Feasibility and usefulness of brain imaging in catatonia.

Catatonia is a well characterized psychomotor syndrome that has recognizable motor, affective, behavioural and vegetative manifestations. Despite recent demonstration that catatonia is often associated with brain imaging abnormalities, there is currently no consensus or guidelines about the role of brain imaging. In this study, we assessed the feasibility of brain imaging in a series of patients with catatonia in a routine clinical setting and estimated the prevalence of clinically relevant radiological abnormalities. Sixty patients with catatonia were evaluated against sixty non-healthy controls subjects with headache. The MRI reports were reviewed, and MRI scans were also interpreted by neuroradiologists using a standardised MRI assessment. In this cohort, more than 85% of brain scans of patients with catatonia revealed abnormalities. The most frequently reported abnormalities in the catatonic group were white matter abnormalities (n = 44), followed by brain atrophy (n = 27). There was no evidence for significant differences in the frequency of abnormalities found in radiology reports and standardised neuroradiological assessments. The frequency of abnormalities was similar to that found in a population of non-healthy controls subjects with headache. This study shows that MRI is feasible in patients with catatonia and that brain imaging abnormalities are common findings in these patients. Most frequently, white matter abnormalities and diffuse brain atrophy are observed.

Spinal infarcts.

Compared to cerebral ischaemia, the frequency of spinal cord ischaemia is rare. Spinal infarcts lead to various types of neurological deficits, usually consisting of an abrupt and complete tetra- or paraplegia. Magnetic resonance imaging is the most valuable tool to show the infarct and to rule out other causes of acute spinal cord syndromes., such as myelitis or acute compressions. Nowadays, in western countries, most spinal cord infarcts are due to aortic diseases (atherosclerosis, aneurysm, dissection) or are of iatrogenic origin (mainly aortic surgery and interventional radiology), while other causes are rare. There is no specific treatment, besides prevention of complications, treatment of the underlying cause and rehabilitation.

COVID-19 Neurologic Complication with CNS Vasculitis-Like Pattern.

Coronavirus disease 2019 (COVID-19) is a viral infection caused by the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), which spreads rapidly from person to person and manifests in most symptomatic patients as a respiratory illness, similar to prior SARS viruses. Neurologic manifestations of COVID-19 are uncommon; those so far reported include encephalopathy, stroke from large-vessel occlusion, and polyneuropathy. We report a unique neurologic complication of COVID-19 in a patient who had extensive cerebral small-vessel ischemic lesions resembling cerebral vasculitis in a characteristic combined imaging pattern of ischemia, hemorrhage, and punctuate postcontrast enhancement. Also, a characteristic lower extremity skin rash was present in our patient. Our observation lends support to the increasingly suspected mechanism of "endotheliitis" associated with this novel coronavirus.

Follow-Up MRI for Small Brain AVMs Treated by Radiosurgery: Is Gadolinium Really Necessary?

BACKGROUND AND PURPOSE: Follow-up MR imaging of brain AVMs currently relies on contrast-enhanced sequences. Noncontrast techniques, including arterial spin-labeling and TOF, may have value in detecting a residual nidus after radiosurgery. The aim of this study was to compare noncontrast with contrast-enhanced MR imaging for the differentiation of residual-versus-obliterated brain AVMs in radiosurgically treated patients. MATERIALS AND METHODS: Twenty-eight consecutive patients with small brain AVMs (<20 mm) treated by radiosurgery were followed with the same MR imaging protocol. Three neuroradiologists, blinded to the results, independently reviewed the following: 1) postcontrast images alone (4D contrast-enhanced MRA and postcontrast 3D T1 gradient recalled-echo), 2) arterial spin-labeling and TOF images alone, and 3) all MR images combined. The primary end point was the detection of residual brain AVMs using a 5-point scale, with DSA as the reference standard. RESULTS: The highest interobserver agreement was for arterial spin-labeling/TOF (κ = 0.81; 95% confidence interval, 0.66-0.93). Regarding brain AVM detection, arterial spin-labeling/TOF had higher sensitivity (sensitivity, 85%; specificity, 100%; 95% CI, 62-97) than contrast-enhanced MR imaging (sensitivity, 55%; specificity, 100%; 95% CI, 27-73) and all MR images combined (sensitivity, 75%; specificity, 100%; 95% CI, 51-91) (P = .008). All nidus obliterations on DSA were detected on MR imaging. In 6 patients, a residual brain AVM present on DSA was only detected with arterial spin-labeling/TOF, including 3 based solely on arterial spin-labeling images. CONCLUSIONS: In this study of radiosurgically treated patients with small brain AVMs, arterial spin-labeling/TOF was found to be superior to gadolinium-enhanced MR imaging in detecting residual AVMs.

Brain Magnetic Susceptibility Changes in Patients with Natalizumab-Associated Progressive Multifocal Leukoencephalopathy.

We investigated the brain magnetic susceptibility changes induced by natalizumab-associated progressive multifocal leukoencephalopathy. We retrospectively included 12 patients with natalizumab-progressive multifocal leukoencephalopathy, 5 with progressive multifocal leukoencephalopathy from other causes, and 55 patients with MS without progressive multifocal leukoencephalopathy for comparison. MR imaging examinations included T2* or SWI sequences in patients with progressive multifocal leukoencephalopathy (86 examinations) and SWI in all patients with MS without progressive multifocal leukoencephalopathy. Signal abnormalities on T2* and SWI were defined as low signal intensity within the cortex and/or U-fibers and the basal ganglia. We observed T2* or SWI signal abnormalities at the chronic stage in all patients with progressive multifocal leukoencephalopathy, whereas no area of low SWI signal intensity was detected in patients without progressive multifocal leukoencephalopathy. Among the 8 patients with asymptomatic natalizumab-progressive multifocal leukoencephalopathy, susceptibility changes were observed in 6 (75%). The basal ganglia adjacent to progressive multifocal leukoencephalopathy lesions systematically appeared hypointense by using T2* and/or SWI. Brain magnetic susceptibility changes may be explained by the increased iron deposition and constitute a useful tool for the diagnosis of progressive multifocal leukoencephalopathy.

[Impact of preoperative breast magnetic resonance imaging on surgical management: experience of two university hospitals]. / Impact de l'IRM mammaire préopératoire sur la prise en charge chirurgicale des cancers du sein: expérience de deux centres hospitaliers universitaires.

OBJECTIVES: Breast magnetic resonance imaging (MRI) has attained a solid position in the diagnosis of breast cancer but its benefit is still to be confirmed in the preoperative staging. The authors assessed the impact of preoperative breast MRI on surgical management of breast cancer in two university hospitals. PATIENTS AND METHODS: This retrospective review was realized in two university hospitals and concerned all patients with breast carcinoma who had a surgical first therapy. We selected 89 patients who underwent preoperative breast MRI in the period between January 2008 and December 2009. RESULTS: The sensitivity of breast MRI for detecting breast tumor was 95%. Fourteen percent of patients had a multifocal disease, 10% a multicentric disease and 2% a synchronous bilateral cancer. The correlation of radiological tumor size with histopathological size was r=0.68 in IRM compared to r=0.45 in conventional imaging (P<0.001). Nineteen additional biopsies were performed and 9.9% of false-positive findings were detected. Retrospectively, planned surgical management was altered in 9% of patients, resulted from use of breast MRI. Six patients had conversion of planned breast conservation to mastectomy and two patients underwent contralateral lumpectomy after discover synchronous bilateral cancer. DISCUSSION AND CONCLUSION: Breast MRI was very sensitive for the detection of breast carcinoma and improved local staging in almost 9% of patients. But, low specificity of this imaging requires a systematically validation of additional lesions by biopsy before surgical planning.

[Imaging of lateral ventricle tumors]. / Imagerie des tumeurs du ventricule latéral.

Lateral ventricular neoplasms are rare, and account for 50% of all intraventricular tumors in adults and 25% in children. Although these neoplasms are easily detected with computed tomography (CT) and magnetic resonance imaging (MRI), both techniques are relatively unspecific in identifying the type of tumor. However, few imaging patterns are specific for a particular pathological process and useful conclusions can be made from the morphological appearance of the lesion, its location and enhancement pattern. The aim of this article was to review and illustrate the CT and MRI findings of a wide spectrum of tumors of the lateral ventricle. We reviewed choroid plexus tumors, meningioma, subependymal giant cell astrocytoma, central neurocytoma, and less frequent lesion such as lymphoma and metastases.

Single-centre prospective comparison between contrast-enhanced ultrasound and computed tomography angiography after EVAR.

AIM: To evaluate contrast-enhanced ultrasound (CEUS) as an effective alternative to CT-angiography (CTA) for endoleak detection and aneurismal sac diameter measurement in the follow-up after endovascular abdominal aortic aneurysm repair (EVAR). METHODS: From January 2006 to December 2010, 395 patients underwent EVAR follow-up with both CTA and CEUS. The diameter of the aneurismal sac and the presence of endoleaks were evaluated in all the 395 paired examinations. RESULTS: Bland-Altman plots showed a good agreement in aneurismal sac diameter evaluation between the two imaging modalities. The mean diameter was 54.93 mm (standard deviation (SD) ±12.57) with CEUS and 56.01 mm (SD ± 13.23) with CTA. The mean difference in aneurismal sac diameter was -1.08 mm ± 3.3543 (95% confidence interval (CI), -0.75 to -1.41), in favour of CTA. The number of observed agreement in endoleak detection was 359/395 (90.89%). The two modalities detected the same type I and type III endoleaks. McNemar's χ(2) test confirmed that CTA and CEUS are equivalent in endoleak detection. CONCLUSIONS: CEUS demonstrated to be as accurate as CTA in endoleak detection and abdominal aortic aneurysm diameter measurements during EVAR follow-up, without carrying the risks of radiation exposure or nephrotoxicity. Even if it cannot be proposed as the sole imaging modality during follow-up, our analysis suggests that it should have a major role.

[Diffusion-weighted MR imaging of the brain]. / IRM de diffusion et encéphale.

Imaging of water diffusion or diffusion-weighted MR imaging provides physiological information about brain diseases that cannot be obtained from conventional sequences. This technique is very sensitive for the detection of cerebral ischemia from arterial origin and can distinguish cerebral ischemia from other non-vascular brain pathologies in patients presenting with abrupt onset of focal neurological deficit. Diffusion-weighted imaging is used for the evaluation of non-vascular diseases as well. Combined with conventional sequences, it is helpful to differentiate brain abscesses from necrotic tumors. Quantitative diffusion-weighted imaging provides additional information in the characterization of tumors or inflammatory, degenerative and metabolic lesions. Finally, diffusion-weighted imaging data also has prognostic value.

Surgical views from three-dimensional digital subtraction angiography for the planning of aneurysm surgery.

AIM: To develop a semi-automatic protocol helping to present directly and quickly three-dimensional digital subtraction angiography (3D-DSA) data in an orientation that reproduces exactly the neurosurgeon's intraoperative view. METHOD: Post-processing of 3D-DSA data (volume-rendering) was performed on an Integris workstation (Philips, Best); surgical views were obtained by visualization of the patient's head through a frontopterional approach: the 3D volume was turned 135 degrees in the sagittal plane (around the X axis) and rotated by 45 degrees and 60 degrees in the coronal plane (around the Y axis). The protocol was evaluated on a consecutive series of nine patients who had ruptured or asymptomatic anterior circulation aneurysms requiring surgical treatment. Frontopterional views of angiographic 3D data were compared with intraoperative views. RESULTS: The proposed semi-automatic algorithm is simple, fast and reproducible, and displays the 3D data in an orientation identical to the intraoperative views. The surgical anatomy of the anterior communicating artery was best reproduced with a coronal rotation of 60 degrees , with a coronal rotation of 45 degrees for the other aneurysm locations. In each case, the surgical reconstructions allowed a more accurate analysis of the vascular anatomy around the aneurysm, and facilitated pre- and perioperative planning. CONCLUSION: The present protocol displays angiographic 3D data in a projection that exactly reproduces the vascular anatomy through a frontopterional approach. It may help neurosurgeons to better anticipate any potential difficulties during access and clip-positioning arising due to the specific vascular anatomy of a given patient.

[Midline tumors of the central nervous system]. / Tumeurs cranio-encéphaliques de la ligne médiane.

The anatomy of the supratentoriel midline structures of the brain is complex: corpus callosum, third ventricle, trigone, choroid plexus, pineal gland, falx cerebri. Different types of tumors can arise from these structures including tumors of the trigone and septum, tumors of the falx, third ventricular tumors and pinal region tumors. These tumors share similar features: minimal clinical symptoms despite their occasional large size, mild non-specific intracranial hypertension syndrome, value of MRI for depiction of tumor location, stereotactic biopsy, relative difficulty of surgical management.

[MR imaging in mental retardation]. / Imagerie par résonance magnétique du retard mental non spécifique.

Mental retardation is considered idiopathic or not otherwise specified when no etiological diagnosis can be identified in spite of comprehensive history, physical examination and metabolic or genetic investigations. In such cases, brain MRI is indicated for patients with abnormal head size or shape, craniofacial malformation, somatic anomalies, neurocutaneous findings, seizures, focal neurological findings or behavioral and/or developmental problems. Brain anomalies are now considered a main category for the etiology of mental retardation. MRI evaluation should include axial images of the entire brain, sagittal images through the midline structures, and coronal images of the posterior fossa or entire brain. MRI allows detection of major and or minor cerebral anomalies or malformations, sometimes multiple. In the literature, the most frequently involved structures include: 1/ corpus callosum (hypoplasia, short corpus callosum and verticalized splenium), 2/ septum pellucidum (cavum septum pellucidum or cavum vergae), 3/ ventricles (ventriculomegaly), 4/ cerebral cortex (cortical dysplasia), 5/ cerebellum (hypoplasia), and 6/ extra-axial CSF spaces (enlargement). In our patient population, dysplasia involving the cerebellum and vermis have been identified, a finding that has not yet been described in the literature. MRI allows detection of multiple minor morphological anomalies. Most have classically been considered as normal variants but they may in fact be markers of cerebral dysgenesis and are currently the only anomaly detected in the work-up of patients with mental retardation. Their role in the pathogenesis of mental retardation is under evaluation.

Clinical outcome in patients with high-grade internal carotid artery stenosis after irradiation.

The authors followed up 41 consecutive patients (21 symptomatic) with internal carotid artery stenosis > or =70% and previous neck irradiation. After 28 months, 15 patients (36.6%) had died, five (12.2%) had had an ischemic stroke, and 15 (36.6%) had a new malignancy. Having a new malignancy was the only independent predictor of death. The major risk for patients with ICA stenosis > or =70% and previous neck irradiation is malignancy, not stroke.

[Headaches in the emergency context]. / Cephalees dans un contexte d'urgence.

Headaches constitute one of the most frequent reason of consultation. Their causes are extremely varied. The first step consists in the analysis of the characteristics of the pain and the associated signs in order to distinguish primary and secondary headaches. Primary headaches, including migraines and tension-type headaches are the most frequent types and do not require imaging evaluation. Secondary headaches are related to an organic cause and require specific investigations. In case of suspected symptomatic or secondary headaches, brain imaging plays an important role in the etiologic work-up. The main purpose of imaging in an emergency setting is to diagnose a life-threatening disease.

[Cerebellar cortical dysplasia: MRI aspects and significance]. / Dysplasie du cortex cérébelleux: aspects en IRM et signification.

Because it is now possible to obtain high-resolution multiplanar MR imaging of the cerebellum and because of the developing interest on the role of the cerebellum on higher brain functions, we have decided to study the process of cerebellar fissuration. All brain MRI examinations performed in children for varied neurological and neurosurgical indications, especially children with non-specific mental retardation and patients with cerebral malformation detected at initial imaging work-up, were reviewed. Fissuration and lobulation anomalies (abnormal orientation of fissures, pseudopolymicrogyria, cortical thickening, subcortical cysts and heterotopia) were identified that we called cerebellar cortical dysplasia (CCD). In order to better understand the origin of this malformation, current data on cerebellar embryogenesis and histogenesis will be reviewed, and the pathological and radiological features will be illustrated. Milder forms of CCD represent a distinct group of anomalies that should be distinguished from other types of cerebellar dysplasia (agenesis, hypoplasia or complex dysplasia with involvement of the cerebellar vermis (rhombencephalosynapsis)) or combined cerebellar and cerebral dysplasia (muscular dystrophies and lissencephaly). Recognition of cerebellar cortical dysplasia could be a first step towards a broader understanding of its pathogenesis and significance.