with malignant potential.

Reversible encephalopathy associated with cholesterol embolism syndrome: magnetic resonance imaging and pathological findings.

We describe a patient found to have acute diffuse and reversible encephalopathy on magnetic resonance imaging (MRI) associated with cholesterol emboli syndrome (CES). The initial MRI showed extensive white matter, basal ganglia and cortical damage without evidence of brain infarction. Dramatic clinical and MRI improvement was observed with corticosteroids. Pathologically, cholesterol crystal emboli were found in the lumen of skin and brain arteries and were associated with varying degrees of inflammation of the arteriole wall. This case suggests that CES may be responsible for extensive, acute and reversible encephalopathy underlined by an inflammation of brain arteries.

[Intracerebral hematoma associated with reduced apparent diffusion coefficient mimicking acute stroke]. / Hématome intracérébral et baisse importante du coefficient de diffusion mimant un accident ischémique cérébral aigu.

We report the case of a 67 year old patient admitted at our institution for acute onset of left hemiplegia. MRI was done 2 h 30 after symptom onset. Diffusion weighted images showed a hyperintense lesion in the right basal ganglia region with restricted apparent diffusion coefficient (ADC=428. 10(-6) mm(2)/s), a 50% decrease in value compared to the normal left side, consistent with acute ischemia. The lesion was hyperintense and moderately heterogeneous at FLAIR imaging, best seen on echo planar T2W images, with hypointense rim consistent with magnetic susceptibility artifact. The appearance and location of the lesion suggested the possibility of hematoma, which was confirmed at CT. Interpretation of ADC values must be performed in correlation with results at imaging including sequences sensitive to magnetic susceptibility artifacts such as echo planar T2*W and T2W sequences in order to exclude the possibility of underlying hematoma.

Long-term survival after gene therapy for a recurrent glioblastoma.

A patient presenting with a recurrent glioblastoma (GBM) survived 3 years after suicide gene therapy and finally died of a disseminated breast cancer with no indication of tumor recurrence on MRI. Postmortem analysis showed no evidence of recurrence of the GBM, neither near the initial tumor localization nor in any other area of the brain. Such an evolution is unusual in the course of this disease and may suggest in this particular case a cure of the GBM.

Carotid artery stenosis: prospective comparison of CT, three-dimensional gadolinium-enhanced MR, and conventional angiography.

PURPOSE: To prospectively compare gadolinium-enhanced magnetic resonance (MR) angiography and computed tomographic (CT) angiography with digital subtraction angiography (DSA) for use in detecting atheromatous stenosis and plaque morphology at the carotid bifurcation. MATERIALS AND METHODS: Forty-four carotid arteries (in 22 patients) were analyzed by using CT angiography, enhanced MR angiography, and DSA. CT and enhanced MR angiograms were reconstructed with maximum intensity projection and multiplanar volume reconstruction. The following four features were analyzed: degree of stenosis on the basis of North American Symptomatic Carotid Endarterectomy Trial criteria, length of stenosis, luminal surface, and presence of ulcers. RESULTS: There was significant correlation between CT angiography, enhanced MR angiography, and DSA for degree and length of stenosis. With enhanced MR angiography and CT angiography, degree of stenosis was underestimated in two of 44 cases. No case of overestimation with CT angiography was found. Severe internal carotid artery stenoses were detected with high sensitivity and specificity: 100% and 100%, respectively, with CT angiography; 93% and 100%, respectively, with enhanced MR angiography. Luminal surface irregularities were most frequently seen at CT angiography. With CT angiography and enhanced MR angiography, more ulceration was detected than with DSA. CONCLUSION: There was a significant correlation between CT angiography, enhanced MR angiography, and DSA in evaluation of carotid artery stenosis. Enhanced MR angiography or CT angiography can be used to adequately evaluate carotid stenosis.

Extent of tumor-brain interface: a new tool to predict evolution of malignant gliomas.

OBJECT: Tumor size is one of the features commonly used in oncology to predict disease evolution. However, for most primary brain tumors it is not predictive of outcome. Taking advantage of a gene therapy trial in which recurrences of glioblastoma were targeted with suicide genes, the authors developed a new parameter: the extent of tumor-brain interface--also called surface of tumor volume (STV)--to better describe three-dimensional conformation and the relationship between tumors and the surrounding normal tissue. Correlations between the STV and the usual clinical parameters were analyzed. METHODS: Between 1995 and 1998, 16 patients presenting with recurrent glioblastomas were enrolled in this study. Preoperative magnetic resonance images were analyzed on a separate workstation; the interface between tumor and normal brain tissue was measured on each 3-mm-thick section to assess STV. The mean STV was 29.2 cm2, and the mean tumor volume (TV) was 23.8 cm3. The STV was significantly correlated with survival (Spearman test: r = -0.54, p = 0.03), but TV was not (Spearman test: r = -0.39, p = 0.15). A separate analysis of responding and nonresponding patients showed that, as expected, STV was negatively correlated with survival among nonresponding patients (p = 0.04), but that among responding patients there was a positive tendency between STV and survival. CONCLUSIONS: These findings indicate that STV may be a useful tool for predicting the evolution of malignant glioma. Moreover, in future gene therapy trials in which such in situ approaches are used, increasing density and improved distribution of transfer cells should be taken into consideration as an important issue for efficacy.

[Exploration of the origin of supra-aortic arterial trunk: can MR angiography with gadolinium injection replace digital angiography?]. / Exploration de l'origine des troncs artériels supra-aortiques: l'angio-irm avec injection de gadolinium peut-elle remplacer l'angiographie numérisée?

Ostial stenosis of the craniocervical vessels are frequently associated with carotid stenosis. Consequently, exploration of the aortic arch is necessary prior to carotid endarterectomy. Contrast-enhanced MR angiography (gRMA) could replace digital substraction angiography (DSA). The goal of this work was to evaluate gRMA for the detection of ostial stenosis of the craniocervical vessels. Twenty two patients with carotid stenosis > 50% on sonography examination prospectively underwent gRMA and DSA. We analyzed the overall quality of each gRMA and the degree of ostial stenosis of the craniocervical vessels (innominate, left carotid, subclavian and vertebral arteries). Thirteen gRMA examination was considered as good quality and 8 as adequate for diagnosis. There was significant correlation between gRMA and DSA for degree of stenosis (k = 0.82, p < 0.0001). gRMA tends to overestimate degree of ostial stenosis, especially for vertebral arteries. We conclude that gRMA is a promising tool but cannot yet be used as a stand-alone procedure for the evaluation of ostial stenosis of the craniocervical vessels.

False-negative diffusion-weighted MR findings in acute ischemic stroke.

BACKGROUND AND PURPOSE: Lesions associated with acute stroke are often missed by diffusion-weighted imaging (DWI), suggesting that the sensitivity of this technique for detecting acute ischemic stroke may not be as high as initially thought. Our aim was to estimate the rate of false-negative DWI studies in patients with persistent neurologic deficit due to an ischemic stroke and to identify which stroke lesions are most likely to be missed by DWI. METHODS: We reviewed MR images obtained within 48 hours after stroke onset in 139 patients admitted for symptoms consistent with ischemic stroke in whom the deficit lasted more than 24 hours. Cases of negative initial DWI findings with an ischemic lesion visible on follow-up MR studies and a final diagnosis of arterial ischemic stroke were analyzed in terms of delay between onset of symptoms and initial DWI (MR latency), size and vascular distribution of the lesions, and relationship to findings in patients with positive initial DWI results. RESULTS: We found eight cases (5.8%) of false-negative initial DWI studies, of which four were positive on initial fluid-attenuated inversion recovery (FLAIR) imaging. Follow-up FLAIR/DWI showed a hyperintensity matching clinical presentation in all eight patients. The mean size of the lesion was 0.19 +/- 0.16 cm3. False-negative studies occurred more often in cases of stroke in the posterior (19%) than in the anterior (2%) circulation or when DWI was obtained within 24 hours after symptom onset. Of the six false-negative vertebrobasilar stroke lesions, five were located in the brain stem. In all, 31% of patients with vertebrobasilar ischemic stroke had a false-negative initial DWI study during the first 24 hours. CONCLUSION: A false-negative DWI study is not uncommon during the first 24 hours of ischemic stroke. Vertebrobasilar stroke should therefore not be ruled out on the basis of early negative DWI, especially when symptoms persist and are suggestive of this diagnosis.

[3D-CT angiography with volume rendering technique in the intracerebral aneurysms]. / Angioscanner des anévrismes intracrâniens en rendu volumique (volume rendering technique).

PURPOSE: Many techniques of 3D reconstruction (MIP, SSD) permit a good evaluation of the circle of Willis in order to detect cerebral aneurysms. More recently, the advent in the clinical practice of a calculation algorithm (VRT) adapted to the workstations for images treatment seems to improve evaluation of the characteristics regarding these aneurysms. MATERIALS AND METHODS: We report 4 cases with cerebral aneurysms studies with CT-angiography using the technique MIP and VRT. RESULTS: The VRT, using the totality of image informations, allows a better understanding than MIP about the intracranial cerebral aneurysms including their constitution and 3D localization. CONCLUSION: The VRT reconstruction permits to obtain quickly good quality and reproductive images, without relationship with threshold.

Intracranial aneurysm on CTA: demonstration using a transparency volume-rendering technique.

We report an interesting transparency study using a volume-rendering technique applied to CT angiography in a patient with a sylvian aneurysm. On a single view, all the information required for the aneurysmal treatment could be analyzed. Comparison with maximum intensity projection and virtual endoscopy reconstructions was performed.

[Diffusion MRI and cerebral ischemia. When to calculate the coefficient of diffusion?]. / IRM de diffusion et ischémie cérébrale. Quand calculer le coefficient de diffusion?

INTRODUCTION: There are two types of diffusion images: so-called "diffusion-weighted" images (DWI) and apparent diffusion coefficient (ADC) images. For certain authors, ADC mapping is crucial for interpreting diffusion images while for others the ADC map adds no further sensitivity or specificity compared with diffusion weighted images. The objective of this work was to determine those situations where ADC mapping modifies image interpretation. MATERIAL AND METHODS: T2-weighted and diffusion-weighted (DIF) MRI sequences were acquired in 197 patients with suspected cerebral ischemia (< or = 48 hr). For each lesion (239 lesions in the 197 patients), we analyzed MRI interpretation with and without ADC mapping and compared the interpretations with the final diagnosis established on clinical data and complementary explorations. RESULTS: We observed 3 groups. In group A (36% of the lesions), ADC mapping did not change image interpretation. This group was subdivided into 3 subgroups. A1: T2 and DIF weighted images are normal: no lesions and normal ACD map (n = 38 patients); A2: High intensity signal on T2 and low intensity signal on DIF: ischemic sequelae, ADC always increased (n = 32 lesions); A3: T2 normal and high intensity signal on DIF: hyper acute ischemia and ADC always decreased (n = 16 patients) In group B (high intensity signal on T2 and DIF, 54.5% of the lesions), ADC mapping changed the MRI interpretation: there was acute ischemia if the ADC was decreased (n = 113) and "pseudo-ischemic" lesions if the ADC was normal or increased (n = 17 patients). Group C was comprised of 23 lesions with a false negative ADC (9.5%). These lesions were always small recent ischemic lesions (< or = 5 mm) with a high intensity signal on DIF and a strictly normal ADC map. CONCLUSION: ADC mapping was found to be useful in 54.5% of the lesions and should not be considered as solely a research tool but also as a useful tool for routine clinical practice.

[The value of MRI for the diagnosis of meningeal hemorrhage during vasospasm]. / Intérêt de l'IRM pour le diagnostic d'hémorragie méningée en période de spasme.

Retrospectively, subarachnoidal hemorrhage can be misdiagnosed when the acute event did not bring the patient to medical attention, when clinical history is unclear and the CT scan is normal. Moreover, days after subarachnoid hemorrhage, cerebral vasospasm can result in neurological deficits that are indistinguishable from that produced by other causes of stroke. We report our experience with two patients who presented with symptoms of ischemia due to an arterial vasospasm that followed unrecognized rupture of an intracranial aneurysm. In both cases, CT scan failed to detect subarachnoid hemorrhage while MR detected the presence of signal changes in the subarachnoidal spaces associated with an ischemic stroke in one case. Neurological symptoms resolved completely after aneurysm treatment. MR can be a critical for the diagnosis of stroke secondary to vasospasm in order to prescribe an adapted treatment, avoid anticoagulant or thrombolytic therapy, and rapidly exclude the recently ruptured aneurysm to protect the patient from the risk of rebleeding.

A phase I/II study of herpes simplex virus type 1 thymidine kinase "suicide" gene therapy for recurrent glioblastoma. Study Group on Gene Therapy for Glioblastoma.

Despite extensive surgery for glioblastoma, residual tumor cells always lead to relapse. Gene therapy based on retrovirus-mediated gene transfer of herpes simplex virus type 1 thymidine kinase (HSV-1 TK), which specifically sensitizes dividing cells to ganciclovir (GCV) toxicity, may help eradicate such cells. During glioblastoma surgery, HSV-1 TK retroviral vector-producing cells (M11) were injected into the surgical cavity margins after tumor debulking. After a 7-day transduction period, GCV was administered for 14 days. Safety was assessed by clinical and laboratory evaluations, and efficacy was assessed by MRI-based relapse-free survival at month 4 and by overall survival. Twelve patients with recurrent glioblastoma were treated without serious adverse events related to M11 cell administration or GCV. Quality of life was not negatively influenced by this treatment. Overall median survival was 206 days, with 25% of the patients surviving longer than 12 months. At 4 months after treatment, 4 of 12 patients had no recurrence; their median overall survival was 528 days, compared with 194 days for patients with recurrence (p=0.03 by the log rank test). One patient is still free of detectable recurrence, steroid free and independent, 2.8 years after treatment. Thus, brain injections of M11 retroviral vector-producing cells for glioblastoma HSV-1 TK gene therapy were well tolerated and associated with significant therapeutic responses. These results warrant further development of this therapeutic strategy in brain tumor, including recurrent glioblastoma.